bsd/sys/sem.h

   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 #ifndef KERNEL
 196
 197 __BEGIN_DECLS
 198 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
 199 int     semsys(int, ...);
 200 #endif /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */
 201 int     semctl(int, int, int, ...) __DARWIN_ALIAS(semctl);
 202 int     semget(key_t, int, int);
 203 int     semop(int, struct sembuf *, size_t);
 204 __END_DECLS
 205
 206 #endif /* !KERNEL */
 207
 208 #endif /* !_SEM_H_ */