thread.h

Linux下比较早的基于命令行的DVD播放器

//
// Copyright (c) 2003 by Istv醤 V醨adi
//
// This file is part of dxr3Player, a DVD player written specifically 
// for the DXR3 (aka Hollywood+) decoder card.

// 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 DXR3PLAYER_SCHED_THREAD_H
#define DXR3PLAYER_SCHED_THREAD_H
//------------------------------------------------------------------------------

#include "sched/FDWaitCondition.h"

#include <pthread.h>

//------------------------------------------------------------------------------

namespace sched {

//------------------------------------------------------------------------------

/**
 * A thread to be used for something that can take a long time but
 * there is no way to do it asynchronously or to break it up into
 * smaller parts. It communicates with the rest of the software using
 * a pipe which can be used to schedule on.
 */
class Thread
{
private:
    /**
     * The function to run the thread.
     */
    static void* thread_function(void* arg);

    /**
     * The low-level thread handle.
     */
    pthread_t pthread;

    /**
     * The pipe descriptors for communicating towards the thread.
     */
    int pipe_tothread[2];
    
    /**
     * The pipe descriptors for communicating from the thread.
     */
    int pipe_fromthread[2];

    /**
     * The wait condition for the reader.
     */
    FDReadableWaitCondition fromThreadFDReadable;
    
    /**
     * Indicate if the thread should stop.
     */
    volatile bool quit;

public:
    /**
     * Construct the thread.
     */
    Thread(const char* name);

    /**
     * Destroy the thread. If the thread has not quit yet, it will try
     * to stop it.
     */
    virtual ~Thread();
    
    /**
     * Start the thread.
     */
    void start();

    /**
     * Trigger the thread asynchronously, i.e. returning immediately
     * after sending the trigger. The result must be read later by
     * finishTrigger().
     */
    void asyncTrigger();

    /**
     * Read the result of an asynchronous trigger. It waits
     * uninterruptably until the result arrives.
     */
    void finishTrigger();

    /**
     * Trigger the thread. It will return when the thread has
     * answered. It cannot be interrupted.
     */
    void trigger();

    /**
     * Stop running the thread.
     */
    void stop();

 private:
    /**
     * Perform the main operation of the thread.
     */
    void run();

    /**
     * The function that does the real operation. It is called by
     * run(), when the client triggers the thread.
     */
    virtual void perform() = 0;
};

//------------------------------------------------------------------------------

} /* namespace sched */

//------------------------------------------------------------------------------
#endif // DXR3PLAYER_SCHED_THREAD_H

// Local variables:
// mode: c++
// End: