[linux.git] / include / linux / sem.h

#ifndef _LINUX_SEM_H
#define _LINUX_SEM_H

#include <linux/ipc.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__
#include <asm/atomic.h>
#include <linux/rcupdate.h>
#include <linux/cache.h>

struct task_struct;

/* One semaphore structure for each semaphore in the system. */
struct sem {
	int	semval;		/* current value */
	int	sempid;		/* pid of last operation */
	struct list_head sem_pending; /* pending single-sop operations */
};

/* One sem_array data structure for each set of semaphores in the system. */
struct sem_array {
	struct kern_ipc_perm	____cacheline_aligned_in_smp
				sem_perm;	/* permissions .. see ipc.h */
	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 list_head	sem_pending;	/* pending operations to be processed */
	struct list_head	list_id;	/* undo requests on this array */
	int			sem_nsems;	/* no. of semaphores in array */
	int			complex_count;	/* pending complex operations */
};

/* One queue for each sleeping process in the system. */
struct sem_queue {
	struct list_head	simple_list; /* queue of pending operations */
	struct list_head	list;	 /* queue of pending operations */
	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 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 list_head	list_proc;	/* per-process list: all undos from one process. */
						/* rcu protected */
	struct rcu_head		rcu;		/* rcu struct for sem_undo() */
	struct sem_undo_list	*ulp;		/* sem_undo_list for the process */
	struct list_head	list_id;	/* per semaphore array list: all undos for one array */
	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 list_head	list_proc;
};

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>
1da177e4 LT	5
	6	/* semop flags */
	7	#define SEM_UNDO 0x1000 /* undo the operation on exit */
	8
	9	/* semctl Command Definitions. */
	10	#define GETPID 11 /* get sempid */
	11	#define GETVAL 12 /* get semval */
	12	#define GETALL 13 /* get all semval's */
	13	#define GETNCNT 14 /* get semncnt */
	14	#define GETZCNT 15 /* get semzcnt */
	15	#define SETVAL 16 /* set semval */
	16	#define SETALL 17 /* set all semval's */
	17
	18	/* ipcs ctl cmds */
	19	#define SEM_STAT 18
	20	#define SEM_INFO 19
	21
	22	/* Obsolete, used only for backwards compatibility and libc5 compiles */
	23	struct semid_ds {
	24	struct ipc_perm sem_perm; /* permissions .. see ipc.h */
	25	__kernel_time_t sem_otime; /* last semop time */
	26	__kernel_time_t sem_ctime; /* last change time */
	27	struct sem sem_base; / ptr to first semaphore in array */
	28	struct sem_queue sem_pending; / pending operations to be processed */
	29	struct sem_queue *sem_pending_last; / last pending operation */
	30	struct sem_undo undo; / undo requests on this array */
	31	unsigned short sem_nsems; /* no. of semaphores in array */
	32	};
	33
	34	/* Include the definition of semid64_ds */
	35	#include <asm/sembuf.h>
	36
	37	/* semop system calls takes an array of these. */
	38	struct sembuf {
	39	unsigned short sem_num; /* semaphore index in array */
	40	short sem_op; /* semaphore operation */
	41	short sem_flg; /* operation flags */
	42	};
	43
	44	/* arg for semctl system calls. */
	45	union semun {
	46	int val; /* value for SETVAL */
	47	struct semid_ds __user buf; / buffer for IPC_STAT & IPC_SET */
	48	unsigned short __user array; / array for GETALL & SETALL */
	49	struct seminfo __user __buf; / buffer for IPC_INFO */
	50	void __user *__pad;
	51	};
	52
	53	struct seminfo {
	54	int semmap;
	55	int semmni;
	56	int semmns;
	57	int semmnu;
	58	int semmsl;
	59	int semopm;
	60	int semume;
	61	int semusz;
	62	int semvmx;
	63	int semaem;
	64	};
	65
	66	#define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */
	67	#define SEMMSL 250 /* <= 8 000 max num of semaphores per id */
	68	#define SEMMNS (SEMMNISEMMSL) / <= INT_MAX max # of semaphores in system */
69	#define SEMOPM 32 /* <= 1 000 max num of ops per semop call */
70	#define SEMVMX 32767 /* <= 32767 semaphore maximum value */
71	#define SEMAEM SEMVMX /* adjust on exit max value */
72
73	/* unused */
74	#define SEMUME SEMOPM /* max num of undo entries per process */
75	#define SEMMNU SEMMNS /* num of undo structures system wide */
76	#define SEMMAP SEMMNS /* # of entries in semaphore map */
77	#define SEMUSZ 20 /* sizeof struct sem_undo */
78
79	#ifdef __KERNEL__
8ffbc759	80	#include <asm/atomic.h>
380af1b3	81	#include <linux/rcupdate.h>
31a7c474	82	#include <linux/cache.h>
1da177e4	83
8c65b4a6 TS	84	struct task_struct;
8c65b4a6 TS	85
1da177e4 LT	86	/* One semaphore structure for each semaphore in the system. */
	87	struct sem {
	88	int semval; /* current value */
	89	int sempid; /* pid of last operation */
b97e820f	90	struct list_head sem_pending; /* pending single-sop operations */
1da177e4 LT	91	};
	92
	93	/* One sem_array data structure for each set of semaphores in the system. */
	94	struct sem_array {
31a7c474 MS	95	struct kern_ipc_perm ____cacheline_aligned_in_smp
31a7c474 MS	96	sem_perm; /* permissions .. see ipc.h */
1da177e4 LT	97	time_t sem_otime; /* last semop time */
	98	time_t sem_ctime; /* last change time */
	99	struct sem sem_base; / ptr to first semaphore in array */
a1193f8e	100	struct list_head sem_pending; /* pending operations to be processed */
4daa28f6	101	struct list_head list_id; /* undo requests on this array */
b97e820f MS	102	int sem_nsems; /* no. of semaphores in array */
b97e820f MS	103	int complex_count; /* pending complex operations */
1da177e4 LT	104	};
	105
	106	/* One queue for each sleeping process in the system. */
	107	struct sem_queue {
b97e820f	108	struct list_head simple_list; /* queue of pending operations */
a1193f8e MS	109	struct list_head list; /* queue of pending operations */
	110	struct task_struct sleeper; / this process */
	111	struct sem_undo undo; / undo structure */
1da177e4 LT	112	int pid; /* process id of requesting process */
1da177e4 LT	113	int status; /* completion status of operation */
a1193f8e	114	struct sembuf sops; / array of pending operations */
1da177e4 LT	115	int nsops; /* number of operations */
	116	int alter; /* does the operation alter the array? */
	117	};
	118
	119	/* Each task has a list of undo requests. They are executed automatically
	120	* when the process exits.
	121	*/
	122	struct sem_undo {
380af1b3 MS	123	struct list_head list_proc; /* per-process list: all undos from one process. */
	124	/* rcu protected */
	125	struct rcu_head rcu; /* rcu struct for sem_undo() */
	126	struct sem_undo_list ulp; / sem_undo_list for the process */
4daa28f6	127	struct list_head list_id; /* per semaphore array list: all undos for one array */
1da177e4 LT	128	int semid; /* semaphore set identifier */
	129	short * semadj; /* array of adjustments, one per semaphore */
	130	};
	131
	132	/* sem_undo_list controls shared access to the list of sem_undo structures
	133	* that may be shared among all a CLONE_SYSVSEM task group.
	134	*/
	135	struct sem_undo_list {
4daa28f6 MS	136	atomic_t refcnt;
	137	spinlock_t lock;
	138	struct list_head list_proc;
1da177e4 LT	139	};
	140
	141	struct sysv_sem {
	142	struct sem_undo_list *undo_list;
	143	};
	144
	145	#ifdef CONFIG_SYSVIPC
	146
	147	extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
	148	extern void exit_sem(struct task_struct *tsk);
	149
	150	#else
	151	static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
	152	{
	153	return 0;
	154	}
	155
	156	static inline void exit_sem(struct task_struct *tsk)
	157	{
	158	return;
	159	}
	160	#endif
	161
	162	#endif /* __KERNEL__ */
	163
	164	#endif /* _LINUX_SEM_H */