NAME

pthread_cond_wait — wait on a condition variable

LIBRARY

POSIX Threads Library (libpthread, -lpthread)

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 blocks the current thread waiting on the condition variable specified by cond, and releases the mutex specified by mutex. The waiting thread unblocks only after another thread calls pthread_cond_signal(3), or pthread_cond_broadcast(3) with the same condition variable, and the current thread reacquires the lock on 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

The pthread_cond_wait() function will fail if:

[EINVAL]

The value specified by cond or the value specified by mutex is invalid.

[EPERM]

The specified mutex was not locked by the calling thread.

[EOWNERDEAD]

The argument mutex points to a robust mutex and the process containing the previous owning thread terminated while holding the mutex lock. The lock was granted to the caller and it is up to the new owner to make the state consistent.

[ENOTRECOVERABLE]

The state protected by the mutex is not recoverable.

SEE ALSO

pthread_cond_broadcast(3), pthread_cond_destroy(3), pthread_cond_init(3), pthread_cond_signal(3), pthread_cond_timedwait(3), pthread_mutex_consistent(3)

STANDARDS

The pthread_cond_wait() function conforms to ISO/IEC 9945-1:1996 (“POSIX.1”).