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pthread_cond_wait(3) [osx man page]

PTHREAD_COND_WAIT(3)					   BSD Library Functions Manual 				      PTHREAD_COND_WAIT(3)

pthread_cond_wait -- wait on a condition variable SYNOPSIS
#include <pthread.h> int pthread_cond_wait(pthread_cond_t *restrict cond, pthread_mutex_t *restrict mutex); DESCRIPTION
The pthread_cond_wait() function atomically unlocks the mutex and blocks the current thread on the condition specified by the cond argument. The current thread unblocks only after another thread calls pthread_cond_signal(3) or pthread_cond_broadcast(3) with the same condition vari- able. The mutex must be locked before calling this function, otherwise the behavior is undefined. Before pthread_cond_wait() returns to the calling function, it re-acquires the mutex. RETURN VALUES
If successful, the pthread_cond_wait() function will return zero; otherwise, an error number will be returned to indicate the error. ERRORS
pthread_cond_wait() will fail if: [EINVAL] The value specified by cond or the value specified by mutex is invalid. SEE ALSO
pthread_cond_broadcast(3), pthread_cond_destroy(3), pthread_cond_init(3), pthread_cond_signal(3), pthread_cond_timedwait(3) STANDARDS
pthread_cond_wait() conforms to ISO/IEC 9945-1:1996 (``POSIX.1''). Darwin November 5, 2001 Darwin

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pthread_cond_signal(3C) 												   pthread_cond_signal(3C)

pthread_cond_signal, pthread_cond_broadcast - signal or broadcast a condition SYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ] #include <pthread.h> int pthread_cond_signal(pthread_cond_t *cond); int pthread_cond_broadcast(pthread_cond_t *cond); These two functions are used to unblock threads blocked on a condition variable. The pthread_cond_signal() call unblocks at least one of the threads that are blocked on the specified condition variable cond (if any threads are blocked on cond). The pthread_cond_broadcast() call unblocks all threads currently blocked on the specified condition variable cond. If more than one thread is blocked on a condition variable, the scheduling policy determines the order in which threads are unblocked. When each thread unblocked as a result of a pthread_cond_signal() or pthread_cond_broadcast() returns from its call to pthread_cond_wait() or pthread_cond_timedwait(), the thread owns the mutex with which it called pthread_cond_wait() or pthread_cond_timedwait(). The thread(s) that are unblocked contend for the mutex according to the scheduling policy (if applicable), and as if each had called pthread_mutex_lock(). The pthread_cond_signal() or pthread_cond_broadcast() functions may be called by a thread whether or not it currently owns the mutex that threads calling pthread_cond_wait() or pthread_cond_timedwait() have associated with the condition variable during their waits; however, if predictable scheduling behavior is required, then that mutex is locked by the thread calling pthread_cond_signal() or pthread_cond_broad- cast(). The pthread_cond_signal() and pthread_cond_broadcast() functions have no effect if there are no threads currently blocked on cond. If successful, the pthread_cond_signal() and pthread_cond_broadcast() functions return 0. Otherwise, an error number is returned to indi- cate the error. The pthread_cond_signal() and pthread_cond_broadcast() function may fail if: EINVAL The value cond does not refer to an initialized condition variable. See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ pthread_cond_init(3C), pthread_cond_wait(3C), pthread_cond_timedwait(3C), attributes(5), condition(5), standards(5) 23 Mar 2005 pthread_cond_signal(3C)
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