workerthread.h

/********************************************************************************
 *  FARSA Experiments Library                                                   *
 *  Copyright (C) 2007-2012                                                     *
 *  Gianluca Massera <emmegian@yahoo.it>                                        *
 *  Stefano Nolfi <stefano.nolfi@istc.cnr.it>                                   *
 *  Tomassino Ferrauto <tomassino.ferrauto@istc.cnr.it>                         *
 *                                                                              *
 *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA  *
 ********************************************************************************/

#ifndef WORKERTHREAD_H
#define WORKERTHREAD_H

#include "utilitiesconfig.h"
#include <QThread>
#include <QMutex>
#include <QWaitCondition>
#include <QQueue>
#include <QList>
#include "baseexception.h"

namespace farsa {

class FARSA_UTIL_TEMPLATE UnknownException : public BaseException
{
public:
    UnknownException() throw() :
        BaseException()
    {
    }

    UnknownException(const UnknownException& other) throw() :
        BaseException(other)
    {
    }

    UnknownException& operator=(const UnknownException& other) throw()
    {
        if (&other == this) {
            return *this;
        }

        BaseException::operator=(other);

        return *this;
    }

    virtual ~UnknownException() throw()
    {
    }

    virtual const char *what() const throw()
    {
        return "Unknown exception thrown by a ThreadOperation, cannot provide further information";
    }

    EXCEPTION_HELPER_FUNCTIONS(UnknownException)
};

class FARSA_UTIL_TEMPLATE ThreadOperation {
public:
    virtual ~ThreadOperation() { };
    virtual void stop() = 0;
    virtual void run() = 0;
};

class FARSA_UTIL_API WorkerThread : public QThread {
    Q_OBJECT

public:
    WorkerThread( QObject* parent );
    ~WorkerThread();
    void addOperation( ThreadOperation* operation, bool deleteAtEnd = true );
    void stopCurrentOperation(bool wait);
    void run();
    void quit();
    bool operationRunning();

signals:
    void exceptionDuringOperation(farsa::BaseException *e);

private:
    struct ThreadOperationInfo
    {
        ThreadOperationInfo() :
            operation(NULL),
            deleteAtEnd(false)
        {
        }

        ThreadOperationInfo(ThreadOperation* o, bool d) :
            operation(o),
            deleteAtEnd(d)
        {
        }

        ThreadOperation* operation;
        bool deleteAtEnd;
    };
    QQueue<ThreadOperationInfo> operations;
    QMutex mutex;
    QWaitCondition waitForOperationsToDo;
    QWaitCondition waitForOperationsToFinish;
    ThreadOperationInfo operation;
    bool quitRequested;
    QList<BaseException *> exceptions;
};

} // end namespace farsa

#endif