CORBA 3.5b1 RTF Avatar
  1. OMG Issue

CORBA35 — Generic port connections

  • Key: CORBA35-24
  • Legacy Issue Number: 5852
  • Status: open  
  • Source: Zuehlke Engineering ( Frank Pilhofer)
  • Summary:

    I propose to introduce generic operations that allow
    interconnecting ports regardless of their type. This
    would ease generic programming.

    The first part of the proposal is to allow generic
    usage of the "connect" and "disconnect" operations
    that are (currently) in the Receptacles interface,
    i.e. to extend the functionality to not only work
    on receptacles, but also on event source ports
    (emits and publishes keywords).

    The names "connect" and "disconnect" are appropriate
    for any kind of port, and their signatures are the
    same as "subscribe" and "unsubscribe" in the Events

    The second part of the proposal is to introduce a
    new operation "get_port" into the CCMObject interface.
    This operation would take a FeatureName parameter and
    return the object reference associated with that
    facet or event sink.

    So I propose the following steps:

    1.) Allow connect, disconnect and get_connections to
    operate on event source ports, and introduce a
    get_port operation.
    This change would be backwards compatible.

    2.) Move connect, disconnect and get_connections from
    the now inappropriate Receptacles interface into
    the CCMObject interface. This step might cause
    minor, easily fixable breakage for software that
    widens an object reference to Receptacles instead
    of CCMObject. (I don't think any such software
    exists, it's more of a theoretical issue.)

    3.) Discourage, then remove the "subscribe" and
    "unsubscribe" operations in the Events interface.
    They don't offer any more type safety than connect
    and disconnect.

    I believe that these changes would also be of interest
    for slimming down CCM for the Lightweight CCM RFP, and
    in light of the Streams for CCM RFP (which will likely
    add another port type that needs interconnecting).

    This change does not have any impact on component
    implementations. The change to CCM implementations
    (ORBs) is neglegible (I would expect a day to make
    these changes in MicoCCM, another day to test them).

    If there is general agreement on this issue, I will
    draft the text updates.

  • Reported: CORBA 3.0.2 — Thu, 6 Feb 2003 05:00 GMT
  • Updated: Wed, 6 Dec 2023 20:17 GMT