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glibc  2.9
Functions
pthread_cond_broadcast.c File Reference
#include <endian.h>
#include <errno.h>
#include <sysdep.h>
#include <lowlevellock.h>
#include <pthread.h>
#include <pthreadP.h>
#include <shlib-compat.h>
#include <kernel-features.h>

Go to the source code of this file.

Functions

int __pthread_cond_broadcast (pthread_cond_t *cond)
 versioned_symbol (libpthread, __pthread_cond_broadcast, pthread_cond_broadcast, GLIBC_2_3_2)

Function Documentation

Definition at line 32 of file pthread_cond_broadcast.c.

{
  int pshared = (cond->__data.__mutex == (void *) ~0l)
              ? LLL_SHARED : LLL_PRIVATE;
  /* Make sure we are alone.  */
  lll_lock (cond->__data.__lock, pshared);

  /* Are there any waiters to be woken?  */
  if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
    {
      /* Yes.  Mark them all as woken.  */
      cond->__data.__wakeup_seq = cond->__data.__total_seq;
      cond->__data.__woken_seq = cond->__data.__total_seq;
      cond->__data.__futex = (unsigned int) cond->__data.__total_seq * 2;
      int futex_val = cond->__data.__futex;
      /* Signal that a broadcast happened.  */
      ++cond->__data.__broadcast_seq;

      /* We are done.  */
      lll_unlock (cond->__data.__lock, pshared);

      /* Do not use requeue for pshared condvars.  */
      if (cond->__data.__mutex == (void *) ~0l)
       goto wake_all;

      /* Wake everybody.  */
      pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex;

      /* XXX: Kernel so far doesn't support requeue to PI futex.  */
      /* XXX: Kernel so far can only requeue to the same type of futex,
        in this case private (we don't requeue for pshared condvars).  */
      if (__builtin_expect (mut->__data.__kind
                         & (PTHREAD_MUTEX_PRIO_INHERIT_NP
                            | PTHREAD_MUTEX_PSHARED_BIT), 0))
       goto wake_all;

      /* lll_futex_requeue returns 0 for success and non-zero
        for errors.  */
      if (__builtin_expect (lll_futex_requeue (&cond->__data.__futex, 1,
                                          INT_MAX, &mut->__data.__lock,
                                          futex_val, LLL_PRIVATE), 0))
       {
         /* The requeue functionality is not available.  */
       wake_all:
         lll_futex_wake (&cond->__data.__futex, INT_MAX, pshared);
       }

      /* That's all.  */
      return 0;
    }

  /* We are done.  */
  lll_unlock (cond->__data.__lock, pshared);

  return 0;
}

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versioned_symbol ( libpthread  ,
__pthread_cond_broadcast  ,
pthread_cond_broadcast  ,
GLIBC_2_3_2   
)