itkSemaphore.h

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/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkSemaphore.h,v $
  Language:  C++
  Date:      $Date: 2009-03-03 15:09:14 $
  Version:   $Revision: 1.12 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/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 notices for more information.

=========================================================================*/
#ifndef __itkSemaphore_h
#define __itkSemaphore_h

#include "itkObjectFactory.h"
#include "itkLightObject.h"
#include "itkConfigure.h"
#include <string>

#ifdef ITK_USE_UNIX_IPC_SEMAPHORES
#include "itkMutexLock.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <errno.h>
#endif

#ifndef ITK_USE_UNIX_IPC_SEMAPHORES
#ifdef ITK_USE_SPROC
#include "itkMultiThreader.h"
#include <ulocks.h>
#endif
#ifdef ITK_USE_PTHREADS
#ifdef sun
#include <synch.h>
#else
#include <semaphore.h>
#endif
#endif
#endif

#ifdef ITK_USE_WIN32_THREADS
#include "itkWindows.h"
#endif

namespace itk {
  
#ifdef ITK_USE_UNIX_IPC_SEMAPHORES
typedef int SemaphoreType;
#endif
  
#ifndef ITK_USE_UNIX_IPC_SEMAPHORES
#ifdef ITK_USE_SPROC
typedef usema_t * SemaphoreType;
#endif
#ifdef ITK_USE_PTHREADS
#ifdef sun
typedef sema_t SemaphoreType;
#else
#ifdef __APPLE__
typedef sem_t *SemaphoreType;
#else
typedef sem_t  SemaphoreType;
#endif
#endif
#endif
#endif

#ifdef ITK_USE_WIN32_THREADS
typedef HANDLE SemaphoreType;
#endif

#ifndef ITK_USE_UNIX_IPC_SEMAPHORES
#ifndef ITK_USE_SPROC
#ifndef ITK_USE_PTHREADS
#ifndef ITK_USE_WIN32_THREADS
typedef int SemaphoreType;
#endif
#endif
#endif
#endif

class ITKCommon_EXPORT Semaphore : public LightObject
{
public:
  typedef Semaphore                 Self;
  typedef LightObject               Superclass;
  typedef SmartPointer<Self>        Pointer;
  typedef SmartPointer<const Self>  ConstPointer;

  itkNewMacro(Self);  

  itkTypeMacro(Semaphore, LightObject);

  void Initialize(unsigned int value);

  void Up();

  void Down();

  void Remove ();

protected:
  Semaphore ();
  ~Semaphore();

private:   

#ifdef ITK_USE_UNIX_IPC_SEMAPHORES

  static int m_IPCSemaphoreKey;

  static SimpleMutexLock m_Mutex;

  int  UnixIpcSemaphoreCreate (int unix_semaphore_key);
  void UnixIpcSemaphoreRemove (int sid);
  void UnixIpcSemaphoreCall   (int sid, int op);
  void UnixIpcSemaphoreDown   (int sid);
  void UnixIpcSemaphoreUp     (int sid);
#endif
  
  char Pad1[128]; // to avoid false sharing in case of shared memory multiprocessor systems
  SemaphoreType m_Sema;
  char Pad2[128]; // to avoid false sharing in case of shared memory multiprocessor systems

#ifdef __APPLE__
  std::string GetUniqueName();
  static int  m_SemaphoreCount;
  std::string m_SemaphoreName;
#endif

#ifdef ITK_USE_PTHREADS
  bool m_PThreadsSemaphoreRemoved;
#endif

};
 
}//itk

#endif