thread.cc

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

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

#include "Thread.h"
#include "Scheduler.h"

#include "util/POSIX.h"

#include <cassert>

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

using sched::Thread;

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

void* Thread::thread_function(void* arg)
{
    Thread* thread = reinterpret_cast<Thread*>(arg);
    thread->run();
    return 0;
}

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

Thread::Thread(const char* name) : 
    fromThreadFDReadable(name, "fromThreadFDReadable"),
    quit(false)
{
    pipe_tothread[0]   = pipe_tothread[1]   = -1;
    pipe_fromthread[0] = pipe_fromthread[1] = -1;
}

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

Thread::~Thread()
{
    if (!quit) {
        stop();
    }
}

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

void Thread::start()
{
    POSIX::pipe(pipe_tothread);
    POSIX::pipe(pipe_fromthread);
    
    int flags = POSIX::fcntl(pipe_fromthread[0], F_GETFL);
    flags |= O_NONBLOCK;
    POSIX::fcntl(pipe_fromthread[0], F_SETFL, flags);
    fromThreadFDReadable.setFileDescriptor(pipe_fromthread[0]);

    pthread_create(&pthread, 0, &thread_function,
                   reinterpret_cast<void*>(this));
}

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

void Thread::asyncTrigger()
{
    char c = 0;

    POSIX::write(pipe_tothread[1], &c, sizeof(c));
}

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

void Thread::finishTrigger()
{
    char c = 0;

    do {
        Scheduler::wait(fromThreadFDReadable);
    } while(POSIX::read(pipe_fromthread[0], &c, sizeof(c))!=sizeof(c));
}

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

void Thread::trigger()
{
    asyncTrigger();
    finishTrigger();
}

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

void Thread::stop()
{
    quit = true;

    trigger();

    POSIX::close(pipe_fromthread[0]);
    POSIX::close(pipe_fromthread[1]);
    POSIX::close(pipe_tothread[0]);
    POSIX::close(pipe_tothread[1]);

    pipe_fromthread[0] = -1;

    pthread_join(pthread, 0);
}

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

void Thread::run()
{
    bool doQuit = false;

    do {
        char c;
        POSIX::read(pipe_tothread[0], &c, sizeof(c));
        
        doQuit = quit;
        if (!doQuit) {
            perform();
        }
        
        POSIX::write(pipe_fromthread[1], &c, sizeof(c));
    } while(!doQuit);
}

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