////////////////////////////////////////////////////////////////////////////////
/// @brief tasks used to handle signals
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2011 triagens GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Achim Brandt
/// @author Copyright 2008-2011, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "SignalTask.h"

#include <Logger/Logger.h>
#include <Basics/MutexLocker.h>

#include "Scheduler/Scheduler.h"

using namespace triagens::basics;

namespace triagens {
  namespace rest {

    // -----------------------------------------------------------------------------
    // constructors and destructors
    // -----------------------------------------------------------------------------

    SignalTask::SignalTask ()
      : Task("SignalTask") {
      for (size_t i = 0;  i < MAX_SIGNALS;  ++i) {
        watcher[i] = 0;
      }
    }



    SignalTask::~SignalTask () {
    }

    // -----------------------------------------------------------------------------
    // public methods
    // -----------------------------------------------------------------------------

    bool SignalTask::addSignal (int signal) {
      MUTEX_LOCKER(changeLock);

      if (signals.size() >= MAX_SIGNALS) {
        LOGGER_ERROR << "maximal number of signals reached";
        return false;
      }
      else {
        if (scheduler != 0) {
          scheduler->unregisterTask(this);
        }

        signals.insert(signal);

        if (scheduler != 0) {
          scheduler->registerTask(this);
        }

        return true;
      }
    }

    // -----------------------------------------------------------------------------
    // Task methods
    // -----------------------------------------------------------------------------

    void SignalTask::setup (Scheduler* scheduler, EventLoop loop) {
      this->scheduler = scheduler;
      this->loop = loop;

      size_t pos = 0;

      for (set<int>::iterator i = signals.begin();  i != signals.end() && pos < MAX_SIGNALS;  ++i, ++pos) {
        watcher[pos] = scheduler->installSignalEvent(loop, this, *i);
      }
    }



    void SignalTask::cleanup () {
      for (size_t pos = 0;  pos < signals.size() && pos < MAX_SIGNALS;  ++pos) {
        scheduler->uninstallEvent(watcher[pos]);
        watcher[pos] = 0;
      }
    }



    bool SignalTask::handleEvent (EventToken token, EventType revents) {
      bool result = true;

      if (revents & EVENT_SIGNAL) {
        for (size_t pos = 0;  pos < signals.size() && pos < MAX_SIGNALS;  ++pos) {
          if (token == watcher[pos]) {
            result = handleSignal();
            break;
          }
        }
      }

      return result;
    }



    bool SignalTask::needsMainEventLoop () const {
      return true;
    }
  }
}