11. Pointers (cyclic: write - read - resolved)

In this test we will create two ServerData objects, both with a pointer to each other. When we send them to the client, the client should update the first object once the second arrives, thereby resolving the "missing pointer".

Client Application

The client application is the same as in the last test.

/// @cond EXCLUDEDTESTSOURCES
/***************************************************************************
 * The contents of this file are subject to the Mozilla Public             *
 * License Version 1.1 (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.mozilla.org/MPL/                              *
 *                                                                         *
 * Software distributed under the License is distributed on an "AS         *
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or              *
 * implied. See the License for the specific language governing            *
 * rights and limitations under the License.                               *
 *                                                                         *
 * The Original Code is Game Network Framework (GaNeF).                    *
 *                                                                         *
 * The Initial Developers of the Original Code are                         *
 * Lars Langer and Emanuel Greisen                                         *
 * Copyright (C) 2005. Lars Langer & Emanuel Greisen                       *
 * All Rights Reserved.                                                    *
 *                                                                         *
 * Contributor(s):                                                         *
 *   none yet....                                                          *
 *                                                                         *
 ***************************************************************************/

#include <iostream>
#include <cstdlib>

#include "../Ganef/client/clientframework.h"
#include "../Ganef/client/clientdata.h"


class MyClientData : public ClientData
{
   private:
      std::string name;
      MyClientData * child;

   public:
      MyClientData(ClientFramework * f, ClientPacket * p) : ClientData(f,p)
      {
         name = p->readString();
         p->readPtr(this, &child, f);
         std::cout << "Constructed a new object of class: MyClientData" << std::endl;
         std::cout << " - ID: " << getFrameworkId() << std::endl;
         std::cout << " - Name: "<<name<<std::endl;
         std::cout << " - Child: "<<(child ? child->name : "No child")<<std::endl;
      }
      virtual void updatePacket(ClientFramework * f, unsigned char updatetype, ClientPacket * p)
      {
         // We get no updates
         std::cout << "Update called on object of class: MyClientData" << std::endl;
         std::cout << " - ID: " << getFrameworkId() << std::endl;
         std::cout << " - Name: "<<name<<std::endl;
         std::cout << " - Child: "<<(child ? child->name : "No child")<<std::endl;
      }

      static ClientData * constructMyClientData(ClientFramework * f, ClientPacket * p)
      {
         return new MyClientData(f,p);
      }
};


/**
 * This is just a test-client-framework.
 * @author Lars Langer and Emanuel Greisen
 */
class TestClientFramework : public ClientFramework
{
   private:
      bool is_running;
      std::string server_hostname;

   public:
      TestClientFramework(const std::string & server_hostname) : ClientFramework(int(0)),server_hostname(server_hostname)
      {
         // Notice how the constructor is registered, now all we need is the
         // server sending a packet telling us to construct an object of
         // class with id: 0x424242
         registerConstructor(0x424242, MyClientData::constructMyClientData);
      }
      ~TestClientFramework()
      {
      };

   protected: // These must be implemented in a derived class
      virtual void writeHandshakeInitMessage( ClientPacket * fp ){}
      virtual void onHandshakingDiscontinue( ClientPacket * fp ){}
      virtual bool onHandshakeDescription( ClientPacket * fp, ClientPacket * reply )
      {
         return true;
      }
      virtual void onDisconnect( ) { std::cout << "Disconnected\n"; }
      virtual void onConnect( ){ std::cout << "Connected\n"; }

   public:
      void mainLoop( )
      {
         std::cout << "Connecting to: " << server_hostname <<":"<< 8000<< std::endl;
         initServerConnection(server_hostname, 8000);
         is_running = true;
         while(is_running)
         {
            // Get/handle Packets from the framework
            keepAlive();

            // Then we sleep to let the CPU live
            psleep(50);
         }
      }
};




int main(int argc, char *argv[])
{
   std::string server_host("localhost");
   if(argc > 1)
      server_host = argv[1];
   TestClientFramework app(server_host);

   // Start the Application
   app.mainLoop();
}

/// @endcond

Server Application

The server in this test tells the two objects to point at each other, that is the only thing different from this test and the previous.

/// @cond EXCLUDEDTESTSOURCES
/***************************************************************************
 * The contents of this file are subject to the Mozilla Public             *
 * License Version 1.1 (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.mozilla.org/MPL/                              *
 *                                                                         *
 * Software distributed under the License is distributed on an "AS         *
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or              *
 * implied. See the License for the specific language governing            *
 * rights and limitations under the License.                               *
 *                                                                         *
 * The Original Code is Game Network Framework (GaNeF).                    *
 *                                                                         *
 * The Initial Developers of the Original Code are                         *
 * Lars Langer and Emanuel Greisen                                         *
 * Copyright (C) 2005. Lars Langer & Emanuel Greisen                       *
 * All Rights Reserved.                                                    *
 *                                                                         *
 * Contributor(s):                                                         *
 *   none yet....                                                          *
 *                                                                         *
 ***************************************************************************/

#include <iostream>
#include <cstdlib>
#include <vector>


#include "../Ganef/server/serverframework.h"


class MyServerData : public ServerData
{
   public:
      std::string name;
      MyServerData * child;

   public:
      // The two last parameters for ServerData is the priority of its updatepackets
      //  and wether they should be sent reliable.
      MyServerData(ServerFramework * fw, const std::string & name, MyServerData * child) : ServerData(fw, 10, false),name(name),child(child)
      {
      };
   public:
      virtual const unsigned int getClassId() const { return 0x424242; };
      /// Here the data-class should fill in data according to update type `type`.
      virtual void fillUpdatePacket(ServerPacket * packet, unsigned char type) const
      {
         // We need no updates for this test
      }
      /// Here the data-class should fill in all data required by the constructor on the client side.
      virtual void fillCreateObjectPacket(ServerPacket * packet) const
      {
         packet->writeString(name);
         packet->writePtr(child);
      }
      /// Called when ever we receive a packet for this object from a client.
      virtual void clientPacket(Client * client, unsigned char type, ServerPacket * packet)
      {
         // We do not receive any actions from the client in this test.
      }
};

/**
 * This is just a test server-framework;
 * @author Lars Langer and Emanuel Greisen
 */
class TestServerFramework : public ServerFramework
{
   MyServerData * m_obj_a;
   MyServerData * m_obj_b;
   public:
      TestServerFramework() : ServerFramework(8000)
      {
      }

      ~TestServerFramework()
      {
      }

   protected: // These method should be implemented on the GameServer
      virtual bool onInitialHandshake(ServerPacket * handshake, ServerPacket * reply)
      {
         return true; // Accept all clients.
      }
      virtual void onClientConnected(Client * client)
      {
         std::cout << "Client: " << client->getId() << " connected\n";
         // Here we send the construction packages for the two objects,
         //  since they are pointing at each other, one of them will arive
         //  before its, "child".
         m_obj_a->sendCreateObject(client);
         m_obj_b->sendCreateObject(client);

         // To force the client into printing out the objects again, we send an empty
         //  update packet on both object.
         m_obj_a->sendUpdate(client, 42, true);
         m_obj_b->sendUpdate(client, 42, true);
      }
      virtual void onClientDisconnected(Client * client)
      {
         std::cout << "Client: " << client->getId() << " disconnected\n";
      }
      virtual Client * createClient(const ipaddress &addr, int port)
      {
         return new Client(this, addr, port);
      }

   public:
      void mainLoop()
      {
         std::cout << "TestServerFramework: Running\n";
         m_obj_a = new MyServerData(this, "Object A", 0);
         m_obj_b = new MyServerData(this, "Object B", m_obj_a);
         m_obj_a->child = m_obj_b;
         while(true)
         {
            // Get all incomming messages
            keepAlive();

            // Sleep a little
            psleep(100);
         }
      }
};




int main(int argc, char *argv[])
{
   try
   {
      // Create a framework
      TestServerFramework framework;

      // Start the framework
      framework.start();

      // GameLoop
      framework.mainLoop();
   }
   catch(FrameworkError *err)
   {
      std::cout << "FrameworkError:" << err->msg << std::endl;
   }
   catch(PacketError *err)
   {
      std::cout << "PacketError:" << err->msg << std::endl;
   }

   return EXIT_SUCCESS;
}

/// @endcond

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