FreeBSD/Linux Kernel Cross Reference
sys/sys/sem.h
1 /* $FreeBSD$ */
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 /*
68 * Permissions
69 */
70 #define SEM_A 0200 /* alter permission */
71 #define SEM_R 0400 /* read permission */
72
73 #ifdef KERNEL
74 /*
75 * Kernel implementation stuff
76 */
77 #define SEMVMX 32767 /* semaphore maximum value */
78 #define SEMAEM 16384 /* adjust on exit max value */
79
80
81 /*
82 * Undo structure (one per process)
83 */
84 struct sem_undo {
85 struct sem_undo *un_next; /* ptr to next active undo structure */
86 struct proc *un_proc; /* owner of this structure */
87 short un_cnt; /* # of active entries */
88 struct undo {
89 short un_adjval; /* adjust on exit values */
90 short un_num; /* semaphore # */
91 int un_id; /* semid */
92 } un_ent[1]; /* undo entries */
93 };
94
95 /*
96 * semaphore info struct
97 */
98 struct seminfo {
99 int semmap, /* # of entries in semaphore map */
100 semmni, /* # of semaphore identifiers */
101 semmns, /* # of semaphores in system */
102 semmnu, /* # of undo structures in system */
103 semmsl, /* max # of semaphores per id */
104 semopm, /* max # of operations per semop call */
105 semume, /* max # of undo entries per process */
106 semusz, /* size in bytes of undo structure */
107 semvmx, /* semaphore maximum value */
108 semaem; /* adjust on exit max value */
109 };
110 extern struct seminfo seminfo;
111
112 /* internal "mode" bits */
113 #define SEM_ALLOC 01000 /* semaphore is allocated */
114 #define SEM_DEST 02000 /* semaphore will be destroyed on last detach */
115
116 /*
117 * Configuration parameters
118 */
119 #ifndef SEMMNI
120 #define SEMMNI 10 /* # of semaphore identifiers */
121 #endif
122 #ifndef SEMMNS
123 #define SEMMNS 60 /* # of semaphores in system */
124 #endif
125 #ifndef SEMUME
126 #define SEMUME 10 /* max # of undo entries per process */
127 #endif
128 #ifndef SEMMNU
129 #define SEMMNU 30 /* # of undo structures in system */
130 #endif
131
132 /* shouldn't need tuning */
133 #ifndef SEMMAP
134 #define SEMMAP 30 /* # of entries in semaphore map */
135 #endif
136 #ifndef SEMMSL
137 #define SEMMSL SEMMNS /* max # of semaphores per id */
138 #endif
139 #ifndef SEMOPM
140 #define SEMOPM 100 /* max # of operations per semop call */
141 #endif
142
143 /*
144 * Due to the way semaphore memory is allocated, we have to ensure that
145 * SEMUSZ is properly aligned.
146 */
147
148 #define SEM_ALIGN(bytes) (((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1))
149
150 /* actual size of an undo structure */
151 #define SEMUSZ SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME]))
152
153 extern struct semid_ds *sema; /* semaphore id pool */
154 extern struct sem *sem; /* semaphore pool */
155 extern int *semu; /* undo structure pool */
156
157 /*
158 * Macro to find a particular sem_undo vector
159 */
160 #define SEMU(ix) ((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz))
161
162 /*
163 * Process sem_undo vectors at proc exit.
164 */
165 void semexit __P((struct proc *p));
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, ...));
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_ */
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