cnd_wait

 

C

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Concurrency support (C11)

Technical Specifications

Symbol index

 

Concurrency support library

Threads thrd_create thrd_equal thrd_current    thrd_sleep thrd_yield thrd_exit thrd_detach thrd_join thrd_successthrd_timedoutthrd_busythrd_nomemthrd_error    Atomic operations atomic_init ATOMIC_VAR_INIT (until C23) ATOMIC_***_LOCK_FREE atomic_is_lock_free atomic_store atomic_load atomic_exchange atomic_compare_exchange atomic_fetch_add atomic_fetch_sub atomic_fetch_or atomic_fetch_xor atomic_fetch_and

Atomic flags atomic_flag ATOMIC_FLAG_INIT atomic_flag_test_and_set atomic_flag_clear Memory ordering memory_order kill_dependency atomic_thread_fence atomic_signal_fence Mutual exclusion mtx_init mtx_lock mtx_timedlock mtx_trylock call_once mtx_unlock mtx_destroy mtx_plainmtx_recursivemtx_timed Condition variables cnd_init cnd_signal cnd_broadcast cnd_wait cnd_timedwait cnd_destroy Thread-local storage thread_local TSS_DTOR_ITERATIONS    tss_create tss_get tss_set tss_delete

 

Defined in header <threads.h>
int cnd_wait( cnd_t* cond, mtx_t* mutex );		(since C11)

Atomically unlocks the mutex pointed to by mutex and blocks on the condition variable pointed to by cond until the thread is signalled by cnd_signal or cnd_broadcast, or until a spurious wake-up occurs. The mutex is locked again before the function returns.

The behavior is undefined if the mutex is not already locked by the calling thread.

Parameters

cond	-	pointer to the condition variable to block on
mutex	-	pointer to the mutex to unlock for the duration of the block

Return value

thrd_success if successful, thrd_error otherwise.

References

• C17 standard (ISO/IEC 9899:2018):

• 7.26.3.6 The cnd_wait function (p: 277)

• C11 standard (ISO/IEC 9899:2011):

• 7.26.3.6 The cnd_wait function (p: 380)

See also

cnd_timedwait (C11)

blocks on a condition variable, with a timeout (function)