text: /*
   * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   * 
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   * 
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   * 
   * The Original Code and all software distributed under the License are
   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   * 
   * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
   */
  /*	$NetBSD: sem.h,v 1.5 1994/06/29 06:45:15 cgd Exp $	*/
  
  /*
   * SVID compatible sem.h file
   *
   * Author:  Daniel Boulet
   * John Bellardo modified the implementation for Darwin. 12/2000
   */
  
  #ifndef _SYS_SEM_H_
  #define _SYS_SEM_H_
  
  
  #include <sys/cdefs.h>
  #include <sys/_types.h>
  
  /*
   * [XSI]	All of the symbols from <sys/ipc.h> SHALL be defined
   *		when this header is included
   */
  #include <sys/ipc.h>
  
  
  /*
   * [XSI] The pid_t, time_t, key_t, and size_t types shall be defined as
   * described in <sys/types.h>.
   *
   * NOTE:	The definition of the key_t type is implicit from the
   *		inclusion of <sys/ipc.h>
   */
  #ifndef _PID_T
  typedef __darwin_pid_t	pid_t;
  #define _PID_T
  #endif
  
  #ifndef	_TIME_T
  #define	_TIME_T
  typedef	__darwin_time_t	time_t;
  #endif
  
  #ifndef _SIZE_T
  #define _SIZE_T
  typedef __darwin_size_t	size_t;
  #endif
  
  /*
   * Technically, we should force all code references to the new structure
   * definition, not in just the standards conformance case, and leave the
   * legacy interface there for binary compatibility only.  Currently, we
   * are only forcing this for programs requesting standards conformance.
   */
  #if __DARWIN_UNIX03 || defined(KERNEL)
  #pragma pack(4)
  /*
   * Structure used internally.
   * 
   * This structure is exposed because standards dictate that it is used as
   * the semun union member 'buf' as the fourth argment to semctl() when the
   * third argument is IPC_STAT or IPC_SET.
   *
   * Note: only the fields sem_perm, sem_nsems, sem_otime, and sem_ctime
   * are meaningful in user space.
   */
  #if (defined(_POSIX_C_SOURCE) && !defined(_DARWIN_C_SOURCE))
  struct semid_ds
  #else
  #define	semid_ds	__semid_ds_new
  struct __semid_ds_new
  #endif
  {
  	struct __ipc_perm_new sem_perm;	/* [XSI] operation permission struct */
  	__int32_t	sem_base;	/* 32 bit base ptr for semaphore set */
  	unsigned short	sem_nsems;	/* [XSI] number of sems in set */
  	time_t		sem_otime;	/* [XSI] last operation time */
  	__int32_t	sem_pad1;	/* RESERVED: DO NOT USE! */
  	time_t		sem_ctime;	/* [XSI] last change time */
      					/* Times measured in secs since */
      					/* 00:00:00 GMT, Jan. 1, 1970 */
  	__int32_t	sem_pad2;	/* RESERVED: DO NOT USE! */
  	__int32_t	sem_pad3[4];	/* RESERVED: DO NOT USE! */
  };
  #pragma pack()
  #else	/* !__DARWIN_UNIX03 */
  #define	semid_ds	__semid_ds_old
  #endif	/* __DARWIN_UNIX03 */
  
  #if !__DARWIN_UNIX03
  struct __semid_ds_old {
  	struct __ipc_perm_old sem_perm;	/* [XSI] operation permission struct */
  	__int32_t	sem_base;	/* 32 bit base ptr for semaphore set */
  	unsigned short	sem_nsems;	/* [XSI] number of sems in set */
  	time_t		sem_otime;	/* [XSI] last operation time */
  	__int32_t	sem_pad1;	/* RESERVED: DO NOT USE! */
  	time_t		sem_ctime;	/* [XSI] last change time */
      					/* Times measured in secs since */
      					/* 00:00:00 GMT, Jan. 1, 1970 */
  	__int32_t	sem_pad2;	/* RESERVED: DO NOT USE! */
  	__int32_t	sem_pad3[4];	/* RESERVED: DO NOT USE! */
  };
  #endif	/* !__DARWIN_UNIX03 */
  
  /*
   * Possible values for the third argument to semctl()
   */
  #define GETNCNT	3	/* [XSI] Return the value of semncnt {READ} */
  #define GETPID	4	/* [XSI] Return the value of sempid {READ} */
  #define GETVAL	5	/* [XSI] Return the value of semval {READ} */
  #define GETALL	6	/* [XSI] Return semvals into arg.array {READ} */
  #define GETZCNT	7	/* [XSI] Return the value of semzcnt {READ} */
  #define SETVAL	8	/* [XSI] Set the value of semval to arg.val {ALTER} */
  #define SETALL	9	/* [XSI] Set semvals from arg.array {ALTER} */
  
  
  /* A semaphore; this is an anonymous structure, not for external use */
  struct sem {
  	unsigned short	semval;		/* semaphore value */
  	pid_t		sempid;		/* pid of last operation */
  	unsigned short	semncnt;	/* # awaiting semval > cval */
  	unsigned short	semzcnt;	/* # awaiting semval == 0 */
  };
  
  
  /*
   * Structure of array element for second argument to semop()
   */
  struct sembuf {
  	unsigned short	sem_num;	/* [XSI] semaphore # */
  	short		sem_op;		/* [XSI] semaphore operation */
  	short		sem_flg;	/* [XSI] operation flags */
  };
  
  /*
   * Possible flag values for sem_flg
   */
  #define SEM_UNDO	010000		/* [XSI] Set up adjust on exit entry */
  
  
  #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
  
  /*
   * Union used as the fourth argment to semctl() in all cases.  Specific
   * member values are used for different values of the third parameter:
   * 
   * Command					Member
   * -------------------------------------------	------
   * GETALL, SETALL				array
   * SETVAL					val
   * IPC_STAT, IPC_SET				buf
   *
   * The union definition is intended to be defined by the user application
   * in conforming applications; it is provided here for two reasons:
   * 
   * 1)	Historical source compatability for non-conforming applications
   *	expecting this header to declare the union type on their behalf
   *
   * 2)	Documentation; specifically, 64 bit applications that do not pass
   *	this structure for 'val', or, alternately, a 64 bit type, will
   *	not function correctly
   */
  union semun {
  	int		val;		/* value for SETVAL */
  	struct semid_ds	*buf;		/* buffer for IPC_STAT & IPC_SET */
  	unsigned short	*array;		/* array for GETALL & SETALL */
  };
  typedef union semun semun_t;
  
  
  /*
   * Permissions
   */
  #define SEM_A		0200	/* alter permission */
  #define SEM_R		0400	/* read permission */
  
  #endif	/* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */
  
  
  
  #ifndef KERNEL
  
  __BEGIN_DECLS
  #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
  int	semsys(int, ...);
  #endif /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */
  int	semctl(int, int, int, ...) __DARWIN_ALIAS(semctl);
  int	semget(key_t, int, int);
  int	semop(int, struct sembuf *, size_t);
  __END_DECLS
  
  #endif /* !KERNEL */
  
  #endif /* !_SEM_H_ */
  