xmem/lib/shmem/ShmemLib.c

   1 /* ==================================================================== */
   2 /* Implement a library to handle reflective memory Shmem back end.      */
   3 /* This device emulates reflective memory via the symp driver.          */
   4 /* Julian Lewis 14th Jan 2008                                           */
   5 /* ==================================================================== */
   6
   7 /* Simple synchronization driver */
   8
   9 #include <sympdrvr.h>
  10
  11 int symp = 0;
  12 static SympDrvrIoBuf iob;
  13 static XmemCallbackStruct *cbs = (XmemCallbackStruct *) &(iob.IoBuf);
  14 static XmemTableId tmsk = 0;
  15
  16 /* ==================================================================== */
  17 /* Try to initialize the specified device                               */
  18
  19 XmemError ShmemInitialize() { /* Initialize hardware/software */
  20
  21 char fnm[32];
  22 int  i, fn;
  23
  24    if (xmem == 0) {
  25       for (i = 1; i <= SympDrvrCLIENT_CONTEXTS; i++) {
  26          sprintf(fnm,"/dev/symp.%1d",i);
  27          if ((fn = open(fnm,O_RDWR,0)) > 0) {
  28             symp = fn;
  29             xmem = symp;
  30             my_nid = 1;
  31             return XmemErrorSUCCESS;
  32          }
  33       }
  34       XmemErrorCallback(XmemErrorNOT_INITIALIZED,0);
  35    }
  36    return XmemErrorSUCCESS;
  37 }
  38
  39 /* ==================================================================== */
  40 /* Get all currently up and running nodes.                              */
  41 /* The set of up and running nodes is determined dynamically through a  */
  42 /* handshake protocol between nodes.                                    */
  43
  44 XmemNodeId ShmemGetAllNodeIds() {
  45
  46    return my_nid;
  47 }
  48
  49 /* ==================================================================== */
  50 /* Register your call back to handle Xmem Events.                       */
  51
  52 XmemError ShmemRegisterCallback(void (*cb)(XmemCallbackStruct *cbs),
  53                                XmemEventMask mask) {
  54
  55    callmask = (unsigned long) mask;
  56    if (ioctl(symp,SympDrvrCONNECT,&callmask) < 0)
  57       return XmemErrorCallback(XmemErrorSYSTEM,errno);
  58
  59    callback = cb;
  60    return XmemErrorSUCCESS;
  61 }
  62
  63 /* ==================================================================== */
  64 /* Wait for an Xmem Event with time out, an incomming event will call   */
  65 /* any registered callback.                                             */
  66
  67 XmemEventMask ShmemWait(int timeout) {
  68
  69 int cc;
  70
  71    if (callmask == 0) return 0;
  72
  73    if (ioctl(symp,SympDrvrSET_TIMEOUT,&timeout) < 0)
  74       return XmemErrorCallback(XmemErrorSYSTEM,errno);
  75
  76    cc = read(symp,&iob,sizeof(SympDrvrIoBuf));
  77    if (cc <= 0) {
  78       bzero((void *) cbs, sizeof(XmemCallbackStruct));
  79       cbs->Mask = XmemEventMaskTIMEOUT;
  80       if (callmask & XmemEventMaskTIMEOUT) callback(cbs);
  81       return XmemEventMaskTIMEOUT;
  82    }
  83    if (cbs->Mask & XmemEventMaskTABLE_UPDATE) {
  84       tmsk |= (1 << (cbs->Table -1));
  85    }
  86
  87    callback(cbs);
  88
  89    return (XmemEventMask) iob.Mask;
  90 }
  91
  92 /* ==================================================================== */
  93 /* Poll for any Xmem Events, an incomming event will call any callback  */
  94 /* that is registered for that event.                                   */
  95
  96 XmemEventMask ShmemPoll() {
  97
  98 unsigned long qsize;
  99
 100    if (ioctl(symp,SympDrvrGET_QUEUE_SIZE,&qsize) < 0) {
 101       XmemErrorCallback(XmemErrorSYSTEM,errno);
 102       return 0;
 103    }
 104    if (qsize) return ShmemWait(0);
 105    return 0;
 106 }
 107
 108 /* ==================================================================== */
 109 /* Send a message to other nodes. If the node parameter is zero, then   */
 110 /* nothing happens, if its equal to 0xFFFFFFFF the message is sent via  */
 111 /* broadcast, else multicast or unicast is used.                        */
 112
 113 XmemError ShmemSendMessage(XmemNodeId nodes, XmemMessage *mess) {
 114
 115 int cc;
 116
 117    cbs->Node  = my_nid;
 118
 119    switch (mess->MessageType) {
 120
 121       case XmemMessageTypeSEND_TABLE:
 122          cbs->Table = mess->Data;
 123          cbs->Mask  = XmemEventMaskSEND_TABLE;
 124       break;
 125
 126       case XmemMessageTypeUSER:
 127          cbs->Data  = mess->Data;
 128          cbs->Mask  = XmemEventMaskUSER;
 129       break;
 130
 131       case XmemMessageTypeTABLE_UPDATE:
 132          cbs->Table = mess->Data;
 133          cbs->Mask  = XmemEventMaskTABLE_UPDATE;
 134       break;
 135
 136       case XmemMessageTypeINITIALIZE_ME:
 137          cbs->Data  = mess->Data;
 138          cbs->Mask = XmemEventMaskINITIALIZED;
 139       break;
 140
 141       case XmemMessageTypeKILL:
 142          cbs->Mask = XmemEventMaskKILL;
 143       break;
 144
 145       default:
 146          return XmemErrorCallback(XmemErrorNO_SUCH_MESSAGE,0);
 147    }
 148    iob.Mask = cbs->Mask;
 149    cc = write(symp,&iob,sizeof(SympDrvrIoBuf));
 150    return XmemErrorSUCCESS;
 151 }
 152
 153 /* ==================================================================== */
 154 /* Send your buffer to a reflective memory table. A table update event  */
 155 /* is broadcast automatically.                                          */
 156
 157 XmemError ShmemSendTable(XmemTableId   tid,     /* Table to be written to      */
 158                                  void *buf,     /* Buffer containing table     */
 159                                  int elems, /* Nr of double words to transfer */
 160                                  int offset,   /* Offset of transfer          */
 161                                  int upflag) { /* Update message flag         */
 162
 163 XmemMessage mess;
 164
 165    if (upflag) {
 166       mess.MessageType = XmemMessageTypeTABLE_UPDATE;
 167       mess.Data        = tid;
 168       return ShmemSendMessage(my_nid,&mess);
 169    }
 170    return XmemErrorSUCCESS;
 171 }
 172
 173 /* ==================================================================== */
 174 /* Update your buffer from a reflective memory table.                   */
 175
 176 XmemError ShmemRecvTable(XmemTableId table, void *buf) {
 177
 178    return XmemErrorSUCCESS;
 179 }
 180
 181 /* ==================================================================== */
 182 /* Check which tables were updated.                                     */
 183
 184 XmemTableId ShmemCheckTables() {
 185 XmemTableId tid;
 186
 187    tid = tmsk;
 188    tmsk = 0;
 189    return tid;
 190 }
 191
 192 XmemError ShmemSendSoftWakeup(uint32_t nodeid, uint32_t data)
 193 {
 194         return 0;
 195 }