c++ - CORBA omniORB 在解析名称上下文后无法获取远程对象

Question

我有如下的 IDL

module IClientServer {

  interface IClient 
  {
    void serverResponse(in string name, in string data);

    void start();

    void stop();

    void shutdown();

  };

  interface IServer 
  {

     // Server calls back to client just once in a
     // recursive call before returning.
     // void one_time(in CallBack cb, in string mesg);
    void DataFromX(in string name,in string data,in long lbytes,in short usg);

    void Authenticate(in IClient client, in string dataToNegotiate);

     // Shuts down the server.
    void shutdown();

  };
};

我使用 idl2cpp 实用程序 (onmiORB) 为此生成了代理和框架，并将生成的文件链接到服务器和客户端应用程序，如文档中所建议的

然后我启动了名称服务 (omniNames) 并按照文档中的建议添加了注册表项 omniORB\InitRef，以便在不使用命令行参数的情况下连接服务器和客户端应用

服务器代码如下

int _tmain(int argc, _TCHAR* argv[])
{
    try 
    {
    int argc = 0;
        _BRDTRACE("Initializing....\n");
        CORBA::ORB_var orb = CORBA::ORB_init(argc, NULL);
//          cerr << "Initialized." << endl;

        CORBA::Object_var obj = orb->resolve_initial_references("RootPOA");
        _BRDTRACE("Resolved.\n");


        PortableServer::POA_var poa = PortableServer::POA::_narrow(obj);
        _BRDTRACE("Narrowed..\n");

            // Obtain a reference to the object, and register it in
            // the naming service.
        server_i* myserver = new server_i();
//          cerr << "Constructed." << endl;

        obj = myserver->_this();
        _BRDTRACE("obj retrieved.\n");

        CORBA::String_var x;
        x = orb->object_to_string(obj);
        _BRDTRACE("obj to string.\n");

        if( !bindObjectToName(orb, obj) )
        {
//            cerr << "Failed to bind obj to name." << endl;
          throw;
        }

        _BRDTRACE("binded\n");
        myserver->_remove_ref();
//          cerr << "removed ref." << endl;

        PortableServer::POAManager_var pman = poa->the_POAManager();
        pman->activate();
        _BRDTRACE("activated.\n");

//          cerr << "Executing..." << endl;
        orb->run();
        _BRDTRACE("Terminated.\n");

        myserver->shutdown();
//          cerr << "Shutdown." << endl;

    }
    catch(CORBA::SystemException&) 
    {
        _BRDTRACE("Caught CORBA::SystemException.\n");
    }
    catch(CORBA::Exception&) {
        _BRDTRACE("Caught CORBA::Exception.\n");
    }
    catch(omniORB::fatalException&) 
    {
        _BRDTRACE("Caught omniORB::fatalException:\n");
//          cerr << "  file: " << fe.file() << endl;
//          cerr << "  line: " << fe.line() << endl;
//          cerr << "  mesg: " << fe.errmsg() << endl;
    }
    catch(...) {
        _BRDTRACE("Caught unknown exception.\n");
    }

}

static CORBA::Boolean
bindObjectToName(CORBA::ORB_ptr orb, CORBA::Object_ptr objref)
{
  CosNaming::NamingContext_var rootContext;

  try {
    // Obtain a reference to the root context of the Name service:
    CORBA::Object_var obj;
    obj = orb->resolve_initial_references("NameService");

    // Narrow the reference returned.
    rootContext = CosNaming::NamingContext::_narrow(obj);
    if( CORBA::is_nil(rootContext) ) {
      _BRDTRACE("Failed to narrow the root naming context.\n");
      return 0;
    }
  }
  catch(CORBA::ORB::InvalidName& ex) {
    // This should not happen!
    _BRDTRACE("Service required is invalid [does not exist].\n");
    return 0;
  }

  try {
    // Bind a context called "test" to the root context:

    CosNaming::Name contextName;
    contextName.length(1);
    contextName[0].id   = (const char*) "birdseye";       // string copied
    contextName[0].kind = (const char*) "collections_context"; // string copied
    // Note on kind: The kind field is used to indicate the type
    // of the object. This is to avoid conventions such as that used
    // by files (name.type -- e.g. test.ps = postscript etc.)

    //CosNaming::NamingContext_var testContext;
    try {
      // Bind the context to root.
      rootContext->bind(contextName, objref);
    }
    catch(CosNaming::NamingContext::AlreadyBound& ex) {
      // If the context already exists, this exception will be raised.
      // In this case, just resolve the name and assign testContext
      // to the object returned:
      CORBA::Object_var obj;
      obj = rootContext->resolve(contextName);
      CosNaming::NamingContext_var testContext = CosNaming::NamingContext::_narrow(obj);
      if( CORBA::is_nil(testContext) ) {
        _BRDTRACE("Failed to narrow naming context.\n");
        return 0;
      }
    }
  } catch(CORBA::COMM_FAILURE& ex) {
   _BRDTRACE("Caught system exception COMM_FAILURE -- unable to contact the naming service.\n");
    return 0;
  }
  catch(CORBA::SystemException&) {
    _BRDTRACE("Caught a CORBA::SystemException while using the naming service.\n");
    return 0;
  }

  return 1;
}

但客户端的以下代码在名称后返回 nil 对象 上下文解析。无法弄清楚这个问题。请帮忙!

int _tmain(int argc, _TCHAR* argv[])
{
    CORBA::ORB_var orb = CORBA::ORB_init(argc, argv);
    CORBA::Object_var objRef = orb->resolve_initial_references("NameService");
    CORBA::Object_var obj = getObjectReference(orb);
    IClientServer::IServer_var svr = IClientServer::IServer::_narrow(obj.in());
  if( CORBA::is_nil(svr) ) {    **//THIS IS WHERE THE ISSUE IS**
 //   _BRDTRACE("cb_client: The server reference is nil!\n");
    return 0;
  }
    return 0;
}

static CORBA::Object_ptr
getObjectReference(CORBA::ORB_ptr orb)
{
  CosNaming::NamingContext_var rootContext;

  try {
    // Obtain a reference to the root context of the Name service:
    CORBA::Object_var obj;
    obj = orb->resolve_initial_references("NameService");

    // Narrow the reference returned.
    rootContext = CosNaming::NamingContext::_narrow(obj);
    if( CORBA::is_nil(rootContext) ) {
//      cerr << "Failed to narrow the root naming context." << endl;
      return CORBA::Object::_nil();
    }
  }
  catch(CORBA::ORB::InvalidName& ) {
    // This should not happen!
    return CORBA::Object::_nil();
  }
  // Create a name object, containing the name test/context:
  CosNaming::Name name;
  name.length(1);

  name[0].id   = (const char*) "birdseye";       // string copied
  name[0].kind = (const char*) "collections_context"; // string copied
  // Note on kind: The kind field is used to indicate the type
  // of the object. This is to avoid conventions such as that used
  // by files (name.type -- e.g. test.ps = postscript etc.)


  try {
    // Resolve the name to an object reference.
    return rootContext->resolve(name);
  }
  catch(CosNaming::NamingContext::NotFound& nf) {
  }
  catch(CORBA::COMM_FAILURE& ) {
  }
  catch(CORBA::SystemException&) {
  }

  return CORBA::Object::_nil();
}

更新至下午 5 点:事实上，服务器端代码也有同样的问题 server->authenticate is never called due to nil reference。

猜测:使用 idl2cpp 工具生成的代理和 stub 会不会有问题？

UPDATE-7:30PMstubs not ok 上的歧义也消失了，在重新生成 stubs 并再次重建客户端和服务器应用程序后问题仍然存在

更新 3-31|11AM我正在使用超过 10 年的 omniORB 4.0.3。这在使用 VC6 编译的早期 Windows 操作系统版本中效果很好，我怀疑在 VS 2008 上重新编译时是否存在问题。只是考虑升级到去年发布的 ommiORB 4.2。就是一头雾水……

更新 3-31|5:30PM目前构建omniORB4.2.1源代码。当我这样做时，我仍然想知道链接在旧系统中生成的 .lib 文件是否有任何问题。在这种情况下，我在 Windows 7 中使用的 omniORB .lib 文件是在 Windows XP 上构建的，这会是一个问题吗？连this帖子无法回答，我有一个旧的 .lib 可以很好地编译和链接，没有任何问题，甚至运行时也没有崩溃

更新 4-01|4:30PM实际上我注意到没有服务器在运行，我之前发布的服务器代码也是客户端，我现在更新了真正的服务器代码(将名称绑定(bind)到服务器obj的代码)。但即使经过此更正，问题仍然存在

Answer 1

我终于解决了这个问题。代码有2个问题问题 1 我已经更新了问题(缺少服务器代码)问题 2 是名称上下文绑定(bind)..

以下是服务器中 bindObjectToName 的修改版本

static CORBA::Boolean
bindObjectToName(CORBA::ORB_ptr orb, CORBA::Object_ptr objref)
{
  CosNaming::NamingContext_var rootContext;

  try {
    // Obtain a reference to the root context of the Name service:
    CORBA::Object_var obj;
    obj = orb->resolve_initial_references("NameService");

    // Narrow the reference returned.
    rootContext = CosNaming::NamingContext::_narrow(obj);
    if( CORBA::is_nil(rootContext) ) {
//      cerr << "Failed to narrow the root naming context." << endl;
      return 0;
    }
  }
  catch(CORBA::ORB::InvalidName& ex) {
    // This should not happen!
  //  cerr << "Service required is invalid [does not exist]." << endl;
    return 0;
  }

  try {
    // Bind a context called "test" to the root context:

    CosNaming::Name contextName;
    contextName.length(1);
    contextName[0].id   = (const char*) "birdsEYE";       // string copied
    contextName[0].kind = (const char*) "DataCollectionS"; // string copied
    // Note on kind: The kind field is used to indicate the type
    // of the object. This is to avoid conventions such as that used
    // by files (name.type -- e.g. test.ps = postscript etc.)

    CosNaming::NamingContext_var testContext;
    try {
      // Bind the context to root.
      testContext = rootContext->bind_new_context(contextName);
    }
    catch(CosNaming::NamingContext::AlreadyBound& ex) {
      // If the context already exists, this exception will be raised.
      // In this case, just resolve the name and assign testContext
      // to the object returned:
      CORBA::Object_var obj;
      obj = rootContext->resolve(contextName);
      testContext = CosNaming::NamingContext::_narrow(obj);
      if( CORBA::is_nil(testContext) ) {
    //    cerr << "Failed to narrow naming context." << endl;
        return 0;
      }
    }

    // Bind sender :
    CosNaming::Name objectName;
    objectName.length(1);
    objectName[0].id   = (const char*) "clienT";   // string copied
    objectName[0].kind = (const char*) "sendeR"; // string copied

    try {
      testContext->bind(objectName, objref);
    }
    catch(CosNaming::NamingContext::AlreadyBound& ex) {
      testContext->rebind(objectName, objref);
    }
    // Note: Using rebind() will overwrite any Object previously bound
    //       to /test/Echo with obj.
    //       Alternatively, bind() can be used, which will raise a
    //       CosNaming::NamingContext::AlreadyBound exception if the name
    //       supplied is already bound to an object.

    // Bind receiver :
    CosNaming::Name objectName2;
    objectName2.length(1);
    objectName2[0].id   = (const char*) "clienT";   // string copied
    objectName2[0].kind = (const char*) "receiveR"; // string copied

    try {
      testContext->bind(objectName2, objref);
    }
    catch(CosNaming::NamingContext::AlreadyBound& ex) {
      testContext->rebind(objectName2, objref);
    }


    // Amendment: When using OrbixNames, it is necessary to first try bind
    // and then rebind, as rebind on it's own will throw a NotFoundexception if
    // the Name has not already been bound. [This is incorrect behaviour -
    // it should just bind].

  }
  catch(CORBA::COMM_FAILURE& ex) {
    //cerr << "Caught system exception COMM_FAILURE -- unable to contact the "
    //     << "naming service." << endl;
    return 0;
  }
  catch(CORBA::SystemException&) {
    //cerr << "Caught a CORBA::SystemException while using the naming service."
    // << endl;
    return 0;
  }

  return 1;
}

以及客户端代码中修改后的getObjectReference下面静态 CORBA::Object_ptr

getObjectReference(CORBA::ORB_ptr orb)
{
  CosNaming::NamingContext_var rootContext;

  try {
    // Obtain a reference to the root context of the Name service:
    CORBA::Object_var obj;
    obj = orb->resolve_initial_references("NameService");

    // Narrow the reference returned.
    rootContext = CosNaming::NamingContext::_narrow(obj);
    if( CORBA::is_nil(rootContext) ) {
//      cerr << "Failed to narrow the root naming context." << endl;
      return CORBA::Object::_nil();
    }
  }
  catch(CORBA::ORB::InvalidName& ex) {
    // This should not happen!
  //  cerr << "Service required is invalid [does not exist]." << endl;
    _BRDTRACE("getObjRef: service required is invalid.\n");
    exit(0);
    return CORBA::Object::_nil();
  }


  // Create a name object, containing the name test/context:
  CosNaming::Name name;
  name.length(2);

  name[0].id   = (const char*) "birdsEYE";       // string copied
  name[0].kind = (const char*) "DataCollectionS"; // string copied
  name[1].id   = (const char*) "clienT";
  name[1].kind = (const char*) "sendeR";
  // Note on kind: The kind field is used to indicate the type
  // of the object. This is to avoid conventions such as that used
  // by files (name.type -- e.g. test.ps = postscript etc.)


  try {
    // Resolve the name to an object reference.
    return rootContext->resolve(name);
  }
  catch(CosNaming::NamingContext::NotFound& ex) {
    // This exception is thrown if any of the components of the
    // path [contexts or the object] aren't found:
    //cerr << "Context not found." << endl;
    _BRDTRACE("getObjRef: context not found.\n");
    exit(0);
  }
  catch(CORBA::COMM_FAILURE& ex) {
    //cerr << "Caught system exception COMM_FAILURE -- unable to contact the "
     //    << "naming service." << endl;
    _BRDTRACE("getObjRef: caught system exception COMM_FAILURE.\n");
    exit(0);
  }
  catch(CORBA::SystemException&) {
    //cerr << "Caught a CORBA::SystemException while using the naming service."
     //<< endl;
    _BRDTRACE("getObjRef: caught system exception while using the name service.\n");
    exit(0);
  }

  return CORBA::Object::_nil();
}