/*
 * Copyright 2008-2012 Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 */
#ifndef _SYS_SEM_H
#define _SYS_SEM_H


#include <sys/cdefs.h>
#include <sys/ipc.h>
#include <sys/types.h>


/* Semaphore operation flags */
#define SEM_UNDO        10

/* Command definition for semctl */
#define GETPID          3       /* Get process ID of last element manipulating */
#define GETVAL          4       /* Get semval */
#define GETALL          5       /* Get all semval */
#define GETNCNT         6       /* Get semncnt */
#define GETZCNT         7       /* Get semzcnt */
#define SETVAL          8       /* Set semval */
#define SETALL          9       /* Set all semval */

struct semid_ds {
        struct ipc_perm         sem_perm;       /* Operation permission structure */
        unsigned short          sem_nsems;      /* Number of semaphores in set */
        time_t                          sem_otime;      /* Last semop */
        time_t                          sem_ctime;      /* Last time changed by semctl */
};

/* Structure passed as parameter to the semop function */
struct sembuf {
        unsigned short  sem_num;        /* Semaphore number */
        short                   sem_op;         /* Semaphore operation */
        short                   sem_flg;        /* Operation flags */
};

/*
 * Semaphore info structure. Useful for the ipcs
 * standard utily
 */
struct seminfo {
        int     semmni; /* Number of semaphore identifies */
        int semmns;     /* Number of semaphore in system */
        int semmnu;     /* Number of undo structures in system */
        int semmsl;     /* Max number of semaphores per id */
        int semopm;     /* Max number of operations per semop call */
        int semume;     /* Max number of undo entries per process */
        int semusz;     /* Size in bytes of undo structure */
        int semvmx;     /* Semaphore maximum valure */
        int semaem;     /* adjust on exit max value */
};


__BEGIN_DECLS

int             semctl(int semID, int semNum, int command, ...);
int             semget(key_t key, int numSems, int semFlags);
int             semop(int semID, struct sembuf *semOps, size_t numSemOps);

__END_DECLS

#endif  /* _SYS_SEM_H */