pthread_cond_timedwait

Causes a thread to wait for a condition variable to be signaled or broadcasted for a specified period of time.

Syntax

pthread_cond_timedwait(
                       cond,
                       mutex,
                       abstime );
 



Argument         Data Type               Access

cond             opaque pthread_cond_t   read

mutex            opaque pthread_mutex_t  read

abstime          structure timespec      read

C Binding

int
pthread_cond_timedwait (
pthread_cond_t *cond,
pthread_mutex_t *mutex,
struct timespec *abstime);

Arguments

cond

Condition variable waited on.

mutex

Mutex associated with the condition variable specified in cond.

abstime

Absolute time at which the wait expires, if the condition has not been signaled or broadcasted. (See the pthread_get_expiration_np routine, which is used to obtain a value for this argument.)

Description

• The specified condition variable is signaled or broadcasted.

• The current system clock time is greater than or equal to the time specified by the abstime argument.

This routine is identical to pthread_cond_wait except that this routine can return before a condition variable is signaled or broadcasted; specifically, when a specified time expires.

If the current time equals or exceeds the expiration time, this routine returns immediately, without causing the current thread to wait. Your code should check the return status whenever this routine returns and take the appropriate action. Otherwise, waiting on the condition variable can become a nonblocking loop.

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

Return Values

Return  Error         Description

0                     Successful completion.

-1      [EINVAL]      The value specified by cond,
                      mutex, or abstime is
                      invalid.

                      Different mutexes are supplied for concurrent
                      pthread_cond_timedwait operations or pthread_
                      cond_wait operations on the same condition
                      variable.

-1      [EAGAIN]      The time specified by abstime
                      expired.

-1      [EDEADLK]     A deadlock condition is detected.