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Introduction

An asynchronous communication is referred to a process that calls an operation and does not wait until that operation is finished but it continue its activity. (Sometimes the developers calls this kind of operations "send and forget method" to emphasize their behavior.) The component support the asynchronous communication in both roles.

Provider and Consumer IDL-First

In CORBA the asynchronous communications is implemented using the keyword oneway defined directly in IDL file used as a modifier of a corba operation.

  interface EchoOnewayInterface{

    oneway void echoOneway(in string message);

  };

The CORBA specifications defines some limitations for this kind of operations. In fact, the requirement is the following:

  • They must not contain any output parameters.
  • They must specify a void return type.
  • They must not declare any application exception (but they should raise a system one).

From the perspective of a corba system this kind of communication is totally delegated to the stub (client) implementation. In fact the skeleton of a corba servant generated is the same for both communication types (asynchronous and synchronous).

The WSDL of the endpoint that exposes a oneway operation is similar to the others but the operation has only the input message (Conforming to the WSDL specifications) and the BUS recognises the In Only MEP thanks this characteristic.

  <wsdl:operation name="echoOneway">
    <wsdl:input name="echoOnewayRequest">
    </wsdl:input>
  </wsdl:operation>

This scenario is completely managed by the component and the user configure it using the standard IDL syntax.

Consumer WSDL-First

This kind of communication is also supported by JBI4CORBA when it acts as a consumer. The endpoint created has an interface (WSDL) that contains the operations without the output message.

    <wsdl:operation name="echoOneway">
      <wsdl:input name="echoOnewayRequest">
      </wsdl:input>
    </wsdl:operation>

The component creates one or more IDL files that can be used to implement the corba client for our service, but the IDL file generated that defines the corba interface does not contain the oneway declaration (This problem is already registered in our issue tracking system), so if you want use it to create a corba client that invoke asynchronously our operations you should add this information to the IDL file.

No other tasks are required to the user.

From the perspective of the BUS the sending operation is performed using the appropriate API (i.e. It it the component that recognise the asynchronous operations).

An example of IDL operation generated.

  interface EchoOnewayInterface{

    void echoOneway(in string message);

  };

An example of how the IDL should be modified by the user.

  interface EchoOnewayInterface{

    oneway void echoOneway(in string message);

  };

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This page (revision-7) was last changed on 26-Jun-09 02:55 AM, -0700 by 213.174.165.189