42 lines
1.1 KiB
Markdown
42 lines
1.1 KiB
Markdown
# PR_NotifyCondVar
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Notifies a condition variable of a change in its associated monitored
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data.
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## Syntax
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```{code}
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#include <prcvar.h>
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PRStatus PR_NotifyCondVar(PRCondVar *cvar);
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```
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### Parameter
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{ref}`PR_NotifyCondVar` has one parameter:
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`cvar`
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: The condition variable to notify.
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### Returns
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The function returns one of the following values:
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- If successful, `PR_SUCCESS`.
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- If unsuccessful (for example, if the caller has not locked the lock
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associated with the condition variable), `PR_FAILURE`.
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## Description
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The calling thread must hold the lock that protects the condition, as
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well as the invariants that are tightly bound to the condition.
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Notification of a condition variable signals a change of state in some
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monitored data. When the notification occurs, the runtime promotes a
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thread that is waiting on the condition variable to a ready state. If
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more than one thread is waiting, the selection of which thread gets
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promoted cannot be predicted. This implies that all threads waiting on a
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single condition variable must have the same semantics. If no thread is
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waiting on the condition variable, the notify operation is a no-op.
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