1/* $OpenBSD: sem.h,v 1.26 2024/10/26 05:39:03 jsg 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
46struct 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
53struct 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 */
69struct 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 */
79union 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 */
116struct 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 */
130struct 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
142struct sem_sysctl_info {
143 struct seminfo seminfo;
144 struct semid_ds semids[1];
145};
146
147extern 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
176extern struct semid_ds **sema; /* semaphore id list */
177
178void seminit(void);
179void semexit(struct process *);
180int sysctl_sysvsem(int *, u_int, void *, size_t *, void *, size_t);
181#endif /* _KERNEL */
182
183#ifndef _KERNEL
184__BEGIN_DECLS
185int semctl(int, int, int, ...);
186int __semctl(int, int, int, union semun *);
187int semget(key_t, int, int);
188int semop(int, struct sembuf *, size_t);
189__END_DECLS
190#endif /* !_KERNEL */
191
192#endif /* !_SYS_SEM_H_ */