[linux-2.6-block.git] / include / linux / sem.h

#ifndef _LINUX_SEM_H
#define _LINUX_SEM_H

#include <linux/ipc.h>
#include <asm/atomic.h>

/* semop flags */
#define SEM_UNDO        0x1000  /* undo the operation on exit */

/* semctl Command Definitions. */
#define GETPID  11       /* get sempid */
#define GETVAL  12       /* get semval */
#define GETALL  13       /* get all semval's */
#define GETNCNT 14       /* get semncnt */
#define GETZCNT 15       /* get semzcnt */
#define SETVAL  16       /* set semval */
#define SETALL  17       /* set all semval's */

/* ipcs ctl cmds */
#define SEM_STAT 18
#define SEM_INFO 19

/* Obsolete, used only for backwards compatibility and libc5 compiles */
struct semid_ds {
	struct ipc_perm	sem_perm;		/* permissions .. see ipc.h */
	__kernel_time_t	sem_otime;		/* last semop time */
	__kernel_time_t	sem_ctime;		/* last change time */
	struct sem	*sem_base;		/* ptr to first semaphore in array */
	struct sem_queue *sem_pending;		/* pending operations to be processed */
	struct sem_queue **sem_pending_last;	/* last pending operation */
	struct sem_undo	*undo;			/* undo requests on this array */
	unsigned short	sem_nsems;		/* no. of semaphores in array */
};

/* Include the definition of semid64_ds */
#include <asm/sembuf.h>

/* semop system calls takes an array of these. */
struct sembuf {
	unsigned short  sem_num;	/* semaphore index in array */
	short		sem_op;		/* semaphore operation */
	short		sem_flg;	/* operation flags */
};

/* arg for semctl system calls. */
union semun {
	int val;			/* value for SETVAL */
	struct semid_ds __user *buf;	/* buffer for IPC_STAT & IPC_SET */
	unsigned short __user *array;	/* array for GETALL & SETALL */
	struct seminfo __user *__buf;	/* buffer for IPC_INFO */
	void __user *__pad;
};

struct  seminfo {
	int semmap;
	int semmni;
	int semmns;
	int semmnu;
	int semmsl;
	int semopm;
	int semume;
	int semusz;
	int semvmx;
	int semaem;
};

#define SEMMNI  128             /* <= IPCMNI  max # of semaphore identifiers */
#define SEMMSL  250             /* <= 8 000 max num of semaphores per id */
#define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
#define SEMOPM  32	        /* <= 1 000 max num of ops per semop call */
#define SEMVMX  32767           /* <= 32767 semaphore maximum value */
#define SEMAEM  SEMVMX          /* adjust on exit max value */

/* unused */
#define SEMUME  SEMOPM          /* max num of undo entries per process */
#define SEMMNU  SEMMNS          /* num of undo structures system wide */
#define SEMMAP  SEMMNS          /* # of entries in semaphore map */
#define SEMUSZ  20		/* sizeof struct sem_undo */

#ifdef __KERNEL__

struct task_struct;

/* One semaphore structure for each semaphore in the system. */
struct sem {
	int	semval;		/* current value */
	int	sempid;		/* pid of last operation */
};

/* One sem_array data structure for each set of semaphores in the system. */
struct sem_array {
	struct kern_ipc_perm	sem_perm;	/* permissions .. see ipc.h */
	int			sem_id;
	time_t			sem_otime;	/* last semop time */
	time_t			sem_ctime;	/* last change time */
	struct sem		*sem_base;	/* ptr to first semaphore in array */
	struct sem_queue	*sem_pending;	/* pending operations to be processed */
	struct sem_queue	**sem_pending_last; /* last pending operation */
	struct sem_undo		*undo;		/* undo requests on this array */
	unsigned long		sem_nsems;	/* no. of semaphores in array */
};

/* One queue for each sleeping process in the system. */
struct sem_queue {
	struct sem_queue *	next;	 /* next entry in the queue */
	struct sem_queue **	prev;	 /* previous entry in the queue, *(q->prev) == q */
	struct task_struct*	sleeper; /* this process */
	struct sem_undo *	undo;	 /* undo structure */
	int    			pid;	 /* process id of requesting process */
	int    			status;	 /* completion status of operation */
	struct sem_array *	sma;	 /* semaphore array for operations */
	int			id;	 /* internal sem id */
	struct sembuf *		sops;	 /* array of pending operations */
	int			nsops;	 /* number of operations */
	int			alter;   /* does the operation alter the array? */
};

/* Each task has a list of undo requests. They are executed automatically
 * when the process exits.
 */
struct sem_undo {
	struct sem_undo *	proc_next;	/* next entry on this process */
	struct sem_undo *	id_next;	/* next entry on this semaphore set */
	int			semid;		/* semaphore set identifier */
	short *			semadj;		/* array of adjustments, one per semaphore */
};

/* sem_undo_list controls shared access to the list of sem_undo structures
 * that may be shared among all a CLONE_SYSVSEM task group.
 */ 
struct sem_undo_list {
	atomic_t	refcnt;
	spinlock_t	lock;
	struct sem_undo	*proc_list;
};

struct sysv_sem {
	struct sem_undo_list *undo_list;
};

#ifdef CONFIG_SYSVIPC

extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
extern void exit_sem(struct task_struct *tsk);

#else
static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
{
	return 0;
}

static inline void exit_sem(struct task_struct *tsk)
{
	return;
}
#endif

#endif /* __KERNEL__ */

#endif /* _LINUX_SEM_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_SEM_H
	2	#define _LINUX_SEM_H
	3
	4	#include <linux/ipc.h>
	5	#include <asm/atomic.h>
	6
	7	/* semop flags */
	8	#define SEM_UNDO 0x1000 /* undo the operation on exit */
	9
	10	/* semctl Command Definitions. */
	11	#define GETPID 11 /* get sempid */
	12	#define GETVAL 12 /* get semval */
	13	#define GETALL 13 /* get all semval's */
	14	#define GETNCNT 14 /* get semncnt */
	15	#define GETZCNT 15 /* get semzcnt */
	16	#define SETVAL 16 /* set semval */
	17	#define SETALL 17 /* set all semval's */
	18
	19	/* ipcs ctl cmds */
	20	#define SEM_STAT 18
	21	#define SEM_INFO 19
	22
	23	/* Obsolete, used only for backwards compatibility and libc5 compiles */
	24	struct semid_ds {
	25	struct ipc_perm sem_perm; /* permissions .. see ipc.h */
	26	__kernel_time_t sem_otime; /* last semop time */
	27	__kernel_time_t sem_ctime; /* last change time */
	28	struct sem sem_base; / ptr to first semaphore in array */
	29	struct sem_queue sem_pending; / pending operations to be processed */
	30	struct sem_queue *sem_pending_last; / last pending operation */
	31	struct sem_undo undo; / undo requests on this array */
	32	unsigned short sem_nsems; /* no. of semaphores in array */
	33	};
	34
	35	/* Include the definition of semid64_ds */
	36	#include <asm/sembuf.h>
	37
	38	/* semop system calls takes an array of these. */
	39	struct sembuf {
	40	unsigned short sem_num; /* semaphore index in array */
	41	short sem_op; /* semaphore operation */
	42	short sem_flg; /* operation flags */
	43	};
	44
	45	/* arg for semctl system calls. */
	46	union semun {
	47	int val; /* value for SETVAL */
	48	struct semid_ds __user buf; / buffer for IPC_STAT & IPC_SET */
	49	unsigned short __user array; / array for GETALL & SETALL */
	50	struct seminfo __user __buf; / buffer for IPC_INFO */
	51	void __user *__pad;
	52	};
	53
	54	struct seminfo {
	55	int semmap;
	56	int semmni;
	57	int semmns;
	58	int semmnu;
	59	int semmsl;
	60	int semopm;
	61	int semume;
	62	int semusz;
	63	int semvmx;
	64	int semaem;
65	};
66
67	#define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */
68	#define SEMMSL 250 /* <= 8 000 max num of semaphores per id */
69	#define SEMMNS (SEMMNISEMMSL) / <= INT_MAX max # of semaphores in system */
70	#define SEMOPM 32 /* <= 1 000 max num of ops per semop call */
71	#define SEMVMX 32767 /* <= 32767 semaphore maximum value */
72	#define SEMAEM SEMVMX /* adjust on exit max value */
73
74	/* unused */
75	#define SEMUME SEMOPM /* max num of undo entries per process */
76	#define SEMMNU SEMMNS /* num of undo structures system wide */
77	#define SEMMAP SEMMNS /* # of entries in semaphore map */
78	#define SEMUSZ 20 /* sizeof struct sem_undo */
79
80	#ifdef __KERNEL__
81
8c65b4a6 TS	82	struct task_struct;
8c65b4a6 TS	83
1da177e4 LT	84	/* One semaphore structure for each semaphore in the system. */
	85	struct sem {
	86	int semval; /* current value */
	87	int sempid; /* pid of last operation */
	88	};
	89
	90	/* One sem_array data structure for each set of semaphores in the system. */
	91	struct sem_array {
	92	struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
19b4946c	93	int sem_id;
1da177e4 LT	94	time_t sem_otime; /* last semop time */
	95	time_t sem_ctime; /* last change time */
	96	struct sem sem_base; / ptr to first semaphore in array */
	97	struct sem_queue sem_pending; / pending operations to be processed */
	98	struct sem_queue *sem_pending_last; / last pending operation */
	99	struct sem_undo undo; / undo requests on this array */
	100	unsigned long sem_nsems; /* no. of semaphores in array */
	101	};
	102
	103	/* One queue for each sleeping process in the system. */
	104	struct sem_queue {
	105	struct sem_queue * next; /* next entry in the queue */
	106	struct sem_queue ** prev; /* previous entry in the queue, (q->prev) == q /
	107	struct task_struct* sleeper; /* this process */
	108	struct sem_undo * undo; /* undo structure */
	109	int pid; /* process id of requesting process */
	110	int status; /* completion status of operation */
	111	struct sem_array * sma; /* semaphore array for operations */
	112	int id; /* internal sem id */
	113	struct sembuf * sops; /* array of pending operations */
	114	int nsops; /* number of operations */
	115	int alter; /* does the operation alter the array? */
	116	};
	117
	118	/* Each task has a list of undo requests. They are executed automatically
	119	* when the process exits.
	120	*/
	121	struct sem_undo {
	122	struct sem_undo * proc_next; /* next entry on this process */
	123	struct sem_undo * id_next; /* next entry on this semaphore set */
	124	int semid; /* semaphore set identifier */
	125	short * semadj; /* array of adjustments, one per semaphore */
	126	};
	127
	128	/* sem_undo_list controls shared access to the list of sem_undo structures
	129	* that may be shared among all a CLONE_SYSVSEM task group.
	130	*/
	131	struct sem_undo_list {
	132	atomic_t refcnt;
	133	spinlock_t lock;
	134	struct sem_undo *proc_list;
	135	};
	136
	137	struct sysv_sem {
	138	struct sem_undo_list *undo_list;
	139	};
	140
	141	#ifdef CONFIG_SYSVIPC
	142
	143	extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
	144	extern void exit_sem(struct task_struct *tsk);
	145
	146	#else
	147	static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
	148	{
	149	return 0;
	150	}
	151
	152	static inline void exit_sem(struct task_struct *tsk)
	153	{
	154	return;
	155	}
	156	#endif
	157
158	#endif /* __KERNEL__ */
159
160	#endif /* _LINUX_SEM_H */