Locking a Mutex Within a Specified Time Interval

Use the pthread_mutex_reltimedlock_np(3C) function to attempt until a specified amount of time elapses to lock a mutex object.

The timeout expires when the time interval specified by rel_timeout passes, as measured by the CLOCK_REALTIME clock, or if the time interval specified by rel_timeout is negative at the time of the call.

pthread_mutex_reltimedlock_np() Syntax

int  pthread_mutex_reltimedlock_np(pthread_mutex_t *restrict mutex, 
          const struct timespec *restrict rel_timeout);

#include <pthread.h>
#include <time.h>

pthread_mutex_t mutex;
timestruct_t rel_timeout;
int ret;

ret = pthread_mutex_reltimedlock_np(&mutex,  &rel_timeout); 

pthread_mutex_reltimedlock_np() Return Values

The pthread_mutex_reltimedlock_np() function returns 0 if it locks the mutex successfully. Otherwise, an error number is returned to indicate the error.

EINVAL

Description:

The mutex was created with the protocol attribute having the value PTHREAD_PRIO_PROTECT and the calling thread's priority is higher than the mutex's current priority ceiling.

Description:

The value specified by mutex does not refer to an initialized mutex object.

Description:

The process or thread would have blocked, and the abs_timeout parameter specified a nanoseconds field value less than 0 or greater than or equal to 1000 million.

ETIMEDOUT

Description:

The mutex could not be locked before the specified timeout expired.

See the discussion in pthread_mutex_lock Return Values.