/*
	Lan Wars.
	Copyright (c) 2009, Darragh Coy.
	All rights reserved.
	Original work(s), source code & author(s) details available at: http://www.darraghcoy.com

	Redistribution and use in source and binary forms, with or without modification, are permitted 
	provided that the following conditions are met:

		* 	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.
		* 	Neither the name of the author nor the names of contributors may be used to endorse or 
			promote products derived from this software without specific prior written permission.
		* 	The use of any third party libraries, modules or data files provided with the source 
			form of the program must follow and respect the individual licensing terms of these 
			components. You do not have permission to modify or circumvent the licensing terms for 
			provided third party components unless the third party licenses specifically allow this. 
			If you do not agree to the terms of provided third party components then you do not have 
			permission to use them in your derived work(s).
		* 	The terms of this license do not apply to separate (but related) distributions if supplied 
			by the author(s), only to the contents of this source distribution, derived works, and the 
			binaries produced by either modified or unmodified versions of the source code. The terms 
			of this license do not also apply to any third party libraries or components provided with 
			the source distribution. Such third party elements are licensed under their own separate 
			agreements.

	THIS SOFTWARE IS PROVIDED BY DARRAGH COY ''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 DARRAGH COY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
	EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
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	OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
	IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef GAME_CONDITION_H
#define GAME_CONDITION_H

//=====================================================================================================================
//=====================================================================================================================

namespace Game
{
	//=================================================================================================================
	/// @brief		This class represents a condition that can be used to synchronise threads waiting for some condition
	///				to be true. The event represents some global condition that is either true or false and differs
	///				from a mutex in that there is no concept of ownership, the condition is either true or it is false.
	/// @remarks	Although the condition can be modified by any thread, only the thread that created the condition is 
	///				allowed to delete it. This follows the master-thread model of the Thread class. The master 
	///				thread should create these conditions and all other sub threads should just use them.
	//=================================================================================================================

	class Condition
	{
		public:
			
			//=========================================================================================================
			// Functions
			//=========================================================================================================
					    
				/// Creates the condition
			    
				Condition( bool initially_true = false , bool exit_on_failure = true );

				/// Destroys the condition

				~Condition();

				/// Waits for the condition to be true. 

				void WaitUntilTrue() const;

				/// Sets the condition to be true

				void SetTrue();

				/// Sets the condition to be false

				void SetFalse();

				/// Tells if the condition is true
				
				bool IsTrue() const;
				
				/// Tells if the condition is false
				
				bool IsFalse() const;

				/// Tells if the condition is valid: no attempt should be made to use an invalid condition

				bool IsValid() const { return m_event_handle != 0; }
			
		private:
		
			//=========================================================================================================
			// Functions
			//=========================================================================================================
			
				/// Cannot be copied
				
				Condition( const Condition & other );
				
				/// Cannot be copied
				
				Condition & operator = ( const Condition & other );
		
			//=========================================================================================================
			// Variables
			//=========================================================================================================
		
				/// Handle to the Win32 event: when this is signalled the condition is considered to be true

				HANDLE m_event_handle;

				#ifdef DEBUG

					/// Debug only variable which indicates the id of the current thread that created the condition

					DWORD m_owner_thread_id;

				#endif
	};
};

#endif 
