/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.

This program 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.

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/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#ifndef hsThread_Defined
#define hsThread_Defined

#include "hsTypes.h"

typedef UInt32 hsMilliseconds;


#if HS_BUILD_FOR_MAC
	#include <Multiprocessing.h>
#elif HS_BUILD_FOR_WIN32
	#include "hsWindows.h"
#elif HS_BUILD_FOR_UNIX
	#include <pthread.h>
	#include <semaphore.h>
	//  We can't wait with a timeout with semas
	#define USE_SEMA
	// Linux kernel 2.4 w/ NTPL threading patch and O(1) scheduler
	// seems to have a problem in it's cond_t implementation that
	// causes a hang under heavy load. This is a workaround that
	// uses select() and pipes.
//	#define PSEUDO_EVENT
#endif

class hsThread 
{
public:
#if HS_BUILD_FOR_MAC
	typedef MPTaskId ThreadId;
#elif HS_BUILD_FOR_WIN32
	typedef DWORD ThreadId;
#elif HS_BUILD_FOR_UNIX
	typedef pthread_t ThreadId;
#endif
private:
	hsBool		fQuit;
	UInt32		fStackSize;
#if HS_BUILD_FOR_MAC
	ThreadId	fTaskId;
	MPQueueId	fNotifyQ;
#elif HS_BUILD_FOR_WIN32
	ThreadId	fThreadId;
	HANDLE		fThreadH;
	HANDLE		fQuitSemaH;
#elif HS_BUILD_FOR_UNIX
	ThreadId	fPThread;
	hsBool		fIsValid;
	pthread_mutex_t	fMutex;
#endif
protected:
	hsBool		GetQuit() const { return hsBool(fQuit); }
	void		SetQuit(hsBool value) { fQuit = value; }
public:
	hsThread(UInt32 stackSize = 0);
	virtual 	~hsThread();	// calls Stop()
#if HS_BUILD_FOR_MAC
	ThreadId		GetThreadId() { return fTaskId; }
#error "Mac is Depricated"
#elif HS_BUILD_FOR_WIN32
	ThreadId		GetThreadId() { return fThreadId; }
	static ThreadId	GetMyThreadId() { return GetCurrentThreadId(); }
#elif HS_BUILD_FOR_UNIX
	ThreadId			GetThreadId() { return fPThread; }
	static ThreadId		GetMyThreadId() { return pthread_self(); }
	pthread_mutex_t* GetStartupMutex() { return &fMutex;  }
#endif
				
	virtual hsError Run() = 0;		// override this to do your work
	virtual void	Start();		// initializes stuff and calls your Run() method
	virtual void	Stop(); 	// sets fQuit = true and the waits for the thread to stop
				
	//	Static functions
	static void*	Alloc(size_t size); // does not call operator::new(), may return nil
	static void Free(void* p);		// does not call operator::delete()
	static void ThreadYield();
				
#if HS_BUILD_FOR_WIN32
	DWORD			WinRun();
#endif
};

//////////////////////////////////////////////////////////////////////////////

class hsMutex {
#if HS_BUILD_FOR_MAC
	MPCriticalRegionId	fCriticalRegion;
#elif HS_BUILD_FOR_WIN32
	HANDLE	fMutexH;
#elif HS_BUILD_FOR_UNIX
	pthread_mutex_t	fPMutex;
#endif
public:
	hsMutex();
	virtual ~hsMutex();
	
	void		Lock();
	hsBool		TryLock();
	void		Unlock();
};

class hsTempMutexLock {
	hsMutex*	fMutex;
public:
	hsTempMutexLock(hsMutex* mutex) : fMutex(mutex)
	{
		fMutex->Lock();
	}
	hsTempMutexLock(hsMutex& mutex) : fMutex(&mutex)
	{
		fMutex->Lock();
	}
	~hsTempMutexLock()
	{
		fMutex->Unlock();
	}
};

//////////////////////////////////////////////////////////////////////////////

class hsSemaphore {
#if HS_BUILD_FOR_MAC
	MPSemaphoreId	fSemaId;
#elif HS_BUILD_FOR_WIN32
	HANDLE	fSemaH;
#elif HS_BUILD_FOR_UNIX
#ifdef USE_SEMA
	sem_t	fPSema;
#else
	pthread_mutex_t	fPMutex;
	pthread_cond_t	fPCond;
	Int32		fCounter;
#endif
#endif
public:
#ifdef HS_BUILD_FOR_WIN32
	hsSemaphore(int initialValue=0, const char *name=nil);
#else
	hsSemaphore(int initialValue=0);
#endif
	~hsSemaphore();
	
	hsBool		Wait(hsMilliseconds timeToWait = kPosInfinity32);
	void		Signal();
};

//////////////////////////////////////////////////////////////////////////////
#if !HS_BUILD_FOR_MAC
class hsEvent
{
#if HS_BUILD_FOR_UNIX
#ifndef PSEUDO_EVENT
	pthread_mutex_t fMutex;
	pthread_cond_t	fCond;
	hsBool	fTriggered;
#else
	enum { kRead, kWrite };
	int		fFds[2];
	hsMutex	fWaitLock;
	hsMutex	fSignalLock;
#endif // PSEUDO_EVENT
#elif HS_BUILD_FOR_WIN32
	HANDLE fEvent;
#endif
public:
	hsEvent();
	~hsEvent();

	hsBool	Wait(hsMilliseconds timeToWait = kPosInfinity32);
	void		Signal();
};
#endif  // HS_BUILD_FOR_MAC

//////////////////////////////////////////////////////////////////////////////
#if !HS_BUILD_FOR_MAC
class hsSleep
{
public:
#if HS_BUILD_FOR_UNIX
	static void Sleep(UInt32 millis);

#elif HS_BUILD_FOR_WIN32
	static void Sleep(UInt32 millis) { ::Sleep(millis); }

#endif
};
#endif  // HS_BUILD_FOR_MAC


//////////////////////////////////////////////////////////////////////////////
// Allows multiple readers, locks out readers for writing.

class hsReaderWriterLock
{
public:
	struct Callback
	{
		virtual void OnLockingForRead( hsReaderWriterLock * lock ) {}
		virtual void OnLockedForRead( hsReaderWriterLock * lock ) {}
		virtual void OnUnlockingForRead( hsReaderWriterLock * lock ) {}
		virtual void OnUnlockedForRead( hsReaderWriterLock * lock ) {}
		virtual void OnLockingForWrite( hsReaderWriterLock * lock ) {}
		virtual void OnLockedForWrite( hsReaderWriterLock * lock ) {}
		virtual void OnUnlockingForWrite( hsReaderWriterLock * lock ) {}
		virtual void OnUnlockedForWrite( hsReaderWriterLock * lock ) {}
	};
	hsReaderWriterLock( const char * name="<unnamed>", Callback * cb=nil );
	~hsReaderWriterLock();
	void LockForReading();
	void UnlockForReading();
	void LockForWriting();
	void UnlockForWriting();
	const char * GetName() const { return fName; }

private:
	int		fReaderCount;
	hsMutex	fReaderCountLock;
	hsMutex	fReaderLock;
	hsSemaphore	fWriterSema;
	Callback *	fCallback;
	char *	fName;
};

class hsLockForReading
{
	hsReaderWriterLock * fLock;
public:
	hsLockForReading( hsReaderWriterLock & lock ): fLock( &lock )
	{
		fLock->LockForReading();
	}
	hsLockForReading( hsReaderWriterLock * lock ): fLock( lock )
	{
		fLock->LockForReading();
	}
	~hsLockForReading()
	{
		fLock->UnlockForReading();
	}
};

class hsLockForWriting
{
	hsReaderWriterLock * fLock;
public:
	hsLockForWriting( hsReaderWriterLock & lock ): fLock( &lock )
	{
		fLock->LockForWriting();
	}
	hsLockForWriting( hsReaderWriterLock * lock ): fLock( lock )
	{
		fLock->LockForWriting();
	}
	~hsLockForWriting()
	{
		fLock->UnlockForWriting();
	}
};

#endif