omniORB on Win32 platforms

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This file contains information on installing, building, and using omniORB3 on Win32 (Windows NT and Windows '95) platforms.

If you are upgrading from 2.2.0, do not miss the important information about omniNames at the end of this note.

OmniORB has been tested with the following software configuration:

  • Operating System : Windows NT 4.0 and Windows 2000
  • Architecture : x86 (and alpha in earlier versions)
  • Compiler : Visual C++ 5.0 and Visual C++ 6.0

The omniORB binaries, when compiled using VC++ 6.0 on Windows NT, will execute on Windows '95/8 machines and vice-versa.

As of 2.6.1, Alpha Windows NT is also supported. Unless otherwise stated, the description below also applies to Alpha NT. Where appropriate the reference to "x86" has to be changed to "alpha".


When the omniORB3 distribution is unpacked, the following are created:

  • <Top-Level Directory>\ : Directory where distribution was unpacked
  • <Top-Level Directory>\doc\ : omniORB Documentation
  • <Top-Level Directory>\include\ : Include files
  • <Top-Level Directory>\include\omniORB3\ : Include files for ORB run-time library
  • <Top-Level Directory>\include\omnithread.h : Main omnithread include file
  • <Top-Level Directory>\include\omnithread\ : Include files for thread library
  • <Top-Level Directory>\src\ : Source files
  • <Top-Level Directory>\src\lib\omniORB2\ : Source files for ORB run-time library
  • <Top-Level Directory>\src\lib\omnithread\ : Source files for thread library
  • <Top-Level Directory>\src\tool\omniidl\ : Source files for IDL Compiler
  • <Top-Level Directory>\src\appl\omniNames\ : Source files for COS Naming Service
  • <Top-Level Directory>\src\appl\utils\ : Source files for utilities
  • <Top-Level Directory>\src\examples\ : Source for example programs


If you downloaded the Win32 binary distribution of omniORB, ready-built binaries are provided. You are ready to go.

The executables and DLLs are in <Top-Level Directory>\bin\x86_win32. The libraries are in <Top-Level Directory>\lib\x86_win32.

You *should* set up your PATH environment to include <Top-Level Directory>\bin\x86_win32 otherwise the DLLs will not be picked up when omniORB programs are run.

If you have the source-only distribution, you will need to build omniORB3. Please read the "Building omniORB3 from the source files" section, below. (If you want the Win32 binary distribution, but don't have it, you can download it from our web site at

omniidl requires Python 1.5.2 or later. You can download the full Python distribution from

Alternatively, for Windows on x86, you can install a minimal version of Python which contains just the functionality required by omniidl. The Win32 binary ditribution of omniORB comes with this minimal python package. Download it from

Unpack the zip file at the top of the omniORB tree. It places files in the bin, lib and include directories.

Configure the naming service

If you are upgrading from 2.2.0, please read the important information about omniNames at the end of this note.

You have to configure the omniORB runtime and the naming service, consult the user guides in ./doc for details. For a quick start, follow these steps:

  1. Make sure that <Top-Level Directory>\bin\x86_win32 is in your PATH environment.
  2. Set the environment variable OMNINAMES_LOGDIR to a directory where the naming service omniNames can store its data. For example: set OMNINAMES_LOGDIR=C:\OMNINAMES
  3. Start omniNames. The binary is in <Install Location>\bin\win32_x86.

    For example: omniNames -start 12345

    Notice that you have to give as a parameter to the option -start the TCP/IP port number omniNames will use to receive IIOP requests.

  4. omniNames writes the stringified object reference for its root context on standard error. Copy the IOR. (including the IOR: prefix).
  5. Start the tool REGEDT32.EXE (on NT) or REGEDIT.EXE (on Windows '95). Select the key HKEY_LOCAL_MACHINE\SOFTWARE\ORL\omniORB\2.0 (or create it if it doesn't exist). Add a string value (known as a REG_SZ data type when using REGEDT32) called NAMESERVICE , and paste the IOR in to the value field associated with it.
  6. Since 2.6.0, an alternative way to set up the configuration data is as follows:

    If omniNames has been started on host wobble and port 1234, use REGEDT32.EXE to enter the following keys into


    Name Value (REG_SZ)
    ORBInitialHost wobble
    ORBInitialPort 1234

    Any omniORB clients of release 2.6.0 or later is able to use this information to locate the root context of the Naming Service.

  7. The registry entries must be duplicated on all machines that will run omniORB programs. It is only necessary to run one instance of omniNames on your network.
  8. Once you are satisfied the naming service is running properly. You can setup omniNames to run as an NT service. See the description below.

Compiling the examples with nmake

Once the installation is completed. You can try compiling and running the examples in <Top-Level Directory>\src\examples.

Just do the following:

cd <Top-Level Directory>\src\examples nmake /f dir.mak

Have a look at the dir.mak file in <Top-Level Directory>\src\examples, it should give you some idea about the compiler flags and libraries to compile and link omniORB programs.

Building Projects using omniORB

Before building anything (or running the examples), you should refer to the omniORB documentation. In particular, you must add the (stringified) object reference of the naming service to the registry (in the (string) value NAMESERVICE, under the key HKEY_LOCAL_MACHINE\SOFTWARE\ORL\omniORB\2.0). You should use the tool REGEDT32.EXE on Windows NT, or REGEDIT.EXE on Windows '95. (See above for quickstart instructions on starting the Naming Service).

Note that the instructions below are for Microsoft Visual C++ 4.2, using Microsoft Developer Studio. If you are using Microsoft Visual C++ 5.0, the setup will be slightly different. The instructions are for using the DLL versions of omniORB and omnithread.

  1. Add the stub (SK.cpp) files generated by the IDL compiler to the project (Insert->"Files into Project")
  2. Set up the search paths for include and library files:
    1. Under Tools->Options, select the Directories tab.
    2. In the "Show directories for" box, select "Include files".
    3. Add the directory where you installed the omniORB include files to the list (this is <Top-Level Directory>\include).
    4. In the "Show directories for" box, select "Library files".
    5. Add the directory where you installed the omniORB library files to the list (this is <Top-Level Directory\lib\x86_win32).
  3. Set up macros and libraries:
    1. Under Build->Settings, select the "C/C++" tab.
    2. In the "Category" box, select "C++ Language". Tick the "Enable exception handling" box.
    3. In the "Category" box, select "Code Generation". In the "Use run-time library" box, select "Multithreaded DLL".
    4. **This is an import step.** In the "Category" box, select "Preprocessor". In the "Preprocessor" box, add the macros __WIN32__,__x86__. If this is NT 4.0, add the macros __NT__ and __OSVERSION__=4 as well.
    5. Select the "Link" tab.
    6. In the "Category" box, select "Input". In the "Object/library modules" box, add the following libraries: wsock32.lib, advapi32.lib, omniORB300_rt.lib, omniDynamic300_rt.lib, omnithread2_rt.lib
    7. If you are building a debug executable, the debug version of the libraries: omniORB300_rtd.lib, omniDynamic300_rtd.lib and omnithread2_rtd.lib should be used.
  4. Your project is now set up, and you can build it.

If you want to use the static versions of omniORB and omnithread, you must add the macro _WINSTATIC (see step (c) 4, above), and replace the libraries omniORB3_rt.lib, omniDynamic300_rt.lib and omnithread3_rt.lib with omniORB3.lib, omniDynamic3.lib and omnithread.lib (see step (c) 6, above).

Important Change to omniNames for users upgrading from version 2.2.0

Since release 2.4.0, the naming service has used the prefix pragma "" in its IDL.

Unfortunately, this is not compatible on-the-wire with clients that are linked with the old library, i.e. any programs linked before version 2.4.0 was released.

The implications of this change are as follows:

  • omniNames built in this release *CANNOT* read the data file of the version 2.2.0 omniNames. A new instance must be started from scratch. If you start omniNames and tell it to use the old data file, it will certainly crash.
  • Possible migration path: At AT&T Laboratories Cambridge, we are running the old and the new omniNames in parallel. The new instance is setup to run on a different port. Also the new tree is built to read by default a different configuration file: (/project/omni/var/omniORB_NEW.cfg instead of /project/omni/var/omniORB.cfg) so that a client will pick up the IOR of the old or the new omniNames depending on whether it is compiled with the old or the new library. When all our services have been recompiled, the old omniNames will be withdrawn.
  • If you want to continue to use the old omniNames, you can undo this change with the following steps:
  1. Edit <Top directory>\src\lib\omniORB2\Naming.idl and remove the #pragma prefix "" line..
  2. Do the same to <Top directory>\idl\Naming.idl.
  3. Remove <Top directory>\include\omniORB3\Naming.hh.
  4. Rebuild everything. You should do a make veryclean at the top of <Top directory>\src to make sure that the naming service stubs are regenerated.

Known Problems

When compiling the stub files generated by omniidl, you may come across some bugs in Microsoft Visual C++ 4.2 (not fixed in Microsoft Visual C++ 5.0). The bugs are to do with the handling of nested classes. You may come across these bugs if you use modules in your IDL files, and in certain other circumstances.

Unlike 2.2.0, this release generates stub code that works around most of the MS VC++ bugs. However, it is not possible to avoid the bugs in all cases. In particular, the following sample IDL will fail to compile:

// IDL
module A {
  struct B { 
    long x;
  enum C { C_1, C_2 }; 
  module D {
    struct B { 
      float y; 
    }; // The stub for struct E would fail to compile
    struct E { 
      A::B e1; 
      B e2; 

Building omniORB3 from the source files

OmniORB3 should be compiled using Visual C++ 5.0 or Visual C++ 6.0.  The following description only applies to x86 platform. For alpha NT, the binary distribution is compiled under Interix (OpenNT) posix subsystem. There is no gnu-win32 utilities available under alpha NT at the moment.


Starting from this release, the omniORB source tree requires the gnu-win32 utilities from Cygnus Solutions to build. It also requires the scripting language Python to both compile and run.


The full gnu-win32 distribution is freely available at:

or in UK

The toolkit is big and you don't need all of it to compile omniORB. Alternatively, you can download a cutdown version from:

The utilities in this version are all you need to build omniORB.

Assume that you have downloaded the toolkit and have unpacked/installed it in some sensible subdirectory, say C:\gnuwin32, you then have to go through the following checklist:

  1. In a command prompt window, make sure that you have the environment variables and path setup properly to use MS Visual C++ (4.2/5.0).

    For instance, I have MS VC++ installed in C:\Program Files\DevStudio. The following environment variables should be set to:

    LIB=C:\Progra~1\DevStudio\VC\lib INCLUDE=C:\Progra~1\DevStudio\VC\include



  2. If you have unpacked in C:\gnuwin32, add C:\gnuwin32\bin to your Path environment variable.

    Warning: If you have installed posix utilities from the Windows resource kits, make sure that C:\gnuwin32 is searched before the directory containing these utilities.

    If you have installed the full gnu-win32 toolkit, just follow its installation instructions and you can skip 3.

  3. Now you have to run a small script *once* to setup in your registry the necessary 'mount' points. Basically, it tells the gnu-win32 runtime how to translate a path such as /bin/sh to the real path name Win32 (e.g. C:\gnuwin32\bin\sh.exe) understands.

    Just execute this command in a command prompt window:

    C:\gnuwin32\bin\checkmounts C:\gnuwin32

    If all goes well, this is what you see:

    C:\> C:\gnuwin32\bin\checkmounts C:\gnuwin32 no /bin/sh.exe, mounting c:\gnuwin32\bin as /bin Completed successfully.

  4. Now you are ready. You can now build the distribution by following the instructions below.


omniidl requires Python 1.5.2. You can download the full Python distribution from:


Alternatively, for Windows on x86, you can install a minimal version of Python which contains just the functionality required by omniidl. Download it from:

Unpack the zip file at the top of the omniORB tree. It places files in the bin, lib and include directories.

Choose the right platform configuration file

Edit <top>\config\ to select one of the following:

  • platform = x86_nt_3.5
  • platform = x86_nt_4.0
  • platform = x86_win95

Set the location of the Pyhton interpreter

Edit <top>\mk\platforms\<platform>.mk

where <platform> is the platform you just chose in, e.g. <top>\mk\platforms\

If you are using the omnipython minimal distribution, uncomment the line which reads

PYTHON = $(ABSTOP)/$(BINDIR)/omnipython

otherwise, set PYTHON to the location of your Python executable. Note that you must use a Unix-style gnu-win32 path.

Building and installing

Go into the directory <top>\src and type 'make export'. If all goes well:

  • The executables and DLLs will be installed into <top>\bin\x86_win32\
  • The libraries will be installed into <top>\lib\x86_win32\

Running omniNames as an NT service

  • Use srvany from the NT resource kit.
  • Follow the instruction provided with srvany to run a program as a service.
  • An example:
    • The binary of omniNames.exe is in C:\omniNames\omniNames.exe
    • The log directory is set to C:\omniNames
    • The standard error output is to be redirected to C:\omniNames\omniNames.errlog
    • Set the following registry parameters with the service applet:
    • Application: REG_SZ C:\omniNames\omniNames.exe
    • AppParameters: REG_SZ -logdir C:\omniNames -errlog C:\omniNames\omniNames.errlog
    • AppDirectory: REG_SZ C:\omniNames

Mailing List

There is a mailing list for discussing the use and development of omniORB. Look here for details on subscribing.

For comments, feedback, etc, please see the 'Keeping in touch' page.
Copyright 2000 - AT&T Laboratories Cambridge