lib/libc/sysvipc/sysvipc_sem.h

   1 /* $FreeBSD: src/sys/kern/sysv_sem.c,v 1.69 2004/03/17 09:37:13 cperciva Exp $ */
   2
   3 /*
   4  * Implementation of SVID semaphores
   5  *
   6  * Author:  Daniel Boulet
   7  * Copyright (c) 2013 Larisa Grigore <larisagrigore@gmail.com>
   8  *
   9  * This software is provided ``AS IS'' without any warranties of any kind.
  10  */
  11
  12 #ifndef _SYSV_SEM_H_
  13 #define _SYSV_SEM_H_
  14
  15 #include <sys/sem.h>
  16
  17 #include "sysvipc_lock.h"
  18 #include "sysvipc_lock_generic.h"
  19
  20 //#define SYSV_SEMS
  21                 /* Used to define if each semaphore in the
  22                  * set is protected by a mutex, the entire
  23                  * group being protected by a read lock.
  24                  * If SYSV_SEMS is not defined, then the entire
  25                  * group is protected only by a write lock.
  26                  */
  27 struct sem {
  28         u_short semval;         /* semaphore value */
  29         pid_t   sempid;         /* pid of last operation */
  30         u_short semncnt;        /* # awaiting semval > cval */
  31         u_short semzcnt;        /* # awaiting semval = 0 */
  32 #ifdef SYSV_SEMS
  33         struct sysv_mutex sem_mutex;
  34 #endif
  35 };
  36
  37 /* Used internally. The struct semid_ds is used only
  38  * by caller, as argument to semctl.
  39  */
  40 struct semid_ds_internal {
  41         struct  ipc_perm sem_perm;      /* operation permission struct */
  42         u_short sem_nsems;      /* number of sems in set */
  43         time_t  sem_otime;      /* last operation time */
  44         time_t  sem_ctime;      /* last change time */
  45                                 /* Times measured in secs since */
  46                                 /* 00:00:00 GMT, Jan. 1, 1970 */
  47         struct  sem sem_base[0];        /* pointer to first semaphore in set */
  48 };
  49
  50 struct semid_pool {
  51 #ifdef SYSV_RWLOCK
  52         struct sysv_rwlock rwlock;
  53 #else
  54         struct sysv_mutex mutex;
  55 #endif
  56         struct semid_ds_internal ds;
  57         char gen;
  58 };
  59
  60 /*
  61  * Undo structure (one per process)
  62  */
  63 struct sem_undo {
  64 //      pthread_rwlock_t un_lock;
  65         int     un_pages;
  66         short   un_cnt;                 /* # of active entries */
  67         short   un_unused;
  68         struct undo {
  69                 short   un_adjval;      /* adjust on exit values */
  70                 short   un_num;         /* semaphore # */
  71                 int     un_id;          /* semid */
  72         } un_ent[0];                    /* undo entries */
  73 };
  74
  75 int sysvipc___semctl (int, int, int, union semun *);
  76 int sysvipc_semget (key_t, int, int);
  77 int sysvipc_semop (int, struct sembuf *, unsigned);
  78
  79 #endif /* !_SEM_H_ */