headers/posix/sys/sem.h

   1 /*
   2  * Copyright 2008-2012 Haiku, Inc. All Rights Reserved.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _SYS_SEM_H
   6 #define _SYS_SEM_H
   7
   8
   9 #include <sys/cdefs.h>
  10 #include <sys/ipc.h>
  11 #include <sys/types.h>
  12
  13
  14 /* Semaphore operation flags */
  15 #define SEM_UNDO        10
  16
  17 /* Command definition for semctl */
  18 #define GETPID          3       /* Get process ID of last element manipulating */
  19 #define GETVAL          4       /* Get semval */
  20 #define GETALL          5       /* Get all semval */
  21 #define GETNCNT         6       /* Get semncnt */
  22 #define GETZCNT         7       /* Get semzcnt */
  23 #define SETVAL          8       /* Set semval */
  24 #define SETALL          9       /* Set all semval */
  25
  26 struct semid_ds {
  27         struct ipc_perm         sem_perm;       /* Operation permission structure */
  28         unsigned short          sem_nsems;      /* Number of semaphores in set */
  29         time_t                          sem_otime;      /* Last semop */
  30         time_t                          sem_ctime;      /* Last time changed by semctl */
  31 };
  32
  33 /* Structure passed as parameter to the semop function */
  34 struct sembuf {
  35         unsigned short  sem_num;        /* Semaphore number */
  36         short                   sem_op;         /* Semaphore operation */
  37         short                   sem_flg;        /* Operation flags */
  38 };
  39
  40 /*
  41  * Semaphore info structure. Useful for the ipcs
  42  * standard utily
  43  */
  44 struct seminfo {
  45         int     semmni; /* Number of semaphore identifies */
  46         int semmns;     /* Number of semaphore in system */
  47         int semmnu;     /* Number of undo structures in system */
  48         int semmsl;     /* Max number of semaphores per id */
  49         int semopm;     /* Max number of operations per semop call */
  50         int semume;     /* Max number of undo entries per process */
  51         int semusz;     /* Size in bytes of undo structure */
  52         int semvmx;     /* Semaphore maximum valure */
  53         int semaem;     /* adjust on exit max value */
  54 };
  55
  56
  57 __BEGIN_DECLS
  58
  59 int             semctl(int semID, int semNum, int command, ...);
  60 int             semget(key_t key, int numSems, int semFlags);
  61 int             semop(int semID, struct sembuf *semOps, size_t numSemOps);
  62
  63 __END_DECLS
  64
  65 #endif  /* _SYS_SEM_H */