requestHandler.h

/* Copyright (c) 2005-2009, Stefan Eilemann <eile@equalizergraphics.com> 
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *  
 * This library 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 library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef EQBASE_REQUESTHANDLER_H
#define EQBASE_REQUESTHANDLER_H

#include <eq/base/base.h>      // EQ_EXPORT definition
#include <eq/base/hash.h>      // member
#include <eq/base/thread.h>    // thread-safety macros
#include <eq/base/timedLock.h> // member

#include <list>

namespace eq
{
namespace base
{
    class Lock;

    class RequestHandler : public NonCopyable
    {

    public:
        EQ_EXPORT RequestHandler( const bool threadSafe = false );

        EQ_EXPORT ~RequestHandler();

        EQ_EXPORT uint32_t registerRequest( void* data = 0 );

        EQ_EXPORT void unregisterRequest( const uint32_t requestID );

        EQ_EXPORT bool waitRequest( const uint32_t requestID, void*& result,
                               const uint32_t timeout = EQ_TIMEOUT_INDEFINITE );

        EQ_EXPORT bool waitRequest( const uint32_t requestID, uint32_t& result,
                               const uint32_t timeout = EQ_TIMEOUT_INDEFINITE );
        EQ_EXPORT bool waitRequest( const uint32_t requestID, bool& result,
                               const uint32_t timeout = EQ_TIMEOUT_INDEFINITE );
        EQ_EXPORT bool waitRequest( const uint32_t requestID );

        EQ_EXPORT bool isServed( const uint32_t requestID ) const;

        EQ_EXPORT void* getRequestData( const uint32_t requestID );

        EQ_EXPORT void serveRequest( const uint32_t requestID, void* result=0 );
        EQ_EXPORT void serveRequest( const uint32_t requestID, uint32_t result);
        EQ_EXPORT void serveRequest( const uint32_t requestID, bool result );

        bool isThreadSafe() const { return ( _mutex != 0 ); }
        bool isEmpty()      const { return _requests.empty( ); }

    private:
        Lock*        _mutex;

        struct Request
        {
            Request()
                {
                    lock.set();
                }
            ~Request(){}
            
            TimedLock lock;
            void*     data;

            union Result
            {
                void*    rPointer;
                uint32_t rUint32;
                bool     rBool;
            } result;
        };
        // @endcond

        typedef stde::hash_map<uint32_t, Request*> RequestHash;

        uint32_t            _requestID;
        RequestHash         _requests;
        std::list<Request*> _freeRequests;

        bool _waitRequest( const uint32_t requestID, Request::Result& result,
                           const uint32_t timeout );

        CHECK_THREAD_DECLARE( _thread );
    };
}

}
#endif //EQBASE_REQUESTHANDLER_H