/*****************************************************************************
The Dark Mod GPL Source Code

This file is part of the The Dark Mod Source Code, originally based
on the Doom 3 GPL Source Code as published in 2011.

The Dark Mod Source Code is free software: you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version. For details, see LICENSE.TXT.

Project: The Dark Mod (http://www.thedarkmod.com/)

******************************************************************************/
#pragma hdrstop
#include "precompiled.h"

/*
================================================================================================
Contains the vartious ThreadingClass implementations.
================================================================================================
*/

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

	idSysThread

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

/*
========================
idSysThread::idSysThread
========================
*/
idSysThread::idSysThread() :
		threadHandle( 0 ),
		isWorker( false ),
		isRunning( false ),
		isTerminating( false ),
		moreWorkToDo( false ),
		signalWorkerDone( true ) {
}

/*
========================
idSysThread::~idSysThread
========================
*/
idSysThread::~idSysThread() {
	StopThread( true );
	if ( threadHandle ) {
		Sys_DestroyThread( threadHandle );
	}
}

/*
========================
idSysThread::StartThread
========================
*/
bool idSysThread::StartThread( const char * name_, core_t core, xthreadPriority priority, int stackSize ) {
	if ( isRunning ) {
		return false;
	}

	name = name_;

	isTerminating = false;

	if ( threadHandle ) {
		Sys_DestroyThread( threadHandle );
	}

	threadHandle = Sys_CreateThread( (xthread_t)ThreadProc, this, priority, name, core, stackSize, false );

	isRunning = true;
	return true;
}

/*
========================
idSysThread::StartWorkerThread
========================
*/
bool idSysThread::StartWorkerThread( const char * name_, core_t core, xthreadPriority priority, int stackSize ) {
	if ( isRunning ) {
		return false;
	}

	isWorker = true;

	bool result = StartThread( name_, core, priority, stackSize );

	signalWorkerDone.Wait( idSysSignal::WAIT_INFINITE );

	return result;
}

/*
========================
idSysThread::StopThread
========================
*/
void idSysThread::StopThread( bool wait ) {
	if ( !isRunning ) {
		return;
	}
	if ( isWorker ) {
		signalMutex.Lock();
		moreWorkToDo = true;
		signalWorkerDone.Clear();
		isTerminating = true;
		signalMoreWorkToDo.Raise();
		signalMutex.Unlock();
	} else {
		isTerminating = true;
	}
	if ( wait ) {
		WaitForThread();
	}
}

/*
========================
idSysThread::WaitForThread
========================
*/
void idSysThread::WaitForThread() {
	if ( isWorker ) {
		signalWorkerDone.Wait( idSysSignal::WAIT_INFINITE );
	} else if ( isRunning ) {
		Sys_DestroyThread( threadHandle );
		threadHandle = 0;
	}
}

/*
========================
idSysThread::SignalWork
========================
*/
void idSysThread::SignalWork() {
	if ( isWorker ) {
		signalMutex.Lock();
		moreWorkToDo = true;
		signalWorkerDone.Clear();
		signalMoreWorkToDo.Raise();
		signalMutex.Unlock();
	}
}

/*
========================
idSysThread::IsWorkDone
========================
*/
bool idSysThread::IsWorkDone() {
	if ( isWorker ) {
		// a timeout of 0 will return immediately with true if signaled
		if ( signalWorkerDone.Wait( 0 ) ) {
			return true;
		}
	}
	return false;
}

/*
========================
idSysThread::ThreadProc
========================
*/
int idSysThread::ThreadProc( idSysThread * thread ) {
	// stgatilov #4550: set FPU props (FTZ + DAZ, etc.)
	sys->ThreadStartup();

	int retVal = 0;

	try {
		if ( thread->isWorker ) {
			for( ; ; ) {
				thread->signalMutex.Lock();
				if ( thread->moreWorkToDo ) {
					thread->moreWorkToDo = false;
					thread->signalMoreWorkToDo.Clear();
					thread->signalMutex.Unlock();
				} else {
					thread->signalWorkerDone.Raise();
					thread->signalMutex.Unlock();
					TRACE_CPU_SCOPE_COLOR( "ThreadProc::Idle", TRACE_COLOR_IDLE )
					thread->signalMoreWorkToDo.Wait( idSysSignal::WAIT_INFINITE );
					continue;
				}

				if ( thread->isTerminating ) {
					break;
				}

				// stgatilov #4550: update FPU props (e.g. NaN exceptions)
				sys->ThreadHeartbeat( thread->GetName() );

				retVal = thread->Run();
			}
			thread->signalWorkerDone.Raise();
		} else {
			retVal = thread->Run();
		}
	} catch ( idException & ex ) {
		idLib::Warning( "Fatal error in thread %s: %s", thread->GetName(), ex.GetError() );
		// We don't handle threads terminating unexpectedly very well, so just terminate the whole process
		std::exit( 0 );
	}

	thread->isRunning = false;

	return retVal;
}

/*
========================
idSysThread::Run
========================
*/
int idSysThread::Run() {
	// The Run() is not pure virtual because on destruction of a derived class
	// the virtual function pointer will be set to NULL before the idSysThread
	// destructor actually stops the thread.
	return 0;
}

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

	test

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

/*
================================================
idMyThread test class.
================================================
*/
class idMyThread : public idSysThread {
public:
	virtual int Run() override {
		// run threaded code here
		return 0;
	}
	// specify thread data here
};

/*
========================
TestThread
========================
*/
void TestThread() {
	idMyThread thread;
	thread.StartThread( "myThread", CORE_ANY );
}

/*
========================
TestWorkers
========================
*/
void TestWorkers() {
	idSysWorkerThreadGroup<idMyThread> workers( "myWorkers", 4 );
	for ( ; ; ) {
		for ( int i = 0; i < workers.GetNumThreads(); i++ ) {
			// workers.GetThread( i )-> // setup work for this thread
		}
		workers.SignalWorkAndWait();
	}
}