--- /dev/null
+/* Copyright (C) 1995-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _SYS_SEM_H
+#define _SYS_SEM_H 1
+
+#include <features.h>
+
+#define __need_size_t
+#include <stddef.h>
+
+/* Get common definition of System V style IPC. */
+#include <sys/ipc.h>
+
+/* Get system dependent definition of `struct semid_ds' and more. */
+#include <bits/sem.h>
+
+#ifdef __USE_GNU
+# include <bits/types/struct_timespec.h>
+#endif
+
+/* The following System V style IPC functions implement a semaphore
+ handling. The definition is found in XPG2. */
+
+/* Structure used for argument to `semop' to describe operations. */
+struct sembuf
+{
+ unsigned short int sem_num; /* semaphore number */
+ short int sem_op; /* semaphore operation */
+ short int sem_flg; /* operation flag */
+};
+
+
+__BEGIN_DECLS
+
+/* Semaphore control operation. */
+extern int semctl (int __semid, int __semnum, int __cmd, ...) __THROW;
+
+/* Get semaphore. */
+extern int semget (key_t __key, int __nsems, int __semflg) __THROW;
+
+/* Operate on semaphore. */
+extern int semop (int __semid, struct sembuf *__sops, size_t __nsops) __THROW;
+
+#ifdef __USE_GNU
+/* Operate on semaphore with timeout. */
+extern int semtimedop (int __semid, struct sembuf *__sops, size_t __nsops,
+ const struct timespec *__timeout) __THROW;
+#endif
+
+__END_DECLS
+
+#endif /* sys/sem.h */