tools/nc_threads/nc_semaphore.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 semaphore API
  35 */
  36
  37 #include <unistd.h>
  38 #include <errno.h>
  39 #include "pthread.h"
  40 #include "pthread_types.h"
  41 #include "semaphore.h"
  42
  43 /* Initialize semaphore  */
  44 int sem_init (sem_t *sem, int pshared, unsigned int value)
  45 {
  46   if (pshared) {
  47     /* we don's support shared semaphores yet */
  48     errno = EINVAL;
  49     return -1;
  50   }
  51   sem->handle = __nacl_create_sem(value);
  52   return (sem->handle < 0);
  53 }
  54
  55 int sem_destroy (sem_t *sem) {
  56   int retval = close(sem->handle);
  57   sem->handle = NC_INVALID_HANDLE;
  58   return retval;
  59 }
  60
  61 int sem_wait (sem_t *sem) {
  62   return __nacl_wait_sem(sem->handle);
  63 }
  64
  65 int sem_post (sem_t *sem) {
  66   int32_t rv = __nacl_post_sem(sem->handle);
  67   if (0 != rv) {
  68     errno = rv;
  69     return -1;
  70   }
  71   return rv;
  72 }