FreeBSD/Linux Kernel Cross Reference
sys/sys/sem.h
1 /* $OpenBSD: sem.h,v 1.25 2022/09/16 15:57:23 mbuhl Exp $ */
2 /* $NetBSD: sem.h,v 1.8 1996/02/09 18:25:29 christos 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 #ifndef _SYS_IPC_H_
14 #include <sys/ipc.h>
15 #endif
16
17 #if __BSD_VISIBLE
18
19 /* sem-specific sysctl variables corresponding to members of struct seminfo */
20 #define KERN_SEMINFO_SEMMNI 1 /* int: # of semaphore identifiers */
21 #define KERN_SEMINFO_SEMMNS 2 /* int: # of semaphores in system */
22 #define KERN_SEMINFO_SEMMNU 3 /* int: # of undo structures in system */
23 #define KERN_SEMINFO_SEMMSL 4 /* int: max semaphores per id */
24 #define KERN_SEMINFO_SEMOPM 5 /* int: max operations per semop call */
25 #define KERN_SEMINFO_SEMUME 6 /* int: max undo entries per process */
26 #define KERN_SEMINFO_SEMUSZ 7 /* int: size in bytes of struct undo */
27 #define KERN_SEMINFO_SEMVMX 8 /* int: semaphore maximum value */
28 #define KERN_SEMINFO_SEMAEM 9 /* int: adjust on exit max value */
29 #define KERN_SEMINFO_MAXID 10 /* number of valid semaphore sysctls */
30
31 #define CTL_KERN_SEMINFO_NAMES { \
32 { 0, 0 }, \
33 { "semmni", CTLTYPE_INT }, \
34 { "semmns", CTLTYPE_INT }, \
35 { "semmnu", CTLTYPE_INT }, \
36 { "semmsl", CTLTYPE_INT }, \
37 { "semopm", CTLTYPE_INT }, \
38 { "semume", CTLTYPE_INT }, \
39 { "semusz", CTLTYPE_INT }, \
40 { "semvmx", CTLTYPE_INT }, \
41 { "semaem", CTLTYPE_INT }, \
42 }
43
44 #endif /* __BSD_VISIBLE */
45
46 struct sem {
47 unsigned short semval; /* semaphore value */
48 pid_t sempid; /* pid of last operation */
49 unsigned short semncnt; /* # awaiting semval > cval */
50 unsigned short semzcnt; /* # awaiting semval = 0 */
51 };
52
53 struct semid_ds {
54 struct ipc_perm sem_perm; /* operation permission struct */
55 struct sem *sem_base; /* pointer to first semaphore in set */
56 unsigned short sem_nsems; /* number of sems in set */
57 time_t sem_otime; /* last operation time */
58 long sem_pad1; /* SVABI/386 says I need this here */
59 time_t sem_ctime; /* last change time */
60 /* Times measured in secs since */
61 /* 00:00:00 GMT, Jan. 1, 1970 */
62 long sem_pad2; /* SVABI/386 says I need this here */
63 long sem_pad3[4]; /* SVABI/386 says I need this here */
64 };
65
66 /*
67 * semop's sops parameter structure
68 */
69 struct sembuf {
70 unsigned short sem_num; /* semaphore # */
71 short sem_op; /* semaphore operation */
72 short sem_flg; /* operation flags */
73 };
74 #define SEM_UNDO 010000
75
76 /*
77 * semctl's arg parameter structure
78 */
79 union semun {
80 int val; /* value for SETVAL */
81 struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */
82 unsigned short *array; /* array for GETALL & SETALL */
83 };
84
85 /*
86 * commands for semctl
87 */
88 #define GETNCNT 3 /* Return the value of semncnt {READ} */
89 #define GETPID 4 /* Return the value of sempid {READ} */
90 #define GETVAL 5 /* Return the value of semval {READ} */
91 #define GETALL 6 /* Return semvals into arg.array {READ} */
92 #define GETZCNT 7 /* Return the value of semzcnt {READ} */
93 #define SETVAL 8 /* Set the value of semval to arg.val {ALTER} */
94 #define SETALL 9 /* Set semvals from arg.array {ALTER} */
95
96
97 /*
98 * Permissions
99 */
100 #define SEM_A 0200 /* alter permission */
101 #define SEM_R 0400 /* read permission */
102
103
104 #ifdef _KERNEL
105 #include <sys/queue.h>
106
107 /*
108 * Kernel implementation stuff
109 */
110 #define SEMVMX 32767 /* semaphore maximum value */
111 #define SEMAEM 16384 /* adjust on exit max value */
112
113 /*
114 * Undo structure (one per process)
115 */
116 struct sem_undo {
117 SLIST_ENTRY(sem_undo) un_next; /* ptr to next active undo structure */
118 struct process *un_proc; /* owner of this structure */
119 short un_cnt; /* # of active entries */
120 struct undo {
121 short un_adjval; /* adjust on exit values */
122 short un_num; /* semaphore # */
123 int un_id; /* semid */
124 } un_ent[1]; /* undo entries */
125 };
126
127 /*
128 * semaphore info struct
129 */
130 struct seminfo {
131 int semmni, /* # of semaphore identifiers */
132 semmns, /* # of semaphores in system */
133 semmnu, /* # of undo structures in system */
134 semmsl, /* max # of semaphores per id */
135 semopm, /* max # of operations per semop call */
136 semume, /* max # of undo entries per process */
137 semusz, /* size in bytes of undo structure */
138 semvmx, /* semaphore maximum value */
139 semaem; /* adjust on exit max value */
140 };
141
142 struct sem_sysctl_info {
143 struct seminfo seminfo;
144 struct semid_ds semids[1];
145 };
146
147 extern struct seminfo seminfo;
148
149 /*
150 * Configuration parameters
151 */
152 #ifndef SEMMNI
153 #define SEMMNI 10 /* # of semaphore identifiers */
154 #endif
155 #ifndef SEMMNS
156 #define SEMMNS 60 /* # of semaphores in system */
157 #endif
158 #ifndef SEMUME
159 #define SEMUME 10 /* max # of undo entries per process */
160 #endif
161 #ifndef SEMMNU
162 #define SEMMNU 30 /* # of undo structures in system */
163 #endif
164
165 /* shouldn't need tuning */
166 #ifndef SEMMSL
167 #define SEMMSL SEMMNS /* max # of semaphores per id */
168 #endif
169 #ifndef SEMOPM
170 #define SEMOPM 100 /* max # of operations per semop call */
171 #endif
172
173 /* actual size of an undo structure */
174 #define SEMUSZ (sizeof(struct sem_undo)+sizeof(struct undo)*SEMUME)
175
176 extern struct semid_ds **sema; /* semaphore id list */
177
178 struct proc;
179
180 void seminit(void);
181 void semexit(struct process *);
182 int sysctl_sysvsem(int *, u_int, void *, size_t *, void *, size_t);
183 #endif /* _KERNEL */
184
185 #ifndef _KERNEL
186 __BEGIN_DECLS
187 int semctl(int, int, int, ...);
188 int __semctl(int, int, int, union semun *);
189 int semget(key_t, int, int);
190 int semop(int, struct sembuf *, size_t);
191 __END_DECLS
192 #endif /* !_KERNEL */
193
194 #endif /* !_SYS_SEM_H_ */
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