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COM and DCOM OS Design Development (Windows Embedded CE 6.0)

1/6/2010

The Component Object Model (COM) is an operating system-independent object-oriented system for creating binary software components that can interact with other COM-based components.

This interaction can occur in the same process space, in other processes, or on remote computers.

The following levels of run-time support for COM-based applications are supported:

  • Minimal COM provides a baseline API set for COM object creation. This Catalog item requires about 10–20K of memory and is only available in headless OS designs.
  • COM provides a midrange implementation of COM and Automation that supports only in-process free-threaded objects and requires about 100–200K of memory.
  • The Distributed Component Object Model (DCOM) provides a full-featured COM implementation equivalent to Microsoft Windows NT® 4.0 SP5 and requires more than 700K of memory.

In addition, you can add storage functionality to any one of the three COM implementations by adding the COM Storage Catalog item.

Note

Distributed COM (DCOM), sometimes also referred to as "COM Remoting", is not included in Windows Embedded CE. Please see Remote DCOM Support for more information.

OS Design Information

The following table shows operating system design information for COM and DCOM.

Concept Description

Dependencies

None

Hardware considerations

None

Modules and Components

The following table shows the components and modules that implement COM and DCOM.

Item Module Component

Minimal COM

uuid, ole32, oleaut32, mcombase, mcommem, mcomstr, mcommon, mcomlib, ole232, docfile, msf, exp

None

COM

uuid, ole32, oleaut32, ole232, com, docfile, msf, exp

None

DCOM

dllhost, dcomssd, rpcrt4, rpcltccm, rpcltscm, ole32, oleaut32, uuid, dcomole, idisproxy

None

COM Storage

stg or mcomstm, depending on the previous COM choices

None

Implementation Considerations

The following table shows the Sysgen variables that control COM and DCOM Catalog items.

Sysgen variable Description

SYSGEN_OLE

Adds a midrange implementation of COM and Automation that supports only in-process free-threaded objects.

SYSGEN_OLE_GUIDS

Adds support for CoCreateGuid used with the standard COM implementation.

SYSGEN_OLE_STG

Adds structured storage functionality to the standard COM implementation.

SYSGEN_DCOM

Adds a full-featured COM implementation equivalent to Microsoft Windows NT® 4.0 Service Pack 5 (SP5).

This catalog item no longer brings in the DCOM component libraries. See DCOM Remote Access

For more information, see Component Services (COM and DCOM).

Ee489439.note(en-US,WinEmbedded.60).gifNote:
Distributed COM (DCOM), sometimes also referred to as "COM Remoting", is not included in Windows Embedded CE. Please see Remote DCOM Support for more information.

SYSGEN_DCOM_STG

Adds structured storage functionality to DCOM.

SYSGEN_MINICOM

Adds a minimal COM implementation that provides a baseline API for COM object creation.

SYSGEN_MINICOM_GUIDS

Adds support for CoCreateGuid used with the minimal COM implementation.

SYSGEN_MINICOM_STG

Adds structured storage functionality to the minimal COM implementation.

Application Development Topics

Component Services (COM and DCOM)

COM and DCOM Registry Settings

Automation

OLE Compound Documents

COM and DCOM Security

COM Threads and Processes

Transport Protocols

Creating and Initializing COM Objects

Marshaling Support

See Also

Other Resources

Component Services (COM and DCOM)