[Bug 2166] New: AsyncCallbacks in Wininet should not be asynchronous

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=2166

Summary: AsyncCallbacks in Wininet should not be asynchronous
           Product: Wine
           Version: 20040309
          Platform: All
        OS/Version: other
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: wine-net
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

My research has shown that the native WININET implementation invokes the
statuscallback from whatever thread that performs the work that requires a
notification. However, the implementation of SendAsyncCallback in Utility.C uses
the INTERNET_FLAG_ASYNC option associated with the connection as the criteria
for generating an async response.

This would cause fault in asynchronous pluggable protocols that perform a close
handle and terminate because the HANDLE_CLOSING notification can arrive after
the APP has terminated. However, on further investigation, I have discovered
that in the native implementation race conditions are avoided by disabling the
statuscallback assocated with the handle before removing the handle thereby
disabling the callback.

I would recommend that the correct fix is to check if the statuscallback is
associated with the handle being closed in InternetCloseHandle, and to disable
the callback.

I would also recommend making callbacks synchronous. In my testing I have not
seen any problems after making this change. However, this change would be
strictly a change with closer consistency and better performance.

I would also recommend a name change from SendAsyncCallback to SendCallback.