Multi threading in CANlib

samples\example\c\thread.c

/*
** This software is furnished as Redistributable under the Ôƺ£ÓÎÏ· Software Licence
** https://www.kvaser.com/canlib-webhelp/page_license_and_copyright.html

** Description:
** This is a multithreaded program that uses CANLIB.
*/
#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include <windows.h>
#include <conio.h>

#include <canlib.h>

#ifdef __BORLANDC__
#pragma argsused
#endif
void Usage(int argc, char* argv[])
{
  printf("\nCANLIB Thread Test 4\n");
  printf("\n");
  printf("\nUsage: thread [flags]\n");
  printf("   -aX         Use channel number X as source\n");
  printf("   -bY         Use channel number Y as destination\n");
  printf("   (note: X must be different from Y. Default X=0, Y=1)\n");
  printf("   -B<value>   Set the bitrate. Value is any of 1000,500,250,125.\n");
  printf("               Default bitrate is 125 kbit/s.\n");
  printf("   -v          Be verbose.\n");
  printf("   -Lnnn       Run nnn \"loops\". Default is 500.\n");

  exit(1);
}

//
// Global variables for the command-line options.
//
int Bitrate = canBITRATE_125K;   //
int Verbose = 0;
int MaxLoops = 500;

//
// Check a status code and issue an error message if the code
// isn't canOK.
//
void Check(char* id, canStatus stat)
{
  if (stat != canOK) {
    char buf[50];
    buf[0] = '\0';
    canGetErrorText(stat, buf, sizeof(buf));
    printf("%s: failed, stat=%d (%s)\n", id, (int)stat, buf);
  }
}

//
// Setup a CAN controller.
//
canHandle InitCtrl(int ctrl)
{
  canStatus stat;
  canHandle hnd;

  hnd = canOpenChannel(ctrl, 0x0020);
  if (hnd < 0) {
    printf("canOpenChannel failed, stat=%d, ctrl=%d\n", hnd, ctrl);
    exit(0);
  }

  //
  // Using our new shiny handle, we specify the baud rate
  // using one of the convenient canBITRATE_xxx constants.
  //
  // The bit layout is in depth discussed in most CAN
  // controller data sheets, and on the web at
  // http://www.kvaser.se.
  //
  stat = canSetBusParams(hnd, Bitrate, 0, 0, 0, 0, 0);
  if (stat < 0) {
    printf("canSetBusParams failed, stat=%d\n", stat);
  }

  //
  // Then we start the ball rolling.
  //
  stat = canBusOn(hnd);
  if (stat < 0) {
    printf("canBusOn failed, stat=%d\n", stat);
  }

  // Return the handle; our caller will need it for
  // further exercising the CAN controller.
  return hnd;
}

CRITICAL_SECTION cs;

static long TimeToLeave;
static long TotalSent[4];
static long TotalReceived[4];

#define NR_MSGS 3
#define SRC_ID  300
#define P_NAP   50
#define C_NAP   0

HANDLE events[4];
int channels[4];


DWORD WINAPI SendAndReceive(PVOID p)
{
  canHandle   hnd;
  long        id_read;
  canStatus   stat;
  BYTE        msg[8];
  int         i, count;
  ULONG       idx;

  idx = PtrToUlong(p);

  hnd = InitCtrl(channels[idx]);
  TotalSent[idx] = 0;
  count = 0;
  WaitForSingleObject(events[idx], INFINITE);

  while (TRUE) {
    long id;

    id = SRC_ID + idx;

    for (i=0; i<NR_MSGS; i++) {
      unsigned int dlc, flags;
      // Send one..
      //memcpy(msg, &i, sizeof(i));
      memcpy(msg, &count, sizeof(count));
      count++;
      stat = canWrite(hnd, id, msg, 8, 0);
      Check("canWrite A", stat);
      TotalSent[idx]++;

      // And receive all that is pending..
      do {
        stat = canRead(hnd, &id_read, NULL, &dlc, &flags, NULL);
        if (stat == canOK) {
          if (Verbose > 1) printf("R");
          TotalReceived[idx]++;
          // if (id_read != SRC_ID) printf("Id=%d dlc=%d flags=0x%x\n", id_read, dlc, flags);
          if (flags & canMSG_ERROR_FRAME) printf("x");
        }
      } while (stat == canOK);
    }
    stat = canWriteSync(hnd, 1000);
    Check("canWriteSync A", stat);
    Sleep(P_NAP);

    if (TimeToLeave) break;
  }
  return 0;
}

DWORD WINAPI ReadOne(PVOID p)
{
  canHandle   hnd;
  canStatus   stat;
  ULONG       idx;

  idx = PtrToUlong(p);

  hnd = InitCtrl(channels[idx]);
  TotalReceived[idx] = 0;
  WaitForSingleObject(events[idx], INFINITE);

  while (TRUE) {

    //
    // Call canReadSyncSpecific to wait for the message(s) that the other threads
    // are sending back and forth, then call canRead to consume the messages.
    //
    do {
      stat = canReadSyncSpecific(hnd, SRC_ID, 500);
      if (stat == canOK) {
        if (Verbose > 1) printf("r");
      } else {
        if (Verbose > 1) printf("T");
      }
      while (canRead(hnd, NULL, NULL, NULL, NULL, NULL) == canOK) {
        TotalReceived[idx]++;
      }
    } while (stat == canOK);

    //
    // Call canReadSyncSpecific again to wait for a non-existent id - this time
    // we expect a timeout.
    //
    do {
      stat = canReadSyncSpecific(hnd, SRC_ID+5, 50);
      if (stat == canOK) {
        printf("Whoops, canReadSyncSpecific failed");
      }
    } while (stat == canOK);

    if (TimeToLeave) break;
    Sleep(C_NAP);
  }

  return 0;
}

//
// Just consume all messages on the bus.
//
DWORD WINAPI Sink(PVOID p)
{
  canHandle hnd;
  ULONG     idx;

  idx = PtrToUlong(p);
  hnd = InitCtrl(channels[idx]);
  TotalReceived[idx] = 0;
  WaitForSingleObject(events[idx], INFINITE);

  while (TRUE) {

    while (canRead(hnd, NULL, NULL, NULL, NULL, NULL) == canOK) {
      if (Verbose > 1) printf("x");
      TotalReceived[idx]++;
    }

    if (TimeToLeave) break;
    Sleep(C_NAP);
  }

  return 0;
}



//
//
void main(int argc, char* argv[])
{
  int i;
  DWORD tid;
  HANDLE t1, t2, t3, t4;


  for (i=0; i<4; i++) channels[i] = i;

  //
  // First, parse the command-line arguments.
  //
  for (i=1; i<argc; i++) {
    int tmp;
    char c;
    if (sscanf(argv[i], "-a%d%c", &tmp, &c) == 1) {
      channels[0] = tmp;
    } else if (sscanf(argv[i], "-b%d%c", &tmp, &c) == 1) {
      channels[1] = tmp;
    } else if (sscanf(argv[i], "-c%d%c", &tmp, &c) == 1) {
      channels[2] = tmp;
    } else if (sscanf(argv[i], "-d%d%c", &tmp, &c) == 1) {
      channels[3] = tmp;
    } else if (sscanf(argv[i], "-B%d%c", &tmp, &c) == 1) {
      switch (tmp) {
      case 1000 : Bitrate = canBITRATE_1M; break;
      case 500  : Bitrate = canBITRATE_500K; break;
      case 250  : Bitrate = canBITRATE_250K; break;
      case 125  : Bitrate = canBITRATE_125K; break;
      default : Usage(argc, argv);
      }
    } else if (strcmp(argv[i], "-v") == 0) {
      Verbose++;
    } else if (sscanf(argv[i], "-L%d%c", &tmp, &c) == 1) {
      MaxLoops = tmp;
    } else {
      Usage(argc, argv);
    }
  }

  printf("\nCANLIB Thread Test 4\n");
  memset(TotalSent, 0, sizeof(TotalSent));
  memset(TotalReceived, 0, sizeof(TotalReceived));

  canInitializeLibrary();

  InitializeCriticalSection(&cs);
  TimeToLeave = FALSE;

  t1 = t2 = t3 = t4 = NULL;

  if (channels[0] != 99) t1 = CreateThread(NULL, 0, SendAndReceive, (LPVOID)0, CREATE_SUSPENDED, &tid);
  if (channels[1] != 99) t2 = CreateThread(NULL, 0, SendAndReceive, (LPVOID)1, CREATE_SUSPENDED, &tid);
  if (channels[2] != 99) t3 = CreateThread(NULL, 0, ReadOne, (LPVOID)2, CREATE_SUSPENDED, &tid);
  if (channels[3] != 99) t4 = CreateThread(NULL, 0, Sink, (LPVOID)3, CREATE_SUSPENDED, &tid);

  printf("\n");
  if (t1) printf("SendAndReceive on channel %d\n", channels[0]);
  if (t2) printf("SendAndReceive on channel %d\n", channels[1]);
  if (t3) printf("ReadOne on channel %d\n", channels[2]);
  if (t4) printf("Sink on channel %d\n", channels[3]);
  printf("\n");

  for (i=0; i<4; i++) events[i] = CreateEvent(0, FALSE, FALSE, 0);

  ResumeThread(t1);
  ResumeThread(t2);
  ResumeThread(t3);
  ResumeThread(t4);

  Sleep(100);
  for (i=0; i<4; i++) SetEvent(events[i]);

  while (TRUE) {
    Sleep(200);
    if (_kbhit()) {
      _getch();
      break;
    }
    if (--MaxLoops == 0) break;
  }

  TimeToLeave = TRUE;
  WaitForSingleObject(t1, 2000);
  WaitForSingleObject(t2, 2000);
  WaitForSingleObject(t3, 2000);
  WaitForSingleObject(t4, 2000);

  printf("\nChannel      Sent     Received\n");
  for (i=0; i<4; i++) {
    printf("%7d%10ld%13ld\n", channels[i], TotalSent[i], TotalReceived[i]);
  }

}