Method SingleMethodExecute

Common/Core/vtkMultiThreader.cxx:188–309

Execute the method set as the SingleMethod on NumberOfThreads threads.

// Execute the method set as the SingleMethod on NumberOfThreads threads.
void vtkMultiThreader::SingleMethodExecute()
{
  int thread_loop = 0;

#ifdef VTK_USE_WIN32_THREADS
  DWORD threadId;
  HANDLE process_id[VTK_MAX_THREADS] = {};
#endif

#ifdef VTK_USE_PTHREADS
  pthread_t process_id[VTK_MAX_THREADS] = {};
#endif

  if (!this->SingleMethod)
  {
    vtkErrorMacro(<< "No single method set!");
    return;
  }

  // obey the global maximum number of threads limit
  if (vtkMultiThreaderGlobalMaximumNumberOfThreads &&
    this->NumberOfThreads > vtkMultiThreaderGlobalMaximumNumberOfThreads)
  {
    this->NumberOfThreads = vtkMultiThreaderGlobalMaximumNumberOfThreads;
  }

#ifdef VTK_USE_WIN32_THREADS
  // Using CreateThread on Windows
  //
  // We want to use CreateThread to start this->NumberOfThreads - 1
  // additional threads which will be used to call this->SingleMethod().
  // The parent thread will also call this routine.  When it is done,
  // it will wait for all the children to finish.
  //
  // First, start up the this->NumberOfThreads-1 processes.  Keep track
  // of their process ids for use later in the waitid call
  for (thread_loop = 1; thread_loop < this->NumberOfThreads; thread_loop++)
  {
    this->ThreadInfoArray[thread_loop].UserData = this->SingleData;
    this->ThreadInfoArray[thread_loop].NumberOfThreads = this->NumberOfThreads;
    process_id[thread_loop] = CreateThread(
      nullptr, 0, this->SingleMethod, ((void*)(&this->ThreadInfoArray[thread_loop])), 0, &threadId);
    if (process_id[thread_loop] == nullptr)
    {
      vtkErrorMacro("Error in thread creation !!!");
    }
  }

  // Now, the parent thread calls this->SingleMethod() itself
  this->ThreadInfoArray[0].UserData = this->SingleData;
  this->ThreadInfoArray[0].NumberOfThreads = this->NumberOfThreads;
  this->SingleMethod((void*)(&this->ThreadInfoArray[0]));

  // The parent thread has finished this->SingleMethod() - so now it
  // waits for each of the other processes to exit
  for (thread_loop = 1; thread_loop < this->NumberOfThreads; thread_loop++)
  {
    WaitForSingleObject(process_id[thread_loop], INFINITE);