Back to index

glibc  2.9
Functions
pthread_condattr_setclock.c File Reference
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <time.h>
#include <sysdep.h>
#include "pthreadP.h"
#include <kernel-features.h>

Go to the source code of this file.

Functions

int pthread_condattr_setclock (pthread_condattr_t *attr, clockid_t clock_id)

Function Documentation

int pthread_condattr_setclock ( pthread_condattr_t attr,
clockid_t  clock_id 
)

Definition at line 30 of file pthread_condattr_setclock.c.

{
  /* Only a few clocks are allowed.  CLOCK_REALTIME is always allowed.
     CLOCK_MONOTONIC only if the kernel has the necessary support.  */
  if (clock_id == CLOCK_MONOTONIC)
    {
#ifndef __ASSUME_POSIX_TIMERS
# ifdef __NR_clock_getres
      /* Check whether the clock is available.  */
      static int avail;

      if (avail == 0)
       {
         struct timespec ts;

         INTERNAL_SYSCALL_DECL (err);
         int val;
         val = INTERNAL_SYSCALL (clock_getres, err, 2, CLOCK_MONOTONIC, &ts);
         avail = INTERNAL_SYSCALL_ERROR_P (val, err) ? -1 : 1;
       }

      if (avail < 0)
# endif
       /* Not available.  */
       return EINVAL;
#endif
    }
  else if (clock_id != CLOCK_REALTIME)
    /* If more clocks are allowed some day the storing of the clock ID
       in the pthread_cond_t structure needs to be adjusted.  */
    return EINVAL;

  /* Make sure the value fits in the bits we reserved.  */
  assert (clock_id < (1 << COND_NWAITERS_SHIFT));

  int *valuep = &((struct pthread_condattr *) attr)->value;

  *valuep = ((*valuep & ~(((1 << COND_NWAITERS_SHIFT) - 1) << 1))
            | (clock_id << 1));

  return 0;
}

Here is the call graph for this function:

Here is the caller graph for this function: