oggthreadclasses.h

OggPlay for Symbian 是symbian上的一个媒体播放程序的源码。它支持ogg,wav等等多媒体格式。

/*
 *  Copyright (c) 2005 S. Fisher
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef _OggThreadClasses_h
#define _OggThreadClasses_h

#if defined(MULTI_THREAD_PLAYBACK)
#include <e32base.h>
#include <e32std.h>


// Thread commands (used by the CThreadCommandHandler)
// Only one command is defined in the base class
enum TThreadCommand
{
	// Command to shutdown the thread
	EThreadShutdown
};

// Interface class for handling thread panics
class MThreadPanicObserver
{
public:
	// HandleThreadPanic is called when the worker thread panics
	// aPanicThread is a reference to the thread that has encountered a panic
	// aErr is the error code (the value returned when RThread::Logon() completes)
	virtual void HandleThreadPanic(RThread& aPanicThread, TInt aErr) = 0;
};

// An active object for handling worker thread panics
// One of these is required in order to instantiate a CThreadCommandHandler
class CThreadPanicHandler : public CActive
{
public:
	CThreadPanicHandler(TInt aPriority, RThread& aThread, MThreadPanicObserver& aPanicObserver);
	~CThreadPanicHandler();

	void HandleCaughtPanic();

private:
	// From CActive
	void RunL();
	void DoCancel();

private:
	RThread iThread;
	MThreadPanicObserver& iPanicObserver;

	TBool iCaughtAPanic;
};

// An active object base class for handling worker threads
// It provides support for handling commands as well as resuming and shutting down the thread
// It must have a panic handler to catch any panics generated by the worker thread
class CThreadCommandHandler : public CActive
{
public:
	CThreadCommandHandler(TInt aPriority, RThread& aCommandThread, RThread& aCommandHandlerThread, CThreadPanicHandler& aPanicHandler);
	~CThreadCommandHandler();

    TInt ResumeCommandHandlerThread();
	void ShutdownCommandHandlerThread();

	void ResumeComplete(TInt aErr);
	void ShutdownComplete(TInt aErr);

protected:
	void ListenForCommands();
	TInt SendCommand(TInt aCommand);
	void RequestComplete(TInt aErr);

private:
	static TInt PanicThread(TAny* aThreadData);
	static void PanicThreadL(MThreadPanicObserver& aSharedData);

private:
	RThread& iCommandThread;
	RThread& iCommandHandlerThread;
	TRequestStatus iCommandStatus;

	CThreadPanicHandler& iPanicHandler;
};

#endif // MULTI_THREAD_PLAYBACK
#endif // _OggThreadClasses_h