haiku/headers/posix/sys/sem.h

66 lines
1.8 KiB
C
Raw Normal View History

/*
* Copyright 2008-2010 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 */