c++ - CORBA omniORB 在解析名称上下文后无法获取远程对象

Question

我有一个如下的 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();

  };
};

为此，我使用 idl2cpp 实用程序 (onmiORB) 生成了代理和骨架，并将生成的文件链接到服务器和客户端应用程序，如文档中建议的那样

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程序

下面是服务器代码

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;
}

但是客户端的以下代码在名称上下文解析后返回 nil 对象。无法弄清楚问题。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();
}

UPDATE-5PM： 事实上，服务器端代码也有同样的问题 server->authenticate 由于没有引用而永远不会被调用。

猜测：使用 idl2cpp 工具生成的代理和存根会不会有问题？

UPDATE-7:30PM 存根不正确的歧义也消失了，在重新生成存根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。只是想升级到去年发布的 ommiORB 4.2。就是一无所知...

更新 3-31|5:30PM 目前正在构建omniORB4.2.1 源代码。虽然我这样做了，但我仍然想知道链接旧系统中生成的 .lib 文件是否存在任何问题。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？即使这篇文章也无法回答，我有一个旧的 .lib 编译和链接很好，没有任何问题，甚至运行时它也没有崩溃

UPDATE 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，我现在更新了真实的服务器代码（将名称绑定到服务器 obj 的代码）。但即使经过这次更正，问题仍然存在

score 0 · Accepted Answer

最后我解决了这个问题。代码问题 1 有 2 个问题我已经更新了问题（缺少服务器代码）问题 2 是名称上下文绑定。

下面是服务器中 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;
}

并且在客户端代码 静态 CORBA::Object_ptr中修改后的 getObjectReference

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();
}

c++ - CORBA omniORB 在解析名称上下文后无法获取远程对象

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