4616 lines
154 KiB
C++
4616 lines
154 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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// Portions of this file were originally under the following license:
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//
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// Copyright (C) 2006-2008 Jason Evans <jasone@FreeBSD.org>.
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// All rights reserved.
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// Copyright (C) 2007-2017 Mozilla Foundation.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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// 1. Redistributions of source code must retain the above copyright
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// notice(s), this list of conditions and the following disclaimer as
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// the first lines of this file unmodified other than the possible
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// addition of one or more copyright notices.
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// 2. Redistributions in binary form must reproduce the above copyright
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// notice(s), this list of conditions and the following disclaimer in
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// the documentation and/or other materials provided with the
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// distribution.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
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// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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// OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// *****************************************************************************
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//
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// This allocator implementation is designed to provide scalable performance
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// for multi-threaded programs on multi-processor systems. The following
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// features are included for this purpose:
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//
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// + Multiple arenas are used if there are multiple CPUs, which reduces lock
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// contention and cache sloshing.
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//
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// + Cache line sharing between arenas is avoided for internal data
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// structures.
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//
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// + Memory is managed in chunks and runs (chunks can be split into runs),
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// rather than as individual pages. This provides a constant-time
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// mechanism for associating allocations with particular arenas.
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//
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// Allocation requests are rounded up to the nearest size class, and no record
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// of the original request size is maintained. Allocations are broken into
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// categories according to size class. Assuming runtime defaults, the size
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// classes in each category are as follows (for x86, x86_64 and Apple Silicon):
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//
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// |=========================================================|
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// | Category | Subcategory | x86 | x86_64 | Mac ARM |
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// |---------------------------+---------+---------+---------|
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// | Word size | 32 bit | 64 bit | 64 bit |
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// | Page size | 4 Kb | 4 Kb | 16 Kb |
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// |=========================================================|
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// | Small | Quantum-spaced | 16 | 16 | 16 |
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// | | | 32 | 32 | 32 |
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// | | | 48 | 48 | 48 |
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// | | | ... | ... | ... |
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// | | | 480 | 480 | 480 |
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// | | | 496 | 496 | 496 |
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// | |----------------+---------|---------|---------|
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// | | Quantum-wide- | 512 | 512 | 512 |
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// | | spaced | 768 | 768 | 768 |
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// | | | ... | ... | ... |
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// | | | 3584 | 3584 | 3584 |
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// | | | 3840 | 3840 | 3840 |
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// | |----------------+---------|---------|---------|
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// | | Sub-page | - | - | 4096 |
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// | | | - | - | 8 kB |
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// |=========================================================|
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// | Large | 4 kB | 4 kB | - |
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// | | 8 kB | 8 kB | - |
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// | | 12 kB | 12 kB | - |
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// | | 16 kB | 16 kB | 16 kB |
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// | | ... | ... | - |
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// | | 32 kB | 32 kB | 32 kB |
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// | | ... | ... | ... |
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// | | 1008 kB | 1008 kB | 1008 kB |
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// | | 1012 kB | 1012 kB | - |
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// | | 1016 kB | 1016 kB | - |
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// | | 1020 kB | 1020 kB | - |
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// |=========================================================|
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// | Huge | 1 MB | 1 MB | 1 MB |
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// | | 2 MB | 2 MB | 2 MB |
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// | | 3 MB | 3 MB | 3 MB |
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// | | ... | ... | ... |
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// |=========================================================|
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//
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// Legend:
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// n: Size class exists for this platform.
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// -: This size class doesn't exist for this platform.
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// ...: Size classes follow a pattern here.
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//
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// A different mechanism is used for each category:
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//
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// Small : Each size class is segregated into its own set of runs. Each run
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// maintains a bitmap of which regions are free/allocated.
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//
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// Large : Each allocation is backed by a dedicated run. Metadata are stored
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// in the associated arena chunk header maps.
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//
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// Huge : Each allocation is backed by a dedicated contiguous set of chunks.
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// Metadata are stored in a separate red-black tree.
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//
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// *****************************************************************************
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#include "mozmemory_wrap.h"
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#include "mozjemalloc.h"
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#include "mozjemalloc_types.h"
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#include "mozjemalloc_profiling.h"
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#include <bit>
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#include <cstring>
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#include <cerrno>
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#include <chrono>
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#ifdef XP_WIN
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# include <io.h>
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# include <windows.h>
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#else
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# include <sys/mman.h>
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# include <unistd.h>
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#endif
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#ifdef XP_DARWIN
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# include <libkern/OSAtomic.h>
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# include <mach/mach_init.h>
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# include <mach/vm_map.h>
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#endif
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#include "mozilla/Atomics.h"
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#include "mozilla/Assertions.h"
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#include "mozilla/CheckedInt.h"
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#include "mozilla/DoublyLinkedList.h"
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#include "mozilla/HelperMacros.h"
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#include "mozilla/Likely.h"
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#include "mozilla/Literals.h"
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#include "mozilla/MathAlgorithms.h"
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#include "mozilla/RandomNum.h"
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#include "mozilla/RefPtr.h"
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// Note: MozTaggedAnonymousMmap() could call an LD_PRELOADed mmap
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// instead of the one defined here; use only MozTagAnonymousMemory().
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#include "mozilla/TaggedAnonymousMemory.h"
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#include "mozilla/ThreadLocal.h"
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#include "mozilla/XorShift128PlusRNG.h"
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#include "mozilla/fallible.h"
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#include "RadixTree.h"
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#include "Arena.h"
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#include "BaseAlloc.h"
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#include "Chunk.h"
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#include "Constants.h"
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#include "Extent.h"
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#include "Globals.h"
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#include "Mutex.h"
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#include "PHC.h"
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#include "RedBlackTree.h"
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#include "Utils.h"
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#include "Zero.h"
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#if defined(XP_WIN)
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# include "mozmemory_stall.h"
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#endif
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using namespace mozilla;
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#ifdef MOZJEMALLOC_PROFILING_CALLBACKS
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// MallocProfilerCallbacks is refcounted so that one thread cannot destroy it
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// while another thread accesses it. This means that clearing this value or
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// otherwise dropping a reference to it must not be done while holding an
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// arena's lock.
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constinit static RefPtr<MallocProfilerCallbacks> sCallbacks;
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#endif
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// ***************************************************************************
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// MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are mutually exclusive.
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#if defined(MALLOC_DECOMMIT) && defined(MALLOC_DOUBLE_PURGE)
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# error MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are mutually exclusive.
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#endif
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// Set to true once the allocator has been initialized.
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#if defined(_MSC_VER) && !defined(__clang__)
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// MSVC may create a static initializer for an Atomic<bool>, which may actually
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// run after `malloc_init` has been called once, which triggers multiple
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// initializations.
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// We work around the problem by not using an Atomic<bool> at all. There is a
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// theoretical problem with using `malloc_initialized` non-atomically, but
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// practically, this is only true if `malloc_init` is never called before
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// threads are created.
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static bool malloc_initialized;
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#else
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// We can rely on Relaxed here because this variable is only ever set when
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// holding gInitLock. A thread that still sees it false while another sets it
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// true will enter the same lock, synchronize with the former and check the
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// flag again under the lock.
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static Atomic<bool, MemoryOrdering::Relaxed> malloc_initialized;
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#endif
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// This lock must be held while bootstrapping us.
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constinit StaticMutex gInitLock MOZ_UNANNOTATED;
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// We cannot instantiate
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// Atomic<std::chrono::time_point<std::chrono::steady_clock>>
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// so we explicitly force timestamps to be uint64_t in ns.
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uint64_t GetTimestampNS() {
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// On most if not all systems we care about the conversion to ns is a no-op,
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// so we prefer to keep the precision here for performance, but let's be
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// explicit about it.
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return std::chrono::floor<std::chrono::nanoseconds>(
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std::chrono::steady_clock::now())
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.time_since_epoch()
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.count();
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}
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namespace mozilla {
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template <>
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struct GetDoublyLinkedListElement<arena_t> {
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static DoublyLinkedListElement<arena_t>& Get(arena_t* aThis) {
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return aThis->mPurgeListElem;
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}
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static const DoublyLinkedListElement<arena_t>& Get(const arena_t* aThis) {
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return aThis->mPurgeListElem;
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}
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};
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} // namespace mozilla
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struct ArenaTreeTrait {
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static RedBlackTreeNode<arena_t>& GetTreeNode(arena_t* aThis) {
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return aThis->mLink;
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}
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static inline Order Compare(arena_t* aNode, arena_t* aOther) {
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MOZ_ASSERT(aNode);
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MOZ_ASSERT(aOther);
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return CompareInt(aNode->mId, aOther->mId);
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}
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using SearchKey = arena_id_t;
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static inline Order Compare(SearchKey aKey, arena_t* aOther) {
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MOZ_ASSERT(aOther);
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return CompareInt(aKey, aOther->mId);
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}
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};
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// Bookkeeping for all the arenas used by the allocator.
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// Arenas are separated in two categories:
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// - "private" arenas, used through the moz_arena_* API
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// - all the other arenas: the default arena, and thread-local arenas,
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// used by the standard API.
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class ArenaCollection {
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public:
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constexpr ArenaCollection() = default;
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bool Init() MOZ_REQUIRES(gInitLock) MOZ_EXCLUDES(mLock) {
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arena_params_t params;
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// The main arena allows more dirty pages than the default for other arenas.
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params.mMaxDirty = opt_dirty_max;
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params.mLabel = "Default";
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mDefaultArena =
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mLock.Init() ? CreateArena(/* aIsPrivate = */ false, ¶ms) : nullptr;
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mPurgeListLock.Init();
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return bool(mDefaultArena);
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}
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// The requested arena must exist.
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inline arena_t* GetById(arena_id_t aArenaId, bool aIsPrivate)
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MOZ_EXCLUDES(mLock);
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arena_t* CreateArena(bool aIsPrivate, arena_params_t* aParams)
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MOZ_EXCLUDES(mLock);
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void DisposeArena(arena_t* aArena) MOZ_EXCLUDES(mLock) {
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// This will not call MayPurge but only unlink the element in case.
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// It returns true if we successfully removed the item from the list,
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// meaning we have exclusive access to it and can delete it.
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bool delete_now = RemoveFromOutstandingPurges(aArena);
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{
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MutexAutoLock lock(mLock);
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MOZ_RELEASE_ASSERT(mPrivateArenas.Search(aArena->mId),
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"Arena not in tree");
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mPrivateArenas.Remove(aArena);
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mNumOperationsDisposedArenas += aArena->Operations();
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}
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{
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MutexAutoLock lock(aArena->mLock);
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if (!aArena->mIsPurgePending) {
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// If no purge was pending then we have exclusive access to the
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// arena and must delete it.
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delete_now = true;
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} else if (!delete_now) {
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// The remaining possibility, when we failed to remove the arena from
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// the list (because a purging thread alredy did so) then that thread
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// will be the last thread holding the arena and is now responsible for
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// deleting it.
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aArena->mMustDeleteAfterPurge = true;
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// Not that it's not possible to have checked the list of pending purges
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// BEFORE the arena was added to the list because that would mean that
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// an operation on the arena (free or realloc) was running concurrently
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// with deletion, which would be a memory error and the assertions in
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// the destructor help check for that.
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}
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}
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if (delete_now) {
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delete aArena;
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}
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}
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void SetDefaultMaxDirtyPageModifier(int32_t aModifier) {
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{
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MutexAutoLock lock(mLock);
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bool decreased = aModifier < mDefaultMaxDirtyPageModifier;
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mDefaultMaxDirtyPageModifier = aModifier;
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for (auto* arena : iter()) {
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// We can only update max-dirty for main-thread-only arenas from the
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// main thread.
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if (!arena->IsMainThreadOnly() || IsOnMainThreadWeak()) {
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arena->UpdateMaxDirty();
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if (decreased) {
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purge_action_t action;
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{
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MaybeMutexAutoLock arena_lock(arena->mLock);
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action = arena->ShouldStartPurge();
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}
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arena->MayDoOrQueuePurge(action, "SetDefaultMaxDirtyPageModifier");
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}
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}
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}
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}
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}
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int32_t DefaultMaxDirtyPageModifier() { return mDefaultMaxDirtyPageModifier; }
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using Tree = RedBlackTree<arena_t, ArenaTreeTrait>;
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class Iterator {
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public:
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explicit Iterator(Tree* aTree, Tree* aSecondTree,
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Tree* aThirdTree = nullptr)
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: mFirstIterator(aTree),
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mSecondTree(aSecondTree),
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mThirdTree(aThirdTree) {}
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class Item {
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private:
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Iterator& mIter;
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arena_t* mArena;
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public:
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Item(Iterator& aIter, arena_t* aArena) : mIter(aIter), mArena(aArena) {}
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bool operator!=(const Item& aOther) const {
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return mArena != aOther.mArena;
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}
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arena_t* operator*() const { return mArena; }
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const Item& operator++() {
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mArena = mIter.Next();
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return *this;
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}
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};
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Item begin() {
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// If the first tree is empty calling Next() would access memory out of
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// bounds, so advance to the next non-empty tree (or last empty tree).
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MaybeNextTree();
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return Item(*this, mFirstIterator.Current());
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}
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Item end() { return Item(*this, nullptr); }
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private:
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Tree::Iterator mFirstIterator;
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Tree* mSecondTree;
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Tree* mThirdTree;
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void MaybeNextTree() {
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while (!mFirstIterator.NotDone() && mSecondTree) {
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mFirstIterator = mSecondTree->iter();
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mSecondTree = mThirdTree;
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mThirdTree = nullptr;
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}
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}
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arena_t* Next() {
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arena_t* arena = mFirstIterator.Next();
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if (arena) {
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return arena;
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}
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// Advance to the next tree if we can, if there's no next tree, or the
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// next tree is empty then Current() will return nullptr.
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MaybeNextTree();
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return mFirstIterator.Current();
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}
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friend Item;
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};
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Iterator iter() MOZ_REQUIRES(mLock) {
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return Iterator(&mArenas, &mPrivateArenas);
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}
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inline arena_t* GetDefault() { return mDefaultArena; }
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// Guards the collection of arenas. Must not be acquired while holding
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// a single arena's lock or mPurgeListLock.
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Mutex mLock MOZ_UNANNOTATED;
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// Guards only the list of outstanding purge requests. Can be acquired
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// while holding gArenas.mLock, but must not be acquired or held while
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// holding or acquiring a single arena's lock.
|
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Mutex mPurgeListLock;
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|
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// We're running on the main thread which is set by a call to SetMainThread().
|
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bool IsOnMainThread() const {
|
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return mMainThreadId.isSome() &&
|
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ThreadIdEqual(mMainThreadId.value(), GetThreadId());
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}
|
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|
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// We're running on the main thread or SetMainThread() has never been called.
|
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bool IsOnMainThreadWeak() const {
|
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return mMainThreadId.isNothing() || IsOnMainThread();
|
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}
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|
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// After a fork set the new thread ID in the child.
|
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// This is done as the first thing after a fork, before mLock even re-inits.
|
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void ResetMainThread() MOZ_EXCLUDES(mLock) {
|
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// The post fork handler in the child can run from a MacOS worker thread,
|
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// so we can't set our main thread to it here. Instead we have to clear it.
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mMainThreadId = Nothing();
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}
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void SetMainThread() MOZ_EXCLUDES(mLock) {
|
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MutexAutoLock lock(mLock);
|
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MOZ_ASSERT(mMainThreadId.isNothing());
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mMainThreadId = Some(GetThreadId());
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}
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|
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// This requires the lock to get a consistent count across all the active
|
|
// + disposed arenas.
|
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uint64_t OperationsDisposedArenas() MOZ_REQUIRES(mLock) {
|
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return mNumOperationsDisposedArenas;
|
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}
|
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|
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// Enable or disable the lazy purge.
|
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//
|
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// Returns the former state of enablement.
|
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// This is a global setting for all arenas. Changing it may cause an
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// immediate purge for all arenas.
|
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bool SetDeferredPurge(bool aEnable) {
|
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MOZ_ASSERT(IsOnMainThreadWeak());
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|
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// We must hold the arena collection lock while updating the status
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// globally AND on each arena.
|
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bool previous;
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{
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MutexAutoLock lock(mLock);
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previous = mIsDeferredPurgeEnabled;
|
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if (previous == aEnable) {
|
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// There's nothing more to do.
|
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return previous;
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}
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mIsDeferredPurgeEnabled = aEnable;
|
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for (auto* arena : iter()) {
|
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MaybeMutexAutoLock lock(arena->mLock);
|
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arena->mIsDeferredPurgeEnabled = aEnable;
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}
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}
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MayPurgeAll(PurgeIfThreshold, __func__);
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return previous;
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}
|
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|
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bool IsDeferredPurgeEnabled() MOZ_REQUIRES(mLock) {
|
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return mIsDeferredPurgeEnabled;
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}
|
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|
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// Set aside a new purge request for aArena.
|
|
void AddToOutstandingPurges(arena_t* aArena) MOZ_EXCLUDES(mPurgeListLock);
|
|
|
|
// Remove an unhandled purge request for aArena. Returns true if the arena
|
|
// was in the list.
|
|
bool RemoveFromOutstandingPurges(arena_t* aArena)
|
|
MOZ_EXCLUDES(mPurgeListLock);
|
|
|
|
// Execute all outstanding purge requests, if any.
|
|
void MayPurgeAll(PurgeCondition aCond, const char* aCaller);
|
|
|
|
// Purge some dirty memory, based on purge requests, returns true if there are
|
|
// more to process.
|
|
//
|
|
// Returns a may_purge_now_result_t with the following meaning:
|
|
// Done: Purge has completed for all arenas.
|
|
// NeedsMore: There may be some arenas that needs to be purged now.
|
|
// WantsLater: There is at least one arena that might want a purge later,
|
|
// according to aReuseGraceMS.
|
|
//
|
|
// Parameters:
|
|
// aPeekOnly: If true, check only if there is work to do without doing it.
|
|
// aReuseGraceMS: The time to wait with purge after a
|
|
// significant re-use happened for an arena.
|
|
// aKeepGoing: If this returns false purging will cease.
|
|
//
|
|
// This could exit for 3 different reasons.
|
|
// - There are no more requests (it returns false)
|
|
// - There are more requests but aKeepGoing() returned false. (returns true)
|
|
// - One arena is completely purged, (returns true).
|
|
//
|
|
may_purge_now_result_t MayPurgeSteps(
|
|
bool aPeekOnly, uint32_t aReuseGraceMS,
|
|
const Maybe<std::function<bool()>>& aKeepGoing);
|
|
|
|
private:
|
|
const static arena_id_t MAIN_THREAD_ARENA_BIT = 0x1;
|
|
|
|
static bool ArenaIdIsMainThreadOnly(arena_id_t aArenaId) {
|
|
return aArenaId & MAIN_THREAD_ARENA_BIT;
|
|
}
|
|
|
|
arena_t* mDefaultArena = nullptr;
|
|
arena_id_t mLastPublicArenaId MOZ_GUARDED_BY(mLock) = 0;
|
|
|
|
// Accessing mArenas and mPrivateArenas can only be done while holding mLock.
|
|
Tree mArenas MOZ_GUARDED_BY(mLock);
|
|
Tree mPrivateArenas MOZ_GUARDED_BY(mLock);
|
|
|
|
// Arena ids are pseudo-obfuscated/deobfuscated based on these values randomly
|
|
// initialized on first use.
|
|
arena_id_t mArenaIdKey = 0;
|
|
int8_t mArenaIdRotation = 0;
|
|
|
|
// Set only rarely and then propagated on the same thread to all arenas via
|
|
// UpdateMaxDirty(). But also read in ExtraCommitPages on arbitrary threads.
|
|
// TODO: Could ExtraCommitPages use arena_t::mMaxDirty instead ?
|
|
Atomic<int32_t> mDefaultMaxDirtyPageModifier;
|
|
// This is never changed except for forking, and it does not need mLock.
|
|
Maybe<ThreadId> mMainThreadId;
|
|
|
|
// The number of operations that happened in arenas that have since been
|
|
// destroyed.
|
|
uint64_t mNumOperationsDisposedArenas = 0;
|
|
|
|
// Linked list of outstanding purges. This list has no particular order.
|
|
// It is ok for an arena to be in this list even if mIsPurgePending is false,
|
|
// it will just cause an extra round of a (most likely no-op) purge.
|
|
// It is not ok to not be in this list but have mIsPurgePending set to true,
|
|
// as this would prevent any future purges for this arena (except for during
|
|
// MayPurgeStep or Purge).
|
|
DoublyLinkedList<arena_t> mOutstandingPurges MOZ_GUARDED_BY(mPurgeListLock);
|
|
|
|
// Flag if we should defer purge to later.
|
|
bool mIsDeferredPurgeEnabled MOZ_GUARDED_BY(mLock) = false;
|
|
};
|
|
|
|
constinit static ArenaCollection gArenas;
|
|
|
|
// Protects huge allocation-related data structures.
|
|
static Mutex huge_mtx;
|
|
|
|
// Tree of chunks that are stand-alone huge allocations.
|
|
static RedBlackTree<extent_node_t, ExtentTreeTrait> huge
|
|
MOZ_GUARDED_BY(huge_mtx);
|
|
|
|
// Huge allocation statistics.
|
|
static size_t huge_allocated MOZ_GUARDED_BY(huge_mtx);
|
|
static size_t huge_mapped MOZ_GUARDED_BY(huge_mtx);
|
|
static uint64_t huge_operations MOZ_GUARDED_BY(huge_mtx);
|
|
|
|
// ******
|
|
// Arenas.
|
|
|
|
// The arena associated with the current thread (per
|
|
// jemalloc_thread_local_arena) On OSX, __thread/thread_local circles back
|
|
// calling malloc to allocate storage on first access on each thread, which
|
|
// leads to an infinite loop, but pthread-based TLS somehow doesn't have this
|
|
// problem.
|
|
#if !defined(XP_DARWIN)
|
|
static MOZ_THREAD_LOCAL(arena_t*) thread_arena;
|
|
#else
|
|
static detail::ThreadLocal<arena_t*, detail::ThreadLocalKeyStorage>
|
|
thread_arena;
|
|
#endif
|
|
|
|
// ***************************************************************************
|
|
// Begin forward declarations.
|
|
|
|
static void huge_dalloc(void* aPtr, arena_t* aArena);
|
|
static bool malloc_init_hard();
|
|
|
|
#ifndef XP_WIN
|
|
# ifdef XP_DARWIN
|
|
# define FORK_HOOK extern "C"
|
|
# else
|
|
# define FORK_HOOK static
|
|
# endif
|
|
FORK_HOOK void _malloc_prefork(void);
|
|
FORK_HOOK void _malloc_postfork_parent(void);
|
|
FORK_HOOK void _malloc_postfork_child(void);
|
|
# ifdef XP_DARWIN
|
|
FORK_HOOK void _malloc_postfork(void);
|
|
# endif
|
|
#endif
|
|
|
|
// End forward declarations.
|
|
// ***************************************************************************
|
|
|
|
// FreeBSD's pthreads implementation calls malloc(3), so the malloc
|
|
// implementation has to take pains to avoid infinite recursion during
|
|
// initialization.
|
|
// Returns whether the allocator was successfully initialized.
|
|
static inline bool malloc_init() {
|
|
if (!malloc_initialized) {
|
|
return malloc_init_hard();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
#ifdef ANDROID
|
|
// Android's pthread.h does not declare pthread_atfork() until SDK 21.
|
|
extern "C" MOZ_EXPORT int pthread_atfork(void (*)(void), void (*)(void),
|
|
void (*)(void));
|
|
#endif
|
|
|
|
// ***************************************************************************
|
|
// Begin Utility functions/macros.
|
|
|
|
#ifdef MOZJEMALLOC_PROFILING_CALLBACKS
|
|
namespace mozilla {
|
|
|
|
void jemalloc_set_profiler_callbacks(
|
|
RefPtr<MallocProfilerCallbacks>&& aCallbacks) {
|
|
sCallbacks = aCallbacks;
|
|
}
|
|
|
|
} // namespace mozilla
|
|
#endif
|
|
|
|
// End Utility functions/macros.
|
|
// ***************************************************************************
|
|
// Begin arena.
|
|
|
|
static inline arena_t* thread_local_arena(bool enabled) {
|
|
arena_t* arena;
|
|
|
|
if (enabled) {
|
|
// The arena will essentially be leaked if this function is
|
|
// called with `false`, but it doesn't matter at the moment.
|
|
// because in practice nothing actually calls this function
|
|
// with `false`, except maybe at shutdown.
|
|
arena_params_t params;
|
|
params.mLabel = "Thread local";
|
|
arena = gArenas.CreateArena(/* aIsPrivate = */ false, ¶ms);
|
|
} else {
|
|
arena = gArenas.GetDefault();
|
|
}
|
|
thread_arena.set(arena);
|
|
return arena;
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_thread_local_arena(bool aEnabled) {
|
|
if (malloc_init()) {
|
|
thread_local_arena(aEnabled);
|
|
}
|
|
}
|
|
|
|
// Choose an arena based on a per-thread value.
|
|
static inline arena_t* choose_arena(size_t size) {
|
|
arena_t* ret = nullptr;
|
|
|
|
// We can only use TLS if this is a PIC library, since for the static
|
|
// library version, libc's malloc is used by TLS allocation, which
|
|
// introduces a bootstrapping issue.
|
|
|
|
if (size > kMaxQuantumClass) {
|
|
// Force the default arena for larger allocations.
|
|
ret = gArenas.GetDefault();
|
|
} else {
|
|
// Check TLS to see if our thread has requested a pinned arena.
|
|
ret = thread_arena.get();
|
|
// If ret is non-null, it must not be in the first page.
|
|
MOZ_DIAGNOSTIC_ASSERT_IF(ret, (size_t)ret >= gPageSize);
|
|
if (!ret) {
|
|
// Nothing in TLS. Pin this thread to the default arena.
|
|
ret = thread_local_arena(false);
|
|
}
|
|
}
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT(ret);
|
|
return ret;
|
|
}
|
|
|
|
inline uint8_t arena_t::FindFreeBitInMask(uint32_t aMask, uint32_t& aRng) {
|
|
if (mPRNG != nullptr) {
|
|
if (aRng == UINT_MAX) {
|
|
aRng = mPRNG->next() % 32;
|
|
}
|
|
uint8_t bitIndex;
|
|
// RotateRight asserts when provided bad input.
|
|
aMask = aRng ? RotateRight(aMask, aRng)
|
|
: aMask; // Rotate the mask a random number of slots
|
|
bitIndex = static_cast<uint8_t>(std::countr_zero(aMask));
|
|
return (bitIndex + aRng) % 32;
|
|
}
|
|
return static_cast<uint8_t>(std::countr_zero(aMask));
|
|
}
|
|
|
|
inline void* arena_t::ArenaRunRegAlloc(arena_run_t* aRun, arena_bin_t* aBin) {
|
|
void* ret;
|
|
unsigned i, mask, bit, regind;
|
|
uint32_t rndPos = UINT_MAX;
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT(aRun->mMagic == ARENA_RUN_MAGIC);
|
|
MOZ_ASSERT(aRun->mRegionsMinElement < aBin->mRunNumRegionsMask);
|
|
|
|
// Move the first check outside the loop, so that aRun->mRegionsMinElement can
|
|
// be updated unconditionally, without the possibility of updating it
|
|
// multiple times.
|
|
i = aRun->mRegionsMinElement;
|
|
mask = aRun->mRegionsMask[i];
|
|
if (mask != 0) {
|
|
bit = FindFreeBitInMask(mask, rndPos);
|
|
|
|
regind = ((i << (LOG2(sizeof(int)) + 3)) + bit);
|
|
MOZ_ASSERT(regind < aBin->mRunNumRegions);
|
|
ret = (void*)(((uintptr_t)aRun) + aBin->mRunFirstRegionOffset +
|
|
(aBin->mSizeClass * regind));
|
|
|
|
// Clear bit.
|
|
mask ^= (1U << bit);
|
|
aRun->mRegionsMask[i] = mask;
|
|
|
|
return ret;
|
|
}
|
|
|
|
for (i++; i < aBin->mRunNumRegionsMask; i++) {
|
|
mask = aRun->mRegionsMask[i];
|
|
if (mask != 0) {
|
|
bit = FindFreeBitInMask(mask, rndPos);
|
|
|
|
regind = ((i << (LOG2(sizeof(int)) + 3)) + bit);
|
|
MOZ_ASSERT(regind < aBin->mRunNumRegions);
|
|
ret = (void*)(((uintptr_t)aRun) + aBin->mRunFirstRegionOffset +
|
|
(aBin->mSizeClass * regind));
|
|
|
|
// Clear bit.
|
|
mask ^= (1U << bit);
|
|
aRun->mRegionsMask[i] = mask;
|
|
|
|
// Make a note that nothing before this element
|
|
// contains a free region.
|
|
aRun->mRegionsMinElement = i; // Low payoff: + (mask == 0);
|
|
|
|
return ret;
|
|
}
|
|
}
|
|
// Not reached.
|
|
MOZ_DIAGNOSTIC_ASSERT(0);
|
|
return nullptr;
|
|
}
|
|
|
|
static inline void arena_run_reg_dalloc(arena_run_t* run, arena_bin_t* bin,
|
|
void* ptr, size_t size) {
|
|
uint32_t diff, regind;
|
|
unsigned elm, bit;
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mMagic == ARENA_RUN_MAGIC);
|
|
|
|
// Avoid doing division with a variable divisor if possible. Using
|
|
// actual division here can reduce allocator throughput by over 20%!
|
|
diff =
|
|
(uint32_t)((uintptr_t)ptr - (uintptr_t)run - bin->mRunFirstRegionOffset);
|
|
|
|
MOZ_ASSERT(diff <=
|
|
(static_cast<unsigned>(bin->mRunSizePages) << gPageSize2Pow));
|
|
regind = diff / bin->mSizeDivisor;
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT(diff == regind * size);
|
|
MOZ_DIAGNOSTIC_ASSERT(regind < bin->mRunNumRegions);
|
|
|
|
elm = regind >> (LOG2(sizeof(int)) + 3);
|
|
if (elm < run->mRegionsMinElement) {
|
|
run->mRegionsMinElement = elm;
|
|
}
|
|
bit = regind - (elm << (LOG2(sizeof(int)) + 3));
|
|
MOZ_RELEASE_ASSERT((run->mRegionsMask[elm] & (1U << bit)) == 0,
|
|
"Double-free?");
|
|
run->mRegionsMask[elm] |= (1U << bit);
|
|
}
|
|
|
|
#ifndef MALLOC_DECOMMIT
|
|
void arena_t::TouchMadvisedPage(arena_chunk_t* aChunk, size_t page) {
|
|
// It should be MADVISED because it's part of the same real page.
|
|
MOZ_ASSERT(aChunk->mPageMap[page].bits & CHUNK_MAP_MADVISED);
|
|
|
|
// But it must not have the other flags.
|
|
MOZ_ASSERT((aChunk->mPageMap[page].bits &
|
|
(CHUNK_MAP_FRESH | CHUNK_MAP_DECOMMITTED | CHUNK_MAP_DIRTY)) ==
|
|
0);
|
|
|
|
// Clear MADVISED and set DIRTY. It's dirty since it may still contain
|
|
// data from a previous use.
|
|
aChunk->mPageMap[page].bits =
|
|
(aChunk->mPageMap[page].bits & ~CHUNK_MAP_MADVISED) | CHUNK_MAP_DIRTY;
|
|
|
|
// Although this increases the number of dirty pages in the chunk, we
|
|
// don't add it to the purge list because these pages can't be purged.
|
|
// DallocRun will add it later.
|
|
aChunk->mNumDirty++;
|
|
mNumDirty++;
|
|
mStats.committed++;
|
|
mNumMAdvised--;
|
|
}
|
|
#endif
|
|
|
|
bool arena_t::SplitAndAllocRun(arena_run_t* aRun, size_t aSize, bool aLarge,
|
|
bool aZero) {
|
|
arena_chunk_t* chunk = GetChunkForPtr(aRun);
|
|
size_t old_ndirty = chunk->mNumDirty;
|
|
size_t run_ind =
|
|
(unsigned)((uintptr_t(aRun) - uintptr_t(chunk)) >> gPageSize2Pow);
|
|
size_t total_pages =
|
|
(chunk->mPageMap[run_ind].bits & ~gPageSizeMask) >> gPageSize2Pow;
|
|
size_t need_pages = (aSize >> gPageSize2Pow);
|
|
MOZ_ASSERT(need_pages > 0);
|
|
MOZ_ASSERT(need_pages <= total_pages);
|
|
size_t rem_pages = total_pages - need_pages;
|
|
|
|
MOZ_ASSERT((chunk->mPageMap[run_ind].bits & CHUNK_MAP_BUSY) == 0);
|
|
|
|
#ifdef MALLOC_DECOMMIT
|
|
size_t i = 0;
|
|
while (i < need_pages) {
|
|
MOZ_ASSERT((chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_BUSY) == 0);
|
|
|
|
// Commit decommitted pages if necessary. If a decommitted
|
|
// page is encountered, commit all needed adjacent decommitted
|
|
// pages in one operation, in order to reduce system call
|
|
// overhead.
|
|
if (chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_DECOMMITTED) {
|
|
// The start of the decommitted area is on a real page boundary.
|
|
MOZ_ASSERT((run_ind + i) % gPagesPerRealPage == 0);
|
|
|
|
// Advance i+j to just past the index of the last page
|
|
// to commit. Clear CHUNK_MAP_DECOMMITTED along the way.
|
|
size_t j;
|
|
for (j = 0; i + j < need_pages && (chunk->mPageMap[run_ind + i + j].bits &
|
|
CHUNK_MAP_DECOMMITTED);
|
|
j++) {
|
|
// DECOMMITTED, MADVISED and FRESH are mutually exclusive.
|
|
MOZ_ASSERT((chunk->mPageMap[run_ind + i + j].bits &
|
|
(CHUNK_MAP_FRESH | CHUNK_MAP_MADVISED)) == 0);
|
|
}
|
|
|
|
// Consider committing more pages to amortise calls to VirtualAlloc.
|
|
// This only makes sense at the edge of our run hence the if condition
|
|
// here.
|
|
if (i + j == need_pages) {
|
|
size_t extra_commit = ExtraCommitPages(j, rem_pages);
|
|
extra_commit =
|
|
PAGES_PER_REAL_PAGE_CEILING(run_ind + i + j + extra_commit) -
|
|
run_ind - i - j;
|
|
for (; i + j < need_pages + extra_commit &&
|
|
(chunk->mPageMap[run_ind + i + j].bits &
|
|
CHUNK_MAP_MADVISED_OR_DECOMMITTED);
|
|
j++) {
|
|
MOZ_ASSERT((chunk->mPageMap[run_ind + i + j].bits &
|
|
(CHUNK_MAP_FRESH | CHUNK_MAP_MADVISED)) == 0);
|
|
}
|
|
}
|
|
// The end of the decommitted area is on a real page boundary.
|
|
MOZ_ASSERT((run_ind + i + j) % gPagesPerRealPage == 0);
|
|
|
|
if (!pages_commit(
|
|
(void*)(uintptr_t(chunk) + ((run_ind + i) << gPageSize2Pow)),
|
|
j << gPageSize2Pow)) {
|
|
return false;
|
|
}
|
|
|
|
// pages_commit zeroes pages, so mark them as such if it succeeded.
|
|
// That's checked further below to avoid manually zeroing the pages.
|
|
for (size_t k = 0; k < j; k++) {
|
|
chunk->mPageMap[run_ind + i + k].bits =
|
|
(chunk->mPageMap[run_ind + i + k].bits & ~CHUNK_MAP_DECOMMITTED) |
|
|
CHUNK_MAP_ZEROED | CHUNK_MAP_FRESH;
|
|
}
|
|
|
|
mNumFresh += j;
|
|
i += j;
|
|
} else {
|
|
i++;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
// Keep track of trailing unused pages for later use.
|
|
if (rem_pages > 0) {
|
|
chunk->mPageMap[run_ind + need_pages].bits =
|
|
(rem_pages << gPageSize2Pow) |
|
|
(chunk->mPageMap[run_ind + need_pages].bits & gPageSizeMask);
|
|
chunk->mPageMap[run_ind + total_pages - 1].bits =
|
|
(rem_pages << gPageSize2Pow) |
|
|
(chunk->mPageMap[run_ind + total_pages - 1].bits & gPageSizeMask);
|
|
mRunsAvail.Insert(&chunk->mPageMap[run_ind + need_pages]);
|
|
}
|
|
|
|
if (chunk->mDirtyRunHint == run_ind) {
|
|
chunk->mDirtyRunHint = run_ind + need_pages;
|
|
}
|
|
|
|
#ifndef MALLOC_DECOMMIT
|
|
bool first_page_was_madvised =
|
|
chunk->mPageMap[run_ind].bits & CHUNK_MAP_MADVISED;
|
|
bool last_page_was_madvised =
|
|
chunk->mPageMap[run_ind + need_pages - 1].bits & CHUNK_MAP_MADVISED;
|
|
#endif
|
|
for (size_t i = 0; i < need_pages; i++) {
|
|
// Zero if necessary.
|
|
if (aZero) {
|
|
if ((chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_ZEROED) == 0) {
|
|
memset((void*)(uintptr_t(chunk) + ((run_ind + i) << gPageSize2Pow)), 0,
|
|
gPageSize);
|
|
// CHUNK_MAP_ZEROED is cleared below.
|
|
}
|
|
}
|
|
|
|
// Update dirty page accounting.
|
|
if (chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_DIRTY) {
|
|
chunk->mNumDirty--;
|
|
mNumDirty--;
|
|
// CHUNK_MAP_DIRTY is cleared below.
|
|
} else if (chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_MADVISED) {
|
|
mStats.committed++;
|
|
mNumMAdvised--;
|
|
} else if (chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_FRESH) {
|
|
mStats.committed++;
|
|
mNumFresh--;
|
|
}
|
|
|
|
// This bit has already been cleared
|
|
MOZ_ASSERT(!(chunk->mPageMap[run_ind + i].bits & CHUNK_MAP_DECOMMITTED));
|
|
|
|
// Initialize the chunk map. This clears the dirty, zeroed and madvised
|
|
// bits, decommitted is cleared above.
|
|
if (aLarge) {
|
|
chunk->mPageMap[run_ind + i].bits = CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
} else {
|
|
chunk->mPageMap[run_ind + i].bits = size_t(aRun) | CHUNK_MAP_ALLOCATED;
|
|
}
|
|
}
|
|
|
|
#ifndef MALLOC_DECOMMIT
|
|
// Remove the MADVISED bit from leading and trailing pages that are part of
|
|
// the same real pages that we've touched. This may cross into other free
|
|
// runs, including busy runs. This is safe because real page boundaries are
|
|
// not crossed by either this code or the purging code.
|
|
if (first_page_was_madvised) {
|
|
for (size_t i = run_ind - 1;
|
|
(i & (gPagesPerRealPage - 1)) != (gPagesPerRealPage - 1); i--) {
|
|
// This loop will never go beyond into the chunk header or touch the guard
|
|
// page because the guard page is always aligned.
|
|
MOZ_ASSERT(gChunkHeaderNumPages <= i);
|
|
|
|
TouchMadvisedPage(chunk, i);
|
|
}
|
|
}
|
|
|
|
if (last_page_was_madvised) {
|
|
for (size_t i = run_ind + need_pages; (i & (gPagesPerRealPage - 1)) != 0;
|
|
i++) {
|
|
// This loop will never go beyond the end of the chunk or touch the guard
|
|
// page because the guard page is always aligned.
|
|
MOZ_ASSERT(i < gChunkNumPages - gPagesPerRealPage);
|
|
|
|
TouchMadvisedPage(chunk, i);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
// Set the run size only in the first element for large runs. This is
|
|
// primarily a debugging aid, since the lack of size info for trailing
|
|
// pages only matters if the application tries to operate on an
|
|
// interior pointer.
|
|
if (aLarge) {
|
|
chunk->mPageMap[run_ind].bits |= aSize;
|
|
}
|
|
|
|
if (chunk->mNumDirty == 0 && old_ndirty > 0 && !chunk->mIsPurging &&
|
|
mChunksDirty.ElementProbablyInList(chunk)) {
|
|
mChunksDirty.remove(chunk);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void arena_t::InitChunk(arena_chunk_t* aChunk, size_t aMinCommittedPages) {
|
|
new (aChunk) arena_chunk_t(this);
|
|
|
|
mStats.mapped += kChunkSize;
|
|
|
|
// Setup the chunk's pages in two phases. First we mark which pages are
|
|
// committed & decommitted and perform the decommit. Then we update the map
|
|
// to create the runs.
|
|
|
|
// Clear the bits for the real header pages.
|
|
size_t i;
|
|
for (i = 0; i < gChunkHeaderNumPages - gPagesPerRealPage; i++) {
|
|
aChunk->mPageMap[i].bits = 0;
|
|
}
|
|
mStats.committed += gChunkHeaderNumPages - gPagesPerRealPage;
|
|
|
|
// Decommit the last header page (=leading page) as a guard.
|
|
MOZ_ASSERT(i % gPagesPerRealPage == 0);
|
|
pages_decommit((void*)(uintptr_t(aChunk) + (i << gPageSize2Pow)),
|
|
gRealPageSize);
|
|
for (; i < gChunkHeaderNumPages; i++) {
|
|
aChunk->mPageMap[i].bits = CHUNK_MAP_DECOMMITTED;
|
|
}
|
|
|
|
// If MALLOC_DECOMMIT is enabled then commit only the pages we're about to
|
|
// use. Otherwise commit all of them.
|
|
#ifdef MALLOC_DECOMMIT
|
|
// The number of usable pages in the chunk, in other words, the total number
|
|
// of pages in the chunk, minus the number of pages in the chunk header
|
|
// (including the guard page at the beginning of the chunk), and the number of
|
|
// pages for the guard page at the end of the chunk.
|
|
size_t chunk_usable_pages =
|
|
gChunkNumPages - gChunkHeaderNumPages - gPagesPerRealPage;
|
|
size_t n_fresh_pages = PAGES_PER_REAL_PAGE_CEILING(
|
|
aMinCommittedPages +
|
|
ExtraCommitPages(aMinCommittedPages,
|
|
chunk_usable_pages - aMinCommittedPages));
|
|
#else
|
|
size_t n_fresh_pages =
|
|
gChunkNumPages - gPagesPerRealPage - gChunkHeaderNumPages;
|
|
#endif
|
|
|
|
// The committed pages are marked as Fresh. Our caller, SplitAndAllocRun will
|
|
// update this when it uses them.
|
|
for (size_t j = 0; j < n_fresh_pages; j++) {
|
|
aChunk->mPageMap[i + j].bits = CHUNK_MAP_ZEROED | CHUNK_MAP_FRESH;
|
|
}
|
|
i += n_fresh_pages;
|
|
mNumFresh += n_fresh_pages;
|
|
|
|
#ifndef MALLOC_DECOMMIT
|
|
// If MALLOC_DECOMMIT isn't defined then all the pages are fresh and setup in
|
|
// the loop above.
|
|
MOZ_ASSERT(i == gChunkNumPages - gPagesPerRealPage);
|
|
#endif
|
|
|
|
// If MALLOC_DECOMMIT is defined, then this will decommit the remainder of the
|
|
// chunk plus the last page which is a guard page, if it is not defined it
|
|
// will only decommit the guard page.
|
|
MOZ_ASSERT(i % gPagesPerRealPage == 0);
|
|
pages_decommit((void*)(uintptr_t(aChunk) + (i << gPageSize2Pow)),
|
|
(gChunkNumPages - i) << gPageSize2Pow);
|
|
for (; i < gChunkNumPages; i++) {
|
|
aChunk->mPageMap[i].bits = CHUNK_MAP_DECOMMITTED;
|
|
}
|
|
|
|
// aMinCommittedPages will create a valid run.
|
|
MOZ_ASSERT(aMinCommittedPages > 0);
|
|
MOZ_ASSERT(aMinCommittedPages <=
|
|
gChunkNumPages - gChunkHeaderNumPages - gPagesPerRealPage);
|
|
|
|
// Create the run.
|
|
aChunk->mPageMap[gChunkHeaderNumPages].bits |= gMaxLargeClass;
|
|
aChunk->mPageMap[gChunkNumPages - gPagesPerRealPage - 1].bits |=
|
|
gMaxLargeClass;
|
|
}
|
|
|
|
void arena_t::RemoveChunk(arena_chunk_t* aChunk) {
|
|
MOZ_ASSERT(aChunk->mArena == this);
|
|
|
|
// The chunk cannot be in either the spare or dirty chunk lists.
|
|
MOZ_ASSERT(!mSpares.ElementProbablyInList(aChunk));
|
|
MOZ_ASSERT(!mChunksDirty.ElementProbablyInList(aChunk));
|
|
|
|
// RemoveChunk is only called with the spare chunk or after purging, so
|
|
// the chunk will never be purging.
|
|
MOZ_ASSERT(!aChunk->mIsPurging);
|
|
|
|
mNumDirty -= aChunk->mNumDirty;
|
|
mStats.committed -= aChunk->mNumDirty;
|
|
|
|
// Count the number of madvised/fresh pages and update the stats.
|
|
size_t madvised = 0;
|
|
size_t fresh = 0;
|
|
for (size_t i = gChunkHeaderNumPages; i < gChunkNumPages - gPagesPerRealPage;
|
|
i++) {
|
|
MOZ_ASSERT((aChunk->mPageMap[i].bits & CHUNK_MAP_ALLOCATED) == 0);
|
|
MOZ_ASSERT((aChunk->mPageMap[i].bits & CHUNK_MAP_BUSY) == 0);
|
|
|
|
if (aChunk->mPageMap[i].bits & CHUNK_MAP_MADVISED) {
|
|
madvised++;
|
|
} else if (aChunk->mPageMap[i].bits & CHUNK_MAP_FRESH) {
|
|
fresh++;
|
|
}
|
|
}
|
|
|
|
mNumMAdvised -= madvised;
|
|
mNumFresh -= fresh;
|
|
|
|
#ifdef MALLOC_DOUBLE_PURGE
|
|
if (mChunksMAdvised.ElementProbablyInList(aChunk)) {
|
|
mChunksMAdvised.remove(aChunk);
|
|
}
|
|
#endif
|
|
|
|
mStats.mapped -= kChunkSize;
|
|
mStats.committed -= gChunkHeaderNumPages - gPagesPerRealPage;
|
|
}
|
|
|
|
void arena_t::DemoteChunkToSpare(arena_chunk_t* aChunk) {
|
|
// Spare chunks can't exist on the dirty chunks list because they use the
|
|
// same element field, so remove it from dirty chunks before adding it to
|
|
// spare chunks. If called after Purge then the chunk won't be on the
|
|
// dirty chunks list, the caller must clear aChunk->mIsPurging after this
|
|
// call.
|
|
if (aChunk->mNumDirty && !aChunk->mIsPurging) {
|
|
MOZ_ASSERT(mChunksDirty.ElementProbablyInList(aChunk));
|
|
mChunksDirty.remove(aChunk);
|
|
}
|
|
MOZ_ASSERT(!mChunksDirty.ElementProbablyInList(aChunk));
|
|
MOZ_ASSERT(!mSpares.ElementProbablyInList(aChunk));
|
|
mSpares.pushFront(aChunk);
|
|
}
|
|
|
|
arena_run_t* arena_t::AllocRun(size_t aSize, bool aLarge, bool aZero) {
|
|
arena_run_t* run;
|
|
arena_chunk_map_t* mapelm;
|
|
|
|
MOZ_ASSERT(aSize <= gMaxLargeClass);
|
|
MOZ_ASSERT((aSize & gPageSizeMask) == 0);
|
|
|
|
// Search the arena's chunks for the best fit.
|
|
mapelm = mRunsAvail.SearchOrNext(aSize);
|
|
if (mapelm) {
|
|
arena_chunk_t* chunk = GetChunkForPtr(mapelm);
|
|
size_t pageind = (uintptr_t(mapelm) - uintptr_t(chunk->mPageMap)) /
|
|
sizeof(arena_chunk_map_t);
|
|
|
|
MOZ_ASSERT((chunk->mPageMap[pageind].bits & CHUNK_MAP_BUSY) == 0);
|
|
run = (arena_run_t*)(uintptr_t(chunk) + (pageind << gPageSize2Pow));
|
|
mRunsAvail.Remove(mapelm);
|
|
} else if (!mSpares.isEmpty()) {
|
|
arena_chunk_t* chunk = mSpares.popFront();
|
|
MOZ_ASSERT(!chunk->mIsPurging);
|
|
|
|
if (chunk->mNumDirty) {
|
|
MOZ_ASSERT(!mChunksDirty.ElementProbablyInList(chunk));
|
|
mChunksDirty.pushFront(chunk);
|
|
}
|
|
|
|
run = (arena_run_t*)(uintptr_t(chunk) +
|
|
(gChunkHeaderNumPages << gPageSize2Pow));
|
|
MOZ_ASSERT((chunk->mPageMap[gChunkHeaderNumPages].bits & CHUNK_MAP_BUSY) ==
|
|
0);
|
|
mapelm = &chunk->mPageMap[gChunkHeaderNumPages];
|
|
} else {
|
|
// No usable runs. Create a new chunk from which to allocate
|
|
// the run.
|
|
arena_chunk_t* chunk = (arena_chunk_t*)arena_chunk_alloc(
|
|
mChunkAllocator, kChunkSize, kChunkSize);
|
|
if (!chunk) {
|
|
return nullptr;
|
|
}
|
|
|
|
InitChunk(chunk, aSize >> gPageSize2Pow);
|
|
run = (arena_run_t*)(uintptr_t(chunk) +
|
|
(gChunkHeaderNumPages << gPageSize2Pow));
|
|
mapelm = &chunk->mPageMap[gChunkHeaderNumPages];
|
|
}
|
|
// Update page map.
|
|
if (!SplitAndAllocRun(run, aSize, aLarge, aZero)) {
|
|
mRunsAvail.Insert(mapelm);
|
|
return nullptr;
|
|
}
|
|
return run;
|
|
}
|
|
|
|
void arena_t::UpdateMaxDirty() {
|
|
MaybeMutexAutoLock lock(mLock);
|
|
int32_t modifier = gArenas.DefaultMaxDirtyPageModifier();
|
|
if (modifier) {
|
|
int32_t arenaOverride =
|
|
modifier > 0 ? mMaxDirtyIncreaseOverride : mMaxDirtyDecreaseOverride;
|
|
if (arenaOverride) {
|
|
modifier = arenaOverride;
|
|
}
|
|
}
|
|
|
|
mMaxDirty =
|
|
modifier >= 0 ? mMaxDirtyBase << modifier : mMaxDirtyBase >> -modifier;
|
|
}
|
|
|
|
#ifdef MALLOC_DECOMMIT
|
|
|
|
size_t arena_t::ExtraCommitPages(size_t aReqPages, size_t aRemainingPages) {
|
|
const int32_t modifier = gArenas.DefaultMaxDirtyPageModifier();
|
|
if (modifier < 0) {
|
|
return 0;
|
|
}
|
|
|
|
// The maximum size of the page cache
|
|
const size_t max_page_cache = mMaxDirty;
|
|
|
|
// The current size of the page cache, note that we use mNumFresh +
|
|
// mNumMAdvised here but Purge() does not.
|
|
const size_t page_cache = mNumDirty + mNumFresh + mNumMAdvised;
|
|
|
|
if (page_cache > max_page_cache) {
|
|
// We're already exceeding our dirty page count even though we're trying
|
|
// to allocate. This can happen due to fragmentation. Don't commit
|
|
// excess memory since we're probably here due to a larger allocation and
|
|
// small amounts of memory are certainly available in the page cache.
|
|
return 0;
|
|
}
|
|
if (modifier > 0) {
|
|
// If modifier is > 0 then we want to keep all the pages we can, but don't
|
|
// exceed the size of the page cache. The subtraction cannot underflow
|
|
// because of the condition above.
|
|
return std::min(aRemainingPages, max_page_cache - page_cache);
|
|
}
|
|
|
|
// The rest is arbitrary and involves a some assumptions. I've broken it down
|
|
// into simple expressions to document them more clearly.
|
|
|
|
// Assumption 1: a quarter of mMaxDirty is a sensible "minimum
|
|
// target" for the dirty page cache. Likewise 3 quarters is a sensible
|
|
// "maximum target". Note that for the maximum we avoid using the whole page
|
|
// cache now so that a free that follows this allocation doesn't immeidatly
|
|
// call Purge (churning memory).
|
|
const size_t min = max_page_cache / 4;
|
|
const size_t max = 3 * max_page_cache / 4;
|
|
|
|
// Assumption 2: Committing 32 pages at a time is sufficient to amortise
|
|
// VirtualAlloc costs.
|
|
size_t amortisation_threshold = 32;
|
|
|
|
// extra_pages is the number of additional pages needed to meet
|
|
// amortisation_threshold.
|
|
size_t extra_pages = aReqPages < amortisation_threshold
|
|
? amortisation_threshold - aReqPages
|
|
: 0;
|
|
|
|
// If committing extra_pages isn't enough to hit the minimum target then
|
|
// increase it.
|
|
if (page_cache + extra_pages < min) {
|
|
extra_pages = min - page_cache;
|
|
} else if (page_cache + extra_pages > max) {
|
|
// If committing extra_pages would exceed our maximum target then it may
|
|
// still be useful to allocate extra pages. One of the reasons this can
|
|
// happen could be fragmentation of the cache,
|
|
|
|
// Therefore reduce the amortisation threshold so that we might allocate
|
|
// some extra pages but avoid exceeding the dirty page cache.
|
|
amortisation_threshold /= 2;
|
|
extra_pages = std::min(aReqPages < amortisation_threshold
|
|
? amortisation_threshold - aReqPages
|
|
: 0,
|
|
max_page_cache - page_cache);
|
|
}
|
|
|
|
// Cap extra_pages to aRemainingPages and adjust aRemainingPages. We will
|
|
// commit at least this many extra pages.
|
|
extra_pages = std::min(extra_pages, aRemainingPages);
|
|
|
|
// Finally if commiting a small number of additional pages now can prevent
|
|
// a small commit later then try to commit a little more now, provided we
|
|
// don't exceed max_page_cache.
|
|
if ((aRemainingPages - extra_pages) < amortisation_threshold / 2 &&
|
|
(page_cache + aRemainingPages) < max_page_cache) {
|
|
return aRemainingPages;
|
|
}
|
|
|
|
return extra_pages;
|
|
}
|
|
#endif
|
|
|
|
ArenaPurgeResult arena_t::Purge(PurgeCondition aCond, PurgeStats& aStats,
|
|
const Maybe<std::function<bool()>>& aKeepGoing)
|
|
MOZ_EXCLUDES(mLock) {
|
|
mLock.Lock();
|
|
|
|
if (mMustDeleteAfterPurge) {
|
|
mIsPurgePending = false;
|
|
mLock.Unlock();
|
|
return Dying;
|
|
}
|
|
|
|
if (!ShouldContinuePurge(aCond)) {
|
|
mIsPurgePending = false;
|
|
mLock.Unlock();
|
|
return ReachedThresholdOrBusy;
|
|
}
|
|
|
|
arena_chunk_t* chunk = PurgeGetSpareChunk(aStats);
|
|
if (chunk) {
|
|
// Release the memory outside of the lock.
|
|
mLock.Unlock();
|
|
arena_chunk_dealloc(mChunkAllocator, (void*)chunk, kChunkSize);
|
|
aStats.system_calls++;
|
|
return NotDone;
|
|
}
|
|
|
|
chunk = PurgeGetDirtyChunk(aCond, aStats);
|
|
mLock.Unlock();
|
|
if (chunk) {
|
|
return PurgeDirtyPages(chunk, aCond, aStats, aKeepGoing);
|
|
}
|
|
|
|
return ReachedThresholdOrBusy;
|
|
}
|
|
|
|
arena_chunk_t* arena_t::PurgeGetSpareChunk(PurgeStats& aStats)
|
|
MOZ_REQUIRES(mLock) {
|
|
if (mSpares.isEmpty()) {
|
|
return nullptr;
|
|
}
|
|
|
|
// Start flushing our cache of spare chunks.
|
|
arena_chunk_t* chunk = mSpares.popBack();
|
|
|
|
// This is not possible. Not because another thread won't be purging
|
|
// memory because that is possible (but rare). But because it'd need
|
|
// to start purging, then become empty before the purge finishes,
|
|
// which cannot happen because busy runs won't be merged and it won't
|
|
// be detected as empty until the end of the purge.
|
|
MOZ_ASSERT(!chunk->mIsPurging);
|
|
|
|
aStats.chunks++;
|
|
aStats.pages_dirty += chunk->mNumDirty;
|
|
aStats.pages_total += (kChunkSize >> gPageSize2Pow) - gPagesPerRealPage * 2;
|
|
RemoveChunk(chunk);
|
|
|
|
return chunk;
|
|
}
|
|
|
|
arena_chunk_t* arena_t::PurgeGetDirtyChunk(PurgeCondition aCond,
|
|
PurgeStats& aStats)
|
|
MOZ_REQUIRES(mLock) {
|
|
#ifdef MOZ_DEBUG
|
|
size_t ndirty = 0;
|
|
for (auto& chunk : mChunksDirty) {
|
|
ndirty += chunk.mNumDirty;
|
|
}
|
|
|
|
// Spare chunks don't appear in mChunksDirty.
|
|
for (auto& chunk : mSpares) {
|
|
ndirty += chunk.mNumDirty;
|
|
}
|
|
|
|
// Not all dirty chunks are in mChunksDirty as some may not have enough
|
|
// dirty pages for purging or might currently be being purged.
|
|
MOZ_ASSERT(ndirty <= mNumDirty);
|
|
#endif
|
|
|
|
// Take a single chunk and attempt to purge some of its dirty pages. The
|
|
// loop below will purge memory from the chunk until either:
|
|
// * The dirty page count for the arena hits its target,
|
|
// * Another thread attempts to delete this chunk, or
|
|
// * The chunk has no more dirty pages.
|
|
// In any of these cases the loop will break and Purge() will return,
|
|
// which means it may return before the arena meets its dirty page count
|
|
// target, the return value is used by the caller to call Purge() again
|
|
// where it will take the next chunk with dirty pages.
|
|
if (mChunksDirty.isEmpty()) {
|
|
// We have to clear the flag to preserve the invariant that if Purge()
|
|
// returns anything other than NotDone then the flag is clear. If
|
|
// there's more purging work to do in other chunks then either other
|
|
// calls to Purge() (in other threads) will handle it or we rely on
|
|
// ShouldStartPurge() returning true at some point in the future.
|
|
mIsPurgePending = false;
|
|
|
|
// There are chunks with dirty pages (because mNumDirty > 0 above) but
|
|
// they're not in mChunksDirty, they might not have enough dirty pages.
|
|
// Or maybe they're busy being purged by other threads.
|
|
return nullptr;
|
|
}
|
|
|
|
arena_chunk_t* chunk = mChunksDirty.popFront();
|
|
MOZ_ASSERT(chunk->mNumDirty > 0);
|
|
MOZ_ASSERT(!chunk->IsEmpty());
|
|
|
|
// Mark the chunk as busy so it won't be deleted and remove it from
|
|
// mChunksDirty so we're the only thread purging it.
|
|
MOZ_ASSERT(!chunk->mIsPurging);
|
|
chunk->mIsPurging = true;
|
|
aStats.chunks++;
|
|
|
|
return chunk;
|
|
}
|
|
|
|
ArenaPurgeResult arena_t::PurgeDirtyPages(
|
|
arena_chunk_t* aChunk, PurgeCondition aCond, PurgeStats& aStats,
|
|
const Maybe<std::function<bool()>>& aKeepGoing) MOZ_EXCLUDES(mLock) {
|
|
// True if we should continue purging memory from this arena.
|
|
bool continue_purge_arena = true;
|
|
|
|
// True if we should continue purging memory in this chunk.
|
|
bool continue_purge_chunk = true;
|
|
|
|
// True if at least one Purge operation has occured and therefore we need to
|
|
// call FinishPurgingInChunk() before returning.
|
|
bool purged_once = false;
|
|
|
|
// False if aKeepGoing prevents us from finishing this chunk in one go.
|
|
bool keep_going = true;
|
|
|
|
while (continue_purge_chunk && continue_purge_arena && keep_going) {
|
|
// This structure is used to communicate between the two PurgePhase
|
|
// functions.
|
|
PurgeInfo purge_info(*this, aChunk, aStats);
|
|
|
|
{
|
|
// Phase 1: Find pages that need purging.
|
|
MaybeMutexAutoLock lock(purge_info.mArena.mLock);
|
|
MOZ_ASSERT(aChunk->mIsPurging);
|
|
|
|
if (purge_info.mArena.mMustDeleteAfterPurge) {
|
|
aChunk->mIsPurging = false;
|
|
purge_info.mArena.mIsPurgePending = false;
|
|
return Dying;
|
|
}
|
|
|
|
continue_purge_chunk = purge_info.FindDirtyPages(purged_once);
|
|
continue_purge_arena = purge_info.mArena.ShouldContinuePurge(aCond);
|
|
|
|
// The code below will exit returning ReachedThresholdOrBusy if these are
|
|
// both false, so clear mIsPurgePending while we still hold the
|
|
// lock.
|
|
if (!continue_purge_chunk && !continue_purge_arena) {
|
|
purge_info.mArena.mIsPurgePending = false;
|
|
}
|
|
}
|
|
if (!continue_purge_chunk) {
|
|
// There's nothing else to do here, our caller may execute Purge() again
|
|
// if continue_purge_arena is true.
|
|
return continue_purge_arena ? NotDone : ReachedThresholdOrBusy;
|
|
}
|
|
// Note that even if continue_purge_arena is false, then the purge may still
|
|
// continue (as long as continue_purge_chunk is true). It must because the
|
|
// pages have already been marked in FindDirtyPages(), then it will exit
|
|
// after phase 2.
|
|
|
|
#ifdef MALLOC_DECOMMIT
|
|
pages_decommit(purge_info.DirtyPtr(), purge_info.DirtyLenBytes());
|
|
#else
|
|
# ifdef XP_SOLARIS
|
|
posix_madvise(purge_info.DirtyPtr(), purge_info.DirtyLenBytes(), MADV_FREE);
|
|
# else
|
|
madvise(purge_info.DirtyPtr(), purge_info.DirtyLenBytes(), MADV_FREE);
|
|
# endif
|
|
#endif
|
|
|
|
// Check budget outside any lock, after the madvise/decommit which is the
|
|
// potentially expensive operation.
|
|
keep_going = aKeepGoing ? (*aKeepGoing)() : true;
|
|
|
|
bool arena_is_dying;
|
|
{
|
|
// Phase 2: Mark the pages with their final state (madvised or
|
|
// decommitted) and fix up any other bookkeeping.
|
|
MaybeMutexAutoLock lock(purge_info.mArena.mLock);
|
|
MOZ_ASSERT(aChunk->mIsPurging);
|
|
|
|
// We can't early exit if the arena is dying, we have to finish the purge
|
|
// (which restores the state so the destructor will check it) and maybe
|
|
// release the old spare arena.
|
|
arena_is_dying = purge_info.mArena.mMustDeleteAfterPurge;
|
|
|
|
continue_purge_chunk = purge_info.UpdatePagesAndCounts();
|
|
continue_purge_arena = purge_info.mArena.ShouldContinuePurge(aCond);
|
|
|
|
if (!continue_purge_chunk || !continue_purge_arena || !keep_going) {
|
|
// We're going to stop (or pause) purging here so update the chunk's
|
|
// bookkeeping to reflect what we did (so far).
|
|
purge_info.FinishPurgingInChunk(true, continue_purge_chunk);
|
|
// Only clear mIsPurgePending when truly done. Otherwise the arena
|
|
// stays marked pending so it gets re-queued for the next purge pass.
|
|
if (!continue_purge_arena) {
|
|
purge_info.mArena.mIsPurgePending = false;
|
|
}
|
|
}
|
|
} // MaybeMutexAutoLock
|
|
|
|
if (arena_is_dying) {
|
|
return Dying;
|
|
}
|
|
purged_once = true;
|
|
}
|
|
|
|
return continue_purge_arena ? NotDone : ReachedThresholdOrBusy;
|
|
}
|
|
|
|
ArenaPurgeResult arena_t::PurgeLoop(PurgeCondition aCond, const char* aCaller,
|
|
uint32_t aReuseGraceMS,
|
|
Maybe<std::function<bool()>> aKeepGoing) {
|
|
PurgeStats purge_stats(mId, mLabel, aCaller);
|
|
|
|
#ifdef MOZJEMALLOC_PROFILING_CALLBACKS
|
|
// We hold our own reference to callbacks for the duration of PurgeLoop to
|
|
// make sure it's not released during purging.
|
|
RefPtr<MallocProfilerCallbacks> callbacks = sCallbacks;
|
|
TimeStamp start;
|
|
if (callbacks) {
|
|
start = TimeStamp::Now();
|
|
}
|
|
#endif
|
|
|
|
uint64_t reuseGraceNS = (uint64_t)aReuseGraceMS * 1000 * 1000;
|
|
uint64_t now;
|
|
ArenaPurgeResult pr;
|
|
do {
|
|
pr = Purge(aCond, purge_stats, aKeepGoing);
|
|
now = aReuseGraceMS ? GetTimestampNS() : 0;
|
|
} while (
|
|
pr == NotDone &&
|
|
(!aReuseGraceMS || (now - mLastSignificantReuseNS >= reuseGraceNS)) &&
|
|
(!aKeepGoing || (*aKeepGoing)()));
|
|
|
|
#ifdef MOZJEMALLOC_PROFILING_CALLBACKS
|
|
if (callbacks) {
|
|
TimeStamp end = TimeStamp::Now();
|
|
// We can't hold an arena lock while committing profiler markers.
|
|
callbacks->OnPurge(start, end, purge_stats, pr);
|
|
}
|
|
#endif
|
|
|
|
return pr;
|
|
}
|
|
|
|
bool arena_t::PurgeInfo::FindDirtyPages(bool aPurgedOnce) {
|
|
// It's possible that the previously dirty pages have now been
|
|
// allocated or the chunk is dying.
|
|
if (mChunk->mNumDirty == 0) {
|
|
// Add the chunk to the mChunksMAdvised list if it's had at least one
|
|
// madvise.
|
|
FinishPurgingInChunk(aPurgedOnce, false);
|
|
return false;
|
|
}
|
|
|
|
// This will locate a span of dirty pages within a single run (unallocated
|
|
// runs never have unallocated neighbours). The span of dirty pages may have
|
|
// "holes" of clean never-allocated pages. We don't know for sure the
|
|
// trade-offs of purging those clean pages. On one hand:
|
|
// * This reduces the number of system calls needed
|
|
// * This may cause less fragmentation in the kernel's structures, but not
|
|
// the CPU's page tables.
|
|
// * It's likely that the pages aren't committed by the OS anyway.
|
|
// On the other hand:
|
|
// * Now accessing those pages will require either pages_commit() or a page
|
|
// fault to ensure they're available.
|
|
do {
|
|
if (!ScanForFirstDirtyPage()) {
|
|
FinishPurgingInChunk(aPurgedOnce, false);
|
|
return false;
|
|
}
|
|
} while (!ScanForLastDirtyPage());
|
|
|
|
MOZ_ASSERT(mFreeRunInd >= gChunkHeaderNumPages);
|
|
MOZ_ASSERT(mFreeRunInd <= mDirtyInd);
|
|
MOZ_ASSERT(mFreeRunLen > 0);
|
|
MOZ_ASSERT(mDirtyInd != 0);
|
|
MOZ_ASSERT(mDirtyLen != 0);
|
|
MOZ_ASSERT(mDirtyLen <= mFreeRunLen);
|
|
MOZ_ASSERT(mDirtyInd + mDirtyLen <= mFreeRunInd + mFreeRunLen);
|
|
MOZ_ASSERT(mDirtyInd % gPagesPerRealPage == 0);
|
|
MOZ_ASSERT(mDirtyLen % gPagesPerRealPage == 0);
|
|
|
|
// Count the number of dirty pages and clear their bits.
|
|
mDirtyNPages = 0;
|
|
for (size_t i = 0; i < mDirtyLen; i++) {
|
|
size_t& bits = mChunk->mPageMap[mDirtyInd + i].bits;
|
|
if (bits & CHUNK_MAP_DIRTY) {
|
|
mDirtyNPages++;
|
|
bits ^= CHUNK_MAP_DIRTY;
|
|
}
|
|
}
|
|
|
|
MOZ_ASSERT(mDirtyNPages > 0);
|
|
MOZ_ASSERT(mDirtyNPages <= mChunk->mNumDirty);
|
|
MOZ_ASSERT(mDirtyNPages <= mDirtyLen);
|
|
|
|
mChunk->mNumDirty -= mDirtyNPages;
|
|
mArena.mNumDirty -= mDirtyNPages;
|
|
|
|
// Mark the run as busy so that another thread freeing memory won't try to
|
|
// coalesce it.
|
|
mChunk->mPageMap[mFreeRunInd].bits |= CHUNK_MAP_BUSY;
|
|
mChunk->mPageMap[FreeRunLastInd()].bits |= CHUNK_MAP_BUSY;
|
|
|
|
// Before we unlock ensure that no other thread can allocate from these
|
|
// pages. Only chunks that are not spare, and therefore not-empty will be in
|
|
// the mRunsAvail list.
|
|
if (!mChunk->IsEmpty()) {
|
|
mArena.mRunsAvail.Remove(&mChunk->mPageMap[mFreeRunInd]);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Look for the first dirty page and the run it belongs to.
|
|
bool arena_t::PurgeInfo::ScanForFirstDirtyPage() {
|
|
// Scan in two nested loops. The outer loop iterates over runs, and the inner
|
|
// loop iterates over pages within unallocated runs.
|
|
size_t run_pages;
|
|
for (size_t run_idx = mChunk->mDirtyRunHint;
|
|
run_idx < gChunkNumPages - gPagesPerRealPage; run_idx += run_pages) {
|
|
size_t run_bits = mChunk->mPageMap[run_idx].bits;
|
|
// We must not find any busy pages because this chunk shouldn't be in
|
|
// the dirty list.
|
|
MOZ_ASSERT((run_bits & CHUNK_MAP_BUSY) == 0);
|
|
|
|
// Determine the run's size, this is used in the loop iteration to move to
|
|
// the next run.
|
|
if (run_bits & CHUNK_MAP_LARGE || !(run_bits & CHUNK_MAP_ALLOCATED)) {
|
|
size_t size = run_bits & ~gPageSizeMask;
|
|
run_pages = size >> gPageSize2Pow;
|
|
} else {
|
|
arena_run_t* run =
|
|
reinterpret_cast<arena_run_t*>(run_bits & ~gPageSizeMask);
|
|
MOZ_ASSERT(run == reinterpret_cast<arena_run_t*>(
|
|
reinterpret_cast<uintptr_t>(mChunk) +
|
|
(run_idx << gPageSize2Pow)));
|
|
run_pages = run->mBin->mRunSizePages;
|
|
}
|
|
MOZ_ASSERT(run_pages > 0);
|
|
MOZ_ASSERT(run_idx + run_pages <= gChunkNumPages);
|
|
|
|
if (run_bits & CHUNK_MAP_ALLOCATED) {
|
|
// Allocated runs won't contain dirty pages.
|
|
continue;
|
|
}
|
|
|
|
mFreeRunInd = run_idx;
|
|
mFreeRunLen = run_pages;
|
|
mDirtyInd = 0;
|
|
// Scan for dirty pages.
|
|
for (size_t page_idx = run_idx; page_idx < run_idx + run_pages;
|
|
page_idx++) {
|
|
size_t& page_bits = mChunk->mPageMap[page_idx].bits;
|
|
// We must not find any busy pages because this chunk shouldn't be in
|
|
// the dirty list.
|
|
MOZ_ASSERT((page_bits & CHUNK_MAP_BUSY) == 0);
|
|
|
|
// gPagesPerRealPage is a power of two, use a bitmask to check if page_idx
|
|
// is a multiple.
|
|
if ((page_idx & (gPagesPerRealPage - 1)) == 0) {
|
|
// A system call can be aligned here.
|
|
mDirtyInd = page_idx;
|
|
}
|
|
|
|
if (page_bits & CHUNK_MAP_DIRTY) {
|
|
MOZ_ASSERT((page_bits & CHUNK_MAP_FRESH_MADVISED_OR_DECOMMITTED) == 0);
|
|
MOZ_ASSERT(mChunk->mDirtyRunHint <= run_idx);
|
|
mChunk->mDirtyRunHint = run_idx;
|
|
|
|
if (mDirtyInd) {
|
|
return true;
|
|
}
|
|
|
|
// This dirty page occurs before a page we can align on,
|
|
// so it can't be purged.
|
|
mPurgeStats.pages_unpurgable++;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool arena_t::PurgeInfo::ScanForLastDirtyPage() {
|
|
mDirtyLen = 0;
|
|
for (size_t i = FreeRunLastInd(); i >= mDirtyInd; i--) {
|
|
size_t& bits = mChunk->mPageMap[i].bits;
|
|
// We must not find any busy pages because this chunk shouldn't be in the
|
|
// dirty list.
|
|
MOZ_ASSERT(!(bits & CHUNK_MAP_BUSY));
|
|
|
|
// gPagesPerRealPage is a power of two, use a bitmask to check if page_idx
|
|
// is a multiple minus one.
|
|
if ((i & (gPagesPerRealPage - 1)) == gPagesPerRealPage - 1) {
|
|
// A system call can be aligned here.
|
|
mDirtyLen = i - mDirtyInd + 1;
|
|
}
|
|
|
|
if (bits & CHUNK_MAP_DIRTY) {
|
|
if (mDirtyLen) {
|
|
return true;
|
|
}
|
|
|
|
// This dirty page occurs after a page we can align on,
|
|
// so it can't be purged.
|
|
mPurgeStats.pages_unpurgable++;
|
|
}
|
|
}
|
|
|
|
// Advance the dirty page hint so that the next scan will make progress.
|
|
mChunk->mDirtyRunHint = FreeRunLastInd() + 1;
|
|
return false;
|
|
}
|
|
|
|
bool arena_t::PurgeInfo::UpdatePagesAndCounts() {
|
|
size_t num_madvised = 0;
|
|
size_t num_decommitted = 0;
|
|
size_t num_fresh = 0;
|
|
|
|
for (size_t i = 0; i < mDirtyLen; i++) {
|
|
size_t& bits = mChunk->mPageMap[mDirtyInd + i].bits;
|
|
|
|
// The page must not have the dirty bit set.
|
|
MOZ_ASSERT((bits & CHUNK_MAP_DIRTY) == 0);
|
|
|
|
#ifdef MALLOC_DECOMMIT
|
|
if (bits & CHUNK_MAP_DECOMMITTED) {
|
|
num_decommitted++;
|
|
}
|
|
#else
|
|
if (bits & CHUNK_MAP_MADVISED) {
|
|
num_madvised++;
|
|
}
|
|
#endif
|
|
else if (bits & CHUNK_MAP_FRESH) {
|
|
num_fresh++;
|
|
}
|
|
|
|
// Clear these page status bits.
|
|
bits &= ~CHUNK_MAP_FRESH_MADVISED_OR_DECOMMITTED;
|
|
|
|
// Set the free_operation bit.
|
|
#ifdef MALLOC_DECOMMIT
|
|
bits |= CHUNK_MAP_DECOMMITTED;
|
|
#else
|
|
bits |= CHUNK_MAP_MADVISED;
|
|
#endif
|
|
}
|
|
|
|
// Remove the CHUNK_MAP_BUSY marks from the run.
|
|
#ifdef MOZ_DEBUG
|
|
MOZ_ASSERT(mChunk->mPageMap[mFreeRunInd].bits & CHUNK_MAP_BUSY);
|
|
MOZ_ASSERT(mChunk->mPageMap[FreeRunLastInd()].bits & CHUNK_MAP_BUSY);
|
|
#endif
|
|
mChunk->mPageMap[mFreeRunInd].bits &= ~CHUNK_MAP_BUSY;
|
|
mChunk->mPageMap[FreeRunLastInd()].bits &= ~CHUNK_MAP_BUSY;
|
|
|
|
#ifndef MALLOC_DECOMMIT
|
|
mArena.mNumMAdvised += mDirtyLen - num_madvised;
|
|
#endif
|
|
|
|
mArena.mNumFresh -= num_fresh;
|
|
mArena.mStats.committed -=
|
|
mDirtyLen - num_madvised - num_decommitted - num_fresh;
|
|
mPurgeStats.pages_dirty += mDirtyNPages;
|
|
mPurgeStats.pages_total += mDirtyLen;
|
|
mPurgeStats.system_calls++;
|
|
|
|
// Note that this code can't update the dirty run hint. There may be other
|
|
// dirty pages within the same run.
|
|
|
|
mFreeRunInd =
|
|
mArena.TryCoalesce(mChunk, mFreeRunInd, mFreeRunLen, FreeRunLenBytes());
|
|
|
|
if (!mChunk->IsEmpty()) {
|
|
mArena.mRunsAvail.Insert(&mChunk->mPageMap[mFreeRunInd]);
|
|
}
|
|
|
|
return mChunk->mNumDirty != 0;
|
|
}
|
|
|
|
void arena_t::PurgeInfo::FinishPurgingInChunk(bool aAddToMAdvised,
|
|
bool aAddToDirty) {
|
|
// If there's no more purge activity for this chunk then finish up while
|
|
// we still have the lock.
|
|
MOZ_ASSERT(mChunk->mIsPurging);
|
|
|
|
if (mChunk->IsEmpty()) {
|
|
// This now-empty chunk will become the spare chunk and the spare
|
|
// chunk will be returned for deletion. Note that mChunk->mIsPurging is
|
|
// still true for this call, that tells DemoteChunkToSpare not to remove
|
|
// the chunk from mChunksDirty.
|
|
mArena.DemoteChunkToSpare(mChunk);
|
|
} else if (mChunk->mNumDirty != 0 && aAddToDirty) {
|
|
// Put the semi-processed chunk on the front of the queue so that it is
|
|
// the first chunk processed next time.
|
|
mArena.mChunksDirty.pushFront(mChunk);
|
|
}
|
|
mChunk->mIsPurging = false;
|
|
|
|
#ifdef MALLOC_DOUBLE_PURGE
|
|
if (aAddToMAdvised) {
|
|
// The chunk might already be in the list, but this
|
|
// makes sure it's at the front.
|
|
if (mArena.mChunksMAdvised.ElementProbablyInList(mChunk)) {
|
|
mArena.mChunksMAdvised.remove(mChunk);
|
|
}
|
|
mArena.mChunksMAdvised.pushFront(mChunk);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
// run_pages and size make each-other redundant. But we use them both and the
|
|
// caller computes both so this function requires both and will assert if they
|
|
// are inconsistent.
|
|
size_t arena_t::TryCoalesce(arena_chunk_t* aChunk, size_t run_ind,
|
|
size_t run_pages, size_t size) {
|
|
// Copy in/out parameters to local variables so that we don't need '*'
|
|
// operators throughout this code but also so that type checking is stricter
|
|
// (references are too easily coerced).
|
|
MOZ_ASSERT(size == run_pages << gPageSize2Pow);
|
|
|
|
// Try to coalesce forward.
|
|
if (run_ind + run_pages < gChunkNumPages - gPagesPerRealPage &&
|
|
(aChunk->mPageMap[run_ind + run_pages].bits &
|
|
(CHUNK_MAP_ALLOCATED | CHUNK_MAP_BUSY)) == 0) {
|
|
size_t nrun_size =
|
|
aChunk->mPageMap[run_ind + run_pages].bits & ~gPageSizeMask;
|
|
|
|
// Remove successor from tree of available runs; the coalesced run is
|
|
// inserted later.
|
|
mRunsAvail.Remove(&aChunk->mPageMap[run_ind + run_pages]);
|
|
|
|
size += nrun_size;
|
|
run_pages = size >> gPageSize2Pow;
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT((aChunk->mPageMap[run_ind + run_pages - 1].bits &
|
|
~gPageSizeMask) == nrun_size);
|
|
aChunk->mPageMap[run_ind].bits =
|
|
size | (aChunk->mPageMap[run_ind].bits & gPageSizeMask);
|
|
aChunk->mPageMap[run_ind + run_pages - 1].bits =
|
|
size | (aChunk->mPageMap[run_ind + run_pages - 1].bits & gPageSizeMask);
|
|
}
|
|
|
|
// Try to coalesce backward.
|
|
if (run_ind > gChunkHeaderNumPages &&
|
|
(aChunk->mPageMap[run_ind - 1].bits &
|
|
(CHUNK_MAP_ALLOCATED | CHUNK_MAP_BUSY)) == 0) {
|
|
size_t prun_size = aChunk->mPageMap[run_ind - 1].bits & ~gPageSizeMask;
|
|
|
|
run_ind -= prun_size >> gPageSize2Pow;
|
|
|
|
// Remove predecessor from tree of available runs; the coalesced run is
|
|
// inserted later.
|
|
mRunsAvail.Remove(&aChunk->mPageMap[run_ind]);
|
|
|
|
size += prun_size;
|
|
run_pages = size >> gPageSize2Pow;
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT((aChunk->mPageMap[run_ind].bits & ~gPageSizeMask) ==
|
|
prun_size);
|
|
aChunk->mPageMap[run_ind].bits =
|
|
size | (aChunk->mPageMap[run_ind].bits & gPageSizeMask);
|
|
aChunk->mPageMap[run_ind + run_pages - 1].bits =
|
|
size | (aChunk->mPageMap[run_ind + run_pages - 1].bits & gPageSizeMask);
|
|
}
|
|
|
|
// If the dirty run hint points within the run then the new greater run
|
|
// is the run with the lowest index containing dirty pages. So update the
|
|
// hint.
|
|
if ((aChunk->mDirtyRunHint > run_ind) &&
|
|
(aChunk->mDirtyRunHint < run_ind + run_pages)) {
|
|
aChunk->mDirtyRunHint = run_ind;
|
|
}
|
|
|
|
return run_ind;
|
|
}
|
|
|
|
void arena_t::DallocRun(arena_run_t* aRun, bool aDirty) {
|
|
arena_chunk_t* chunk = GetChunkForPtr(aRun);
|
|
size_t run_ind =
|
|
(size_t)((uintptr_t(aRun) - uintptr_t(chunk)) >> gPageSize2Pow);
|
|
MOZ_DIAGNOSTIC_ASSERT(run_ind >= gChunkHeaderNumPages);
|
|
MOZ_RELEASE_ASSERT(run_ind < gChunkNumPages - 1);
|
|
|
|
size_t size, run_pages;
|
|
if ((chunk->mPageMap[run_ind].bits & CHUNK_MAP_LARGE) != 0) {
|
|
size = chunk->mPageMap[run_ind].bits & ~gPageSizeMask;
|
|
run_pages = (size >> gPageSize2Pow);
|
|
} else {
|
|
run_pages = aRun->mBin->mRunSizePages;
|
|
size = run_pages << gPageSize2Pow;
|
|
}
|
|
|
|
// Mark pages as unallocated in the chunk map, at the same time clear all the
|
|
// page bits and size information, set the dirty bit if the pages are now
|
|
// dirty..
|
|
for (size_t i = 0; i < run_pages; i++) {
|
|
size_t& bits = chunk->mPageMap[run_ind + i].bits;
|
|
|
|
// No bits other than ALLOCATED or LARGE may be set.
|
|
MOZ_DIAGNOSTIC_ASSERT(
|
|
(bits & gPageSizeMask & ~(CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED)) == 0);
|
|
bits = aDirty ? CHUNK_MAP_DIRTY : 0;
|
|
}
|
|
|
|
if (aDirty) {
|
|
// One of the reasons we check mIsPurging here is so that we don't add a
|
|
// chunk that's currently in the middle of purging to the list, which could
|
|
// start a concurrent purge.
|
|
if (!chunk->mIsPurging &&
|
|
(chunk->mNumDirty == 0 || !mChunksDirty.ElementProbablyInList(chunk))) {
|
|
mChunksDirty.pushBack(chunk);
|
|
}
|
|
chunk->mNumDirty += run_pages;
|
|
mNumDirty += run_pages;
|
|
}
|
|
|
|
chunk->mPageMap[run_ind].bits |= size;
|
|
chunk->mPageMap[run_ind + run_pages - 1].bits |= size;
|
|
|
|
run_ind = TryCoalesce(chunk, run_ind, run_pages, size);
|
|
|
|
// Now that run_ind is finalised we can update the dirty run hint.
|
|
if (aDirty && run_ind < chunk->mDirtyRunHint) {
|
|
chunk->mDirtyRunHint = run_ind;
|
|
}
|
|
|
|
// Deallocate chunk if it is now completely unused.
|
|
if (chunk->IsEmpty()) {
|
|
if (!chunk->mIsPurging) {
|
|
DemoteChunkToSpare(chunk);
|
|
}
|
|
} else {
|
|
// Insert into tree of available runs, now that coalescing is complete.
|
|
mRunsAvail.Insert(&chunk->mPageMap[run_ind]);
|
|
}
|
|
}
|
|
|
|
void arena_t::TrimRunHead(arena_chunk_t* aChunk, arena_run_t* aRun,
|
|
size_t aOldSize, size_t aNewSize) {
|
|
size_t pageind = (uintptr_t(aRun) - uintptr_t(aChunk)) >> gPageSize2Pow;
|
|
size_t head_npages = (aOldSize - aNewSize) >> gPageSize2Pow;
|
|
|
|
MOZ_ASSERT(aOldSize > aNewSize);
|
|
|
|
// Update the chunk map so that arena_t::RunDalloc() can treat the
|
|
// leading run as separately allocated.
|
|
aChunk->mPageMap[pageind].bits =
|
|
(aOldSize - aNewSize) | CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
aChunk->mPageMap[pageind + head_npages].bits =
|
|
aNewSize | CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
|
|
DallocRun(aRun, false);
|
|
}
|
|
|
|
void arena_t::TrimRunTail(arena_chunk_t* aChunk, arena_run_t* aRun,
|
|
size_t aOldSize, size_t aNewSize, bool aDirty) {
|
|
size_t pageind = (uintptr_t(aRun) - uintptr_t(aChunk)) >> gPageSize2Pow;
|
|
size_t npages = aNewSize >> gPageSize2Pow;
|
|
|
|
MOZ_ASSERT(aOldSize > aNewSize);
|
|
|
|
// Update the chunk map so that arena_t::RunDalloc() can treat the
|
|
// trailing run as separately allocated.
|
|
aChunk->mPageMap[pageind].bits =
|
|
aNewSize | CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
aChunk->mPageMap[pageind + npages].bits =
|
|
(aOldSize - aNewSize) | CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
|
|
DallocRun((arena_run_t*)(uintptr_t(aRun) + aNewSize), aDirty);
|
|
}
|
|
|
|
arena_run_t* arena_t::GetNewEmptyBinRun(arena_bin_t* aBin) {
|
|
arena_run_t* run;
|
|
unsigned i, remainder;
|
|
|
|
// Allocate a new run.
|
|
run = AllocRun(static_cast<size_t>(aBin->mRunSizePages) << gPageSize2Pow,
|
|
false, false);
|
|
if (!run) {
|
|
return nullptr;
|
|
}
|
|
|
|
// Initialize run internals.
|
|
run->mBin = aBin;
|
|
|
|
for (i = 0; i < aBin->mRunNumRegionsMask - 1; i++) {
|
|
run->mRegionsMask[i] = UINT_MAX;
|
|
}
|
|
remainder = aBin->mRunNumRegions & ((1U << (LOG2(sizeof(int)) + 3)) - 1);
|
|
if (remainder == 0) {
|
|
run->mRegionsMask[i] = UINT_MAX;
|
|
} else {
|
|
// The last element has spare bits that need to be unset.
|
|
run->mRegionsMask[i] =
|
|
(UINT_MAX >> ((1U << (LOG2(sizeof(int)) + 3)) - remainder));
|
|
}
|
|
|
|
run->mRegionsMinElement = 0;
|
|
|
|
run->mNumFree = aBin->mRunNumRegions;
|
|
#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
|
|
run->mMagic = ARENA_RUN_MAGIC;
|
|
#endif
|
|
|
|
// Make sure we continue to use this run for subsequent allocations.
|
|
new (&run->mRunListElem) DoublyLinkedListElement<arena_run_t>();
|
|
aBin->mNonFullRuns.pushFront(run);
|
|
|
|
aBin->mNumRuns++;
|
|
return run;
|
|
}
|
|
|
|
arena_run_t* arena_t::GetNonFullBinRun(arena_bin_t* aBin) {
|
|
auto mrf_head = aBin->mNonFullRuns.begin();
|
|
if (mrf_head) {
|
|
// Take the head and if we are going to fill it, remove it from our list.
|
|
arena_run_t* run = &(*mrf_head);
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mMagic == ARENA_RUN_MAGIC);
|
|
if (run->mNumFree == 1) {
|
|
aBin->mNonFullRuns.remove(run);
|
|
}
|
|
return run;
|
|
}
|
|
return GetNewEmptyBinRun(aBin);
|
|
}
|
|
|
|
arena_bin_t::arena_bin_t(SizeClass aSizeClass) : mSizeClass(aSizeClass.Size()) {
|
|
size_t try_run_size;
|
|
unsigned try_nregs, try_mask_nelms, try_reg0_offset;
|
|
// Size of the run header, excluding mRegionsMask.
|
|
static const size_t kFixedHeaderSize = offsetof(arena_run_t, mRegionsMask);
|
|
|
|
MOZ_ASSERT(aSizeClass.Size() <= gMaxBinClass);
|
|
|
|
try_run_size = gMinimumRunSize;
|
|
|
|
// Run size expansion loop.
|
|
while (true) {
|
|
try_nregs = ((try_run_size - kFixedHeaderSize) / mSizeClass) +
|
|
1; // Counter-act try_nregs-- in loop.
|
|
|
|
// The do..while loop iteratively reduces the number of regions until
|
|
// the run header and the regions no longer overlap. A closed formula
|
|
// would be quite messy, since there is an interdependency between the
|
|
// header's mask length and the number of regions.
|
|
do {
|
|
try_nregs--;
|
|
try_mask_nelms =
|
|
(try_nregs >> (LOG2(sizeof(int)) + 3)) +
|
|
((try_nregs & ((1U << (LOG2(sizeof(int)) + 3)) - 1)) ? 1 : 0);
|
|
try_reg0_offset = try_run_size - (try_nregs * mSizeClass);
|
|
} while (kFixedHeaderSize + (sizeof(unsigned) * try_mask_nelms) >
|
|
try_reg0_offset);
|
|
|
|
// Try to keep the run overhead below kRunOverhead.
|
|
if (Fraction(try_reg0_offset, try_run_size) <= kRunOverhead) {
|
|
break;
|
|
}
|
|
|
|
// If the overhead is larger than the size class, it means the size class
|
|
// is small and doesn't align very well with the header. It's desirable to
|
|
// have smaller run sizes for them, so relax the overhead requirement.
|
|
if (try_reg0_offset > mSizeClass) {
|
|
if (Fraction(try_reg0_offset, try_run_size) <= kRunRelaxedOverhead) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// The run header includes one bit per region of the given size. For sizes
|
|
// small enough, the number of regions is large enough that growing the run
|
|
// size barely moves the needle for the overhead because of all those bits.
|
|
// For example, for a size of 8 bytes, adding 4KiB to the run size adds
|
|
// close to 512 bits to the header, which is 64 bytes.
|
|
// With such overhead, there is no way to get to the wanted overhead above,
|
|
// so we give up if the required size for mRegionsMask more than doubles the
|
|
// size of the run header.
|
|
if (try_mask_nelms * sizeof(unsigned) >= kFixedHeaderSize) {
|
|
break;
|
|
}
|
|
|
|
// If next iteration is going to be larger than the largest possible large
|
|
// size class, then we didn't find a setup where the overhead is small
|
|
// enough, and we can't do better than the current settings, so just use
|
|
// that.
|
|
if (try_run_size + gPageSize > gMaxLargeClass) {
|
|
break;
|
|
}
|
|
|
|
// Try more aggressive settings.
|
|
try_run_size += gPageSize;
|
|
}
|
|
|
|
MOZ_ASSERT(kFixedHeaderSize + (sizeof(unsigned) * try_mask_nelms) <=
|
|
try_reg0_offset);
|
|
MOZ_ASSERT((try_mask_nelms << (LOG2(sizeof(int)) + 3)) >= try_nregs);
|
|
|
|
// Our list management would break if mRunNumRegions == 1 and we should use
|
|
// a large size class instead, anyways.
|
|
MOZ_ASSERT(try_nregs > 1);
|
|
|
|
// Copy final settings.
|
|
MOZ_ASSERT((try_run_size >> gPageSize2Pow) <= UINT8_MAX);
|
|
mRunSizePages = static_cast<uint8_t>(try_run_size >> gPageSize2Pow);
|
|
mRunNumRegions = try_nregs;
|
|
mRunNumRegionsMask = try_mask_nelms;
|
|
mRunFirstRegionOffset = try_reg0_offset;
|
|
mSizeDivisor = FastDivisor<uint16_t>(aSizeClass.Size(), try_run_size);
|
|
}
|
|
|
|
void arena_t::ResetSmallAllocRandomization() {
|
|
if (MOZ_UNLIKELY(opt_randomize_small)) {
|
|
MaybeMutexAutoLock lock(mLock);
|
|
InitPRNG();
|
|
}
|
|
mRandomizeSmallAllocations = opt_randomize_small;
|
|
}
|
|
|
|
void arena_t::InitPRNG() {
|
|
// Both another thread could race and the code backing RandomUint64
|
|
// (arc4random for example) may allocate memory while here, so we must
|
|
// ensure to start the mPRNG initialization only once and to not hold
|
|
// the lock while initializing.
|
|
mIsPRNGInitializing = true;
|
|
{
|
|
mLock.Unlock();
|
|
mozilla::Maybe<uint64_t> prngState1 = mozilla::RandomUint64();
|
|
mozilla::Maybe<uint64_t> prngState2 = mozilla::RandomUint64();
|
|
mLock.Lock();
|
|
|
|
mozilla::non_crypto::XorShift128PlusRNG prng(prngState1.valueOr(0),
|
|
prngState2.valueOr(0));
|
|
if (mPRNG) {
|
|
*mPRNG = prng;
|
|
} else {
|
|
void* backing =
|
|
sBaseAlloc.alloc(sizeof(mozilla::non_crypto::XorShift128PlusRNG));
|
|
mPRNG = new (backing)
|
|
mozilla::non_crypto::XorShift128PlusRNG(std::move(prng));
|
|
}
|
|
}
|
|
mIsPRNGInitializing = false;
|
|
}
|
|
|
|
void* arena_t::MallocSmall(size_t aSize, bool aZero) {
|
|
void* ret;
|
|
arena_bin_t* bin;
|
|
arena_run_t* run;
|
|
SizeClass sizeClass(aSize);
|
|
aSize = sizeClass.Size();
|
|
|
|
switch (sizeClass.Type()) {
|
|
case SizeClass::Quantum:
|
|
// Although we divide 2 things by kQuantum, the compiler will
|
|
// reduce `kMinQuantumClass / kQuantum` to a single constant.
|
|
bin = &mBins[(aSize / kQuantum) - (kMinQuantumClass / kQuantum)];
|
|
break;
|
|
case SizeClass::QuantumWide:
|
|
bin = &mBins[kNumQuantumClasses + (aSize / kQuantumWide) -
|
|
(kMinQuantumWideClass / kQuantumWide)];
|
|
break;
|
|
case SizeClass::SubPage:
|
|
bin = &mBins[kNumQuantumClasses + kNumQuantumWideClasses +
|
|
(FloorLog2(aSize) - LOG2(kMinSubPageClass))];
|
|
break;
|
|
default:
|
|
MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Unexpected size class type");
|
|
}
|
|
MOZ_DIAGNOSTIC_ASSERT(aSize == bin->mSizeClass);
|
|
|
|
size_t num_dirty_before, num_dirty_after;
|
|
{
|
|
MaybeMutexAutoLock lock(mLock);
|
|
|
|
#ifdef MOZ_DEBUG
|
|
bool isInitializingThread(false);
|
|
#endif
|
|
|
|
if (MOZ_UNLIKELY(mRandomizeSmallAllocations && mPRNG == nullptr &&
|
|
!mIsPRNGInitializing)) {
|
|
#ifdef MOZ_DEBUG
|
|
isInitializingThread = true;
|
|
#endif
|
|
InitPRNG();
|
|
}
|
|
|
|
MOZ_ASSERT(!mRandomizeSmallAllocations || mPRNG ||
|
|
(mIsPRNGInitializing && !isInitializingThread));
|
|
|
|
num_dirty_before = mNumDirty;
|
|
run = GetNonFullBinRun(bin);
|
|
num_dirty_after = mNumDirty;
|
|
if (MOZ_UNLIKELY(!run)) {
|
|
return nullptr;
|
|
}
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mMagic == ARENA_RUN_MAGIC);
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mNumFree > 0);
|
|
ret = ArenaRunRegAlloc(run, bin);
|
|
MOZ_DIAGNOSTIC_ASSERT(ret);
|
|
run->mNumFree--;
|
|
if (!ret) {
|
|
return nullptr;
|
|
}
|
|
|
|
mStats.allocated_small += aSize;
|
|
mStats.operations++;
|
|
}
|
|
if (num_dirty_after < num_dirty_before) {
|
|
NotifySignificantReuse();
|
|
}
|
|
if (!aZero) {
|
|
ApplyZeroOrJunk(ret, aSize);
|
|
} else {
|
|
memset(ret, 0, aSize);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void* arena_t::MallocLarge(size_t aSize, bool aZero) {
|
|
void* ret;
|
|
|
|
// Large allocation.
|
|
aSize = PAGE_CEILING(aSize);
|
|
|
|
size_t num_dirty_before, num_dirty_after;
|
|
{
|
|
MaybeMutexAutoLock lock(mLock);
|
|
num_dirty_before = mNumDirty;
|
|
ret = AllocRun(aSize, true, aZero);
|
|
num_dirty_after = mNumDirty;
|
|
if (!ret) {
|
|
return nullptr;
|
|
}
|
|
mStats.allocated_large += aSize;
|
|
mStats.operations++;
|
|
}
|
|
if (num_dirty_after < num_dirty_before) {
|
|
NotifySignificantReuse();
|
|
}
|
|
|
|
if (!aZero) {
|
|
ApplyZeroOrJunk(ret, aSize);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void* arena_t::Malloc(size_t aSize, bool aZero) {
|
|
MOZ_DIAGNOSTIC_ASSERT(mMagic == ARENA_MAGIC);
|
|
MOZ_ASSERT(aSize != 0);
|
|
|
|
if (aSize <= gMaxBinClass) {
|
|
return MallocSmall(aSize, aZero);
|
|
}
|
|
if (aSize <= gMaxLargeClass) {
|
|
return MallocLarge(aSize, aZero);
|
|
}
|
|
return MallocHuge(aSize, aZero);
|
|
}
|
|
|
|
// Only handles large allocations that require more than page alignment.
|
|
void* arena_t::PallocLarge(size_t aAlignment, size_t aSize, size_t aAllocSize) {
|
|
void* ret;
|
|
size_t offset;
|
|
arena_chunk_t* chunk;
|
|
|
|
MOZ_ASSERT((aSize & gPageSizeMask) == 0);
|
|
MOZ_ASSERT((aAlignment & gPageSizeMask) == 0);
|
|
|
|
size_t num_dirty_before, num_dirty_after;
|
|
{
|
|
MaybeMutexAutoLock lock(mLock);
|
|
num_dirty_before = mNumDirty;
|
|
ret = AllocRun(aAllocSize, true, false);
|
|
if (!ret) {
|
|
return nullptr;
|
|
}
|
|
|
|
chunk = GetChunkForPtr(ret);
|
|
|
|
offset = uintptr_t(ret) & (aAlignment - 1);
|
|
MOZ_ASSERT((offset & gPageSizeMask) == 0);
|
|
MOZ_ASSERT(offset < aAllocSize);
|
|
if (offset == 0) {
|
|
TrimRunTail(chunk, (arena_run_t*)ret, aAllocSize, aSize, false);
|
|
} else {
|
|
size_t leadsize, trailsize;
|
|
|
|
leadsize = aAlignment - offset;
|
|
if (leadsize > 0) {
|
|
TrimRunHead(chunk, (arena_run_t*)ret, aAllocSize,
|
|
aAllocSize - leadsize);
|
|
ret = (void*)(uintptr_t(ret) + leadsize);
|
|
}
|
|
|
|
trailsize = aAllocSize - leadsize - aSize;
|
|
if (trailsize != 0) {
|
|
// Trim trailing space.
|
|
MOZ_ASSERT(trailsize < aAllocSize);
|
|
TrimRunTail(chunk, (arena_run_t*)ret, aSize + trailsize, aSize, false);
|
|
}
|
|
}
|
|
num_dirty_after = mNumDirty;
|
|
|
|
mStats.allocated_large += aSize;
|
|
mStats.operations++;
|
|
}
|
|
if (num_dirty_after < num_dirty_before) {
|
|
NotifySignificantReuse();
|
|
}
|
|
// Note that since Bug 1488780we don't attempt purge dirty memory on this code
|
|
// path. In general there won't be dirty memory above the threshold after an
|
|
// allocation, only after free. The exception is if the dirty page threshold
|
|
// has changed.
|
|
|
|
ApplyZeroOrJunk(ret, aSize);
|
|
return ret;
|
|
}
|
|
|
|
void* arena_t::Palloc(size_t aAlignment, size_t aSize) {
|
|
void* ret;
|
|
size_t ceil_size;
|
|
|
|
// Round size up to the nearest multiple of alignment.
|
|
//
|
|
// This done, we can take advantage of the fact that for each small
|
|
// size class, every object is aligned at the smallest power of two
|
|
// that is non-zero in the base two representation of the size. For
|
|
// example:
|
|
//
|
|
// Size | Base 2 | Minimum alignment
|
|
// -----+----------+------------------
|
|
// 96 | 1100000 | 32
|
|
// 144 | 10100000 | 32
|
|
// 192 | 11000000 | 64
|
|
//
|
|
// Depending on runtime settings, it is possible that arena_malloc()
|
|
// will further round up to a power of two, but that never causes
|
|
// correctness issues.
|
|
ceil_size = ALIGNMENT_CEILING(aSize, aAlignment);
|
|
|
|
// (ceil_size < aSize) protects against the combination of maximal
|
|
// alignment and size greater than maximal alignment.
|
|
if (ceil_size < aSize) {
|
|
// size_t overflow.
|
|
return nullptr;
|
|
}
|
|
|
|
if (ceil_size <= gPageSize ||
|
|
(aAlignment <= gPageSize && ceil_size <= gMaxLargeClass)) {
|
|
ret = Malloc(ceil_size, false);
|
|
} else {
|
|
size_t run_size;
|
|
|
|
// We can't achieve sub-page alignment, so round up alignment
|
|
// permanently; it makes later calculations simpler.
|
|
aAlignment = PAGE_CEILING(aAlignment);
|
|
ceil_size = PAGE_CEILING(aSize);
|
|
|
|
// (ceil_size < aSize) protects against very large sizes within
|
|
// pagesize of SIZE_T_MAX.
|
|
//
|
|
// (ceil_size + aAlignment < ceil_size) protects against the
|
|
// combination of maximal alignment and ceil_size large enough
|
|
// to cause overflow. This is similar to the first overflow
|
|
// check above, but it needs to be repeated due to the new
|
|
// ceil_size value, which may now be *equal* to maximal
|
|
// alignment, whereas before we only detected overflow if the
|
|
// original size was *greater* than maximal alignment.
|
|
if (ceil_size < aSize || ceil_size + aAlignment < ceil_size) {
|
|
// size_t overflow.
|
|
return nullptr;
|
|
}
|
|
|
|
// Calculate the size of the over-size run that arena_palloc()
|
|
// would need to allocate in order to guarantee the alignment.
|
|
if (ceil_size >= aAlignment) {
|
|
run_size = ceil_size + aAlignment - gPageSize;
|
|
} else {
|
|
// It is possible that (aAlignment << 1) will cause
|
|
// overflow, but it doesn't matter because we also
|
|
// subtract pagesize, which in the case of overflow
|
|
// leaves us with a very large run_size. That causes
|
|
// the first conditional below to fail, which means
|
|
// that the bogus run_size value never gets used for
|
|
// anything important.
|
|
run_size = (aAlignment << 1) - gPageSize;
|
|
}
|
|
|
|
if (run_size <= gMaxLargeClass) {
|
|
ret = PallocLarge(aAlignment, ceil_size, run_size);
|
|
} else if (aAlignment <= kChunkSize) {
|
|
ret = MallocHuge(ceil_size, false);
|
|
} else {
|
|
ret = PallocHuge(ceil_size, aAlignment, false);
|
|
}
|
|
}
|
|
|
|
MOZ_ASSERT((uintptr_t(ret) & (aAlignment - 1)) == 0);
|
|
return ret;
|
|
}
|
|
|
|
class AllocInfo {
|
|
public:
|
|
template <bool Validate = false>
|
|
static inline AllocInfo Get(const void* aPtr) {
|
|
// If the allocator is not initialized, the pointer can't belong to it.
|
|
if (Validate && !malloc_initialized) {
|
|
return AllocInfo();
|
|
}
|
|
|
|
auto chunk = GetChunkForPtr(aPtr);
|
|
if (Validate) {
|
|
if (!chunk || !gChunkRTree.Get(chunk)) {
|
|
return AllocInfo();
|
|
}
|
|
}
|
|
|
|
if (chunk != aPtr) {
|
|
MOZ_DIAGNOSTIC_ASSERT(chunk->mArena->mMagic == ARENA_MAGIC);
|
|
size_t pageind = (((uintptr_t)aPtr - (uintptr_t)chunk) >> gPageSize2Pow);
|
|
return GetInChunk(aPtr, chunk, pageind);
|
|
}
|
|
|
|
// Huge allocation
|
|
MutexAutoLock lock(huge_mtx);
|
|
extent_node_t* node = huge.Search(chunk);
|
|
if (Validate && !node) {
|
|
return AllocInfo();
|
|
}
|
|
return AllocInfo(node->mSize, node);
|
|
}
|
|
|
|
// Get the allocation information for a pointer we know is within a chunk
|
|
// (Small or large, not huge).
|
|
static inline AllocInfo GetInChunk(const void* aPtr, arena_chunk_t* aChunk,
|
|
size_t pageind) {
|
|
size_t mapbits = aChunk->mPageMap[pageind].bits;
|
|
MOZ_DIAGNOSTIC_ASSERT((mapbits & CHUNK_MAP_ALLOCATED) != 0);
|
|
|
|
size_t size;
|
|
if ((mapbits & CHUNK_MAP_LARGE) == 0) {
|
|
arena_run_t* run = (arena_run_t*)(mapbits & ~gPageSizeMask);
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mMagic == ARENA_RUN_MAGIC);
|
|
size = run->mBin->mSizeClass;
|
|
} else {
|
|
size = mapbits & ~gPageSizeMask;
|
|
MOZ_DIAGNOSTIC_ASSERT(size != 0);
|
|
}
|
|
|
|
return AllocInfo(size, aChunk);
|
|
}
|
|
|
|
// Validate ptr before assuming that it points to an allocation. Currently,
|
|
// the following validation is performed:
|
|
//
|
|
// + Check that ptr is not nullptr.
|
|
//
|
|
// + Check that ptr lies within a mapped chunk.
|
|
static inline AllocInfo GetValidated(const void* aPtr) {
|
|
return Get<true>(aPtr);
|
|
}
|
|
|
|
AllocInfo() : mSize(0), mChunk(nullptr) {}
|
|
|
|
explicit AllocInfo(size_t aSize, arena_chunk_t* aChunk)
|
|
: mSize(aSize), mChunk(aChunk) {
|
|
MOZ_ASSERT(mSize <= gMaxLargeClass);
|
|
}
|
|
|
|
explicit AllocInfo(size_t aSize, extent_node_t* aNode)
|
|
: mSize(aSize), mNode(aNode) {
|
|
MOZ_ASSERT(mSize > gMaxLargeClass);
|
|
}
|
|
|
|
size_t Size() { return mSize; }
|
|
|
|
arena_t* Arena() {
|
|
if (mSize <= gMaxLargeClass) {
|
|
return mChunk->mArena;
|
|
}
|
|
|
|
// Best effort detection that we're not trying to access an already
|
|
// disposed arena. arena_t's destructor will clear mMagic and mId;
|
|
// any other use of the same memory will usually set them to some other
|
|
// value.
|
|
MOZ_DIAGNOSTIC_ASSERT(mNode->mArena->mMagic == ARENA_MAGIC);
|
|
MOZ_RELEASE_ASSERT(mNode->mArenaId == mNode->mArena->mId);
|
|
return mNode->mArena;
|
|
}
|
|
|
|
bool IsValid() const { return !!mSize; }
|
|
|
|
private:
|
|
size_t mSize;
|
|
union {
|
|
// Pointer to the chunk associated with the allocation for small
|
|
// and large allocations.
|
|
arena_chunk_t* mChunk;
|
|
|
|
// Pointer to the extent node for huge allocations.
|
|
extent_node_t* mNode;
|
|
};
|
|
};
|
|
|
|
inline void MozJemalloc::jemalloc_ptr_info(const void* aPtr,
|
|
jemalloc_ptr_info_t* aInfo) {
|
|
arena_chunk_t* chunk = GetChunkForPtr(aPtr);
|
|
|
|
// Is the pointer null, or within one chunk's size of null?
|
|
// Alternatively, if the allocator is not initialized yet, the pointer
|
|
// can't be known.
|
|
if (!chunk || !malloc_initialized) {
|
|
*aInfo = {TagUnknown, nullptr, 0, 0};
|
|
return;
|
|
}
|
|
|
|
// Look for huge allocations before looking for |chunk| in gChunkRTree.
|
|
// This is necessary because |chunk| won't be in gChunkRTree if it's
|
|
// the second or subsequent chunk in a huge allocation.
|
|
extent_node_t* node;
|
|
{
|
|
MutexAutoLock lock(huge_mtx);
|
|
node =
|
|
reinterpret_cast<RedBlackTree<extent_node_t, ExtentTreeBoundsTrait>*>(
|
|
&huge)
|
|
->Search(const_cast<void*>(aPtr));
|
|
if (node) {
|
|
*aInfo = {TagLiveAlloc, node->mAddr, node->mSize, node->mArena->mId};
|
|
return;
|
|
}
|
|
}
|
|
|
|
// It's not a huge allocation. Check if we have a known chunk.
|
|
if (!gChunkRTree.Get(chunk)) {
|
|
*aInfo = {TagUnknown, nullptr, 0, 0};
|
|
return;
|
|
}
|
|
|
|
MOZ_DIAGNOSTIC_ASSERT(chunk->mArena->mMagic == ARENA_MAGIC);
|
|
|
|
// Get the page number within the chunk.
|
|
size_t pageind = (((uintptr_t)aPtr - (uintptr_t)chunk) >> gPageSize2Pow);
|
|
if (pageind < gChunkHeaderNumPages) {
|
|
// Within the chunk header.
|
|
*aInfo = {TagUnknown, nullptr, 0, 0};
|
|
return;
|
|
}
|
|
|
|
size_t mapbits = chunk->mPageMap[pageind].bits;
|
|
|
|
if (!(mapbits & CHUNK_MAP_ALLOCATED)) {
|
|
void* pageaddr = (void*)(uintptr_t(aPtr) & ~gPageSizeMask);
|
|
*aInfo = {TagFreedPage, pageaddr, gPageSize, chunk->mArena->mId};
|
|
return;
|
|
}
|
|
|
|
if (mapbits & CHUNK_MAP_LARGE) {
|
|
// It's a large allocation. Only the first page of a large
|
|
// allocation contains its size, so if the address is not in
|
|
// the first page, scan back to find the allocation size.
|
|
size_t size;
|
|
while (true) {
|
|
size = mapbits & ~gPageSizeMask;
|
|
if (size != 0) {
|
|
break;
|
|
}
|
|
|
|
// The following two return paths shouldn't occur in
|
|
// practice unless there is heap corruption.
|
|
pageind--;
|
|
MOZ_DIAGNOSTIC_ASSERT(pageind >= gChunkHeaderNumPages);
|
|
if (pageind < gChunkHeaderNumPages) {
|
|
*aInfo = {TagUnknown, nullptr, 0, 0};
|
|
return;
|
|
}
|
|
|
|
mapbits = chunk->mPageMap[pageind].bits;
|
|
MOZ_DIAGNOSTIC_ASSERT(mapbits & CHUNK_MAP_LARGE);
|
|
if (!(mapbits & CHUNK_MAP_LARGE)) {
|
|
*aInfo = {TagUnknown, nullptr, 0, 0};
|
|
return;
|
|
}
|
|
}
|
|
|
|
void* addr = ((char*)chunk) + (pageind << gPageSize2Pow);
|
|
*aInfo = {TagLiveAlloc, addr, size, chunk->mArena->mId};
|
|
return;
|
|
}
|
|
|
|
// It must be a small allocation.
|
|
auto run = (arena_run_t*)(mapbits & ~gPageSizeMask);
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mMagic == ARENA_RUN_MAGIC);
|
|
|
|
// The allocation size is stored in the run metadata.
|
|
size_t size = run->mBin->mSizeClass;
|
|
|
|
// Address of the first possible pointer in the run after its headers.
|
|
uintptr_t reg0_addr = (uintptr_t)run + run->mBin->mRunFirstRegionOffset;
|
|
if (aPtr < (void*)reg0_addr) {
|
|
// In the run header.
|
|
*aInfo = {TagUnknown, nullptr, 0, 0};
|
|
return;
|
|
}
|
|
|
|
// Position in the run.
|
|
unsigned regind = ((uintptr_t)aPtr - reg0_addr) / size;
|
|
|
|
// Pointer to the allocation's base address.
|
|
void* addr = (void*)(reg0_addr + regind * size);
|
|
|
|
// Check if the allocation has been freed.
|
|
unsigned elm = regind >> (LOG2(sizeof(int)) + 3);
|
|
unsigned bit = regind - (elm << (LOG2(sizeof(int)) + 3));
|
|
PtrInfoTag tag =
|
|
((run->mRegionsMask[elm] & (1U << bit))) ? TagFreedAlloc : TagLiveAlloc;
|
|
|
|
*aInfo = {tag, addr, size, chunk->mArena->mId};
|
|
}
|
|
|
|
namespace Debug {
|
|
// Helper for debuggers. We don't want it to be inlined and optimized out.
|
|
MOZ_NEVER_INLINE jemalloc_ptr_info_t* jemalloc_ptr_info(const void* aPtr) {
|
|
static jemalloc_ptr_info_t info;
|
|
MozJemalloc::jemalloc_ptr_info(aPtr, &info);
|
|
return &info;
|
|
}
|
|
} // namespace Debug
|
|
|
|
void arena_t::DallocSmall(arena_chunk_t* aChunk, void* aPtr,
|
|
arena_chunk_map_t* aMapElm) {
|
|
arena_run_t* run;
|
|
arena_bin_t* bin;
|
|
size_t size;
|
|
|
|
run = (arena_run_t*)(aMapElm->bits & ~gPageSizeMask);
|
|
MOZ_DIAGNOSTIC_ASSERT(run->mMagic == ARENA_RUN_MAGIC);
|
|
bin = run->mBin;
|
|
size = bin->mSizeClass;
|
|
MOZ_DIAGNOSTIC_ASSERT(uintptr_t(aPtr) >=
|
|
uintptr_t(run) + bin->mRunFirstRegionOffset);
|
|
|
|
arena_run_reg_dalloc(run, bin, aPtr, size);
|
|
run->mNumFree++;
|
|
|
|
if (run->mNumFree == bin->mRunNumRegions) {
|
|
// This run is entirely freed, remove it from our bin.
|
|
#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
|
|
run->mMagic = 0;
|
|
#endif
|
|
MOZ_ASSERT(bin->mNonFullRuns.ElementProbablyInList(run));
|
|
bin->mNonFullRuns.remove(run);
|
|
DallocRun(run, true);
|
|
bin->mNumRuns--;
|
|
} else if (run->mNumFree == 1) {
|
|
// This is first slot we freed from this run, start tracking.
|
|
MOZ_ASSERT(!bin->mNonFullRuns.ElementProbablyInList(run));
|
|
bin->mNonFullRuns.pushFront(run);
|
|
}
|
|
// else we just keep the run in mNonFullRuns where it is.
|
|
// Note that we could move it to the head of the list here to get a strict
|
|
// "most-recently-freed" order, but some of our benchmarks seem to be more
|
|
// sensible to the increased overhead that this brings than to the order
|
|
// supposedly slightly better for keeping CPU caches warm if we do.
|
|
// In general we cannot foresee the future, so any order we choose might
|
|
// perform different for different use cases and needs to be balanced with
|
|
// the book-keeping overhead via measurements.
|
|
|
|
mStats.allocated_small -= size;
|
|
mStats.operations++;
|
|
}
|
|
|
|
void arena_t::DallocLarge(arena_chunk_t* aChunk, void* aPtr) {
|
|
MOZ_DIAGNOSTIC_ASSERT((uintptr_t(aPtr) & gPageSizeMask) == 0);
|
|
size_t pageind = (uintptr_t(aPtr) - uintptr_t(aChunk)) >> gPageSize2Pow;
|
|
size_t size = aChunk->mPageMap[pageind].bits & ~gPageSizeMask;
|
|
|
|
mStats.allocated_large -= size;
|
|
mStats.operations++;
|
|
|
|
DallocRun((arena_run_t*)aPtr, true);
|
|
}
|
|
|
|
static inline void arena_dalloc(void* aPtr, size_t aOffset, arena_t* aArena) {
|
|
MOZ_ASSERT(aPtr);
|
|
MOZ_ASSERT(aOffset != 0);
|
|
MOZ_ASSERT(GetChunkOffsetForPtr(aPtr) == aOffset);
|
|
|
|
auto chunk = (arena_chunk_t*)((uintptr_t)aPtr - aOffset);
|
|
auto arena = chunk->mArena;
|
|
MOZ_ASSERT(arena);
|
|
MOZ_DIAGNOSTIC_ASSERT(arena->mMagic == ARENA_MAGIC);
|
|
MOZ_RELEASE_ASSERT(!aArena || arena == aArena);
|
|
|
|
size_t pageind = aOffset >> gPageSize2Pow;
|
|
if (opt_poison) {
|
|
AllocInfo info = AllocInfo::GetInChunk(aPtr, chunk, pageind);
|
|
MOZ_ASSERT(info.IsValid());
|
|
MaybePoison(aPtr, info.Size());
|
|
}
|
|
|
|
purge_action_t purge_action;
|
|
{
|
|
MOZ_DIAGNOSTIC_ASSERT(arena->mLock.SafeOnThisThread());
|
|
MaybeMutexAutoLock lock(arena->mLock);
|
|
arena_chunk_map_t* mapelm = &chunk->mPageMap[pageind];
|
|
MOZ_RELEASE_ASSERT(
|
|
(mapelm->bits &
|
|
(CHUNK_MAP_FRESH_MADVISED_OR_DECOMMITTED | CHUNK_MAP_ZEROED)) == 0,
|
|
"Freeing in a page with bad bits.");
|
|
MOZ_RELEASE_ASSERT((mapelm->bits & CHUNK_MAP_ALLOCATED) != 0,
|
|
"Double-free?");
|
|
if ((mapelm->bits & CHUNK_MAP_LARGE) == 0) {
|
|
// Small allocation.
|
|
arena->DallocSmall(chunk, aPtr, mapelm);
|
|
} else {
|
|
// Large allocation.
|
|
arena->DallocLarge(chunk, aPtr);
|
|
}
|
|
|
|
purge_action = arena->ShouldStartPurge();
|
|
}
|
|
|
|
arena->MayDoOrQueuePurge(purge_action, "arena_dalloc");
|
|
}
|
|
|
|
static inline void idalloc(void* ptr, arena_t* aArena) {
|
|
size_t offset;
|
|
|
|
MOZ_ASSERT(ptr);
|
|
|
|
offset = GetChunkOffsetForPtr(ptr);
|
|
if (offset != 0) {
|
|
arena_dalloc(ptr, offset, aArena);
|
|
} else {
|
|
huge_dalloc(ptr, aArena);
|
|
}
|
|
}
|
|
|
|
inline purge_action_t arena_t::ShouldStartPurge() {
|
|
if (mNumDirty > mMaxDirty) {
|
|
if (!mIsDeferredPurgeEnabled) {
|
|
return purge_action_t::PurgeNow;
|
|
}
|
|
if (mIsPurgePending) {
|
|
return purge_action_t::None;
|
|
}
|
|
mIsPurgePending = true;
|
|
return purge_action_t::Queue;
|
|
}
|
|
return purge_action_t::None;
|
|
}
|
|
|
|
inline void arena_t::MayDoOrQueuePurge(purge_action_t aAction,
|
|
const char* aCaller) {
|
|
switch (aAction) {
|
|
case purge_action_t::Queue:
|
|
// Note that this thread committed earlier by setting
|
|
// mIsPurgePending to add us to the list. There is a low
|
|
// chance that in the meantime another thread ran Purge() and cleared
|
|
// the flag, but that is fine, we'll adjust our bookkeeping when calling
|
|
// ShouldStartPurge() or Purge() next time.
|
|
gArenas.AddToOutstandingPurges(this);
|
|
break;
|
|
case purge_action_t::PurgeNow: {
|
|
ArenaPurgeResult pr = PurgeLoop(PurgeIfThreshold, aCaller);
|
|
// Arenas cannot die here because the caller is still using the arena, if
|
|
// they did it'd be a use-after-free: the arena is destroyed but then used
|
|
// afterwards.
|
|
MOZ_RELEASE_ASSERT(pr != ArenaPurgeResult::Dying);
|
|
break;
|
|
}
|
|
case purge_action_t::None:
|
|
// do nothing.
|
|
break;
|
|
}
|
|
}
|
|
|
|
inline void arena_t::NotifySignificantReuse() {
|
|
// Note that there is a chance here for a race between threads calling
|
|
// GetTimeStampNS in a different order than writing it to the Atomic,
|
|
// resulting in mLastSignificantReuseNS going potentially backwards.
|
|
// Our use case is not sensitive to small deviations, the worse that can
|
|
// happen is a slightly earlier purge.
|
|
mLastSignificantReuseNS = GetTimestampNS();
|
|
}
|
|
|
|
void arena_t::RallocShrinkLarge(arena_chunk_t* aChunk, void* aPtr, size_t aSize,
|
|
size_t aOldSize) {
|
|
MOZ_ASSERT(aSize < aOldSize);
|
|
|
|
// Shrink the run, and make trailing pages available for other
|
|
// allocations.
|
|
purge_action_t purge_action;
|
|
{
|
|
MaybeMutexAutoLock lock(mLock);
|
|
TrimRunTail(aChunk, (arena_run_t*)aPtr, aOldSize, aSize, true);
|
|
mStats.allocated_large -= aOldSize - aSize;
|
|
mStats.operations++;
|
|
|
|
purge_action = ShouldStartPurge();
|
|
}
|
|
MayDoOrQueuePurge(purge_action, "RallocShrinkLarge");
|
|
}
|
|
|
|
// Returns whether reallocation was successful.
|
|
bool arena_t::RallocGrowLarge(arena_chunk_t* aChunk, void* aPtr, size_t aSize,
|
|
size_t aOldSize) {
|
|
size_t pageind = (uintptr_t(aPtr) - uintptr_t(aChunk)) >> gPageSize2Pow;
|
|
size_t npages = aOldSize >> gPageSize2Pow;
|
|
|
|
size_t num_dirty_before, num_dirty_after;
|
|
{
|
|
MaybeMutexAutoLock lock(mLock);
|
|
MOZ_DIAGNOSTIC_ASSERT(aOldSize ==
|
|
(aChunk->mPageMap[pageind].bits & ~gPageSizeMask));
|
|
|
|
// Try to extend the run.
|
|
MOZ_ASSERT(aSize > aOldSize);
|
|
if (pageind + npages < gChunkNumPages - 1 &&
|
|
(aChunk->mPageMap[pageind + npages].bits &
|
|
(CHUNK_MAP_ALLOCATED | CHUNK_MAP_BUSY)) == 0 &&
|
|
(aChunk->mPageMap[pageind + npages].bits & ~gPageSizeMask) >=
|
|
aSize - aOldSize) {
|
|
num_dirty_before = mNumDirty;
|
|
// The next run is available and sufficiently large. Split the
|
|
// following run, then merge the first part with the existing
|
|
// allocation.
|
|
mRunsAvail.Remove(&aChunk->mPageMap[pageind + npages]);
|
|
if (!SplitAndAllocRun(
|
|
(arena_run_t*)(uintptr_t(aChunk) +
|
|
((pageind + npages) << gPageSize2Pow)),
|
|
aSize - aOldSize, true, false)) {
|
|
mRunsAvail.Insert(&aChunk->mPageMap[pageind + npages]);
|
|
return false;
|
|
}
|
|
|
|
aChunk->mPageMap[pageind].bits =
|
|
aSize | CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
aChunk->mPageMap[pageind + npages].bits =
|
|
CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
|
|
|
|
mStats.allocated_large += aSize - aOldSize;
|
|
mStats.operations++;
|
|
num_dirty_after = mNumDirty;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
if (num_dirty_after < num_dirty_before) {
|
|
NotifySignificantReuse();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
#ifdef XP_DARWIN
|
|
# define VM_COPY_MIN kChunkSize
|
|
static inline void pages_copy(void* dest, const void* src, size_t n) {
|
|
MOZ_ASSERT((void*)((uintptr_t)dest & ~gPageSizeMask) == dest);
|
|
MOZ_ASSERT(n >= VM_COPY_MIN);
|
|
MOZ_ASSERT((void*)((uintptr_t)src & ~gPageSizeMask) == src);
|
|
|
|
kern_return_t r = vm_copy(mach_task_self(), (vm_address_t)src, (vm_size_t)n,
|
|
(vm_address_t)dest);
|
|
if (r != KERN_SUCCESS) {
|
|
MOZ_CRASH("vm_copy() failed");
|
|
}
|
|
}
|
|
#endif
|
|
|
|
void* arena_t::RallocSmallOrLarge(void* aPtr, size_t aSize, size_t aOldSize) {
|
|
void* ret;
|
|
size_t copysize;
|
|
SizeClass sizeClass(aSize);
|
|
|
|
// Try to avoid moving the allocation.
|
|
if (aOldSize <= gMaxLargeClass && sizeClass.Size() == aOldSize) {
|
|
if (aSize < aOldSize) {
|
|
MaybePoison((void*)(uintptr_t(aPtr) + aSize), aOldSize - aSize);
|
|
}
|
|
return aPtr;
|
|
}
|
|
if (sizeClass.Type() == SizeClass::Large && aOldSize > gMaxBinClass &&
|
|
aOldSize <= gMaxLargeClass) {
|
|
arena_chunk_t* chunk = GetChunkForPtr(aPtr);
|
|
if (sizeClass.Size() < aOldSize) {
|
|
// Fill before shrinking in order to avoid a race.
|
|
MaybePoison((void*)((uintptr_t)aPtr + aSize), aOldSize - aSize);
|
|
RallocShrinkLarge(chunk, aPtr, sizeClass.Size(), aOldSize);
|
|
return aPtr;
|
|
}
|
|
if (RallocGrowLarge(chunk, aPtr, sizeClass.Size(), aOldSize)) {
|
|
ApplyZeroOrJunk((void*)((uintptr_t)aPtr + aOldSize), aSize - aOldSize);
|
|
return aPtr;
|
|
}
|
|
}
|
|
|
|
// If we get here, then aSize and aOldSize are different enough that we
|
|
// need to move the object or the run can't be expanded because the memory
|
|
// after it is allocated or busy. In that case, fall back to allocating new
|
|
// space and copying. Allow non-private arenas to switch arenas.
|
|
ret = (mIsPrivate ? this : choose_arena(aSize))->Malloc(aSize, false);
|
|
if (!ret) {
|
|
return nullptr;
|
|
}
|
|
|
|
// Junk/zero-filling were already done by arena_t::Malloc().
|
|
copysize = (aSize < aOldSize) ? aSize : aOldSize;
|
|
#ifdef VM_COPY_MIN
|
|
if (copysize >= VM_COPY_MIN) {
|
|
pages_copy(ret, aPtr, copysize);
|
|
} else
|
|
#endif
|
|
{
|
|
memcpy(ret, aPtr, copysize);
|
|
}
|
|
idalloc(aPtr, this);
|
|
return ret;
|
|
}
|
|
|
|
void* arena_t::Ralloc(void* aPtr, size_t aSize, size_t aOldSize) {
|
|
MOZ_DIAGNOSTIC_ASSERT(mMagic == ARENA_MAGIC);
|
|
MOZ_ASSERT(aPtr);
|
|
MOZ_ASSERT(aSize != 0);
|
|
|
|
return (aSize <= gMaxLargeClass) ? RallocSmallOrLarge(aPtr, aSize, aOldSize)
|
|
: RallocHuge(aPtr, aSize, aOldSize);
|
|
}
|
|
|
|
void* arena_t::operator new(size_t aCount, const fallible_t&) noexcept {
|
|
MOZ_ASSERT(aCount == sizeof(arena_t));
|
|
// Ignore aCount, instead allocate axtra space for the trailing array of
|
|
// bins.
|
|
return sBaseAlloc.alloc(sizeof(arena_t) +
|
|
(sizeof(arena_bin_t) * NUM_SMALL_CLASSES));
|
|
}
|
|
|
|
arena_t::arena_t(arena_params_t* aParams, bool aIsPrivate)
|
|
: mRandomizeSmallAllocations(opt_randomize_small),
|
|
mIsPrivate(aIsPrivate),
|
|
// The default maximum amount of dirty pages allowed on arenas is a
|
|
// fraction of opt_dirty_max.
|
|
mMaxDirtyBase((aParams && aParams->mMaxDirty) ? aParams->mMaxDirty
|
|
: (opt_dirty_max / 8)),
|
|
mLastSignificantReuseNS(GetTimestampNS()),
|
|
mChunkAllocator(&gSystemChunkAllocator) {
|
|
MaybeMutex::DoLock doLock = MaybeMutex::MUST_LOCK;
|
|
if (aParams) {
|
|
uint32_t randFlags = aParams->mFlags & ARENA_FLAG_RANDOMIZE_SMALL_MASK;
|
|
switch (randFlags) {
|
|
case ARENA_FLAG_RANDOMIZE_SMALL_ENABLED:
|
|
mRandomizeSmallAllocations = true;
|
|
break;
|
|
case ARENA_FLAG_RANDOMIZE_SMALL_DISABLED:
|
|
mRandomizeSmallAllocations = false;
|
|
break;
|
|
case ARENA_FLAG_RANDOMIZE_SMALL_DEFAULT:
|
|
default:
|
|
break;
|
|
}
|
|
|
|
uint32_t threadFlags = aParams->mFlags & ARENA_FLAG_THREAD_MASK;
|
|
if (threadFlags == ARENA_FLAG_THREAD_MAIN_THREAD_ONLY) {
|
|
// At the moment we require that any ARENA_FLAG_THREAD_MAIN_THREAD_ONLY
|
|
// arenas are created and therefore always accessed by the main thread.
|
|
// This is for two reasons:
|
|
// * it allows jemalloc_stats to read their statistics (we also require
|
|
// that jemalloc_stats is only used on the main thread).
|
|
// * Only main-thread or threadsafe arenas can be guanteed to be in a
|
|
// consistent state after a fork() from the main thread. If fork()
|
|
// occurs off-thread then the new child process cannot use these arenas
|
|
// (new children should usually exec() or exit() since other data may
|
|
// also be inconsistent).
|
|
MOZ_ASSERT(gArenas.IsOnMainThread());
|
|
MOZ_ASSERT(aIsPrivate);
|
|
doLock = MaybeMutex::AVOID_LOCK_UNSAFE;
|
|
}
|
|
|
|
mMaxDirtyIncreaseOverride = aParams->mMaxDirtyIncreaseOverride;
|
|
mMaxDirtyDecreaseOverride = aParams->mMaxDirtyDecreaseOverride;
|
|
|
|
if (aParams->mLabel) {
|
|
// The string may be truncated so always place a null-byte in the last
|
|
// position.
|
|
strncpy(mLabel, aParams->mLabel, LABEL_MAX_CAPACITY - 1);
|
|
mLabel[LABEL_MAX_CAPACITY - 1] = 0;
|
|
|
|
// If the string was truncated, then replace its end with "..."
|
|
if (strlen(aParams->mLabel) >= LABEL_MAX_CAPACITY) {
|
|
for (int i = 0; i < 3; i++) {
|
|
mLabel[LABEL_MAX_CAPACITY - 2 - i] = '.';
|
|
}
|
|
}
|
|
}
|
|
|
|
if (aParams->mChunkAllocator) {
|
|
MOZ_ASSERT(aIsPrivate);
|
|
mChunkAllocator = aParams->mChunkAllocator;
|
|
}
|
|
}
|
|
|
|
MOZ_RELEASE_ASSERT(mLock.Init(doLock));
|
|
|
|
UpdateMaxDirty();
|
|
|
|
// Initialize bins.
|
|
SizeClass sizeClass(1);
|
|
|
|
unsigned i;
|
|
for (i = 0;; i++) {
|
|
new (&mBins[i]) arena_bin_t(sizeClass);
|
|
|
|
// SizeClass doesn't want sizes larger than gMaxBinClass for now.
|
|
if (sizeClass.Size() == gMaxBinClass) {
|
|
break;
|
|
}
|
|
sizeClass = sizeClass.Next();
|
|
}
|
|
MOZ_ASSERT(i == NUM_SMALL_CLASSES - 1);
|
|
}
|
|
|
|
arena_t::~arena_t() {
|
|
size_t i;
|
|
MaybeMutexAutoLock lock(mLock);
|
|
|
|
MOZ_RELEASE_ASSERT(!mLink.Left() && !mLink.Right(),
|
|
"Arena is still registered");
|
|
MOZ_RELEASE_ASSERT(!mStats.allocated_small && !mStats.allocated_large,
|
|
"Arena is not empty");
|
|
while (!mSpares.isEmpty()) {
|
|
arena_chunk_t* spare = mSpares.popFront();
|
|
arena_chunk_dealloc(mChunkAllocator, spare, kChunkSize);
|
|
}
|
|
for (i = 0; i < NUM_SMALL_CLASSES; i++) {
|
|
MOZ_RELEASE_ASSERT(mBins[i].mNonFullRuns.isEmpty(), "Bin is not empty");
|
|
}
|
|
#ifdef MOZ_DEBUG
|
|
{
|
|
MutexAutoLock lock(huge_mtx);
|
|
// This is an expensive check, so we only do it on debug builds.
|
|
for (auto node : huge.iter()) {
|
|
MOZ_RELEASE_ASSERT(node->mArenaId != mId, "Arena has huge allocations");
|
|
}
|
|
}
|
|
#endif
|
|
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
|
|
mMagic = 0;
|
|
#endif
|
|
mId = 0;
|
|
}
|
|
|
|
arena_t* ArenaCollection::CreateArena(bool aIsPrivate,
|
|
arena_params_t* aParams) {
|
|
// Allocate the memory for the arena before taking any locks, since it
|
|
// will use the base allocator locks and could run a system call.
|
|
arena_t* ret = new (fallible) arena_t(aParams, aIsPrivate);
|
|
if (!ret) {
|
|
// Only reached if there is an OOM error.
|
|
|
|
// OOM here is quite inconvenient to propagate, since dealing with it
|
|
// would require a check for failure in the fast path. Instead, punt
|
|
// by using the first arena.
|
|
// In practice, this is an extremely unlikely failure.
|
|
_malloc_message(_getprogname(), ": (malloc) Error initializing arena\n");
|
|
|
|
return mDefaultArena;
|
|
}
|
|
|
|
MutexAutoLock lock(mLock);
|
|
|
|
// Updating the arena's mIsDeferredPurgeEnabled needs to happen in the
|
|
// same critical section as enrolling the arena in the collection, which
|
|
// is why it's set here and not by arena_t's constructor.
|
|
{
|
|
// The arena lock here isn't necessary because nothing else has a
|
|
// pointer to the arena yet, but the alternative is
|
|
// MOZ_PUSH_IGNORE_THREAD_SAFETY.
|
|
MaybeMutexAutoLock arena_lock(ret->mLock);
|
|
ret->mIsDeferredPurgeEnabled = mIsDeferredPurgeEnabled;
|
|
}
|
|
|
|
// For public arenas, it's fine to just use incrementing arena id
|
|
if (!aIsPrivate) {
|
|
ret->mId = mLastPublicArenaId++;
|
|
mArenas.Insert(ret);
|
|
return ret;
|
|
}
|
|
|
|
// For private arenas, slightly obfuscate the id by XORing a key generated
|
|
// once, and rotate the bits by an amount also generated once.
|
|
if (mArenaIdKey == 0) {
|
|
mozilla::Maybe<uint64_t> maybeRandom = mozilla::RandomUint64();
|
|
MOZ_RELEASE_ASSERT(maybeRandom.isSome());
|
|
mArenaIdKey = maybeRandom.value();
|
|
maybeRandom = mozilla::RandomUint64();
|
|
MOZ_RELEASE_ASSERT(maybeRandom.isSome());
|
|
mArenaIdRotation = maybeRandom.value() & (sizeof(void*) * 8 - 1);
|
|
}
|
|
arena_id_t id = reinterpret_cast<arena_id_t>(ret) ^ mArenaIdKey;
|
|
ret->mId =
|
|
(id >> mArenaIdRotation) | (id << (sizeof(void*) * 8 - mArenaIdRotation));
|
|
mPrivateArenas.Insert(ret);
|
|
return ret;
|
|
}
|
|
|
|
// End arena.
|
|
// ***************************************************************************
|
|
// Begin general internal functions.
|
|
|
|
// Initialize huge allocation data.
|
|
static void huge_init() MOZ_REQUIRES(gInitLock) {
|
|
huge_mtx.Init();
|
|
MOZ_PUSH_IGNORE_THREAD_SAFETY
|
|
huge_allocated = 0;
|
|
huge_mapped = 0;
|
|
huge_operations = 0;
|
|
MOZ_POP_THREAD_SAFETY
|
|
}
|
|
|
|
void* arena_t::MallocHuge(size_t aSize, bool aZero) {
|
|
return PallocHuge(aSize, kChunkSize, aZero);
|
|
}
|
|
|
|
void* arena_t::PallocHuge(size_t aSize, size_t aAlignment, bool aZero) {
|
|
void* ret;
|
|
size_t csize;
|
|
size_t psize;
|
|
extent_node_t* node;
|
|
|
|
// We're going to configure guard pages in the region between the
|
|
// page-aligned size and the chunk-aligned size, so if those are the same
|
|
// then we need to force that region into existence.
|
|
csize = CHUNK_CEILING(aSize + gRealPageSize);
|
|
if (csize < aSize) {
|
|
// size is large enough to cause size_t wrap-around.
|
|
return nullptr;
|
|
}
|
|
|
|
// Allocate an extent node with which to track the chunk.
|
|
node = new (fallible) extent_node_t();
|
|
if (!node) {
|
|
return nullptr;
|
|
}
|
|
|
|
// Allocate one or more contiguous chunks for this request.
|
|
ret = arena_chunk_alloc(mChunkAllocator, csize, aAlignment);
|
|
if (!ret) {
|
|
delete node;
|
|
return nullptr;
|
|
}
|
|
psize = REAL_PAGE_CEILING(aSize);
|
|
MOZ_ASSERT(psize < csize);
|
|
#ifdef MOZ_DEBUG
|
|
if (aZero) {
|
|
chunk_assert_zero(ret, psize);
|
|
}
|
|
#endif
|
|
|
|
// Insert node into huge.
|
|
node->mAddr = ret;
|
|
node->mSize = psize;
|
|
node->mArena = this;
|
|
node->mArenaId = mId;
|
|
|
|
{
|
|
MutexAutoLock lock(huge_mtx);
|
|
huge.Insert(node);
|
|
|
|
// Although we allocated space for csize bytes, we indicate that we've
|
|
// allocated only psize bytes.
|
|
//
|
|
// If DECOMMIT is defined, this is a reasonable thing to do, since
|
|
// we'll explicitly decommit the bytes in excess of psize.
|
|
//
|
|
// If DECOMMIT is not defined, then we're relying on the OS to be lazy
|
|
// about how it allocates physical pages to mappings. If we never
|
|
// touch the pages in excess of psize, the OS won't allocate a physical
|
|
// page, and we won't use more than psize bytes of physical memory.
|
|
//
|
|
// A correct program will only touch memory in excess of how much it
|
|
// requested if it first calls malloc_usable_size and finds out how
|
|
// much space it has to play with. But because we set node->mSize =
|
|
// psize above, malloc_usable_size will return psize, not csize, and
|
|
// the program will (hopefully) never touch bytes in excess of psize.
|
|
// Thus those bytes won't take up space in physical memory, and we can
|
|
// reasonably claim we never "allocated" them in the first place.
|
|
huge_allocated += psize;
|
|
huge_mapped += csize;
|
|
huge_operations++;
|
|
}
|
|
|
|
pages_decommit((void*)((uintptr_t)ret + psize), csize - psize);
|
|
|
|
if (!aZero) {
|
|
ApplyZeroOrJunk(ret, psize);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void* arena_t::RallocHuge(void* aPtr, size_t aSize, size_t aOldSize) {
|
|
void* ret;
|
|
size_t copysize;
|
|
|
|
// Avoid moving the allocation if the size class would not change.
|
|
if (aOldSize > gMaxLargeClass &&
|
|
CHUNK_CEILING(aSize + gRealPageSize) ==
|
|
CHUNK_CEILING(aOldSize + gRealPageSize)) {
|
|
size_t psize = REAL_PAGE_CEILING(aSize);
|
|
if (aSize < aOldSize) {
|
|
MaybePoison((void*)((uintptr_t)aPtr + aSize), aOldSize - aSize);
|
|
}
|
|
if (psize < aOldSize) {
|
|
pages_decommit((void*)((uintptr_t)aPtr + psize), aOldSize - psize);
|
|
|
|
// Update recorded size.
|
|
MutexAutoLock lock(huge_mtx);
|
|
extent_node_t* node = huge.Search(aPtr);
|
|
MOZ_ASSERT(node);
|
|
MOZ_ASSERT(node->mSize == aOldSize);
|
|
MOZ_RELEASE_ASSERT(node->mArena == this);
|
|
huge_allocated -= aOldSize - psize;
|
|
huge_operations++;
|
|
// No need to change huge_mapped, because we didn't (un)map anything.
|
|
node->mSize = psize;
|
|
} else if (psize > aOldSize) {
|
|
if (!pages_commit((void*)((uintptr_t)aPtr + aOldSize),
|
|
psize - aOldSize)) {
|
|
return nullptr;
|
|
}
|
|
|
|
// We need to update the recorded size if the size increased,
|
|
// so malloc_usable_size doesn't return a value smaller than
|
|
// what was requested via realloc().
|
|
MutexAutoLock lock(huge_mtx);
|
|
extent_node_t* node = huge.Search(aPtr);
|
|
MOZ_ASSERT(node);
|
|
MOZ_ASSERT(node->mSize == aOldSize);
|
|
MOZ_RELEASE_ASSERT(node->mArena == this);
|
|
huge_allocated += psize - aOldSize;
|
|
huge_operations++;
|
|
// No need to change huge_mapped, because we didn't
|
|
// (un)map anything.
|
|
node->mSize = psize;
|
|
}
|
|
|
|
if (aSize > aOldSize) {
|
|
ApplyZeroOrJunk((void*)((uintptr_t)aPtr + aOldSize), aSize - aOldSize);
|
|
}
|
|
return aPtr;
|
|
}
|
|
|
|
// If we get here, then aSize and aOldSize are different enough that we
|
|
// need to use a different size class. In that case, fall back to allocating
|
|
// new space and copying. Allow non-private arenas to switch arenas.
|
|
ret = (mIsPrivate ? this : choose_arena(aSize))->MallocHuge(aSize, false);
|
|
if (!ret) {
|
|
return nullptr;
|
|
}
|
|
|
|
copysize = (aSize < aOldSize) ? aSize : aOldSize;
|
|
#ifdef VM_COPY_MIN
|
|
if (copysize >= VM_COPY_MIN) {
|
|
pages_copy(ret, aPtr, copysize);
|
|
} else
|
|
#endif
|
|
{
|
|
memcpy(ret, aPtr, copysize);
|
|
}
|
|
idalloc(aPtr, this);
|
|
return ret;
|
|
}
|
|
|
|
static void huge_dalloc(void* aPtr, arena_t* aArena) {
|
|
extent_node_t* node;
|
|
size_t mapped = 0;
|
|
{
|
|
MutexAutoLock lock(huge_mtx);
|
|
|
|
// Extract from tree of huge allocations.
|
|
node = huge.Search(aPtr);
|
|
MOZ_RELEASE_ASSERT(node, "Double-free?");
|
|
MOZ_ASSERT(node->mAddr == aPtr);
|
|
MOZ_RELEASE_ASSERT(!aArena || node->mArena == aArena);
|
|
// See AllocInfo::Arena.
|
|
MOZ_RELEASE_ASSERT(node->mArenaId == node->mArena->mId);
|
|
huge.Remove(node);
|
|
|
|
mapped = CHUNK_CEILING(node->mSize + gRealPageSize);
|
|
huge_allocated -= node->mSize;
|
|
huge_mapped -= mapped;
|
|
huge_operations++;
|
|
}
|
|
|
|
// Unmap chunk.
|
|
arena_chunk_dealloc(node->mArena->mChunkAllocator, node->mAddr, mapped);
|
|
|
|
delete node;
|
|
}
|
|
|
|
// Returns whether the allocator was successfully initialized.
|
|
static bool malloc_init_hard() {
|
|
unsigned i;
|
|
const char* opts;
|
|
|
|
AutoLock<StaticMutex> lock(gInitLock);
|
|
|
|
if (malloc_initialized) {
|
|
// Another thread initialized the allocator before this one
|
|
// acquired gInitLock.
|
|
return true;
|
|
}
|
|
|
|
if (!thread_arena.init()) {
|
|
return true;
|
|
}
|
|
|
|
// Get page size and number of CPUs
|
|
const size_t page_size = GetKernelPageSize();
|
|
// We assume that the page size is a power of 2.
|
|
MOZ_ASSERT(std::has_single_bit(page_size));
|
|
#ifdef MALLOC_STATIC_PAGESIZE
|
|
if (gRealPageSize % page_size) {
|
|
_malloc_message(
|
|
_getprogname(),
|
|
"Compile-time page size does not divide the runtime one.\n");
|
|
MOZ_CRASH();
|
|
}
|
|
#else
|
|
gRealPageSize = page_size;
|
|
gPageSize = page_size;
|
|
#endif
|
|
|
|
// Get runtime configuration.
|
|
if ((opts = getenv("MALLOC_OPTIONS"))) {
|
|
for (i = 0; opts[i] != '\0'; i++) {
|
|
// All options are single letters, some take a *prefix* numeric argument.
|
|
|
|
// Parse the argument.
|
|
unsigned prefix_arg = 0;
|
|
while (opts[i] >= '0' && opts[i] <= '9') {
|
|
prefix_arg *= 10;
|
|
prefix_arg += opts[i] - '0';
|
|
i++;
|
|
}
|
|
|
|
switch (opts[i]) {
|
|
case 'f':
|
|
opt_dirty_max >>= prefix_arg ? prefix_arg : 1;
|
|
break;
|
|
case 'F':
|
|
prefix_arg = prefix_arg ? prefix_arg : 1;
|
|
if (opt_dirty_max == 0) {
|
|
opt_dirty_max = 1;
|
|
prefix_arg--;
|
|
}
|
|
opt_dirty_max <<= prefix_arg;
|
|
if (opt_dirty_max == 0) {
|
|
// If the shift above overflowed all the bits then clamp the result
|
|
// instead. If we started with DIRTY_MAX_DEFAULT then this will
|
|
// always be a power of two so choose the maximum power of two that
|
|
// fits in a size_t.
|
|
opt_dirty_max = size_t(1) << (sizeof(size_t) * CHAR_BIT - 1);
|
|
}
|
|
break;
|
|
#ifdef MALLOC_RUNTIME_CONFIG
|
|
case 'j':
|
|
opt_junk = false;
|
|
break;
|
|
case 'J':
|
|
opt_junk = true;
|
|
break;
|
|
case 'q':
|
|
// The argument selects how much poisoning to do.
|
|
opt_poison = NONE;
|
|
break;
|
|
case 'Q':
|
|
if (opts[i + 1] == 'Q') {
|
|
// Maximum poisoning.
|
|
i++;
|
|
opt_poison = ALL;
|
|
} else {
|
|
opt_poison = SOME;
|
|
opt_poison_size = kCacheLineSize * prefix_arg;
|
|
}
|
|
break;
|
|
case 'z':
|
|
opt_zero = false;
|
|
break;
|
|
case 'Z':
|
|
opt_zero = true;
|
|
break;
|
|
# ifndef MALLOC_STATIC_PAGESIZE
|
|
case 'P':
|
|
MOZ_ASSERT(gPageSize >= 1_KiB);
|
|
MOZ_ASSERT(gPageSize <= 64_KiB);
|
|
prefix_arg = prefix_arg ? prefix_arg : 1;
|
|
gPageSize <<= prefix_arg;
|
|
// We know that if the shift causes gPageSize to be zero then it's
|
|
// because it shifted all the bits off. We didn't start with zero.
|
|
// Therefore if gPageSize is out of bounds we set it to 64KiB.
|
|
if (gPageSize < 1_KiB || gPageSize > 64_KiB) {
|
|
gPageSize = 64_KiB;
|
|
}
|
|
// We also limit gPageSize to be no larger than gRealPageSize, there's
|
|
// no reason to support this.
|
|
if (gPageSize > gRealPageSize) {
|
|
gPageSize = gRealPageSize;
|
|
}
|
|
break;
|
|
case 'p':
|
|
MOZ_ASSERT(gPageSize >= 1_KiB);
|
|
MOZ_ASSERT(gPageSize <= 64_KiB);
|
|
prefix_arg = prefix_arg ? prefix_arg : 1;
|
|
gPageSize >>= prefix_arg;
|
|
if (gPageSize < 1_KiB) {
|
|
gPageSize = 1_KiB;
|
|
}
|
|
break;
|
|
# endif
|
|
#endif
|
|
case 'r':
|
|
opt_randomize_small = false;
|
|
break;
|
|
case 'R':
|
|
opt_randomize_small = true;
|
|
break;
|
|
default: {
|
|
char cbuf[2];
|
|
|
|
cbuf[0] = opts[i];
|
|
cbuf[1] = '\0';
|
|
_malloc_message(_getprogname(),
|
|
": (malloc) Unsupported character "
|
|
"in malloc options: '",
|
|
cbuf, "'\n");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
MOZ_ASSERT(gPageSize <= gRealPageSize);
|
|
#ifndef MALLOC_STATIC_PAGESIZE
|
|
DefineGlobals();
|
|
#endif
|
|
|
|
#ifndef XP_WIN
|
|
gCache.Init();
|
|
#endif
|
|
|
|
huge_init();
|
|
sBaseAlloc.Init();
|
|
|
|
// Initialize arenas collection here.
|
|
if (!gArenas.Init()) {
|
|
return false;
|
|
}
|
|
|
|
// Assign the default arena to the initial thread.
|
|
thread_arena.set(gArenas.GetDefault());
|
|
|
|
if (!gChunkRTree.Init()) {
|
|
return false;
|
|
}
|
|
|
|
malloc_initialized = true;
|
|
|
|
// Dummy call so that the function is not removed by dead-code elimination
|
|
Debug::jemalloc_ptr_info(nullptr);
|
|
|
|
#if !defined(XP_WIN) && !defined(XP_DARWIN)
|
|
// Prevent potential deadlock on malloc locks after fork.
|
|
pthread_atfork(_malloc_prefork, _malloc_postfork_parent,
|
|
_malloc_postfork_child);
|
|
#endif
|
|
|
|
#ifdef MOZ_PHC
|
|
// PHC must be initialised after mozjemalloc.
|
|
phc_init();
|
|
#endif
|
|
|
|
return true;
|
|
}
|
|
|
|
// End general internal functions.
|
|
// ***************************************************************************
|
|
// Begin malloc(3)-compatible functions.
|
|
|
|
// The BaseAllocator class is a helper class that implements the base allocator
|
|
// functions (malloc, calloc, realloc, free, memalign) for a given arena,
|
|
// or an appropriately chosen arena (per choose_arena()) when none is given.
|
|
struct BaseAllocator {
|
|
#define MALLOC_DECL(name, return_type, ...) \
|
|
inline return_type name(__VA_ARGS__);
|
|
|
|
#define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
|
|
#include "malloc_decls.h"
|
|
|
|
explicit BaseAllocator(arena_t* aArena) : mArena(aArena) {}
|
|
|
|
private:
|
|
arena_t* mArena;
|
|
};
|
|
|
|
#define MALLOC_DECL(name, return_type, ...) \
|
|
inline return_type MozJemalloc::name( \
|
|
ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) { \
|
|
BaseAllocator allocator(nullptr); \
|
|
return allocator.name(ARGS_HELPER(ARGS, ##__VA_ARGS__)); \
|
|
}
|
|
#define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
|
|
#include "malloc_decls.h"
|
|
|
|
inline void* BaseAllocator::malloc(size_t aSize) {
|
|
void* ret;
|
|
arena_t* arena;
|
|
|
|
if (!malloc_init()) {
|
|
ret = nullptr;
|
|
goto RETURN;
|
|
}
|
|
|
|
if (aSize == 0) {
|
|
aSize = 1;
|
|
}
|
|
// If mArena is non-null, it must not be in the first page.
|
|
MOZ_DIAGNOSTIC_ASSERT_IF(mArena, (size_t)mArena >= gPageSize);
|
|
arena = mArena ? mArena : choose_arena(aSize);
|
|
ret = arena->Malloc(aSize, /* aZero = */ false);
|
|
|
|
RETURN:
|
|
if (!ret) {
|
|
errno = ENOMEM;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
inline void* BaseAllocator::memalign(size_t aAlignment, size_t aSize) {
|
|
MOZ_ASSERT(((aAlignment - 1) & aAlignment) == 0);
|
|
|
|
if (!malloc_init()) {
|
|
return nullptr;
|
|
}
|
|
|
|
if (aSize == 0) {
|
|
aSize = 1;
|
|
}
|
|
|
|
aAlignment = aAlignment < sizeof(void*) ? sizeof(void*) : aAlignment;
|
|
arena_t* arena = mArena ? mArena : choose_arena(aSize);
|
|
return arena->Palloc(aAlignment, aSize);
|
|
}
|
|
|
|
inline void* BaseAllocator::calloc(size_t aNum, size_t aSize) {
|
|
void* ret;
|
|
|
|
if (malloc_init()) {
|
|
CheckedInt<size_t> checkedSize = CheckedInt<size_t>(aNum) * aSize;
|
|
if (checkedSize.isValid()) {
|
|
size_t allocSize = checkedSize.value();
|
|
if (allocSize == 0) {
|
|
allocSize = 1;
|
|
}
|
|
arena_t* arena = mArena ? mArena : choose_arena(allocSize);
|
|
ret = arena->Malloc(allocSize, /* aZero = */ true);
|
|
} else {
|
|
ret = nullptr;
|
|
}
|
|
} else {
|
|
ret = nullptr;
|
|
}
|
|
|
|
if (!ret) {
|
|
errno = ENOMEM;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
inline void* BaseAllocator::realloc(void* aPtr, size_t aSize) {
|
|
void* ret;
|
|
|
|
if (aSize == 0) {
|
|
aSize = 1;
|
|
}
|
|
|
|
if (aPtr) {
|
|
MOZ_RELEASE_ASSERT(malloc_initialized);
|
|
|
|
auto info = AllocInfo::Get(aPtr);
|
|
auto arena = info.Arena();
|
|
MOZ_RELEASE_ASSERT(!mArena || arena == mArena);
|
|
ret = arena->Ralloc(aPtr, aSize, info.Size());
|
|
} else {
|
|
if (!malloc_init()) {
|
|
ret = nullptr;
|
|
} else {
|
|
arena_t* arena = mArena ? mArena : choose_arena(aSize);
|
|
ret = arena->Malloc(aSize, /* aZero = */ false);
|
|
}
|
|
}
|
|
|
|
if (!ret) {
|
|
errno = ENOMEM;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
inline void BaseAllocator::free(void* aPtr) {
|
|
size_t offset;
|
|
|
|
// A version of idalloc that checks for nullptr pointer.
|
|
offset = GetChunkOffsetForPtr(aPtr);
|
|
if (offset != 0) {
|
|
MOZ_RELEASE_ASSERT(malloc_initialized);
|
|
arena_dalloc(aPtr, offset, mArena);
|
|
} else if (aPtr) {
|
|
MOZ_RELEASE_ASSERT(malloc_initialized);
|
|
huge_dalloc(aPtr, mArena);
|
|
}
|
|
}
|
|
|
|
inline int MozJemalloc::posix_memalign(void** aMemPtr, size_t aAlignment,
|
|
size_t aSize) {
|
|
return AlignedAllocator<memalign>::posix_memalign(aMemPtr, aAlignment, aSize);
|
|
}
|
|
|
|
inline void* MozJemalloc::aligned_alloc(size_t aAlignment, size_t aSize) {
|
|
return AlignedAllocator<memalign>::aligned_alloc(aAlignment, aSize);
|
|
}
|
|
|
|
inline void* MozJemalloc::valloc(size_t aSize) {
|
|
return AlignedAllocator<memalign>::valloc(aSize);
|
|
}
|
|
|
|
// End malloc(3)-compatible functions.
|
|
// ***************************************************************************
|
|
// Begin non-standard functions.
|
|
|
|
// This was added by Mozilla for use by SQLite.
|
|
inline size_t MozJemalloc::malloc_good_size(size_t aSize) {
|
|
if (aSize == 0) {
|
|
aSize = SizeClass(1).Size();
|
|
} else if (aSize <= gMaxLargeClass) {
|
|
// Small or large
|
|
aSize = SizeClass(aSize).Size();
|
|
} else {
|
|
// Huge. We use PAGE_CEILING to get psize, instead of using
|
|
// CHUNK_CEILING to get csize. This ensures that this
|
|
// malloc_usable_size(malloc(n)) always matches
|
|
// malloc_good_size(n).
|
|
aSize = REAL_PAGE_CEILING(aSize);
|
|
}
|
|
return aSize;
|
|
}
|
|
|
|
inline size_t MozJemalloc::malloc_usable_size(usable_ptr_t aPtr) {
|
|
return AllocInfo::GetValidated(aPtr).Size();
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_stats_internal(
|
|
jemalloc_stats_t* aStats, jemalloc_bin_stats_t* aBinStats) {
|
|
size_t non_arena_mapped, chunk_header_size;
|
|
|
|
if (!aStats) {
|
|
return;
|
|
}
|
|
if (!malloc_init()) {
|
|
memset(aStats, 0, sizeof(*aStats));
|
|
return;
|
|
}
|
|
if (aBinStats) {
|
|
memset(aBinStats, 0, sizeof(jemalloc_bin_stats_t) * NUM_SMALL_CLASSES);
|
|
}
|
|
|
|
// Gather runtime settings.
|
|
aStats->opt_junk = opt_junk;
|
|
aStats->opt_randomize_small = opt_randomize_small;
|
|
aStats->opt_zero = opt_zero;
|
|
aStats->quantum = kQuantum;
|
|
aStats->quantum_max = kMaxQuantumClass;
|
|
aStats->quantum_wide = kQuantumWide;
|
|
aStats->quantum_wide_max = kMaxQuantumWideClass;
|
|
aStats->subpage_max = gMaxSubPageClass;
|
|
aStats->large_max = gMaxLargeClass;
|
|
aStats->chunksize = kChunkSize;
|
|
aStats->page_size = gPageSize;
|
|
aStats->real_page_size = gRealPageSize;
|
|
aStats->dirty_max = opt_dirty_max;
|
|
aStats->arena_run_header = offsetof(arena_run_t, mRegionsMask);
|
|
|
|
// Gather current memory usage statistics.
|
|
aStats->narenas = 0;
|
|
aStats->mapped = 0;
|
|
aStats->allocated = 0;
|
|
aStats->waste = 0;
|
|
aStats->pages_dirty = 0;
|
|
aStats->pages_fresh = 0;
|
|
aStats->pages_madvised = 0;
|
|
aStats->bookkeeping = 0;
|
|
aStats->bin_unused = 0;
|
|
|
|
non_arena_mapped = 0;
|
|
|
|
// Get huge mapped/allocated.
|
|
{
|
|
MutexAutoLock lock(huge_mtx);
|
|
non_arena_mapped += huge_mapped;
|
|
aStats->allocated += huge_allocated;
|
|
aStats->num_operations += huge_operations;
|
|
MOZ_ASSERT(huge_mapped >= huge_allocated);
|
|
}
|
|
|
|
// Get base mapped/allocated.
|
|
auto base_stats = sBaseAlloc.GetStats();
|
|
non_arena_mapped += base_stats.mMapped;
|
|
aStats->bookkeeping += base_stats.mCommitted;
|
|
|
|
gArenas.mLock.Lock();
|
|
|
|
// Stats can only read complete information if its run on the main thread.
|
|
MOZ_ASSERT(gArenas.IsOnMainThreadWeak());
|
|
|
|
// Iterate over arenas.
|
|
for (auto arena : gArenas.iter()) {
|
|
// Cannot safely read stats for this arena and therefore stats would be
|
|
// incomplete.
|
|
MOZ_ASSERT(arena->mLock.SafeOnThisThread());
|
|
|
|
size_t arena_mapped, arena_allocated, arena_committed, arena_dirty,
|
|
arena_fresh, arena_madvised, j, arena_unused, arena_headers;
|
|
|
|
arena_headers = 0;
|
|
arena_unused = 0;
|
|
|
|
{
|
|
MaybeMutexAutoLock lock(arena->mLock);
|
|
|
|
arena_mapped = arena->mStats.mapped;
|
|
|
|
// "committed" counts dirty and allocated memory.
|
|
arena_committed = arena->mStats.committed << gPageSize2Pow;
|
|
|
|
arena_allocated =
|
|
arena->mStats.allocated_small + arena->mStats.allocated_large;
|
|
|
|
arena_dirty = arena->mNumDirty << gPageSize2Pow;
|
|
arena_fresh = arena->mNumFresh << gPageSize2Pow;
|
|
arena_madvised = arena->mNumMAdvised << gPageSize2Pow;
|
|
|
|
aStats->num_operations += arena->mStats.operations;
|
|
|
|
for (j = 0; j < NUM_SMALL_CLASSES; j++) {
|
|
arena_bin_t* bin = &arena->mBins[j];
|
|
size_t bin_unused = 0;
|
|
size_t num_non_full_runs = 0;
|
|
|
|
for (arena_run_t& run : bin->mNonFullRuns) {
|
|
MOZ_DIAGNOSTIC_ASSERT(run.mMagic == ARENA_RUN_MAGIC);
|
|
MOZ_RELEASE_ASSERT(run.mNumFree > 0 &&
|
|
run.mNumFree < bin->mRunNumRegions);
|
|
MOZ_RELEASE_ASSERT(run.mBin == bin);
|
|
MOZ_RELEASE_ASSERT(bin->mNonFullRuns.ElementIsLinkedWell(&run));
|
|
arena_chunk_t* chunk = GetChunkForPtr(&run);
|
|
MOZ_RELEASE_ASSERT(chunk->mArena == arena);
|
|
bin_unused += run.mNumFree * bin->mSizeClass;
|
|
num_non_full_runs++;
|
|
}
|
|
|
|
arena_unused += bin_unused;
|
|
arena_headers += bin->mNumRuns * bin->mRunFirstRegionOffset;
|
|
if (aBinStats) {
|
|
aBinStats[j].size = bin->mSizeClass;
|
|
aBinStats[j].num_non_full_runs += num_non_full_runs;
|
|
aBinStats[j].num_runs += bin->mNumRuns;
|
|
aBinStats[j].bytes_unused += bin_unused;
|
|
size_t bytes_per_run = static_cast<size_t>(bin->mRunSizePages)
|
|
<< gPageSize2Pow;
|
|
aBinStats[j].bytes_total +=
|
|
bin->mNumRuns * (bytes_per_run - bin->mRunFirstRegionOffset);
|
|
aBinStats[j].bytes_per_run = bytes_per_run;
|
|
aBinStats[j].regions_per_run = bin->mRunNumRegions;
|
|
}
|
|
}
|
|
}
|
|
|
|
MOZ_ASSERT(arena_mapped >= arena_committed);
|
|
MOZ_ASSERT(arena_committed >= arena_allocated + arena_dirty);
|
|
|
|
aStats->mapped += arena_mapped;
|
|
aStats->allocated += arena_allocated;
|
|
aStats->pages_dirty += arena_dirty;
|
|
aStats->pages_fresh += arena_fresh;
|
|
aStats->pages_madvised += arena_madvised;
|
|
// "waste" is committed memory that is neither dirty nor
|
|
// allocated. If you change this definition please update
|
|
// memory/replace/logalloc/replay/Replay.cpp's jemalloc_stats calculation of
|
|
// committed.
|
|
MOZ_ASSERT(arena_committed >=
|
|
(arena_allocated + arena_dirty + arena_unused + arena_headers));
|
|
aStats->waste += arena_committed - arena_allocated - arena_dirty -
|
|
arena_unused - arena_headers;
|
|
aStats->bin_unused += arena_unused;
|
|
aStats->bookkeeping += arena_headers;
|
|
aStats->narenas++;
|
|
}
|
|
gArenas.mLock.Unlock();
|
|
|
|
// Account for arena chunk headers in bookkeeping rather than waste.
|
|
chunk_header_size =
|
|
((aStats->mapped / aStats->chunksize) * (gChunkHeaderNumPages - 1))
|
|
<< gPageSize2Pow;
|
|
|
|
aStats->mapped += non_arena_mapped;
|
|
aStats->bookkeeping += chunk_header_size;
|
|
aStats->waste -= chunk_header_size;
|
|
|
|
MOZ_ASSERT(aStats->mapped >= aStats->allocated + aStats->waste +
|
|
aStats->pages_dirty + aStats->bookkeeping);
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_stats_lite(jemalloc_stats_lite_t* aStats) {
|
|
if (!aStats) {
|
|
return;
|
|
}
|
|
if (!malloc_init()) {
|
|
memset(aStats, 0, sizeof(*aStats));
|
|
return;
|
|
}
|
|
|
|
aStats->allocated_bytes = 0;
|
|
aStats->num_operations = 0;
|
|
|
|
// Get huge mapped/allocated.
|
|
{
|
|
MutexAutoLock lock(huge_mtx);
|
|
aStats->allocated_bytes += huge_allocated;
|
|
aStats->num_operations += huge_operations;
|
|
MOZ_ASSERT(huge_mapped >= huge_allocated);
|
|
}
|
|
|
|
{
|
|
MutexAutoLock lock(gArenas.mLock);
|
|
for (auto arena : gArenas.iter()) {
|
|
// We don't need to lock the arena to access these fields.
|
|
aStats->allocated_bytes += arena->AllocatedBytes();
|
|
aStats->num_operations += arena->Operations();
|
|
}
|
|
aStats->num_operations += gArenas.OperationsDisposedArenas();
|
|
}
|
|
}
|
|
|
|
inline size_t MozJemalloc::jemalloc_stats_num_bins() {
|
|
return NUM_SMALL_CLASSES;
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_set_main_thread() {
|
|
MOZ_ASSERT(malloc_initialized);
|
|
gArenas.SetMainThread();
|
|
}
|
|
|
|
#ifdef MALLOC_DOUBLE_PURGE
|
|
|
|
// Explicitly remove all of this chunk's MADV_FREE'd pages from memory.
|
|
static size_t hard_purge_chunk(arena_chunk_t* aChunk) {
|
|
size_t total_npages = 0;
|
|
// See similar logic in arena_t::Purge().
|
|
for (size_t i = gChunkHeaderNumPages; i < gChunkNumPages; i++) {
|
|
// Find all adjacent pages with CHUNK_MAP_MADVISED set.
|
|
size_t npages;
|
|
for (npages = 0; aChunk->mPageMap[i + npages].bits & CHUNK_MAP_MADVISED &&
|
|
i + npages < gChunkNumPages;
|
|
npages++) {
|
|
// Turn off the page's CHUNK_MAP_MADVISED bit and turn on its
|
|
// CHUNK_MAP_FRESH bit.
|
|
MOZ_DIAGNOSTIC_ASSERT(!(aChunk->mPageMap[i + npages].bits &
|
|
(CHUNK_MAP_FRESH | CHUNK_MAP_DECOMMITTED)));
|
|
aChunk->mPageMap[i + npages].bits ^=
|
|
(CHUNK_MAP_MADVISED | CHUNK_MAP_FRESH);
|
|
}
|
|
|
|
// We could use mincore to find out which pages are actually
|
|
// present, but it's not clear that's better.
|
|
if (npages > 0) {
|
|
// i and npages should be aligned because they needed to be for the
|
|
// purge code that set CHUNK_MAP_MADVISED.
|
|
MOZ_ASSERT((i % gPagesPerRealPage) == 0);
|
|
MOZ_ASSERT((npages % gPagesPerRealPage) == 0);
|
|
pages_decommit(((char*)aChunk) + (i << gPageSize2Pow),
|
|
npages << gPageSize2Pow);
|
|
(void)pages_commit(((char*)aChunk) + (i << gPageSize2Pow),
|
|
npages << gPageSize2Pow);
|
|
}
|
|
total_npages += npages;
|
|
i += npages;
|
|
}
|
|
|
|
return total_npages;
|
|
}
|
|
|
|
// Explicitly remove all of this arena's MADV_FREE'd pages from memory.
|
|
void arena_t::HardPurge() {
|
|
MaybeMutexAutoLock lock(mLock);
|
|
|
|
while (!mChunksMAdvised.isEmpty()) {
|
|
arena_chunk_t* chunk = mChunksMAdvised.popFront();
|
|
size_t npages = hard_purge_chunk(chunk);
|
|
mNumMAdvised -= npages;
|
|
mNumFresh += npages;
|
|
}
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_purge_freed_pages() {
|
|
if (malloc_initialized) {
|
|
MutexAutoLock lock(gArenas.mLock);
|
|
MOZ_ASSERT(gArenas.IsOnMainThreadWeak());
|
|
for (auto arena : gArenas.iter()) {
|
|
arena->HardPurge();
|
|
}
|
|
}
|
|
}
|
|
|
|
#else // !defined MALLOC_DOUBLE_PURGE
|
|
|
|
inline void MozJemalloc::jemalloc_purge_freed_pages() {
|
|
// Do nothing.
|
|
}
|
|
|
|
#endif // defined MALLOC_DOUBLE_PURGE
|
|
|
|
inline void MozJemalloc::jemalloc_free_dirty_pages(void) {
|
|
if (malloc_initialized) {
|
|
gArenas.MayPurgeAll(PurgeUnconditional, __func__);
|
|
}
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_free_excess_dirty_pages(void) {
|
|
if (malloc_initialized) {
|
|
gArenas.MayPurgeAll(PurgeIfThreshold, __func__);
|
|
}
|
|
}
|
|
|
|
inline arena_t* ArenaCollection::GetById(arena_id_t aArenaId, bool aIsPrivate) {
|
|
if (!malloc_initialized) {
|
|
return nullptr;
|
|
}
|
|
|
|
// This function is never called with aIsPrivate = false, let's make sure it
|
|
// doesn't silently change while we're making that assumption below because
|
|
// we can't resolve non-private arenas this way.
|
|
MOZ_RELEASE_ASSERT(aIsPrivate);
|
|
// This function is not expected to be called before at least one private
|
|
// arena was created.
|
|
// coverity[missing_lock]
|
|
MOZ_RELEASE_ASSERT(mArenaIdKey);
|
|
arena_id_t id = (aArenaId << mArenaIdRotation) |
|
|
(aArenaId >> (sizeof(void*) * 8 - mArenaIdRotation));
|
|
arena_t* result = reinterpret_cast<arena_t*>(id ^ mArenaIdKey);
|
|
MOZ_RELEASE_ASSERT(result);
|
|
MOZ_DIAGNOSTIC_ASSERT(result->mMagic == ARENA_MAGIC);
|
|
MOZ_RELEASE_ASSERT(result->mId == aArenaId);
|
|
return result;
|
|
}
|
|
|
|
inline arena_id_t MozJemalloc::moz_create_arena_with_params(
|
|
arena_params_t* aParams) {
|
|
if (malloc_init()) {
|
|
arena_t* arena = gArenas.CreateArena(/* IsPrivate = */ true, aParams);
|
|
return arena->mId;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
inline void MozJemalloc::moz_dispose_arena(arena_id_t aArenaId) {
|
|
arena_t* arena = gArenas.GetById(aArenaId, /* IsPrivate = */ true);
|
|
gArenas.DisposeArena(arena);
|
|
}
|
|
|
|
inline void MozJemalloc::moz_set_max_dirty_page_modifier(int32_t aModifier) {
|
|
if (malloc_init()) {
|
|
gArenas.SetDefaultMaxDirtyPageModifier(aModifier);
|
|
}
|
|
}
|
|
|
|
inline void MozJemalloc::jemalloc_reset_small_alloc_randomization(
|
|
bool aRandomizeSmall) {
|
|
// When this process got forked by ForkServer then it inherited the existing
|
|
// state of mozjemalloc. Specifically, parsing of MALLOC_OPTIONS has already
|
|
// been done but it may not reflect anymore the current set of options after
|
|
// the fork().
|
|
//
|
|
// Similar behavior is also present on Android where it is also required to
|
|
// perform this step.
|
|
//
|
|
// Content process will have randomization on small malloc disabled via the
|
|
// MALLOC_OPTIONS environment variable set by parent process, missing this
|
|
// will lead to serious performance regressions because CPU prefetch will
|
|
// break, cf bug 1912262. However on forkserver-forked Content processes, the
|
|
// environment is not yet reset when the postfork child handler is being
|
|
// called.
|
|
//
|
|
// This API is here to allow those Content processes (spawned by ForkServer or
|
|
// Android service) to notify jemalloc to turn off the randomization on small
|
|
// allocations and perform the required reinitialization of already existing
|
|
// arena's PRNG. It is important to make sure that the PRNG state is properly
|
|
// re-initialized otherwise child processes would share all the same state.
|
|
|
|
{
|
|
AutoLock<StaticMutex> lock(gInitLock);
|
|
opt_randomize_small = aRandomizeSmall;
|
|
}
|
|
|
|
MutexAutoLock lock(gArenas.mLock);
|
|
for (auto* arena : gArenas.iter()) {
|
|
// We can only initialize the PRNG for main-thread-only arenas from the main
|
|
// thread.
|
|
if (!arena->IsMainThreadOnly() || gArenas.IsOnMainThreadWeak()) {
|
|
arena->ResetSmallAllocRandomization();
|
|
}
|
|
}
|
|
}
|
|
|
|
inline bool MozJemalloc::moz_enable_deferred_purge(bool aEnabled) {
|
|
return gArenas.SetDeferredPurge(aEnabled);
|
|
}
|
|
|
|
inline may_purge_now_result_t MozJemalloc::moz_may_purge_now(
|
|
bool aPeekOnly, uint32_t aReuseGraceMS,
|
|
const Maybe<std::function<bool()>>& aKeepGoing) {
|
|
return gArenas.MayPurgeSteps(aPeekOnly, aReuseGraceMS, aKeepGoing);
|
|
}
|
|
|
|
inline void ArenaCollection::AddToOutstandingPurges(arena_t* aArena) {
|
|
MOZ_ASSERT(aArena);
|
|
|
|
// We cannot trust the caller to know whether the element was already added
|
|
// from another thread given we have our own lock.
|
|
MutexAutoLock lock(mPurgeListLock);
|
|
if (!mOutstandingPurges.ElementProbablyInList(aArena)) {
|
|
mOutstandingPurges.pushBack(aArena);
|
|
}
|
|
}
|
|
|
|
inline bool ArenaCollection::RemoveFromOutstandingPurges(arena_t* aArena) {
|
|
MOZ_ASSERT(aArena);
|
|
|
|
// We cannot trust the caller to know whether the element was already removed
|
|
// from another thread given we have our own lock.
|
|
MutexAutoLock lock(mPurgeListLock);
|
|
if (mOutstandingPurges.ElementProbablyInList(aArena)) {
|
|
mOutstandingPurges.remove(aArena);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
may_purge_now_result_t ArenaCollection::MayPurgeSteps(
|
|
bool aPeekOnly, uint32_t aReuseGraceMS,
|
|
const Maybe<std::function<bool()>>& aKeepGoing) {
|
|
// This only works on the main thread because it may process main-thread-only
|
|
// arenas.
|
|
MOZ_ASSERT(IsOnMainThreadWeak());
|
|
|
|
uint64_t now = GetTimestampNS();
|
|
uint64_t reuseGraceNS = (uint64_t)aReuseGraceMS * 1000 * 1000;
|
|
arena_t* found = nullptr;
|
|
{
|
|
MutexAutoLock lock(mPurgeListLock);
|
|
if (mOutstandingPurges.isEmpty()) {
|
|
return may_purge_now_result_t::Done;
|
|
}
|
|
for (arena_t& arena : mOutstandingPurges) {
|
|
if (now - arena.mLastSignificantReuseNS >= reuseGraceNS) {
|
|
found = &arena;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
return may_purge_now_result_t::WantsLater;
|
|
}
|
|
if (aPeekOnly) {
|
|
return may_purge_now_result_t::NeedsMore;
|
|
}
|
|
|
|
// We need to avoid the invalid state where mIsPurgePending is set
|
|
// but the arena is not in the list or about to be added. So remove the
|
|
// arena from the list before calling Purge().
|
|
mOutstandingPurges.remove(found);
|
|
}
|
|
|
|
ArenaPurgeResult pr =
|
|
found->PurgeLoop(PurgeIfThreshold, __func__, aReuseGraceMS, aKeepGoing);
|
|
|
|
if (pr == ArenaPurgeResult::NotDone) {
|
|
// If there's more work to do we re-insert the arena into the purge queue.
|
|
// If the arena was busy we don't since the other thread that's purging it
|
|
// will finish that work.
|
|
|
|
// Note that after the above Purge() and taking the lock below there's a
|
|
// chance another thread may be purging the arena and clear
|
|
// mIsPurgePending. Resulting in the state of being in the list
|
|
// with that flag clear. That's okay since the next time a purge occurs
|
|
// (and one will because it's in the list) it'll clear the flag and the
|
|
// state will be consistent again.
|
|
MutexAutoLock lock(mPurgeListLock);
|
|
if (!mOutstandingPurges.ElementProbablyInList(found)) {
|
|
// Given we want to continue to purge this arena, push it to the front
|
|
// to increase the probability to find it fast.
|
|
mOutstandingPurges.pushFront(found);
|
|
}
|
|
} else if (pr == ArenaPurgeResult::Dying) {
|
|
delete found;
|
|
}
|
|
|
|
// Even if there is no other arena that needs work, let the caller just call
|
|
// us again and we will do the above checks then and return their result.
|
|
// Note that in the current surrounding setting this may (rarely) cause a
|
|
// new slice of our idle task runner if we are exceeding idle budget.
|
|
return may_purge_now_result_t::NeedsMore;
|
|
}
|
|
|
|
void ArenaCollection::MayPurgeAll(PurgeCondition aCond, const char* aCaller) {
|
|
MutexAutoLock lock(mLock);
|
|
for (auto* arena : iter()) {
|
|
// Arenas that are not IsMainThreadOnly can be purged from any thread.
|
|
// So we do what we can even if called from another thread.
|
|
if (!arena->IsMainThreadOnly() || IsOnMainThreadWeak()) {
|
|
RemoveFromOutstandingPurges(arena);
|
|
ArenaPurgeResult pr = arena->PurgeLoop(aCond, aCaller);
|
|
|
|
// No arena can die here because we're holding the arena collection lock.
|
|
// Arenas are removed from the collection before setting their
|
|
// mMustDeleteAfterPurge flag.
|
|
MOZ_RELEASE_ASSERT(pr != ArenaPurgeResult::Dying);
|
|
}
|
|
}
|
|
}
|
|
|
|
#define MALLOC_DECL(name, return_type, ...) \
|
|
inline return_type MozJemalloc::moz_arena_##name( \
|
|
arena_id_t aArenaId, ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) { \
|
|
BaseAllocator allocator( \
|
|
gArenas.GetById(aArenaId, /* IsPrivate = */ true)); \
|
|
return allocator.name(ARGS_HELPER(ARGS, ##__VA_ARGS__)); \
|
|
}
|
|
#define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
|
|
#include "malloc_decls.h"
|
|
|
|
// End non-standard functions.
|
|
// ***************************************************************************
|
|
#ifndef XP_WIN
|
|
// Begin library-private functions, used by threading libraries for protection
|
|
// of malloc during fork(). These functions are only called if the program is
|
|
// running in threaded mode, so there is no need to check whether the program
|
|
// is threaded here.
|
|
//
|
|
// Note that the only way to keep the main-thread-only arenas in a consistent
|
|
// state for the child is if fork is called from the main thread only. Or the
|
|
// child must not use them, eg it should call exec(). We attempt to prevent the
|
|
// child for accessing these arenas by refusing to re-initialise them.
|
|
//
|
|
// This is only accessed in the fork handlers while gArenas.mLock is held.
|
|
static pthread_t gForkingThread;
|
|
|
|
# ifdef XP_DARWIN
|
|
// This is only accessed in the fork handlers while gArenas.mLock is held.
|
|
static pid_t gForkingProcess;
|
|
# endif
|
|
|
|
FORK_HOOK
|
|
void _malloc_prefork(void) MOZ_NO_THREAD_SAFETY_ANALYSIS {
|
|
// Acquire all mutexes in a safe order.
|
|
gArenas.mLock.Lock();
|
|
gForkingThread = pthread_self();
|
|
# ifdef XP_DARWIN
|
|
gForkingProcess = getpid();
|
|
# endif
|
|
|
|
for (auto arena : gArenas.iter()) {
|
|
if (arena->mLock.LockIsEnabled()) {
|
|
arena->mLock.Lock();
|
|
}
|
|
}
|
|
|
|
gArenas.mPurgeListLock.Lock();
|
|
|
|
sBaseAlloc.mMutex.Lock();
|
|
|
|
huge_mtx.Lock();
|
|
}
|
|
|
|
FORK_HOOK
|
|
void _malloc_postfork_parent(void) MOZ_NO_THREAD_SAFETY_ANALYSIS {
|
|
// Release all mutexes, now that fork() has completed.
|
|
huge_mtx.Unlock();
|
|
|
|
sBaseAlloc.mMutex.Unlock();
|
|
|
|
gArenas.mPurgeListLock.Unlock();
|
|
|
|
for (auto arena : gArenas.iter()) {
|
|
if (arena->mLock.LockIsEnabled()) {
|
|
arena->mLock.Unlock();
|
|
}
|
|
}
|
|
|
|
gArenas.mLock.Unlock();
|
|
}
|
|
|
|
FORK_HOOK
|
|
void _malloc_postfork_child(void) {
|
|
// Do this before iterating over the arenas.
|
|
gArenas.ResetMainThread();
|
|
|
|
// Reinitialize all mutexes, now that fork() has completed.
|
|
huge_mtx.Init();
|
|
|
|
sBaseAlloc.mMutex.Init();
|
|
|
|
gArenas.mPurgeListLock.Init();
|
|
|
|
MOZ_PUSH_IGNORE_THREAD_SAFETY
|
|
for (auto arena : gArenas.iter()) {
|
|
arena->mLock.Reinit(gForkingThread);
|
|
}
|
|
MOZ_POP_THREAD_SAFETY
|
|
|
|
gArenas.mLock.Init();
|
|
}
|
|
|
|
# ifdef XP_DARWIN
|
|
FORK_HOOK
|
|
void _malloc_postfork(void) {
|
|
// On MacOS we need to check if this is running in the parent or child
|
|
// process.
|
|
bool is_in_parent = getpid() == gForkingProcess;
|
|
gForkingProcess = 0;
|
|
if (is_in_parent) {
|
|
_malloc_postfork_parent();
|
|
} else {
|
|
_malloc_postfork_child();
|
|
}
|
|
}
|
|
# endif // XP_DARWIN
|
|
#endif // ! XP_WIN
|
|
|
|
// End library-private functions.
|
|
// ***************************************************************************
|
|
#ifdef MOZ_REPLACE_MALLOC
|
|
// Windows doesn't come with weak imports as they are possible with
|
|
// LD_PRELOAD or DYLD_INSERT_LIBRARIES on Linux/OSX. On this platform,
|
|
// the replacement functions are defined as variable pointers to the
|
|
// function resolved with GetProcAddress() instead of weak definitions
|
|
// of functions. On Android, the same needs to happen as well, because
|
|
// the Android linker doesn't handle weak linking with non LD_PRELOADed
|
|
// libraries, but LD_PRELOADing is not very convenient on Android, with
|
|
// the zygote.
|
|
# ifdef XP_DARWIN
|
|
# define MOZ_REPLACE_WEAK __attribute__((weak_import))
|
|
# elif defined(XP_WIN) || defined(ANDROID)
|
|
# define MOZ_DYNAMIC_REPLACE_INIT
|
|
# define replace_init replace_init_decl
|
|
# elif defined(__GNUC__)
|
|
# define MOZ_REPLACE_WEAK __attribute__((weak))
|
|
# endif
|
|
|
|
# include "replace_malloc.h"
|
|
|
|
# define MALLOC_DECL(name, return_type, ...) CanonicalMalloc::name,
|
|
|
|
// The default malloc table, i.e. plain allocations. It never changes. It's
|
|
// used by init(), and not used after that.
|
|
static const malloc_table_t gDefaultMallocTable = {
|
|
# include "malloc_decls.h"
|
|
};
|
|
|
|
// The malloc table installed by init(). It never changes from that point
|
|
// onward. It will be the same as gDefaultMallocTable if no replace-malloc tool
|
|
// is enabled at startup.
|
|
static malloc_table_t gOriginalMallocTable = {
|
|
# include "malloc_decls.h"
|
|
};
|
|
|
|
// The malloc table installed by jemalloc_replace_dynamic(). (Read the
|
|
// comments above that function for more details.)
|
|
static malloc_table_t gDynamicMallocTable = {
|
|
# include "malloc_decls.h"
|
|
};
|
|
|
|
// This briefly points to gDefaultMallocTable at startup. After that, it points
|
|
// to either gOriginalMallocTable or gDynamicMallocTable. It's atomic to avoid
|
|
// races when switching between tables.
|
|
static Atomic<malloc_table_t const*, mozilla::MemoryOrdering::Relaxed>
|
|
gMallocTablePtr;
|
|
|
|
# ifdef MOZ_DYNAMIC_REPLACE_INIT
|
|
# undef replace_init
|
|
typedef decltype(replace_init_decl) replace_init_impl_t;
|
|
static replace_init_impl_t* replace_init = nullptr;
|
|
# endif
|
|
|
|
# ifdef XP_WIN
|
|
typedef HMODULE replace_malloc_handle_t;
|
|
|
|
static replace_malloc_handle_t replace_malloc_handle() {
|
|
wchar_t replace_malloc_lib[1024];
|
|
if (GetEnvironmentVariableW(L"MOZ_REPLACE_MALLOC_LIB", replace_malloc_lib,
|
|
std::size(replace_malloc_lib)) > 0) {
|
|
return LoadLibraryW(replace_malloc_lib);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
# define REPLACE_MALLOC_GET_INIT_FUNC(handle) \
|
|
(replace_init_impl_t*)GetProcAddress(handle, "replace_init")
|
|
|
|
# elif defined(ANDROID)
|
|
# include <dlfcn.h>
|
|
|
|
typedef void* replace_malloc_handle_t;
|
|
|
|
static replace_malloc_handle_t replace_malloc_handle() {
|
|
const char* replace_malloc_lib = getenv("MOZ_REPLACE_MALLOC_LIB");
|
|
if (replace_malloc_lib && *replace_malloc_lib) {
|
|
return dlopen(replace_malloc_lib, RTLD_LAZY);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
# define REPLACE_MALLOC_GET_INIT_FUNC(handle) \
|
|
(replace_init_impl_t*)dlsym(handle, "replace_init")
|
|
|
|
# endif
|
|
|
|
static void replace_malloc_init_funcs(malloc_table_t*);
|
|
|
|
# ifdef MOZ_REPLACE_MALLOC_STATIC
|
|
extern "C" void logalloc_init(malloc_table_t*, ReplaceMallocBridge**);
|
|
|
|
extern "C" void dmd_init(malloc_table_t*, ReplaceMallocBridge**);
|
|
# endif
|
|
|
|
void phc_init(malloc_table_t*, ReplaceMallocBridge**);
|
|
|
|
bool Equals(const malloc_table_t& aTable1, const malloc_table_t& aTable2) {
|
|
return memcmp(&aTable1, &aTable2, sizeof(malloc_table_t)) == 0;
|
|
}
|
|
|
|
// Below is the malloc implementation overriding jemalloc and calling the
|
|
// replacement functions if they exist.
|
|
static ReplaceMallocBridge* gReplaceMallocBridge = nullptr;
|
|
static void init() {
|
|
malloc_table_t tempTable = gDefaultMallocTable;
|
|
|
|
# ifdef MOZ_DYNAMIC_REPLACE_INIT
|
|
replace_malloc_handle_t handle = replace_malloc_handle();
|
|
if (handle) {
|
|
replace_init = REPLACE_MALLOC_GET_INIT_FUNC(handle);
|
|
}
|
|
# endif
|
|
|
|
// Set this *before* calling replace_init, otherwise if replace_init calls
|
|
// malloc() we'll get an infinite loop.
|
|
gMallocTablePtr = &gDefaultMallocTable;
|
|
|
|
// Pass in the default allocator table so replace functions can copy and use
|
|
// it for their allocations. The replace_init() function should modify the
|
|
// table if it wants to be active, otherwise leave it unmodified.
|
|
if (replace_init) {
|
|
replace_init(&tempTable, &gReplaceMallocBridge);
|
|
}
|
|
# ifdef MOZ_REPLACE_MALLOC_STATIC
|
|
if (Equals(tempTable, gDefaultMallocTable)) {
|
|
logalloc_init(&tempTable, &gReplaceMallocBridge);
|
|
}
|
|
# ifdef MOZ_DMD
|
|
if (Equals(tempTable, gDefaultMallocTable)) {
|
|
dmd_init(&tempTable, &gReplaceMallocBridge);
|
|
}
|
|
# endif
|
|
# endif
|
|
if (!Equals(tempTable, gDefaultMallocTable)) {
|
|
replace_malloc_init_funcs(&tempTable);
|
|
}
|
|
gOriginalMallocTable = tempTable;
|
|
gMallocTablePtr = &gOriginalMallocTable;
|
|
}
|
|
|
|
// WARNING WARNING WARNING: this function should be used with extreme care. It
|
|
// is not as general-purpose as it looks. It is currently used by
|
|
// tools/profiler/core/memory_hooks.cpp for counting allocations and probably
|
|
// should not be used for any other purpose.
|
|
//
|
|
// This function allows the original malloc table to be temporarily replaced by
|
|
// a different malloc table. Or, if the argument is nullptr, it switches back to
|
|
// the original malloc table.
|
|
//
|
|
// Limitations:
|
|
//
|
|
// - It is not threadsafe. If multiple threads pass it the same
|
|
// `replace_init_func` at the same time, there will be data races writing to
|
|
// the malloc_table_t within that function.
|
|
//
|
|
// - Only one replacement can be installed. No nesting is allowed.
|
|
//
|
|
// - The new malloc table must be able to free allocations made by the original
|
|
// malloc table, and upon removal the original malloc table must be able to
|
|
// free allocations made by the new malloc table. This means the new malloc
|
|
// table can only do simple things like recording extra information, while
|
|
// delegating actual allocation/free operations to the original malloc table.
|
|
//
|
|
MOZ_JEMALLOC_API void jemalloc_replace_dynamic(
|
|
jemalloc_init_func replace_init_func) {
|
|
if (replace_init_func) {
|
|
malloc_table_t tempTable = gOriginalMallocTable;
|
|
(*replace_init_func)(&tempTable, &gReplaceMallocBridge);
|
|
if (!Equals(tempTable, gOriginalMallocTable)) {
|
|
replace_malloc_init_funcs(&tempTable);
|
|
|
|
// Temporarily switch back to the original malloc table. In the
|
|
// (supported) non-nested case, this is a no-op. But just in case this is
|
|
// a (unsupported) nested call, it makes the overwriting of
|
|
// gDynamicMallocTable less racy, because ongoing calls to malloc() and
|
|
// friends won't go through gDynamicMallocTable.
|
|
gMallocTablePtr = &gOriginalMallocTable;
|
|
|
|
gDynamicMallocTable = tempTable;
|
|
gMallocTablePtr = &gDynamicMallocTable;
|
|
// We assume that dynamic replaces don't occur close enough for a
|
|
// thread to still have old copies of the table pointer when the 2nd
|
|
// replace occurs.
|
|
}
|
|
} else {
|
|
// Switch back to the original malloc table.
|
|
gMallocTablePtr = &gOriginalMallocTable;
|
|
}
|
|
}
|
|
|
|
# define MALLOC_DECL(name, return_type, ...) \
|
|
inline return_type ReplaceMalloc::name( \
|
|
ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) { \
|
|
if (MOZ_UNLIKELY(!gMallocTablePtr)) { \
|
|
init(); \
|
|
} \
|
|
return (*gMallocTablePtr).name(ARGS_HELPER(ARGS, ##__VA_ARGS__)); \
|
|
}
|
|
# include "malloc_decls.h"
|
|
|
|
MOZ_JEMALLOC_API struct ReplaceMallocBridge* get_bridge(void) {
|
|
if (MOZ_UNLIKELY(!gMallocTablePtr)) {
|
|
init();
|
|
}
|
|
return gReplaceMallocBridge;
|
|
}
|
|
|
|
// posix_memalign, aligned_alloc, memalign and valloc all implement some kind
|
|
// of aligned memory allocation. For convenience, a replace-malloc library can
|
|
// skip defining replace_posix_memalign, replace_aligned_alloc and
|
|
// replace_valloc, and default implementations will be automatically derived
|
|
// from replace_memalign.
|
|
static void replace_malloc_init_funcs(malloc_table_t* table) {
|
|
if (table->posix_memalign == CanonicalMalloc::posix_memalign &&
|
|
table->memalign != CanonicalMalloc::memalign) {
|
|
table->posix_memalign =
|
|
AlignedAllocator<ReplaceMalloc::memalign>::posix_memalign;
|
|
}
|
|
if (table->aligned_alloc == CanonicalMalloc::aligned_alloc &&
|
|
table->memalign != CanonicalMalloc::memalign) {
|
|
table->aligned_alloc =
|
|
AlignedAllocator<ReplaceMalloc::memalign>::aligned_alloc;
|
|
}
|
|
if (table->valloc == CanonicalMalloc::valloc &&
|
|
table->memalign != CanonicalMalloc::memalign) {
|
|
table->valloc = AlignedAllocator<ReplaceMalloc::memalign>::valloc;
|
|
}
|
|
if (table->moz_create_arena_with_params ==
|
|
CanonicalMalloc::moz_create_arena_with_params &&
|
|
table->malloc != CanonicalMalloc::malloc) {
|
|
# define MALLOC_DECL(name, ...) \
|
|
table->name = DummyArenaAllocator<ReplaceMalloc>::name;
|
|
# define MALLOC_FUNCS MALLOC_FUNCS_ARENA_BASE
|
|
# include "malloc_decls.h"
|
|
}
|
|
if (table->moz_arena_malloc == CanonicalMalloc::moz_arena_malloc &&
|
|
table->malloc != CanonicalMalloc::malloc) {
|
|
# define MALLOC_DECL(name, ...) \
|
|
table->name = DummyArenaAllocator<ReplaceMalloc>::name;
|
|
# define MALLOC_FUNCS MALLOC_FUNCS_ARENA_ALLOC
|
|
# include "malloc_decls.h"
|
|
}
|
|
}
|
|
|
|
#endif // MOZ_REPLACE_MALLOC
|
|
// ***************************************************************************
|
|
// Definition of all the _impl functions
|
|
// GENERIC_MALLOC_DECL2_MINGW is only used for the MinGW build, and aliases
|
|
// the malloc funcs (e.g. malloc) to the je_ versions. It does not generate
|
|
// aliases for the other functions (jemalloc and arena functions).
|
|
//
|
|
// We do need aliases for the other mozglue.def-redirected functions though,
|
|
// these are done at the bottom of mozmemory_wrap.cpp
|
|
#define GENERIC_MALLOC_DECL2_MINGW(name, name_impl, return_type, ...) \
|
|
return_type name(ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) \
|
|
__attribute__((alias(MOZ_STRINGIFY(name_impl))));
|
|
|
|
#define GENERIC_MALLOC_DECL2(attributes, name, name_impl, return_type, ...) \
|
|
return_type name_impl(ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) attributes { \
|
|
return DefaultMalloc::name(ARGS_HELPER(ARGS, ##__VA_ARGS__)); \
|
|
}
|
|
|
|
#ifndef __MINGW32__
|
|
# define GENERIC_MALLOC_DECL(attributes, name, return_type, ...) \
|
|
GENERIC_MALLOC_DECL2(attributes, name, name##_impl, return_type, \
|
|
##__VA_ARGS__)
|
|
#else
|
|
# define GENERIC_MALLOC_DECL(attributes, name, return_type, ...) \
|
|
GENERIC_MALLOC_DECL2(attributes, name, name##_impl, return_type, \
|
|
##__VA_ARGS__) \
|
|
GENERIC_MALLOC_DECL2_MINGW(name, name##_impl, return_type, ##__VA_ARGS__)
|
|
#endif
|
|
|
|
#define NOTHROW_MALLOC_DECL(...) \
|
|
MOZ_MEMORY_API MACRO_CALL(GENERIC_MALLOC_DECL, (noexcept(true), __VA_ARGS__))
|
|
#define MALLOC_DECL(...) \
|
|
MOZ_MEMORY_API MACRO_CALL(GENERIC_MALLOC_DECL, (, __VA_ARGS__))
|
|
#define MALLOC_FUNCS MALLOC_FUNCS_MALLOC
|
|
#include "malloc_decls.h"
|
|
|
|
#undef GENERIC_MALLOC_DECL
|
|
#define GENERIC_MALLOC_DECL(attributes, name, return_type, ...) \
|
|
GENERIC_MALLOC_DECL2(attributes, name, name, return_type, ##__VA_ARGS__)
|
|
|
|
#define MALLOC_DECL(...) \
|
|
MOZ_JEMALLOC_API MACRO_CALL(GENERIC_MALLOC_DECL, (, __VA_ARGS__))
|
|
#define MALLOC_FUNCS (MALLOC_FUNCS_JEMALLOC | MALLOC_FUNCS_ARENA)
|
|
#include "malloc_decls.h"
|
|
// ***************************************************************************
|
|
|
|
#ifdef HAVE_DLFCN_H
|
|
# include <dlfcn.h>
|
|
#endif
|
|
|
|
#if defined(__GLIBC__) && !defined(__UCLIBC__)
|
|
// glibc provides the RTLD_DEEPBIND flag for dlopen which can make it possible
|
|
// to inconsistently reference libc's malloc(3)-compatible functions
|
|
// (bug 493541).
|
|
//
|
|
// These definitions interpose hooks in glibc. The functions are actually
|
|
// passed an extra argument for the caller return address, which will be
|
|
// ignored.
|
|
|
|
extern "C" {
|
|
MOZ_EXPORT void (*__free_hook)(void*) = free_impl;
|
|
MOZ_EXPORT void* (*__malloc_hook)(size_t) = malloc_impl;
|
|
MOZ_EXPORT void* (*__realloc_hook)(void*, size_t) = realloc_impl;
|
|
MOZ_EXPORT void* (*__memalign_hook)(size_t, size_t) = memalign_impl;
|
|
}
|
|
|
|
#elif defined(RTLD_DEEPBIND)
|
|
// XXX On systems that support RTLD_GROUP or DF_1_GROUP, do their
|
|
// implementations permit similar inconsistencies? Should STV_SINGLETON
|
|
// visibility be used for interposition where available?
|
|
# error \
|
|
"Interposing malloc is unsafe on this system without libc malloc hooks."
|
|
#endif
|
|
|
|
#ifdef XP_WIN
|
|
MOZ_EXPORT void* _recalloc(void* aPtr, size_t aCount, size_t aSize) {
|
|
size_t oldsize = aPtr ? AllocInfo::Get(aPtr).Size() : 0;
|
|
CheckedInt<size_t> checkedSize = CheckedInt<size_t>(aCount) * aSize;
|
|
|
|
if (!checkedSize.isValid()) {
|
|
return nullptr;
|
|
}
|
|
|
|
size_t newsize = checkedSize.value();
|
|
|
|
// In order for all trailing bytes to be zeroed, the caller needs to
|
|
// use calloc(), followed by recalloc(). However, the current calloc()
|
|
// implementation only zeros the bytes requested, so if recalloc() is
|
|
// to work 100% correctly, calloc() will need to change to zero
|
|
// trailing bytes.
|
|
aPtr = DefaultMalloc::realloc(aPtr, newsize);
|
|
if (aPtr && oldsize < newsize) {
|
|
memset((void*)((uintptr_t)aPtr + oldsize), 0, newsize - oldsize);
|
|
}
|
|
|
|
return aPtr;
|
|
}
|
|
|
|
// This impl of _expand doesn't ever actually expand or shrink blocks: it
|
|
// simply replies that you may continue using a shrunk block.
|
|
MOZ_EXPORT void* _expand(void* aPtr, size_t newsize) {
|
|
if (AllocInfo::Get(aPtr).Size() >= newsize) {
|
|
return aPtr;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
MOZ_EXPORT size_t _msize(void* aPtr) {
|
|
return DefaultMalloc::malloc_usable_size(aPtr);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOZ_PHC
|
|
// Compile PHC and mozjemalloc together so that PHC can inline mozjemalloc.
|
|
# include "PHC.cpp"
|
|
#endif
|