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/*

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This file is part of CanFestival, a library implementing CanOpen Stack.

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CanFestival Copyright (C): Edouard TISSERANT and Francis DUPIN

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CanFestival Win32 port Copyright (C) 2007 Leonid Tochinski, ChattenAssociates, Inc.

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See COPYING file for copyrights details.

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This library is free software; you can redistribute it and/or

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modify it under the terms of the GNU Lesser General Public

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License as published by the Free Software Foundation; either

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version 2.1 of the License, or (at your option) any later version.

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This library is distributed in the hope that it will be useful,

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but WITHOUT ANY WARRANTY; without even the implied warranty of

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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

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Lesser General Public License for more details.

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You should have received a copy of the GNU Lesser General Public

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License along with this library; if not, write to the Free Software

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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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*/

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// thread safe que

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#ifndef __async_access_que_h__

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#define __async_access_que_h__

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#include <deque>

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#include "AutoReleaseCS.h"

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template<typename type>

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class async_access_que

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   {

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   public:

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      async_access_que()

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         {

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         ::InitializeCriticalSection(&m_cs);

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

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

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

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		 m_commands[0] = m_newObject;

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		 m_commands[1] = m_stop;

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         }

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      ~async_access_que()

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         {

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		 SignalObjectAndWait(m_stop, m_stopped, 500, FALSE);

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         ::DeleteCriticalSection(&m_cs);

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		 CloseHandle(m_stop);

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		 CloseHandle(m_stopped);

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		 CloseHandle(m_newObject);

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         }

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      void append(const type& data)

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         {

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         AutoReleaseCS acs(m_cs);

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         m_data.push_back(data);

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	 SetEvent(m_newObject);

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         }

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      bool extract_top(type& data)

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         {

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			 bool empty = true;

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			 {

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				 AutoReleaseCS acs(m_cs);

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				 empty = m_data.empty();

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			 }

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			 if (empty)

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			 {

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				 DWORD objectIndex;

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				 do

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				 {

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					objectIndex = WaitForMultipleObjects(sizeof(m_commands) / sizeof(&(m_commands[0])), m_commands, FALSE, INFINITE);

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					if (objectIndex - WAIT_OBJECT_0 == 1)  //m_stop

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					{

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						SetEvent(m_stopped);

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						return false; //This will exit the canReceive-loop

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					}

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				} while (objectIndex - WAIT_OBJECT_0 != 0);

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			 }

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			 {

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				AutoReleaseCS acs(m_cs);

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				if (m_data.empty())

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				{

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					return false; //This will exit the canReceive-loop

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				}

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				data = m_data.front();

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				m_data.pop_front();

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				ResetEvent(m_newObject);

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				return true;

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			}

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         }

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      void clear()

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         {

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         AutoReleaseCS acs(m_cs);

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         m_data.clear();

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         }

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   protected:

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      std::deque<type> m_data;

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      CRITICAL_SECTION m_cs;

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	  HANDLE m_newObject;

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	  HANDLE m_stop;

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	  HANDLE m_stopped;

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	  HANDLE m_commands[2];

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   };

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#endif //__async_access_que_h__