pthread_cond_broadcast

Wakes all threads that are waiting on a condition variable.

Syntax

pthread_cond_broadcast( cond );

Argument Data Type Access

cond opaque pthread_cond_t modify

C Binding

#include 


int
pthread_cond_broadcast (
         pthread_cond_t   *cond);

Arguments

cond: Condition variable upon which the threads (to be awakened) are waiting.

Description

This routine unblocks all threads waiting on the specified condition variable cond. Calling this routine implies that data guarded by the associated mutex has changed, so that it might be possible for one or more waiting threads to proceed. The threads that are unblocked shall contend for the mutex according to the scheduling policy (if applicable).

If only one of the threads waiting on a condition variable may be able to proceed, but any single thread can proceed, then use pthread_cond_signal instead.

Whether the associated mutex is locked or unlocked, you can still call this routine. However, if predictable scheduling behavior is required, then that mutex should then be locked by the thread calling the pthread_cond_broadcast routine.

If no threads are waiting on the specified condition variable, then this routine takes no action. The broadcast does not propagate to the next condition variable wait.

Return Values

If an error condition occurs, this routine returns an integer value indicating the type of error. Possible return values are as follows:

Return Description

0 Successful completion. [EINVAL] The value specified by cond is invalid.

Associated Routines

   pthread_cond_destroy
   pthread_cond_init
   pthread_cond_signal
   pthread_cond_timedwait
   pthread_cond_wait