bsd/sys/sem.h

   1 /*
   2  * Copyright (c) 2000-2002 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  * John Bellardo modified the implementation for Darwin. 12/2000
  31  */
  32
  33 #ifndef _SYS_SEM_H_
  34 #define _SYS_SEM_H_
  35
  36 #include <sys/appleapiopts.h>
  37 #include <sys/ipc.h>
  38
  39 struct sem {
  40         u_short semval;         /* semaphore value */
  41         pid_t   sempid;         /* pid of last operation */
  42         u_short semncnt;        /* # awaiting semval > cval */
  43         u_short semzcnt;        /* # awaiting semval = 0 */
  44 };
  45
  46 struct semid_ds {
  47         struct  ipc_perm sem_perm;      /* operation permission struct */
  48         struct  sem *sem_base;  /* pointer to first semaphore in set */
  49         u_short sem_nsems;      /* number of sems in set */
  50         time_t  sem_otime;      /* last operation time */
  51         long    sem_pad1;       /* SVABI/386 says I need this here */
  52         time_t  sem_ctime;      /* last change time */
  53                                 /* Times measured in secs since */
  54                                 /* 00:00:00 GMT, Jan. 1, 1970 */
  55         long    sem_pad2;       /* SVABI/386 says I need this here */
  56         long    sem_pad3[4];    /* SVABI/386 says I need this here */
  57 };
  58
  59 /*
  60  * semop's sops parameter structure
  61  */
  62 struct sembuf {
  63         u_short sem_num;        /* semaphore # */
  64         short   sem_op;         /* semaphore operation */
  65         short   sem_flg;        /* operation flags */
  66 };
  67 #define SEM_UNDO        010000
  68
  69 #define MAX_SOPS        5       /* maximum # of sembuf's per semop call */
  70
  71 /*
  72  * semctl's arg parameter structure
  73  */
  74 union semun {
  75         int     val;            /* value for SETVAL */
  76         struct  semid_ds *buf;  /* buffer for IPC_STAT & IPC_SET */
  77         u_short *array;         /* array for GETALL & SETALL */
  78 };
  79
  80 /*
  81  * commands for semctl
  82  */
  83 #define GETNCNT 3       /* Return the value of semncnt {READ} */
  84 #define GETPID  4       /* Return the value of sempid {READ} */
  85 #define GETVAL  5       /* Return the value of semval {READ} */
  86 #define GETALL  6       /* Return semvals into arg.array {READ} */
  87 #define GETZCNT 7       /* Return the value of semzcnt {READ} */
  88 #define SETVAL  8       /* Set the value of semval to arg.val {ALTER} */
  89 #define SETALL  9       /* Set semvals from arg.array {ALTER} */
  90
  91 /*
  92  * Permissions
  93  */
  94 #define SEM_A           0200    /* alter permission */
  95 #define SEM_R           0400    /* read permission */
  96
  97 #ifdef KERNEL
  98 #ifdef __APPLE_API_PRIVATE
  99 /*
 100  * Kernel implementation stuff
 101  */
 102 #define SEMVMX  32767           /* semaphore maximum value */
 103 #define SEMAEM  16384           /* adjust on exit max value */
 104
 105 /*
 106  * Configuration parameters.  SEMMNI, SEMMNS, and SEMMNU are hard limits.
 107  * The code dynamically allocates enough memory to satisfy the current
 108  * demand in even increments of SEMMNI_INC, SEMMNS_INC, and SEMMNU_INC.
 109  * The code will never allocate more than the hard limits.  The *_INC's
 110  * are defined in the kernel section of the header.
 111  */
 112 /*
 113  * Configuration parameters
 114  */
 115 #ifndef SEMMNS                  /* # of semaphores in system */
 116 #define SEMMNS  (1048576/sizeof(struct sem))
 117 #endif                          /* no more than 1M of semaphore data */
 118 #ifndef SEMMNI                  /* # of semaphore identifiers */
 119 #define SEMMNI  SEMMNS          /* max of 1 for each semaphore */
 120 #endif
 121 #ifndef SEMUME
 122 #define SEMUME  10              /* max # of undo entries per process */
 123 #endif
 124 #ifndef SEMMNU                  /* # of undo structures in system */
 125 #define SEMMNU  SEMMNS          /* 1 for each semaphore.  This is quite large */
 126 #endif                          /* This should be max 1 for each process */
 127
 128 /* shouldn't need tuning */
 129 #ifndef SEMMAP
 130 #define SEMMAP  30              /* # of entries in semaphore map */
 131 #endif
 132 #ifndef SEMMSL
 133 #define SEMMSL  SEMMNS          /* max # of semaphores per id */
 134 #endif
 135 #ifndef SEMOPM
 136 #define SEMOPM  100             /* max # of operations per semop call */
 137 #endif
 138
 139
 140 /*
 141  * Undo structure (one per process)
 142  */
 143 struct sem_undo {
 144         struct  sem_undo *un_next;      /* ptr to next active undo structure */
 145         struct  proc *un_proc;          /* owner of this structure */
 146         short   un_cnt;                 /* # of active entries */
 147         struct undo {
 148                 short   un_adjval;      /* adjust on exit values */
 149                 short   un_num;         /* semaphore # */
 150                 int     un_id;          /* semid */
 151         } un_ent[SEMUME];               /* undo entries */
 152 };
 153
 154 /*
 155  * semaphore info struct
 156  */
 157 struct seminfo {
 158         int     semmap,         /* # of entries in semaphore map */
 159                 semmni,         /* # of semaphore identifiers */
 160                 semmns,         /* # of semaphores in system */
 161                 semmnu,         /* # of undo structures in system */
 162                 semmsl,         /* max # of semaphores per id */
 163                 semopm,         /* max # of operations per semop call */
 164                 semume,         /* max # of undo entries per process */
 165                 semusz,         /* size in bytes of undo structure */
 166                 semvmx,         /* semaphore maximum value */
 167                 semaem;         /* adjust on exit max value */
 168 };
 169 extern struct seminfo   seminfo;
 170
 171 /* internal "mode" bits */
 172 #define SEM_ALLOC       01000   /* semaphore is allocated */
 173 #define SEM_DEST        02000   /* semaphore will be destroyed on last detach */
 174
 175 #define SEMMNI_INC      8       /* increment value for semaphore identifiers */
 176 #define SEMMNS_INC      64      /* increment value for semaphores */
 177 #define SEMMNU_INC      32      /* increment value for undo structures */
 178
 179 /*
 180  * Due to the way semaphore memory is allocated, we have to ensure that
 181  * SEMUSZ is properly aligned.
 182  *
 183  * We are not doing strange semaphore memory allocation anymore, so
 184  * these macros are no longer needed.
 185  */
 186
 187 /*
 188  * #define SEM_ALIGN(bytes) (((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1))
 189  */
 190
 191 /* actual size of an undo structure */
 192 /*
 193  * #define SEMUSZ       SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME]))
 194  */
 195 #define SEMUSZ          sizeof(struct sem_undo)
 196
 197 extern struct semid_ds *sema;   /* semaphore id pool */
 198 extern struct sem *sem;         /* semaphore pool */
 199 /* This is now a struct sem_undo with the new memory allocation
 200  * extern int   *semu;          /* undo structure pool
 201  */
 202 extern struct sem_undo  *semu;          /* undo structure pool */
 203
 204 /*
 205  * Macro to find a particular sem_undo vector
 206  */
 207 /* Until we can initialize seminfo.semusz to SEMUSZ, we hard code the size macro
 208  * in SEMU.  This should be fixed when (if) we implement dynamic pool sizes
 209  *
 210  * #define SEMU(ix)     ((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz))
 211  */
 212 /*
 213  * This macro doesn't work because we are using a staticly allocated array
 214  * for semu now.
 215  * #define SEMU(ix)        ((struct sem_undo *)(((intptr_t)semu)+ix * SEMUSZ))
 216  */
 217 #define SEMU(ix)        (&semu[ix])
 218
 219
 220 /*
 221  * Process sem_undo vectors at proc exit.
 222  */
 223 void    semexit __P((struct proc *p));
 224
 225 /*
 226  * Parameters to the semconfig system call
 227  */
 228 typedef enum {
 229         SEM_CONFIG_FREEZE,      /* Freeze the semaphore facility. */
 230         SEM_CONFIG_THAW         /* Thaw the semaphore facility. */
 231 } semconfig_ctl_t;
 232
 233 #endif /* __APPLE_API_PRIVATE */
 234
 235 #endif /* KERNEL */
 236
 237 #ifndef KERNEL
 238 #include <sys/cdefs.h>
 239
 240 __BEGIN_DECLS
 241 int semsys __P((int, ...));
 242 int semctl __P((int, int, int, union semun));
 243 int semget __P((key_t, int, int));
 244 int semop __P((int, struct sembuf *,unsigned));
 245 __END_DECLS
 246 #endif /* !KERNEL */
 247
 248 #endif /* !_SEM_H_ */