text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkThreadMessager.h
  
    Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
    All rights reserved.
    See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
  
       This software is distributed WITHOUT ANY WARRANTY; without even
       the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.  See the above copyright notice for more information.
  
  =========================================================================*/
  // .NAME vtkThreadMessager - A class for performing inter-thread messaging
  // .SECTION Description
  // vtkMultithreader is a class that provides support for messaging between
  // threads multithreaded using pthreads or Windows messaging.
  
  #ifndef vtkThreadMessager_h
  #define vtkThreadMessager_h
  
  #include "vtkCommonSystemModule.h" // For export macro
  #include "vtkObject.h"
  
  #if defined(VTK_USE_PTHREADS) || defined(VTK_HP_PTHREADS)
  #include <pthread.h> // Needed for pthread types
  #endif
  
  class VTKCOMMONSYSTEM_EXPORT vtkThreadMessager : public vtkObject
  {
  public:
    static vtkThreadMessager *New();
  
    vtkTypeMacro(vtkThreadMessager,vtkObject);
    void PrintSelf(ostream& os, vtkIndent indent) VTK_OVERRIDE;
  
    // Description:
    // Wait (block, non-busy) until another thread sends a
    // message.
    void WaitForMessage();
  
    // Description:
    // Send a message to all threads who are waiting via
    // WaitForMessage().
    void SendWakeMessage();
  
    // Description:
    // pthreads only. If the wait is enabled, the thread who
    // is to call WaitForMessage() will block until a receiver
    // thread is ready to receive.
    void EnableWaitForReceiver();
  
    // Description:
    // pthreads only. If the wait is enabled, the thread who
    // is to call WaitForMessage() will block until a receiver
    // thread is ready to receive.
    void DisableWaitForReceiver();
  
    // Description:
    // pthreads only.
    // If wait is enable, this will block until one thread is ready
    // to receive a message.
    void WaitForReceiver();
  
  protected:
    vtkThreadMessager();
    ~vtkThreadMessager();
  
  #ifdef VTK_USE_PTHREADS
    pthread_mutex_t Mutex;
    pthread_cond_t PSignal;
  #endif
  
  #ifdef VTK_USE_WIN32_THREADS
    vtkWindowsHANDLE WSignal;
  #endif
  
  private:
    vtkThreadMessager(const vtkThreadMessager&) VTK_DELETE_FUNCTION;
    void operator=(const vtkThreadMessager&) VTK_DELETE_FUNCTION;
  };
  
  #endif
  