lib/sysvipc/sem.c

   1 #define __USE_MISC
   2 #define _SYSTEM 1
   3 #define _MINIX 1
   4
   5 #include <minix/com.h>
   6 #include <minix/config.h>
   7 #include <minix/ipc.h>
   8 #include <minix/endpoint.h>
   9 #include <minix/sysutil.h>
  10 #include <minix/const.h>
  11 #include <minix/type.h>
  12 #include <minix/rs.h>
  13
  14 #include <lib.h>
  15 #include <sys/types.h>
  16 #include <sys/ipc.h>
  17 #include <sys/sem.h>
  18 #include <time.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <stdarg.h>
  22 #include <errno.h>
  23
  24 PRIVATE int get_ipc_endpt(endpoint_t *pt)
  25 {
  26         return minix_rs_lookup("ipc", pt);
  27 }
  28
  29 /* Get semaphore.  */
  30 PUBLIC int semget(key_t key, int nsems, int semflag)
  31 {
  32         message m;
  33         endpoint_t ipc_pt;
  34         int r;
  35
  36         if (get_ipc_endpt(&ipc_pt) != OK) {
  37                 errno = ENOSYS;
  38                 return -1;
  39         }
  40
  41         m.SEMGET_KEY = key;
  42         m.SEMGET_NR = nsems;
  43         m.SEMGET_FLAG = semflag;
  44
  45         r = _syscall(ipc_pt, IPC_SEMGET, &m);
  46         if (r != OK)
  47                 return r;
  48
  49         return m.SEMGET_RETID;
  50 }
  51
  52 /* Semaphore control operation.  */
  53 PUBLIC int semctl(int semid, int semnum, int cmd, ...)
  54 {
  55         message m;
  56         endpoint_t ipc_pt;
  57         va_list ap;
  58         int r;
  59
  60         if (get_ipc_endpt(&ipc_pt) != OK) {
  61                 errno = ENOSYS;
  62                 return -1;
  63         }
  64
  65         m.SEMCTL_ID = semid;
  66         m.SEMCTL_NUM = semnum;
  67         m.SEMCTL_CMD = cmd;
  68         va_start(ap, cmd);
  69         if (cmd == IPC_STAT || cmd == IPC_SET || cmd == IPC_INFO ||
  70                 cmd == SEM_INFO || cmd == SEM_STAT || cmd == GETALL ||
  71                 cmd == SETALL || cmd == SETVAL)
  72                 m.SEMCTL_OPT = (long) va_arg(ap, long);
  73         va_end(ap);
  74
  75         r = _syscall(ipc_pt, IPC_SEMCTL, &m);
  76         if ((r != -1) && (cmd == GETNCNT || cmd == GETZCNT || cmd == GETPID ||
  77                 cmd == GETVAL || cmd == IPC_INFO || cmd == SEM_INFO ||
  78                 cmd == SEM_STAT))
  79                 return m.SHMCTL_RET;
  80         return r;
  81 }
  82
  83 /* Operate on semaphore.  */
  84 PUBLIC int semop(int semid, struct sembuf *sops, size_t nsops)
  85 {
  86         message m;
  87         endpoint_t ipc_pt;
  88
  89         if (get_ipc_endpt(&ipc_pt) != OK) {
  90                 errno = ENOSYS;
  91                 return -1;
  92         }
  93
  94         m.SEMOP_ID = semid;
  95         m.SEMOP_OPS = (long) sops;
  96         m.SEMOP_SIZE = nsops;
  97
  98         return _syscall(ipc_pt, IPC_SEMOP, &m);
  99 }
 100