minix3/lib/libc/sys/sem.c

100 lines
1.9 KiB
C

#define __USE_MISC
#define _SYSTEM 1
#define _MINIX_SYSTEM 1
#include <sys/cdefs.h>
#include <lib.h>
#include "namespace.h"
#include <lib.h>
#include <minix/rs.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <stdlib.h>
#include <stdarg.h>
#include <errno.h>
#include <string.h>
static int get_ipc_endpt(endpoint_t *pt)
{
return minix_rs_lookup("ipc", pt);
}
/* Get semaphore. */
int semget(key_t key, int nsems, int semflag)
{
message m;
endpoint_t ipc_pt;
int r;
if (get_ipc_endpt(&ipc_pt) != OK) {
errno = ENOSYS;
return -1;
}
memset(&m, 0, sizeof(m));
m.m_lc_ipc_semget.key = key;
m.m_lc_ipc_semget.nr = nsems;
m.m_lc_ipc_semget.flag = semflag;
r = _syscall(ipc_pt, IPC_SEMGET, &m);
if (r != OK)
return r;
return m.m_lc_ipc_semget.retid;
}
/* Semaphore control operation. */
int semctl(int semid, int semnum, int cmd, ...)
{
message m;
endpoint_t ipc_pt;
va_list ap;
int r;
if (get_ipc_endpt(&ipc_pt) != OK) {
errno = ENOSYS;
return -1;
}
memset(&m, 0, sizeof(m));
m.m_lc_ipc_semctl.id = semid;
m.m_lc_ipc_semctl.num = semnum;
m.m_lc_ipc_semctl.cmd = cmd;
va_start(ap, cmd);
if (cmd == IPC_STAT || cmd == IPC_SET || cmd == IPC_INFO ||
cmd == SEM_INFO || cmd == SEM_STAT || cmd == GETALL ||
cmd == SETALL || cmd == SETVAL)
m.m_lc_ipc_semctl.opt = (long) va_arg(ap, long);
va_end(ap);
r = _syscall(ipc_pt, IPC_SEMCTL, &m);
if ((r != -1) && (cmd == GETNCNT || cmd == GETZCNT || cmd == GETPID ||
cmd == GETVAL || cmd == IPC_INFO || cmd == SEM_INFO ||
cmd == SEM_STAT))
return m.m_lc_ipc_semctl.ret;
return r;
}
/* Operate on semaphore. */
int semop(int semid, struct sembuf *sops, size_t nsops)
{
message m;
endpoint_t ipc_pt;
if (get_ipc_endpt(&ipc_pt) != OK) {
errno = ENOSYS;
return -1;
}
memset(&m, 0, sizeof(m));
m.m_lc_ipc_semop.id = semid;
m.m_lc_ipc_semop.ops = sops;
m.m_lc_ipc_semop.size = nsops;
return _syscall(ipc_pt, IPC_SEMOP, &m);
}