minix/lib/libc/sys/sem.c

   1 #define _SYSTEM 1
   2 #define _MINIX_SYSTEM   1
   3
   4 #include <sys/cdefs.h>
   5 #include <lib.h>
   6 #include "namespace.h"
   7
   8 #include <lib.h>
   9 #include <minix/rs.h>
  10
  11 #include <sys/types.h>
  12 #include <sys/ipc.h>
  13 #include <sys/sem.h>
  14 #include <stdlib.h>
  15 #include <stdarg.h>
  16 #include <errno.h>
  17 #include <string.h>
  18
  19 static int get_ipc_endpt(endpoint_t *pt)
  20 {
  21         return minix_rs_lookup("ipc", pt);
  22 }
  23
  24 /* Get semaphore.  */
  25 int semget(key_t key, int nsems, int semflag)
  26 {
  27         message m;
  28         endpoint_t ipc_pt;
  29         int r;
  30
  31         if (get_ipc_endpt(&ipc_pt) != OK) {
  32                 errno = ENOSYS;
  33                 return -1;
  34         }
  35
  36         memset(&m, 0, sizeof(m));
  37         m.m_lc_ipc_semget.key = key;
  38         m.m_lc_ipc_semget.nr = nsems;
  39         m.m_lc_ipc_semget.flag = semflag;
  40
  41         r = _syscall(ipc_pt, IPC_SEMGET, &m);
  42         if (r != OK)
  43                 return r;
  44
  45         return m.m_lc_ipc_semget.retid;
  46 }
  47
  48 /* Semaphore control operation.  */
  49 int semctl(int semid, int semnum, int cmd, ...)
  50 {
  51         message m;
  52         endpoint_t ipc_pt;
  53         va_list ap;
  54         int r;
  55
  56         if (get_ipc_endpt(&ipc_pt) != OK) {
  57                 errno = ENOSYS;
  58                 return -1;
  59         }
  60
  61         memset(&m, 0, sizeof(m));
  62         m.m_lc_ipc_semctl.id = semid;
  63         m.m_lc_ipc_semctl.num = semnum;
  64         m.m_lc_ipc_semctl.cmd = cmd;
  65         va_start(ap, cmd);
  66         switch (cmd) {
  67         case SETVAL:
  68                 m.m_lc_ipc_semctl.opt = (vir_bytes)va_arg(ap, int);
  69                 break;
  70         case IPC_STAT:
  71         case IPC_SET:
  72         case IPC_INFO:
  73         case SEM_INFO:
  74         case SEM_STAT:
  75         case GETALL:
  76         case SETALL:
  77                 m.m_lc_ipc_semctl.opt = (vir_bytes)va_arg(ap, void *);
  78                 break;
  79         default:
  80                 m.m_lc_ipc_semctl.opt = 0;
  81                 break;
  82         }
  83         va_end(ap);
  84
  85         r = _syscall(ipc_pt, IPC_SEMCTL, &m);
  86         if ((r != -1) && (cmd == GETNCNT || cmd == GETZCNT || cmd == GETPID ||
  87                 cmd == GETVAL || cmd == IPC_INFO || cmd == SEM_INFO ||
  88                 cmd == SEM_STAT))
  89                 return m.m_lc_ipc_semctl.ret;
  90         return r;
  91 }
  92
  93 /* Operate on semaphore.  */
  94 int semop(int semid, struct sembuf *sops, size_t nsops)
  95 {
  96         message m;
  97         endpoint_t ipc_pt;
  98
  99         if (get_ipc_endpt(&ipc_pt) != OK) {
 100                 errno = ENOSYS;
 101                 return -1;
 102         }
 103
 104         memset(&m, 0, sizeof(m));
 105         m.m_lc_ipc_semop.id = semid;
 106         m.m_lc_ipc_semop.ops = sops;
 107         m.m_lc_ipc_semop.size = nsops;
 108
 109         return _syscall(ipc_pt, IPC_SEMOP, &m);
 110 }
 111