Strong/Weak Marshaling of Proxies Is Not Supported (148374)



The information in this article applies to:

  • Microsoft OLE Libraries, when used with:
    • the operating system: Microsoft Windows NT 3.51
    • the operating system: Microsoft Windows NT 4.0
    • the operating system: Microsoft Windows 95
    • the operating system: Microsoft Windows 2000

This article was previously published under Q148374

SUMMARY

Marshaling a proxy of an interface belonging to another thread or process is supported with MSHLFLAGS_NORMAL, but it is not supported with MSHLFLAGS_TABLESTRONG or MSHLFLAGS_TABLEWEAK. This means that CoMarshalInterface with MSHLFLAGS_TABLESTRONG/MSHLFLAGS_TABLEWEAK and IRunningObjectTable::Register will return E_INVALIDARG for proxies.

MORE INFORMATION

When an interface is marshaled to another thread or process, a proxy of the interface is created in that thread or process. This proxy cannot be marshaled again using the MSHLFLAGS_TABLESTRONG or MSHLFLAGS_TABLEWEAK values of the MSHLFLAGS enumerator. However it can be marshaled using MSHLFLAGS_NORMAL. Marshaling of interfaces that are not proxies are supported using any of the MSHLFLAGS enumerator values.

IRunningObjectTable::Register will marshal the interface pointer given to it by using MSHLFLAGS_TABLESTRONG or MSHLFLAGS_TABLEWEAK, as specified by the grfFlags parameter. Consequently IRunningObjectTable::Register will fail with E_INVALIDARG if is asked to register a proxy.

Windows 3.x supported marshaling of proxies using MSHLFLAGS_TABLESTRONG and MSHLFLAGS_TABLEWEAK. This is not supported on Windows 95 or Windows NT.

Modification Type:MajorLast Reviewed:12/3/2003
Keywords:KB148374