pthread_cond_wait(3-thr) — Reliant UNIX 5.44c4

pthread_cond_wait(3-thr)                           pthread_cond_wait(3-thr)

NAME
     pthreadcondwait - causes a thread to wait for a condition variable
     to be signaled or broadcast

SYNOPSIS
     #include <pthread.h>

     int pthreadcondwait(
          pthreadcondt *cond,
          pthreadmutext *mutex);

PARAMETERS
     cond      Condition variable waited on.

     mutex     Mutex associated with the condition variable specified in
               cond.

DESCRIPTION
     The pthreadcondwait() routine causes a thread to wait for a condi-
     tion variable to be signaled or broadcast. Each condition corresponds
     to one or more predicates based on shared data. The calling thread
     waits for the data to reach a particular state (for the predicate to
     become true).

     Call this routine after you have locked the mutex specified in mutex.
     The results of this routine are unpredictable if this routine is
     called without first locking the mutex.

     This routine automatically releases the mutex and causes the calling
     thread to wait on the condition. If the wait is satisfied as a result
     of some thread calling pthreadcondsignal() or
     pthreadcondbroadcast(), the mutex is reacquired and the routine
     returns.

     A thread that changes the state of storage protected by the mutex in
     such a way that a predicate associated with a condition variable might
     now be true must call either pthreadcondsignal() or
     pthreadcondbroadcast() for that condition variable. If neither call
     is made, any thread waiting on the condition variable continues to
     wait.

     This routine might (with low probability) return when the condition
     variable has not been signaled or broadcast. When a spurious wakeup
     occurs, the mutex is reacquired before the routine returns. (To handle
     this type of situation, enclose this routine in a loop that checks the
     predicate.)









Page 1                       Reliant UNIX 5.44                Printed 11/98

pthread_cond_wait(3-thr)                           pthread_cond_wait(3-thr)

RETURN VALUES
     If the function fails, errno may be set to one of the following
     values:

     EINVAL    The value specified by cond or mutex is invalid.

     EDEADLK   A deadlock condition is detected.

SEE ALSO
     pthreadcondbroadcast(3-thr), pthreadconddestroy(3-thr),
     pthreadcondinit(3-thr), pthreadcondsignal(3-thr),
     pthreadcondtimedwait(3-thr).










































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