linuxthreads/semaphore.h

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program is distributed in the hope that it will be useful,      */
  11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
  12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 #ifndef _SEMAPHORE_H
  16 #define _SEMAPHORE_H    1
  17
  18 #include <features.h>
  19 #include <sys/types.h>
  20
  21 #include <limits.h>
  22
  23 #define SEM_VALUE_MAX INT_MAX
  24
  25 typedef struct {
  26   struct { long status; int spinlock; } sem_lock;
  27   int sem_value;
  28   _pthread_descr sem_waiting;
  29 } sem_t;
  30
  31 __BEGIN_DECLS
  32
  33 extern int sem_init __P((sem_t *__sem, int __pshared, unsigned int __value));
  34 extern int sem_destroy __P((sem_t *__sem));
  35 extern int sem_wait __P((sem_t *__sem));
  36 extern int sem_trywait __P((sem_t *__sem));
  37 extern int sem_post __P((sem_t *__sem));
  38 extern int sem_getvalue __P((sem_t *__sem, int *__sval));
  39
  40 __END_DECLS
  41
  42 #endif  /* semaphore.h */