/**

  * vim: set ts=4 :

  * =============================================================================

  * SourceMod

  * Copyright (C) 2004-2007 AlliedModders LLC.  All rights reserved.

  * =============================================================================

  *

  * This program is free software; you can redistribute it and/or modify it under

  * the terms of the GNU General Public License, version 3.0, as published by the

  * Free Software Foundation.

  * 

  * This program is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

  * details.

  *

  * You should have received a copy of the GNU General Public License along with

  * this program.  If not, see <http://www.gnu.org/licenses/>.

  *

  * As a special exception, AlliedModders LLC gives you permission to link the

  * code of this program (as well as its derivative works) to "Half-Life 2," the

  * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

  * by the Valve Corporation.  You must obey the GNU General Public License in

  * all respects for all other code used.  Additionally, AlliedModders LLC grants

  * this exception to all derivative works.  AlliedModders LLC defines further

  * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

  * or <http://www.sourcemod.net/license.php>.

  *

  * Version: $Id$

  */

 #include "ThreadWorker.h"

 ThreadWorker::ThreadWorker(IThreadWorkerCallbacks *hooks) : BaseWorker(hooks),

 	m_Threader(NULL),

 	m_QueueLock(NULL),

 	m_StateLock(NULL),

 	m_PauseSignal(NULL),

 	m_AddSignal(NULL),

 	me(NULL),

 	m_think_time(DEFAULT_THINK_TIME_MS)

 {

 	m_state = Worker_Invalid;

 }

 ThreadWorker::ThreadWorker(IThreadWorkerCallbacks *hooks, IThreader *pThreader, unsigned int thinktime) : 

 	BaseWorker(hooks),

 	m_Threader(pThreader),

 	m_QueueLock(NULL),

 	m_StateLock(NULL),

 	m_PauseSignal(NULL),

 	m_AddSignal(NULL),

 	me(NULL),

 	m_think_time(thinktime)

 {

 	if (m_Threader)

 	{

 		m_state = Worker_Stopped;

 	} else {

 		m_state = Worker_Invalid;

 	}

 }

 ThreadWorker::~ThreadWorker()

 {

 	if (m_state != Worker_Stopped || m_state != Worker_Invalid)

 	{

 		Stop(true);

 	}

 	if (m_ThreadQueue.size())

 	{

 		Flush(true);

 	}

 }

 void ThreadWorker::OnTerminate(IThreadHandle *pHandle, bool cancel)

 {

 	//we don't particularly care

 	return;

 }

 void ThreadWorker::RunThread(IThreadHandle *pHandle)

 {

 	WorkerState this_state = Worker_Running;

 	size_t num;

 	if (m_pHooks)

 	{

 		m_pHooks->OnWorkerStart(this);

 	}

 	while (true)

 	{

 		/**

 		 * Check number of items in the queue

 		 */

 		m_StateLock->Lock();

 		this_state = m_state;

 		m_StateLock->Unlock();

 		if (this_state != Worker_Stopped)

 		{

 			m_QueueLock->Lock();

 			num = m_ThreadQueue.size();

 			if (!num)

 			{

 				/** 

 				 * if none, wait for an item

 				 */

 				m_Waiting = true;

 				m_QueueLock->Unlock();

 				/* first check if we should end again */

 				if (this_state == Worker_Stopped)

 				{

 					break;

 				}

 				m_AddSignal->Wait();

 				m_Waiting = false;

 			} else {

 				m_QueueLock->Unlock();

 			}

 		}

 		m_StateLock->Lock();

 		this_state = m_state;

 		m_StateLock->Unlock();

 		if (this_state != Worker_Running)

 		{

 			if (this_state == Worker_Paused || this_state == Worker_Stopped)

 			{

 				//wait until the lock is cleared.

 				if (this_state == Worker_Paused)

 				{

 					m_PauseSignal->Wait();

 				}

 				if (this_state == Worker_Stopped)

 				{

 					//if we're supposed to flush cleanrly, 

 					// run all of the remaining frames first.

 					if (!m_FlushType)

 					{

 						while (m_ThreadQueue.size())

 						{

 							RunFrame();

 						}

 					}

 					break;

 				}

 			}

 		}

 		/**

 		 * Run the frame.

 		 */

 		RunFrame();

 		/**

 		 * wait in between threads if specified

 		 */

 		if (m_think_time)

 		{

 			m_Threader->ThreadSleep(m_think_time);

 		}

 	}

 	if (m_pHooks)

 	{

 		m_pHooks->OnWorkerStop(this);

 	}

 }

 SWThreadHandle *ThreadWorker::PopThreadFromQueue()

 {

 	if (m_state <= Worker_Stopped && !m_QueueLock)

 	{

 		return NULL;

 	}

 	SWThreadHandle *swt;

 	m_QueueLock->Lock();

 	swt = BaseWorker::PopThreadFromQueue();

 	m_QueueLock->Unlock();

 	return swt;

 }

 void ThreadWorker::AddThreadToQueue(SWThreadHandle *pHandle)

 {

 	if (m_state <= Worker_Stopped)

 	{

 		return;

 	}

 	m_QueueLock->Lock();

 	BaseWorker::AddThreadToQueue(pHandle);

 	if (m_Waiting)

 	{

 		m_AddSignal->Signal();

 	}

 	m_QueueLock->Unlock();

 }

 WorkerState ThreadWorker::GetStatus(unsigned int *threads)

 {

 	WorkerState state;

 	m_StateLock->Lock();

 	state = BaseWorker::GetStatus(threads);

 	m_StateLock->Unlock();

 	return state;

 }

 bool ThreadWorker::Start()

 {

 	if (m_state == Worker_Invalid)

 	{

 		if (m_Threader == NULL)

 		{

 			return false;

 		}

 	} else if (m_state != Worker_Stopped) {

 		return false;

 	}

 	m_Waiting = false;

 	m_QueueLock = m_Threader->MakeMutex();

 	m_StateLock = m_Threader->MakeMutex();

 	m_PauseSignal = m_Threader->MakeEventSignal();

 	m_AddSignal = m_Threader->MakeEventSignal();

 	m_state = Worker_Running;

 	ThreadParams pt;

 	pt.flags = Thread_Default;

 	pt.prio = ThreadPrio_Normal;

 	me = m_Threader->MakeThread(this, &pt);

 	return true;

 }

 bool ThreadWorker::Stop(bool flush_cancel)

 {

 	if (m_state == Worker_Invalid || m_state == Worker_Stopped)

 	{

 		return false;

 	}

 	WorkerState oldstate;

 	//set new state

 	m_StateLock->Lock();

 	oldstate = m_state;

 	m_state = Worker_Stopped;

 	m_FlushType = flush_cancel;

 	m_StateLock->Unlock();

 	if (oldstate == Worker_Paused)

 	{

 		Unpause();

 	} else {

 		m_QueueLock->Lock();

 		if (m_Waiting)

 		{

 			m_AddSignal->Signal();

 		}

 		m_QueueLock->Unlock();

 	}

 	me->WaitForThread();

 	//destroy it

 	me->DestroyThis();

 	//flush all remaining events

 	Flush(true);

 	//free mutex locks

 	m_QueueLock->DestroyThis();

 	m_StateLock->DestroyThis();

 	m_PauseSignal->DestroyThis();

 	m_AddSignal->DestroyThis();

 	//invalidizzle

 	m_QueueLock = NULL;

 	m_StateLock = NULL;

 	m_PauseSignal = NULL;

 	m_AddSignal = NULL;

 	me = NULL;

 	return true;

 }

 bool ThreadWorker::Pause()

 {

 	if (m_state != Worker_Running)

 	{

 		return false;

 	}

 	m_StateLock->Lock();

 	m_state = Worker_Paused;

 	m_StateLock->Unlock();

 	return true;

 }

 bool ThreadWorker::Unpause()

 {

 	if (m_state != Worker_Paused)

 	{

 		return false;

 	}

 	m_StateLock->Lock();

 	m_state = Worker_Running;

 	m_StateLock->Unlock();

 	m_PauseSignal->Signal();

 	if (m_Waiting)

 	{

 		m_AddSignal->Signal();

 	}

 	return true;

 }