vtkConditionVariable.h

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/*=========================================================================
 
  Program:   Visualization Toolkit
  Module:    vtkConditionVariable.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.
 
=========================================================================*/
#ifndef vtkConditionVariable_h
#define vtkConditionVariable_h
 
#include "vtkCommonCoreModule.h" // For export macro
#include "vtkObject.h"
 
#include "vtkMutexLock.h" // Need for friend access to vtkSimpleMutexLock
 
#if defined(VTK_USE_PTHREADS)
#include <pthread.h> // Need POSIX thread implementation of mutex (even win32 provides mutexes)
typedef pthread_cond_t vtkConditionType;
#endif
 
// Typically a top level windows application sets _WIN32_WINNT. If it is not set we set it to
// 0x0501 (Windows XP)
#ifdef VTK_USE_WIN32_THREADS
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0501 // 0x0501 means target Windows XP or later
#endif
#include "vtkWindows.h" // Needed for win32 CRITICAL_SECTION, HANDLE, etc.
#endif
 
#ifdef VTK_USE_WIN32_THREADS
#if 1
typedef struct
{
  // Number of threads waiting on condition.
  int WaitingThreadCount;
 
  // Lock for WaitingThreadCount
  CRITICAL_SECTION WaitingThreadCountCritSec;
 
  // Semaphore to block threads waiting for the condition to change.
  vtkWindowsHANDLE Semaphore;
 
  // An event used to wake up thread(s) waiting on the semaphore
  // when pthread_cond_signal or pthread_cond_broadcast is called.
  vtkWindowsHANDLE DoneWaiting;
 
  // Was pthread_cond_broadcast called?
  size_t WasBroadcast;
} pthread_cond_t;
 
typedef pthread_cond_t vtkConditionType;
#else  // 0
typedef struct
{
  // Number of threads waiting on condition.
  int WaitingThreadCount;
 
  // Lock for WaitingThreadCount
  CRITICAL_SECTION WaitingThreadCountCritSec;
 
  // Number of threads to release when pthread_cond_broadcast()
  // or pthread_cond_signal() is called.
  int ReleaseCount;
 
  // Used to prevent one thread from decrementing ReleaseCount all
  // by itself instead of letting others respond.
  int NotifyCount;
 
  // A manual-reset event that's used to block and release waiting threads.
  vtkWindowsHANDLE Event;
} pthread_cond_t;
 
typedef pthread_cond_t vtkConditionType;
#endif // 0
#endif // VTK_USE_WIN32_THREADS
 
#ifndef VTK_USE_PTHREADS
#ifndef VTK_USE_WIN32_THREADS
typedef int vtkConditionType;
#endif
#endif
 
// Condition variable that is not a vtkObject.
class VTKCOMMONCORE_EXPORT vtkSimpleConditionVariable
{
public:
  vtkSimpleConditionVariable();
  ~vtkSimpleConditionVariable();
 
  static vtkSimpleConditionVariable* New();
 
  void Delete() { delete this; }
 
  void Signal();
 
  void Broadcast();
 
  int Wait(vtkSimpleMutexLock& mutex);
 
protected:
  vtkConditionType ConditionVariable;
 
private:
  vtkSimpleConditionVariable(const vtkSimpleConditionVariable& other) = delete;
  vtkSimpleConditionVariable& operator=(const vtkSimpleConditionVariable& rhs) = delete;
};
 
class VTKCOMMONCORE_EXPORT vtkConditionVariable : public vtkObject
{
public:
  static vtkConditionVariable* New();
  vtkTypeMacro(vtkConditionVariable, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;
 
  void Signal();
 
  void Broadcast();
 
  int Wait(vtkMutexLock* mutex);
 
protected:
  vtkConditionVariable() {}
 
  vtkSimpleConditionVariable SimpleConditionVariable;
 
private:
  vtkConditionVariable(const vtkConditionVariable&) = delete;
  void operator=(const vtkConditionVariable&) = delete;
};
 
inline void vtkConditionVariable::Signal()
{
  this->SimpleConditionVariable.Signal();
}
 
inline void vtkConditionVariable::Broadcast()
{
  this->SimpleConditionVariable.Broadcast();
}
 
inline int vtkConditionVariable::Wait(vtkMutexLock* lock)
{
  return this->SimpleConditionVariable.Wait(lock->SimpleMutexLock);
}
 
#endif // vtkConditionVariable_h