lib/sysvipc/shm.c

   1 #define _SYSTEM 1
   2 #define _MINIX 1
   3
   4 #include <minix/callnr.h>
   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/shm.h>
  18 #include <time.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <errno.h>
  22
  23 PRIVATE int get_ipc_endpt(endpoint_t *pt)
  24 {
  25         return minix_rs_lookup("ipc", pt);
  26 }
  27
  28 /* Shared memory control operation. */
  29 PUBLIC int shmctl(int shmid, int cmd, struct shmid_ds *buf)
  30 {
  31         message m;
  32         endpoint_t ipc_pt;
  33         int r;
  34
  35         if (get_ipc_endpt(&ipc_pt) != OK) {
  36                 errno = ENOSYS;
  37                 return -1;
  38         }
  39
  40         m.SHMCTL_ID = shmid;
  41         m.SHMCTL_CMD = cmd;
  42         m.SHMCTL_BUF = (long) buf;
  43
  44         r = _syscall(ipc_pt, IPC_SHMCTL, &m);
  45         if ((cmd == IPC_INFO || cmd == SHM_INFO || cmd == SHM_STAT)
  46                 && (r == OK))
  47                 return m.SHMCTL_RET;
  48         return r;
  49 }
  50
  51 /* Get shared memory segment. */
  52 PUBLIC int shmget(key_t key, size_t size, int shmflg)
  53 {
  54         message m;
  55         endpoint_t ipc_pt;
  56         int r;
  57
  58         if (get_ipc_endpt(&ipc_pt) != OK) {
  59                 errno = ENOSYS;
  60                 return -1;
  61         }
  62
  63         m.SHMGET_KEY = key;
  64         m.SHMGET_SIZE = size;
  65         m.SHMGET_FLAG = shmflg;
  66
  67         r = _syscall(ipc_pt, IPC_SHMGET, &m);
  68         if (r != OK)
  69                 return r;
  70         return m.SHMGET_RETID;
  71 }
  72
  73 /* Attach shared memory segment. */
  74 PUBLIC void *shmat(int shmid, const void *shmaddr, int shmflg)
  75 {
  76         message m;
  77         endpoint_t ipc_pt;
  78         int r;
  79
  80         if (get_ipc_endpt(&ipc_pt) != OK) {
  81                 errno = ENOSYS;
  82                 return NULL;
  83         }
  84
  85         m.SHMAT_ID = shmid;
  86         m.SHMAT_ADDR = (long) shmaddr;
  87         m.SHMAT_FLAG = shmflg;
  88
  89         r = _syscall(ipc_pt, IPC_SHMAT, &m);
  90         if (r != OK)
  91                 return (void *) -1;
  92         return (void *) m.SHMAT_RETADDR;
  93 }
  94
  95 /* Deattach shared memory segment. */
  96 PUBLIC int shmdt(const void *shmaddr)
  97 {
  98         message m;
  99         endpoint_t ipc_pt;
 100
 101         if (get_ipc_endpt(&ipc_pt) != OK) {
 102                 errno = ENOSYS;
 103                 return -1;
 104         }
 105
 106         m.SHMDT_ADDR = (long) shmaddr;
 107
 108         return _syscall(ipc_pt, IPC_SHMDT, &m);
 109 }
 110