WaitForMultipleObjects doesn't work

WaitForMultipleObjects doesn't work

• Ruhina

  Viorel. wrote:

  Maybe you should replace this: LARGE_INTEGER check_elapse = {10000}; with this: LARGE_INTEGER check_elapse = {-10000};  Otherwise the second argument of SetWaitableTimer is treated as an absolute time value, which is never reached, since it is in the past (1/1/1601).   I hope this helps.

  LARGE_INTEGER check_elapse = {-10000}; 

  check_elapse now is not a NEGATIVE. Becase, only low dword wich is unsigned filled with 0xfff..., the high dword is still being filled with zero. Its mean a number is positive.

  To make check_elapse negative, use this code

  check_elapse.QuadPart=-100000000;

  Moreove, its doesn't metter in this example value of this varible, the timer is periodic.

  lChekPeriod = 1000; //1000

  Its mean after check_elapse time the timer will be in signal state every second.

   Code works fine in XP.

  
  

• Manubhaskar

  Maybe you should replace this:

  LARGE_INTEGER check_elapse = {10000};

  with this:

  LARGE_INTEGER check_elapse = {-10000}; 

  Otherwise the second argument of SetWaitableTimer is treated as an absolute time value, which is never reached, since it is in the past (1/1/1601).

   

  I hope this helps.

  
  

• Ronaldlee Ejalu

  Can you give us GetLastError after:

  CreateWaitableTimer

  SetWaitableTimer

  And return results of this functions.

  Are you sure, that

  CHECK_PERIOD == 1000

  May be it's zero.

  
  

• DanParks

  Vladimir_V wrote:

  Now I'm using LARGE_INTEGER check_elapse = {-10000}; When I try to receive a return code (just for test) while (1) { printf("step 1"); dwObject = WaitForMultipleObjects(dwCount, hControl, FALSE, INFINITE); //1 printf("dwObject = %d", dwObject); printf("step 2"); ... I receive the following step 1 and that's all:)

  So by returns nothing, you actually mean that it doesn't return at all In this case, the problem is that you are never properly signaling either of the objects in the hControl structure.

  
  
  

• anubisascends

  Vladimir_V wrote:

  //WaitForMultipleObjects returns nothing in WinNT

  That is not possible. If it returns, then it returns something. If it returns zero, then doesn't that mean that hGlobalStop is signaled
  
  

• Thore

  yes, CHECK_PERIOD == 1000,

  I defined it:

  #define CHECK_PERIOD 1000

  
  

• Ioanna

  Please show us how you use the function.
  
  

• aboeing

  GetLastError after CreateWaitableTimer and SetWaitableTimer returns 0.

  And, as I already told, in WinXp everything is fine, code works, but in WinNT I have problems and can not understand, why

  
  

• r.matteja

  Vladimir, so what you're saying is that your call to WFMO returns immediately with a value of WAIT_FAILED
  
  

• Muzzzy

  In WinXP SP2 everything is ok,

  but in WinNT nothing happens:

  I cannot receive a code of return at all. Function WaitForMultipleObjects returns nothing.

  
  

• MickBeth

  Now I'm using LARGE_INTEGER check_elapse = {-10000};

  When I try to receive a return code (just for test)

  while (1)

  {

  printf("step 1");

  dwObject = WaitForMultipleObjects(dwCount, hControl, FALSE, INFINITE); //1

  printf("dwObject = %d", dwObject);

  printf("step 2");

  ...

  I receive the following

  step 1

  and that's all:)

  
  

• newindotnet

  What do you mean by "it doesn't work" Could you show some code, elaborate on error messages or similar
  
  

• HeathM

  Are you sure, that

  CHECK_PERIOD == 1000

  May be it's zero.

  Try to set 1000 manualy.

  
  

• Vaish

  So, fragment of a code from the program

  HANDLE hGlobalStop;

  HANDLE hCheckTimer;

  SHORT ReadStatus()

  {

  hGlobalStop = CreateEvent(NULL, FALSE, FALSE, NULL);

  hCheckTimer = ::CreateWaitableTimer(NULL, FALSE, NULL);

  if (( hCheckTimer ) && ( hGlobalStop ))

  {

  LARGE_INTEGER check_elapse = {10000};

  lChekPeriod = CHECK_PERIOD; //1000

  ::SetWaitableTimer(hCheckTimer, &check_elapse, lChekPeriod, NULL, NULL, FALSE);

  DWORD dwThreadId;

  HANDLE hThread;

  hThread = CreateThread( NULL, // no security attributes

  0, // use default stack size

  (LPTHREAD_START_ROUTINE)ThreadFunc, // thread function

  &hCheckTimer, // argument to thread function

  0, // use default creation flags

  &dwThreadId); // returns the thread identifier

  if (hThread == NULL)

  {//error}

  ::CancelWaitableTimer(hCheckTimer);

  ::CloseHandle(hCheckTimer);

  }

  }

  VOID WINAPI ThreadFunc(LPVOID lpParam)

  {

  HANDLE hControl[2];

  hControl[0] = hGlobalStop;

  hControl[1] = *(HANDLE*)lpParam;

  DWORD dwCount = sizeof(hControl) / sizeof(HANDLE);

  DWORD dwObject = 0;

  //this code doesn't work at all :

  //WaitForMultipleObjects returns nothing in WinNT

  while (WAIT_FAILED != (dwObject = WaitForMultipleObjects(dwCount, hControl, FALSE, INFINITE))) //1

  {

  switch (dwObject)

  {

  //STOP

  case WAIT_OBJECT_0:

  break;

  case (WAIT_OBJECT_0 + 1):

  //...

  break;

  // An error occurred.

  default:

  //...

  break;

  }

  }

  ExitThread(0);

  }

  
  
• WaitForMultipleObjects doesn't work