sem.h revision 2729 
1/* $Id$ */
2/*	$NetBSD: sem.h,v 1.5 1994/06/29 06:45:15 cgd Exp $	*/
3
4/*
5 * SVID compatible sem.h file
6 *
7 * Author:  Daniel Boulet
8 */
9
10#ifndef _SYS_SEM_H_
11#define _SYS_SEM_H_
12
13#include <sys/ipc.h>
14
15struct sem {
16	u_short	semval;		/* semaphore value */
17	pid_t	sempid;		/* pid of last operation */
18	u_short	semncnt;	/* # awaiting semval > cval */
19	u_short	semzcnt;	/* # awaiting semval = 0 */
20};
21
22struct semid_ds {
23	struct	ipc_perm sem_perm;	/* operation permission struct */
24	struct	sem *sem_base;	/* pointer to first semaphore in set */
25	u_short	sem_nsems;	/* number of sems in set */
26	time_t	sem_otime;	/* last operation time */
27	long	sem_pad1;	/* SVABI/386 says I need this here */
28	time_t	sem_ctime;	/* last change time */
29    				/* Times measured in secs since */
30    				/* 00:00:00 GMT, Jan. 1, 1970 */
31	long	sem_pad2;	/* SVABI/386 says I need this here */
32	long	sem_pad3[4];	/* SVABI/386 says I need this here */
33};
34
35/*
36 * semop's sops parameter structure
37 */
38struct sembuf {
39	u_short	sem_num;	/* semaphore # */
40	short	sem_op;		/* semaphore operation */
41	short	sem_flg;	/* operation flags */
42};
43#define SEM_UNDO	010000
44
45#define MAX_SOPS	5	/* maximum # of sembuf's per semop call */
46
47/*
48 * semctl's arg parameter structure
49 */
50union semun {
51	int	val;		/* value for SETVAL */
52	struct	semid_ds *buf;	/* buffer for IPC_STAT & IPC_SET */
53	u_short	*array;		/* array for GETALL & SETALL */
54};
55
56/*
57 * commands for semctl
58 */
59#define GETNCNT	3	/* Return the value of semncnt {READ} */
60#define GETPID	4	/* Return the value of sempid {READ} */
61#define GETVAL	5	/* Return the value of semval {READ} */
62#define GETALL	6	/* Return semvals into arg.array {READ} */
63#define GETZCNT	7	/* Return the value of semzcnt {READ} */
64#define SETVAL	8	/* Set the value of semval to arg.val {ALTER} */
65#define SETALL	9	/* Set semvals from arg.array {ALTER} */
66
67#ifdef KERNEL
68/*
69 * Kernel implementation stuff
70 */
71#define SEMVMX	32767		/* semaphore maximum value */
72#define SEMAEM	16384		/* adjust on exit max value */
73
74/*
75 * Permissions
76 */
77#define SEM_A		0200	/* alter permission */
78#define SEM_R		0400	/* read permission */
79
80/*
81 * Undo structure (one per process)
82 */
83struct sem_undo {
84	struct	sem_undo *un_next;	/* ptr to next active undo structure */
85	struct	proc *un_proc;		/* owner of this structure */
86	short	un_cnt;			/* # of active entries */
87	struct undo {
88		short	un_adjval;	/* adjust on exit values */
89		short	un_num;		/* semaphore # */
90		int	un_id;		/* semid */
91	} un_ent[1];			/* undo entries */
92};
93
94/*
95 * semaphore info struct
96 */
97struct seminfo {
98	int	semmap,		/* # of entries in semaphore map */
99		semmni,		/* # of semaphore identifiers */
100		semmns,		/* # of semaphores in system */
101		semmnu,		/* # of undo structures in system */
102		semmsl,		/* max # of semaphores per id */
103		semopm,		/* max # of operations per semop call */
104		semume,		/* max # of undo entries per process */
105		semusz,		/* size in bytes of undo structure */
106		semvmx,		/* semaphore maximum value */
107		semaem;		/* adjust on exit max value */
108};
109struct seminfo	seminfo;
110
111/* internal "mode" bits */
112#define	SEM_ALLOC	01000	/* semaphore is allocated */
113#define	SEM_DEST	02000	/* semaphore will be destroyed on last detach */
114
115/*
116 * Configuration parameters
117 */
118#ifndef SEMMNI
119#define SEMMNI	10		/* # of semaphore identifiers */
120#endif
121#ifndef SEMMNS
122#define SEMMNS	60		/* # of semaphores in system */
123#endif
124#ifndef SEMUME
125#define SEMUME	10		/* max # of undo entries per process */
126#endif
127#ifndef SEMMNU
128#define SEMMNU	30		/* # of undo structures in system */
129#endif
130
131/* shouldn't need tuning */
132#ifndef SEMMAP
133#define SEMMAP	30		/* # of entries in semaphore map */
134#endif
135#ifndef SEMMSL
136#define SEMMSL	SEMMNS		/* max # of semaphores per id */
137#endif
138#ifndef SEMOPM
139#define SEMOPM	100		/* max # of operations per semop call */
140#endif
141
142/* actual size of an undo structure */
143#define SEMUSZ	(sizeof(struct sem_undo)+sizeof(struct undo)*SEMUME)
144
145/*
146 * Structures allocated in machdep.c
147 */
148struct	semid_ds *sema;		/* semaphore id pool */
149struct	sem *sem;		/* semaphore pool */
150struct	map *semmap;		/* semaphore allocation map */
151struct	sem_undo *semu_list;	/* list of active undo structures */
152int	*semu;			/* undo structure pool */
153
154/*
155 * Macro to find a particular sem_undo vector
156 */
157#define SEMU(ix)	((struct sem_undo *)(((long)semu)+ix * SEMUSZ))
158
159/*
160 * Parameters to the semconfig system call
161 */
162typedef enum {
163	SEM_CONFIG_FREEZE,	/* Freeze the semaphore facility. */
164	SEM_CONFIG_THAW		/* Thaw the semaphore facility. */
165} semconfig_ctl_t;
166#endif /* KERNEL */
167
168#ifndef KERNEL
169#include <sys/cdefs.h>
170
171__BEGIN_DECLS
172int semsys __P((int, ...));
173int semctl __P((int, int, int, union semun));
174int semget __P((key_t, int, int));
175int semop __P((int, struct sembuf *,unsigned));
176__END_DECLS
177#endif /* !KERNEL */
178
179#endif /* !_SEM_H_ */
180