sem.h (7291B) - Raw
1 /* 2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 /* $NetBSD: sem.h,v 1.5 1994/06/29 06:45:15 cgd Exp $ */ 29 30 /* 31 * SVID compatible sem.h file 32 * 33 * Author: Daniel Boulet 34 * John Bellardo modified the implementation for Darwin. 12/2000 35 */ 36 37 #ifndef _SYS_SEM_H_ 38 #define _SYS_SEM_H_ 39 40 41 #include <sys/cdefs.h> 42 #include <sys/_types.h> 43 #include <machine/types.h> /* __int32_t */ 44 45 /* 46 * [XSI] All of the symbols from <sys/ipc.h> SHALL be defined 47 * when this header is included 48 */ 49 #include <sys/ipc.h> 50 51 52 /* 53 * [XSI] The pid_t, time_t, key_t, and size_t types shall be defined as 54 * described in <sys/types.h>. 55 * 56 * NOTE: The definition of the key_t type is implicit from the 57 * inclusion of <sys/ipc.h> 58 */ 59 #include <sys/_types/_pid_t.h> 60 #include <sys/_types/_time_t.h> 61 #include <sys/_types/_size_t.h> 62 63 /* 64 * Technically, we should force all code references to the new structure 65 * definition, not in just the standards conformance case, and leave the 66 * legacy interface there for binary compatibility only. Currently, we 67 * are only forcing this for programs requesting standards conformance. 68 */ 69 #if __DARWIN_UNIX03 || defined(KERNEL) 70 #pragma pack(4) 71 /* 72 * Structure used internally. 73 * 74 * This structure is exposed because standards dictate that it is used as 75 * the semun union member 'buf' as the fourth argment to semctl() when the 76 * third argument is IPC_STAT or IPC_SET. 77 * 78 * Note: only the fields sem_perm, sem_nsems, sem_otime, and sem_ctime 79 * are meaningful in user space. 80 */ 81 #if (defined(_POSIX_C_SOURCE) && !defined(_DARWIN_C_SOURCE)) 82 struct semid_ds 83 #else 84 #define semid_ds __semid_ds_new 85 struct __semid_ds_new 86 #endif 87 { 88 struct __ipc_perm_new sem_perm; /* [XSI] operation permission struct */ 89 __int32_t sem_base; /* 32 bit base ptr for semaphore set */ 90 unsigned short sem_nsems; /* [XSI] number of sems in set */ 91 time_t sem_otime; /* [XSI] last operation time */ 92 __int32_t sem_pad1; /* RESERVED: DO NOT USE! */ 93 time_t sem_ctime; /* [XSI] last change time */ 94 /* Times measured in secs since */ 95 /* 00:00:00 GMT, Jan. 1, 1970 */ 96 __int32_t sem_pad2; /* RESERVED: DO NOT USE! */ 97 __int32_t sem_pad3[4]; /* RESERVED: DO NOT USE! */ 98 }; 99 #pragma pack() 100 #else /* !__DARWIN_UNIX03 */ 101 #define semid_ds __semid_ds_old 102 #endif /* __DARWIN_UNIX03 */ 103 104 #if !__DARWIN_UNIX03 105 struct __semid_ds_old { 106 struct __ipc_perm_old sem_perm; /* [XSI] operation permission struct */ 107 __int32_t sem_base; /* 32 bit base ptr for semaphore set */ 108 unsigned short sem_nsems; /* [XSI] number of sems in set */ 109 time_t sem_otime; /* [XSI] last operation time */ 110 __int32_t sem_pad1; /* RESERVED: DO NOT USE! */ 111 time_t sem_ctime; /* [XSI] last change time */ 112 /* Times measured in secs since */ 113 /* 00:00:00 GMT, Jan. 1, 1970 */ 114 __int32_t sem_pad2; /* RESERVED: DO NOT USE! */ 115 __int32_t sem_pad3[4]; /* RESERVED: DO NOT USE! */ 116 }; 117 #endif /* !__DARWIN_UNIX03 */ 118 119 /* 120 * Possible values for the third argument to semctl() 121 */ 122 #define GETNCNT 3 /* [XSI] Return the value of semncnt {READ} */ 123 #define GETPID 4 /* [XSI] Return the value of sempid {READ} */ 124 #define GETVAL 5 /* [XSI] Return the value of semval {READ} */ 125 #define GETALL 6 /* [XSI] Return semvals into arg.array {READ} */ 126 #define GETZCNT 7 /* [XSI] Return the value of semzcnt {READ} */ 127 #define SETVAL 8 /* [XSI] Set the value of semval to arg.val {ALTER} */ 128 #define SETALL 9 /* [XSI] Set semvals from arg.array {ALTER} */ 129 130 131 /* A semaphore; this is an anonymous structure, not for external use */ 132 struct sem { 133 unsigned short semval; /* semaphore value */ 134 pid_t sempid; /* pid of last operation */ 135 unsigned short semncnt; /* # awaiting semval > cval */ 136 unsigned short semzcnt; /* # awaiting semval == 0 */ 137 }; 138 139 140 /* 141 * Structure of array element for second argument to semop() 142 */ 143 struct sembuf { 144 unsigned short sem_num; /* [XSI] semaphore # */ 145 short sem_op; /* [XSI] semaphore operation */ 146 short sem_flg; /* [XSI] operation flags */ 147 }; 148 149 /* 150 * Possible flag values for sem_flg 151 */ 152 #define SEM_UNDO 010000 /* [XSI] Set up adjust on exit entry */ 153 154 155 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE) 156 157 /* 158 * Union used as the fourth argment to semctl() in all cases. Specific 159 * member values are used for different values of the third parameter: 160 * 161 * Command Member 162 * ------------------------------------------- ------ 163 * GETALL, SETALL array 164 * SETVAL val 165 * IPC_STAT, IPC_SET buf 166 * 167 * The union definition is intended to be defined by the user application 168 * in conforming applications; it is provided here for two reasons: 169 * 170 * 1) Historical source compatability for non-conforming applications 171 * expecting this header to declare the union type on their behalf 172 * 173 * 2) Documentation; specifically, 64 bit applications that do not pass 174 * this structure for 'val', or, alternately, a 64 bit type, will 175 * not function correctly 176 */ 177 union semun { 178 int val; /* value for SETVAL */ 179 struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */ 180 unsigned short *array; /* array for GETALL & SETALL */ 181 }; 182 typedef union semun semun_t; 183 184 185 /* 186 * Permissions 187 */ 188 #define SEM_A 0200 /* alter permission */ 189 #define SEM_R 0400 /* read permission */ 190 191 #endif /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */ 192 193 194 195 196 __BEGIN_DECLS 197 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE) 198 int semsys(int, ...); 199 #endif /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */ 200 int semctl(int, int, int, ...) __DARWIN_ALIAS(semctl); 201 int semget(key_t, int, int); 202 int semop(int, struct sembuf *, size_t); 203 __END_DECLS 204 205 206 #endif /* !_SEM_H_ */