xref: /freebsd/sys/sys/sem.h (revision 417ed37975261df51f61d13e179ad04d8f4839c7)
1 /* $Id: sem.h,v 1.1 1994/09/13 14:47:35 dfr Exp $ */
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 
15 struct 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 
22 struct 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  */
38 struct 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  */
50 union 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  */
83 struct 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  */
97 struct 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 };
109 extern struct 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  */
148 struct	semid_ds *sema;		/* semaphore id pool */
149 struct	sem *sem;		/* semaphore pool */
150 struct	map *semmap;		/* semaphore allocation map */
151 struct	sem_undo *semu_list;	/* list of active undo structures */
152 int	*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  */
162 typedef 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
172 int semsys __P((int, ...));
173 int semctl __P((int, int, int, union semun));
174 int semget __P((key_t, int, int));
175 int semop __P((int, struct sembuf *,unsigned));
176 __END_DECLS
177 #endif /* !KERNEL */
178 
179 #endif /* !_SEM_H_ */
180