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diff --git a/include/semaphore.h b/include/semaphore.h
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+/* Linuxthreads - a simple clone()-based implementation of Posix */
+/* threads for Linux. */
+/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
+/* */
+/* This program is free software; you can redistribute it and/or */
+/* modify it under the terms of the GNU Library General Public License */
+/* as published by the Free Software Foundation; either version 2 */
+/* of the License, or (at your option) any later version. */
+/* */
+/* This program is distributed in the hope that it will be useful, */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
+/* GNU Library General Public License for more details. */
+
+#ifndef _SEMAPHORE_H
+#define _SEMAPHORE_H 1
+
+#include <features.h>
+#include <sys/types.h>
+
+#ifndef _PTHREAD_DESCR_DEFINED
+/* Thread descriptors. Needed for `sem_t' definition. */
+typedef struct _pthread_descr_struct *_pthread_descr;
+# define _PTHREAD_DESCR_DEFINED
+#endif
+
+/* System specific semaphore definition. */
+typedef struct
+{
+ struct
+ {
+ long int status;
+ int spinlock;
+ } __sem_lock;
+ int __sem_value;
+ _pthread_descr __sem_waiting;
+} sem_t;
+
+
+
+/* Value returned if `sem_open' failed. */
+#define SEM_FAILED ((sem_t *) 0)
+
+/* Maximum value the semaphore can have. */
+#define SEM_VALUE_MAX ((int) ((~0u) >> 1))
+
+
+__BEGIN_DECLS
+
+/* Initialize semaphore object SEM to VALUE. If PSHARED then share it
+ with other processes. */
+extern int sem_init __P ((sem_t *__sem, int __pshared, unsigned int __value));
+
+/* Free resources associated with semaphore object SEM. */
+extern int sem_destroy __P ((sem_t *__sem));
+
+/* Open a named semaphore NAME with open flaot OFLAG. */
+extern sem_t *sem_open __P ((__const char *__name, int __oflag, ...));
+
+/* Close descriptor for named semaphore SEM. */
+extern int sem_close __P ((sem_t *__sem));
+
+/* Remove named semaphore NAME. */
+extern int sem_unlink __P ((__const char *__name));
+
+/* Wait for SEM being posted. */
+extern int sem_wait __P ((sem_t *__sem));
+
+/* Test whether SEM is posted. */
+extern int sem_trywait __P ((sem_t *__sem));
+
+/* Post SEM. */
+extern int sem_post __P ((sem_t *__sem));
+
+/* Get current value of SEM and store it in *SVAL. */
+extern int sem_getvalue __P ((sem_t *__sem, int *__sval));
+
+__END_DECLS
+
+#endif /* semaphore.h */