tools/nc_threads/nc_condvar.c

   1 /*
   2  * Copyright 2008, Google Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  *     * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *     * Redistributions in binary form must reproduce the above
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *     * Neither the name of Google Inc. nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32
  33 /*
  34  * Native Client condition variable API
  35  */
  36
  37 #include <unistd.h>
  38 #include "pthread.h"
  39 #include "pthread_types.h"
  40
  41 void pthread_cond_validate(pthread_cond_t* cond) {
  42   nc_spinlock_lock(&cond->spinlock);
  43
  44   if (NC_INVALID_HANDLE == cond->handle) {
  45     pthread_cond_init(cond, NULL);
  46   }
  47
  48   nc_spinlock_unlock(&cond->spinlock);
  49 }
  50
  51
  52 /* Initialize condition variable COND using attributes ATTR, or use
  53 the default values if later is NULL.  */
  54 int pthread_cond_init (pthread_cond_t *cond,
  55                        pthread_condattr_t *cond_attr) {
  56   cond->handle = __nacl_create_condvar();
  57
  58   /* 0 for success, 1 for failure */
  59   return (cond->handle < 0);
  60 }
  61
  62 /* Destroy condition variable COND.  */
  63 int pthread_cond_destroy (pthread_cond_t *cond) {
  64   pthread_cond_validate(cond);
  65   int retval = close(cond->handle);
  66   cond->handle = NC_INVALID_HANDLE;
  67   return retval;
  68 }
  69
  70 /* Wake up one thread waiting for condition variable COND.  */
  71 int pthread_cond_signal (pthread_cond_t *cond) {
  72   pthread_cond_validate(cond);
  73   return __nacl_signal_condvar(cond->handle);
  74 }
  75
  76
  77 int pthread_cond_broadcast (pthread_cond_t *cond) {
  78   pthread_cond_validate(cond);
  79   return __nacl_broadcast_condvar(cond->handle);
  80 }
  81
  82 int pthread_cond_wait (pthread_cond_t *cond,
  83                        pthread_mutex_t *mutex) {
  84   pthread_cond_validate(cond);
  85   return __nacl_wait_condvar(cond->handle, mutex->mutex_handle);
  86 }
  87
  88 int pthread_cond_timedwait_abs(pthread_cond_t *cond,
  89                                pthread_mutex_t *mutex,
  90                                struct timespec *abstime) {
  91   pthread_cond_validate(cond);
  92   return __nacl_absolute_timed_wait_condvar(cond->handle,
  93                                             mutex->mutex_handle,
  94                                             abstime);
  95
  96 }
  97
  98 int nc_pthread_condvar_ctor(pthread_cond_t * cond)
  99 {
 100   cond->handle = NC_INVALID_HANDLE;
 101   cond->spinlock = 0;
 102   return 1;
 103 }