xref: /minix3/minix/lib/libc/sys/sem.c (revision 433d6423c39e34ec4b79c950597bb2d236f886be)
1 #define __USE_MISC
2 #define _SYSTEM	1
3 #define _MINIX_SYSTEM	1
4 
5 #include <sys/cdefs.h>
6 #include <lib.h>
7 #include "namespace.h"
8 
9 #include <lib.h>
10 #include <minix/rs.h>
11 
12 #include <sys/types.h>
13 #include <sys/ipc.h>
14 #include <sys/sem.h>
15 #include <stdlib.h>
16 #include <stdarg.h>
17 #include <errno.h>
18 #include <string.h>
19 
20 static int get_ipc_endpt(endpoint_t *pt)
21 {
22 	return minix_rs_lookup("ipc", pt);
23 }
24 
25 /* Get semaphore.  */
26 int semget(key_t key, int nsems, int semflag)
27 {
28 	message m;
29 	endpoint_t ipc_pt;
30 	int r;
31 
32 	if (get_ipc_endpt(&ipc_pt) != OK) {
33 		errno = ENOSYS;
34 		return -1;
35 	}
36 
37 	memset(&m, 0, sizeof(m));
38 	m.m_lc_ipc_semget.key = key;
39 	m.m_lc_ipc_semget.nr = nsems;
40 	m.m_lc_ipc_semget.flag = semflag;
41 
42 	r = _syscall(ipc_pt, IPC_SEMGET, &m);
43 	if (r != OK)
44 		return r;
45 
46 	return m.m_lc_ipc_semget.retid;
47 }
48 
49 /* Semaphore control operation.  */
50 int semctl(int semid, int semnum, int cmd, ...)
51 {
52 	message m;
53 	endpoint_t ipc_pt;
54 	va_list ap;
55 	int r;
56 
57 	if (get_ipc_endpt(&ipc_pt) != OK) {
58 		errno = ENOSYS;
59 		return -1;
60 	}
61 
62 	memset(&m, 0, sizeof(m));
63 	m.m_lc_ipc_semctl.id = semid;
64 	m.m_lc_ipc_semctl.num = semnum;
65 	m.m_lc_ipc_semctl.cmd = cmd;
66 	va_start(ap, cmd);
67 	if (cmd == IPC_STAT || cmd == IPC_SET || cmd == IPC_INFO ||
68 		cmd == SEM_INFO || cmd == SEM_STAT || cmd == GETALL ||
69 		cmd == SETALL || cmd == SETVAL)
70 		m.m_lc_ipc_semctl.opt = (long) va_arg(ap, long);
71 	va_end(ap);
72 
73 	r = _syscall(ipc_pt, IPC_SEMCTL, &m);
74 	if ((r != -1) && (cmd == GETNCNT || cmd == GETZCNT || cmd == GETPID ||
75 		cmd == GETVAL || cmd == IPC_INFO || cmd == SEM_INFO ||
76 		cmd == SEM_STAT))
77 		return m.m_lc_ipc_semctl.ret;
78 	return r;
79 }
80 
81 /* Operate on semaphore.  */
82 int semop(int semid, struct sembuf *sops, size_t nsops)
83 {
84 	message m;
85 	endpoint_t ipc_pt;
86 
87 	if (get_ipc_endpt(&ipc_pt) != OK) {
88 		errno = ENOSYS;
89 		return -1;
90 	}
91 
92 	memset(&m, 0, sizeof(m));
93 	m.m_lc_ipc_semop.id = semid;
94 	m.m_lc_ipc_semop.ops = sops;
95 	m.m_lc_ipc_semop.size = nsops;
96 
97 	return _syscall(ipc_pt, IPC_SEMOP, &m);
98 }
99 
100