/* $FreeBSD: src/sys/sys/sem.h,v 1.29 2004/11/17 13:12:06 rwatson Exp $ */

/*	$NetBSD: sem.h,v 1.5 1994/06/29 06:45:15 cgd Exp $	*/

/*

 * SVID compatible sem.h file

 *

 * Author:  Daniel Boulet

 */

#ifndef _SYS_SEM_H_

#define _SYS_SEM_H_

#include <sys/ipc.h>

struct sem {

	u_short	semval;		/* semaphore value */

	pid_t	sempid;		/* process ID of last operation */

	u_short	semncnt;	/* number of processes waiting for semval

                           to become greater than current value */

	u_short	semzcnt;	/* number of processes waiting for semval

                           to become 0 */

    };

struct semid_ds {

	struct ipc_perm	sem_perm;	/* operation permission struct */

	struct sem	*sem_base;	/* pointer to first semaphore in set */

	unsigned short	sem_nsems;	/* number of sems in set */

	time_t		sem_otime;	/* last operation time */

	long		sem_pad1;	/* SVABI/386 says I need this here */

	time_t		sem_ctime;	/* last change time */

    					/* Times measured in secs since */

    					/* 00:00:00 GMT, Jan. 1, 1970 */

	long		sem_pad2;	/* SVABI/386 says I need this here */

	long		sem_pad3[4];	/* SVABI/386 says I need this here */

};

/*

 * semop's sops parameter structure

 */

struct sembuf {

	unsigned short	sem_num;	/* semaphore # */

	short		sem_op;		/* semaphore operation */

	short		sem_flg;	/* operation flags */

};

#define SEM_UNDO	010000

/*

 * semctl's arg parameter structure

 */

union semun {

	int		val;		/* value for SETVAL */

	struct		semid_ds *buf;	/* buffer for IPC_STAT & IPC_SET */

	unsigned short	*array;		/* array for GETALL & SETALL */

};

/*

 * commands for semctl

 */

#define GETNCNT	3	/* Return the value of semncnt {READ} */

#define GETPID	4	/* Return the value of sempid {READ} */

#define GETVAL	5	/* Return the value of semval {READ} */

#define GETALL	6	/* Return semvals into arg.array {READ} */

#define GETZCNT	7	/* Return the value of semzcnt {READ} */

#define SETVAL	8	/* Set the value of semval to arg.val {ALTER} */

#define SETALL	9	/* Set semvals from arg.array {ALTER} */

#define SEM_STAT 10	/* Like IPC_STAT but treats semid as sema-index */

#define SEM_INFO 11	/* Like IPC_INFO but treats semid as sema-index */

/*

 * Permissions

 */

#define SEM_A		IPC_W	/* alter permission */

#define SEM_R		IPC_R	/* read permission */

#ifdef _KERNEL

/*

 * semaphore info struct

 */

struct seminfo {

	int	semmap,		/* # of entries in semaphore map */

		semmni,		/* # of semaphore identifiers */

		semmns,		/* # of semaphores in system */

		semmnu,		/* # of undo structures in system */

		semmsl,		/* max # of semaphores per id */

		semopm,		/* max # of operations per semop call */

		semume,		/* max # of undo entries per process */

		semusz,		/* size in bytes of undo structure */

		semvmx,		/* semaphore maximum value */

		semaem;		/* adjust on exit max value */

};

extern struct seminfo	seminfo;

/*

 * Kernel wrapper for the user-level structure

 */

struct semid_kernel {

	struct	semid_ds u;

	struct	label *label;	/* MAC framework label */

};

/* internal "mode" bits */

#define	SEM_ALLOC	01000	/* semaphore is allocated */

#define	SEM_DEST	02000	/* semaphore will be destroyed on last detach */

/*

 * Process sem_undo vectors at proc exit.

 */

void	semexit(struct proc *p);

#endif /* _KERNEL */

#ifndef _KERNEL

#include <sys/cdefs.h>

#include <sys/_types.h>

#ifndef _SIZE_T_DECLARED

typedef __size_t        size_t;

#define _SIZE_T_DECLARED

#endif

#ifndef _PID_T_DECLARED

typedef __pid_t         pid_t;

#define _PID_T_DECLARED

#endif

// FUNCTION PROTOTYPES

// FORWARD DECLARATIONS

// CLASS/STRUCT/FUNCTION DECLARATION

__BEGIN_DECLS

/*

* Get semaphore identifier using the IPC key generated by ftok.

*/

IMPORT_C int semget(key_t key, int nsems, int semflg);

/*

* Perform atomically a user-defined array of semaphore operations on the set of 

* semaphores associated with the semaphore identifier specified by the argument semid.

*/

IMPORT_C int semop(int semid, struct sembuf *sops, unsigned nsops);

/*

* Provides a variety of semaphore control operations as specified by cmd.

*/

IMPORT_C int semctl(int semid, int semnum, int cmd, ...);

__END_DECLS

#endif // #ifndef _KERNEL

#endif // _SYS_SEM_H_

//  End of File