Release Notes for omniORB 3.0.0

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The last release was 2.8.0 (31st August 1999).

Latest source code is available via anonymous CVS. Please see:

If you have an existing build of omniORB3, you must "make veryclean" or remove the tree and start again.

NOTE the new section about omniidl and Python below!!!


This version of omniORB incorporates a major re-write of the core runtime. Key features include:
  • support for the Portable Object Adapter (POA)
  • support for the Interoperable Naming Service (INS)
  • new IDL compiler
  • identical semantics for local and remote object invocations
  • location forwarding into and out of the local address space
  • new dynamically growing object table (improves performance for applications with large numbers of objects)
  • legacy support for the BOA (including using both BOA and POA together in the same process)
  • improved message logging, including logging application level requests and throwing of system exceptions
  • lots of other stuff

Changes since 2.8.0

  1. Support for the Portable Object Adapter (POA)

    The following features are not implemented:

    • PortableServer::Current
    • DSI is incomplete (depends on Current).

  2. Support for the Interoperable Naming Service. See chapter 4 of the omniORB manual for details.

  3. New IDL compiler

    omniidl2 has been replaced by a new general-purpose IDL compiler simply named omniidl. This has several important consequences:

    • omniidl requires Python 1.5.2 to build and run. We recommend that you use a full Python installation, but we have made minimal binary versions for Windows, Solaris and Linux available at:

      You must point the makefiles to your Python installation. See README.unix or README.win32 for details.

    • If you move omniidl out of the omniORB tree, it may be unable to find Python files which it requires. In this case, either use the -p flag to give the full path to the lib/python directory, or set the PYTHONPATH environment variable to contain that location.

    • omniidl aims for strict compliance to the IDL specification. You may find that some IDL which used to pass omniidl2 now has compilation errors.

    • omniidl's command-line flags are different. Use

      omniidl -bcxx -u

      for the full list.

      In particular, where before you said:

      omniidl2 echo.idl

      to generate the basic stubs and skeletons, you must now say:

      omniidl -bcxx echo.idl

      (The -bcxx tells the compiler to use the C++ back-end. If you have omniORBpy installed, you can also say -bpython to generate Python stubs.)

      There are several new general (non backend-specific) omniidl arguments:

      omniidl flag Meaning
      -N Do not run preprocessor
      -b<backend> Select a back-end to be used. (More than one permitted.)
      -nf Do not warn about unresolved forward declarations
      -k Comments after declarations are kept for the back-ends
      -K Comments before declarations are kept for the back-ends
      -Cdir Change directory to dir before writing output
      -d Dump the parsed IDL then exit
      -pdir Path to omniidl back-ends ($TOP/lib/python)

      The omniidl2 flag -t has been replaced by two new C++ backend options (these are equivalent to the omniidl3 flags, -tp and -tf):

      -Wbtp produce tie implementation skeletons
      -Wbtf generate flattened tie implementation skeletons

      The latter is needed if on your platform modules are mapped to C++ classes, and your compiler does not support template members of classes.

      Some C++ backend arguments have been renamed:

      -Wbh=<suffix> Specify suffix for generated header files (was -h suffix)
      -Wbs=<suffix> Specify suffix for generated stub files (was -s suffix)
      -Wba Generate code for TypeCodes and Any (was -a)
      -WbF Generate code fragments (for expert only) (was -F)
      -Wbold_prefix Map C++ reserved words with prefix _ (was -c)

      There are some new C++ backend arguments with no omniidl2 equivalents:

      -Wbboa generate BOA skeletons (_sk_foo). By default only POA skeletons are generated. (equivalent to -Bboa in omniidl3)
      -Wbold use pre CORBA 2.2 mapping for skeleton operations (equivalent to -Bold_signatures in omniidl3)
      -Wbd=suffix changes the file suffix
      -Wbsplice-modules Splice together multiply opened modules into one (used to be the default in omniidl2- see below)
      -Wbexample Generate example implementation code
      -Wbkeep_inc_path Preserves IDL #include path in generated C++ header
      -Wbuse_quotes Uses "" rather than <> in C++ header #includes

      To generate the old-style (BOA compatible) tie skeletons you must supply both the -Wbboa and -Wbtf flags.

      Note that omniidl2 would always splice reopened modules together (regardless of the -m flag). omniidl defaults to reopening modules- if your compiler does not support this then you must use the option "-Wbsplice-modules" to regain the old behaviour.

    • The make rules for omniidl have not been tested on all platforms (since we don't have access to them). If you encounter build difficulties on your platform, please look at src/tool/omniidl/cxx/ to see if it is obvious how to fix it.

  4. IDL stubs.

    There are a number of improvements. You may find that the size of the stub code generated is smaller.

    The stubs must be regenerated with the new IDL compiler to be compatible with the runtime library.

  5. New mapping for signatures of operations in skeletons.

    The mapping for the arguments to operations in implementation skeletons changed in the spec between versions 2.1 and 2.2. You are now required to use T_out types (where applicable) for 'out' arguments.

    This may mean that you have to modify your object implementations. However the old signatures can still be used by passing the -Wbold flag to omniidl.

  6. New command line options and ORB configuration variables:

    • -ORBtraceInvocations, omniORB::traceInvocations- enable tracing of invocations of CORBA objects.
    • -ORBpoa_iiop_port <port number>- tells the POA the port number to use.
    • -ORBpoa_iiop_name_port <hostname [:port number]>- tells the POA the hostname and optionally the port number to use.

      NB. The BOA and POA will both use the same port if used together.

    • omniORB::objectTableSize- The default value is zero, and indicates that omniORB should grow the object table as necassary. It is recommended that you use this facility.

      Setting another value sets a fixed size for the object table, thus eliminating the overhead of resizing the table if you know in advance the likely number of objects. Since an open hash table is used, performance does not suffer disasterously if this number of objects is exceeded.

      If set, this value must be modified before calling CORBA::ORB_init()

    • omniORB::poaHoldRequestTimeout- If a POA is in the HOLDING state, then this value gives the number of seconds after which the POA will timeout and throw a TRANSIENT exception to the client (if the POA is not transitioned to another state).

      The default is zero, which indicates no timeout.

  7. Shared runtime version number change

    On various unices: ---> -->
    On IBM AIX:
    On Windows NT/95, the omniORB runtime DLLs for this version are:
    Make sure you update your Visual Studio to pick up the right library.

  8. Updated user manual.

  9. Fixed assignment to an element of a sequence of string and a sequence of object reference. Previous version does not work if the compiler does not do the obvious optimisation. Only DEC v5.6 C++ compiler is known to be affected by this bug.

  10. Client side call timeout now works on Windows NT and HPUX 11.00.

  11. COMM_FAILURE exception propagated from the server side will be reported as an exception to the application. This allows the invocation code to distinguish between transport problems and COMM_FAILURE propagated from the server side.

  12. Update omkdepend and the various win32 wrappers for Cygwin's new "mounts v2" registry subtree. Old Gnuwin32 mounts should still work.

  13. The member function CORBA::ORB::NP_destroy() is deprecated. Use CORBA::ORB::destroy() instead.

  14. Location Forwarding.

    A new omniORB specific exception omniORB::LOCATION_FORWARD is included. This may be thrown from an object implementation to indicate to the client that the request should be re-directed to another object.

    For portability you are better off using PortableServer::ForwardRequest within a ServantManager. However omniORB::LOCATION_FORWARD is more flexible, since it can be thrown from any object implementation.

    See include/omniORB3/omniORB.h

  15. Logging and omniORB::traceLevel. All omniORB log messages are now prefixed with 'omniORB:' to make it easy to separate omniORB messages from other messages that might be generated by an application.

    omniORB log messages are now emitted atomically (wrt fprintf()), which ensures that parts of omniORB log messages will never be interleaved.

    A new logging class is used internally for generating log messages, omniORB::log. This may be useful for generating messages in application programs. In this case a different prefix from the default can be specified.

    It is possible for the ORB to emit a log message each time a CORBA operation is invoked on a local or remote object. See the section on command line options and configuration variables.

    A log message is now written whenever a system exception is thrown from the omniORB runtime. For example:

      omniORB: throw COMM_FAILURE from
    This is enabled if the omniORB::traceLevel is 10 or greater.

  16. Examples.

    The standard echo examples have been updated to use the POA. There is a 'boa' directory which uses the old-style BOA interface. There is also a 'poa' directory which isn't very exciting yet, but will soon have a few more samples of POA code.

  17. Lots of other minor changes and bug fixes. Refer to the <top>/update.log file for details.

  18. Things that don't work.
    1. The PortableServer::Current interface is not supported. Any behaviour depending per-thread context information is not supported.
    2. The DSI interface has changed significantly. Old code will have to be re-written to the new interface. There is no support for using the DSI with the BOA. This part of the ORB is incomplete, since it depends in part on PortableServer::Current. See the example in src/examples/dsi for a way to workaround this problem for now.
    3. The Lifecycle service has not yet been re-implemented.
    4. The name of tie implementation skeletons has changed (in line with the POA mapping).

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