/*===========================================================================
FILE:
   Event.h

DESCRIPTION:
   Declaration of cEvent class
   
PUBLIC CLASSES AND METHODS:
   WaitOnMultipleEvents
   cEvent
      Functionality to mimic Windows events using UNIX pipes (enhanced
      somewhat to allow one to specify a DWORD value to pass through
      when signalling the event)

   WARNING:
      This class is not designed to be thread safe

Copyright (c) 2013, The Linux Foundation. All rights reserved.

Redistribution and use in source and binary forms, with or without
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    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of The Linux Foundation nor the names of its
      contributors may be used to endorse or promote products derived from 
      this software without specific prior written permission.


THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
===========================================================================*/

//---------------------------------------------------------------------------
// Pragmas
//---------------------------------------------------------------------------
#pragma once

//---------------------------------------------------------------------------
// Include Files
//---------------------------------------------------------------------------
#include "StdAfx.h"
#include <vector>

//---------------------------------------------------------------------------
// Prototype
//---------------------------------------------------------------------------

class cEvent;

/*=========================================================================*/
// Free methods
/*=========================================================================*/

// Wait for any of the events to be set and return the value
int WaitOnMultipleEvents(
   std::vector <cEvent *>        events,
   DWORD                         timeoutMS, 
   DWORD &                       val,
   DWORD &                       eventIndex );

/*=========================================================================*/
// Class cEvent
/*=========================================================================*/
class cEvent
{
   public:
      // Constructor
      cEvent();
      
      // Destructor
      ~cEvent();

      // Set/signal the event with the specified value
      int Set( DWORD val );

      // Wait for the event to be signalled and return the read in value
      int Wait( 
         DWORD                      timeoutMS, 
         DWORD &                    val );

      // Read and discard all values currently in the pipe
      void Clear();

   protected:
      // Close pipe (used in errors or normal exit)
      int Close();

      // Read from the pipe
      int Read( DWORD & val );

      /* Internal error status */
      int mError;
      
      /*  Internal pipes */
      int mPipes[2];

      // WaitOnMultipleEvents gets full access
      friend int WaitOnMultipleEvents(
         std::vector <cEvent *>        events,
         DWORD                         timeoutMS, 
         DWORD &                       val,
         DWORD &                       eventIndex );
};

