bsd/sys/sem.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: sem.h,v 1.5 1994/06/29 06:45:15 cgd Exp $      */
  23
  24 /*
  25  * SVID compatible sem.h file
  26  *
  27  * Author:  Daniel Boulet
  28  */
  29
  30 #ifndef _SYS_SEM_H_
  31 #define _SYS_SEM_H_
  32
  33 #include <sys/ipc.h>
  34
  35 struct sem {
  36         u_short semval;         /* semaphore value */
  37         pid_t   sempid;         /* pid of last operation */
  38         u_short semncnt;        /* # awaiting semval > cval */
  39         u_short semzcnt;        /* # awaiting semval = 0 */
  40 };
  41
  42 struct semid_ds {
  43         struct  ipc_perm sem_perm;      /* operation permission struct */
  44         struct  sem *sem_base;  /* pointer to first semaphore in set */
  45         u_short sem_nsems;      /* number of sems in set */
  46         time_t  sem_otime;      /* last operation time */
  47         long    sem_pad1;       /* SVABI/386 says I need this here */
  48         time_t  sem_ctime;      /* last change time */
  49                                 /* Times measured in secs since */
  50                                 /* 00:00:00 GMT, Jan. 1, 1970 */
  51         long    sem_pad2;       /* SVABI/386 says I need this here */
  52         long    sem_pad3[4];    /* SVABI/386 says I need this here */
  53 };
  54
  55 /*
  56  * semop's sops parameter structure
  57  */
  58 struct sembuf {
  59         u_short sem_num;        /* semaphore # */
  60         short   sem_op;         /* semaphore operation */
  61         short   sem_flg;        /* operation flags */
  62 };
  63 #define SEM_UNDO        010000
  64
  65 #define MAX_SOPS        5       /* maximum # of sembuf's per semop call */
  66
  67 /*
  68  * semctl's arg parameter structure
  69  */
  70 union semun {
  71         int     val;            /* value for SETVAL */
  72         struct  semid_ds *buf;  /* buffer for IPC_STAT & IPC_SET */
  73         u_short *array;         /* array for GETALL & SETALL */
  74 };
  75
  76 /*
  77  * commands for semctl
  78  */
  79 #define GETNCNT 3       /* Return the value of semncnt {READ} */
  80 #define GETPID  4       /* Return the value of sempid {READ} */
  81 #define GETVAL  5       /* Return the value of semval {READ} */
  82 #define GETALL  6       /* Return semvals into arg.array {READ} */
  83 #define GETZCNT 7       /* Return the value of semzcnt {READ} */
  84 #define SETVAL  8       /* Set the value of semval to arg.val {ALTER} */
  85 #define SETALL  9       /* Set semvals from arg.array {ALTER} */
  86
  87 /*
  88  * Permissions
  89  */
  90 #define SEM_A           0200    /* alter permission */
  91 #define SEM_R           0400    /* read permission */
  92
  93 #ifdef KERNEL
  94 /*
  95  * Kernel implementation stuff
  96  */
  97 #define SEMVMX  32767           /* semaphore maximum value */
  98 #define SEMAEM  16384           /* adjust on exit max value */
  99
 100
 101 /*
 102  * Undo structure (one per process)
 103  */
 104 struct sem_undo {
 105         struct  sem_undo *un_next;      /* ptr to next active undo structure */
 106         struct  proc *un_proc;          /* owner of this structure */
 107         short   un_cnt;                 /* # of active entries */
 108         struct undo {
 109                 short   un_adjval;      /* adjust on exit values */
 110                 short   un_num;         /* semaphore # */
 111                 int     un_id;          /* semid */
 112         } un_ent[1];                    /* undo entries */
 113 };
 114
 115 /*
 116  * semaphore info struct
 117  */
 118 struct seminfo {
 119         int     semmap,         /* # of entries in semaphore map */
 120                 semmni,         /* # of semaphore identifiers */
 121                 semmns,         /* # of semaphores in system */
 122                 semmnu,         /* # of undo structures in system */
 123                 semmsl,         /* max # of semaphores per id */
 124                 semopm,         /* max # of operations per semop call */
 125                 semume,         /* max # of undo entries per process */
 126                 semusz,         /* size in bytes of undo structure */
 127                 semvmx,         /* semaphore maximum value */
 128                 semaem;         /* adjust on exit max value */
 129 };
 130 extern struct seminfo   seminfo;
 131
 132 /* internal "mode" bits */
 133 #define SEM_ALLOC       01000   /* semaphore is allocated */
 134 #define SEM_DEST        02000   /* semaphore will be destroyed on last detach */
 135
 136 /*
 137  * Configuration parameters
 138  */
 139 #ifndef SEMMNI
 140 #define SEMMNI  10              /* # of semaphore identifiers */
 141 #endif
 142 #ifndef SEMMNS
 143 #define SEMMNS  60              /* # of semaphores in system */
 144 #endif
 145 #ifndef SEMUME
 146 #define SEMUME  10              /* max # of undo entries per process */
 147 #endif
 148 #ifndef SEMMNU
 149 #define SEMMNU  30              /* # of undo structures in system */
 150 #endif
 151
 152 /* shouldn't need tuning */
 153 #ifndef SEMMAP
 154 #define SEMMAP  30              /* # of entries in semaphore map */
 155 #endif
 156 #ifndef SEMMSL
 157 #define SEMMSL  SEMMNS          /* max # of semaphores per id */
 158 #endif
 159 #ifndef SEMOPM
 160 #define SEMOPM  100             /* max # of operations per semop call */
 161 #endif
 162
 163 /*
 164  * Due to the way semaphore memory is allocated, we have to ensure that
 165  * SEMUSZ is properly aligned.
 166  */
 167
 168 #define SEM_ALIGN(bytes) (((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1))
 169
 170 /* actual size of an undo structure */
 171 #define SEMUSZ  SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME]))
 172
 173 extern struct semid_ds *sema;   /* semaphore id pool */
 174 extern struct sem *sem;         /* semaphore pool */
 175 extern int      *semu;          /* undo structure pool */
 176
 177 /*
 178  * Macro to find a particular sem_undo vector
 179  */
 180 #define SEMU(ix)        ((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz))
 181
 182 /*
 183  * Process sem_undo vectors at proc exit.
 184  */
 185 void    semexit __P((struct proc *p));
 186
 187 /*
 188  * Parameters to the semconfig system call
 189  */
 190 typedef enum {
 191         SEM_CONFIG_FREEZE,      /* Freeze the semaphore facility. */
 192         SEM_CONFIG_THAW         /* Thaw the semaphore facility. */
 193 } semconfig_ctl_t;
 194 #endif /* KERNEL */
 195
 196 #ifndef KERNEL
 197 #include <sys/cdefs.h>
 198
 199 __BEGIN_DECLS
 200 int semsys __P((int, ...));
 201 int semctl __P((int, int, int, ...));
 202 int semget __P((key_t, int, int));
 203 int semop __P((int, struct sembuf *,unsigned));
 204 __END_DECLS
 205 #endif /* !KERNEL */
 206
 207 #endif /* !_SEM_H_ */