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