/*
 * ThreadManager.cpp
 *
 * Copyright (C) 2009 Matthias Schiffer <matthias@gamezock.de>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "ThreadManager.h"

#include "Application.h"
#include "LogManager.h"

#include <boost/bind.hpp>

namespace Mad {
namespace Core {

void ThreadManager::workerFunc() {
  while(true) {
    boost::unique_lock<boost::mutex> lock(runLock);

    if(!running || !isThisWorkerThread())
      break;

    lock.unlock();

    boost::unique_lock<boost::mutex> lock2(workLock);
    while(work.empty()) {
      workCond.wait(lock2);

      if(!running)
        return;
    }

    boost::function0<void> nextWork = work.front();
    work.pop();

    lock2.unlock();

    nextWork();
  }

  // And let the new worker thread join us...
  pushWork(boost::bind(&ThreadManager::threadFinished, this, boost::this_thread::get_id()));
}

void ThreadManager::detach() {
  {
    boost::lock_guard<boost::mutex> lock(runLock);
    if(!running)
      return; // There's no point in creating a new worker thread when we aren't running anymore
  }

  threadLock.lock();

  if(workerThread->get_id() == boost::this_thread::get_id()) {// Already detached or no worker thread?
    threads.insert(std::make_pair(boost::this_thread::get_id(), workerThread));

    workerThread.reset(new boost::thread(std::mem_fun(&ThreadManager::workerFunc), this));
  }

  threadLock.unlock();
}

void ThreadManager::pushWork(const boost::function0<void> &newWork) {
  workLock.lock();
  work.push(newWork);
  workLock.unlock();

  workCond.notify_one();
}


ThreadManager::ThreadManager(Application *application0) : application(application0), running(true) {
  threadLock.lock();

  ioWorker.reset(new boost::asio::io_service::work(application->getIOService()));

  mainThreadId = boost::this_thread::get_id();
  workerThread.reset(new boost::thread(&ThreadManager::workerFunc, this));
  loggerThread.reset(new boost::thread(&LogManager::loggerThread, application->getLogManager()));
  ioThread.reset(new boost::thread((std::size_t(boost::asio::io_service::*)())&boost::asio::io_service::run, &application->getIOService()));

  threadLock.unlock();
}

ThreadManager::~ThreadManager() {
  if(!isThisMainThread()) {
    // TODO Critical error!!!
    return;
  }

  // First set running = false so the worker threads quit
  boost::lock(runLock, workLock);
  running = false;

  workLock.unlock();
  runLock.unlock();

  workCond.notify_one();

  // We don't have to lock threadLock as detach() won't change workerThread when running is false
  workerThread->join();

  // Now wait for all detached threads
  while(!threads.empty()) {
    threadFinished(threads.begin()->first);
  }

  // IO thread is next
  ioWorker.reset();
  ioThread->join();

  // Finally, the logger thread has to die
  application->getLogManager()->stopLoggerThread();
  loggerThread->join();
}

}
}