Changes Between Win 3.1 and WFW 3.1 Versions of DDEML

The information in this article applies to:

• Microsoft Windows Software Development Kit (SDK) version 3.1

The following changes have been made from the Windows 3.1 version of DDEML to the version that shipped with Windows for Workgroups (WFW) version 3.1:

• The default shutdown timeout was changed from 3,000 milliseconds to 30,000 milliseconds.
• DdeQueryConvInfo() added support for the new hwnd and hwndPartner fields.
• DdeQueryConvInfo() added more robust handling for improper setting of the CONVINFO structure's cb field when called.
• Rewrote DdePostAdvise() to supply the correct count of remaining transactions to be processed on the same topic!item!format name set for the XTYP_ADVREQ transaction.
• Disallow synchronous calls if the application is shutting down, or if already in the middle of a synchronous transaction.
• DdeUninitialize() was fixed to defer processing if called while in the middle of a synchronous transaction.
• DdeUninitialize() was fixed to dispatch any pending DDE messages and to make necessary callbacks before quitting.
• Added call to DdeUninitialize() from within DdeClientTransaction() when in the middle of a synchronous transaction and DdeUninitialize() had been called.
• Allow any instance to call DdeCreateStringHandle().
• Have DdeAbandonTransaction() only mark abandoned transactions, rather than trying to remove the transaction from internal structures.
• Alter PostMessage() overflow queuing to queue based on target instead of on the same task, so that one target queue overflow does not bog down all PostMessage() calls.