When a function (say gethostbyname) is to be used, it is tested by configure, and if found, a HAVE_GETHOSTBYNAME macro is defined.

Latest version of wineapi_check reports some incoherence between the known HAVE_XXX macros and the effectively used functions.

A discussion ensued between Patrik and Alexandre Julliard. The output, and the general rule of thumb for handling this type of function, is to:

• check for the existence of the file with configure
• do not use the HAVE_XXX macros for functions in the main code, but just add a stub (possibly returning error condition) in misc/port.c when the HAVE_XXX macro is not defined (this could also be added to another .c file if the function is only used in this place)
• if needed, missing structures shall be added to include/wine/port.h.

With those rules, the code will not be encumbered with #ifdef / #endif pairs all over the place, which degrades both readability and maintenability.

The first one was that CreateProcess implementation didn't use the CREATE_SUSPENDED flag, and thus made some trouble. Alexandre Julliard and Ulrich Weigand discussed a bit the implementation of such a feature and Alexandre provided the patch.

Basically, when a new process is created, several things have to be taken into account:

• let the process calling CreateProcess wait until the new process is created (so that a correct error code can be returned)
• have the newly created process do some initialization (part of this can be done a the context of process calling CreateProcess, but most of it must be done in the context of the new process).

Therefore, some synchronization is needed. Most of it was already in place. There is an event created at each process creation, used by the created process to signal its creator that it's initialization is done and it can return from CreateProcess. What has been done is that the server now handles this event signalling (so that the created process can be suspended by the server).

Peter's second issue was a bit more tricky. Peter wanted to have a WineLib program be launched by the Wine emulator (this is supported and works fine) but also be integrated with the Wine emulator (e.g use the same thread/process ids...).

Unfortunately, this is not supported yet and would require the (in)famous address space separation in place. The best solution right now is to create a PE (or NE) executable and run it in the emulator. Peter then asked for a list of tools to be used to create it under Linux (in other words: a cross compilation chain running under Linux generating Windows executable).

Several tools are known:

• Uwe Bonnes proposed to have a look at http://www.sourceware.cygnus.com/cygwin for mingw (find pointer to it on the http page above); it uses Windows crtdll and supports threading.
• and also If you want a light weighted tool and don't need c++ support, look for lcc-win32: http://www.cs.virginia.edu/~lcc-win32/. For some old version of lcc I have a linux port available, but the command line tools then run under wine too. I don't know the present status.
• Ove Kåven proposed to to install the Cygnus GNU-Win32 stuff and configure gcc to cross-compile with that ( http://web.ukonline.co.uk/julian.smart/wxwin/technote/crosscmp.htm).
• and of course, you can check http://www.winehq.com/tools.html

Ove Kåven (at Moshe's request) gave some more information on this: Overlapped I/O is simply asynchronous I/O. The ReadFile call requests that data be read (asynchronously, in the background), then returns and lets the app do other stuff until the request is satisfied/completed. When that is the case, the OS can signal an event object specified in the overlapped buffer, if the app so desires. When that happens, it can call GetOverlappedResult and process the data now in the data buffer...

I'm not sure why such a mechanism would exist in Windows, since normal multi-threading can accomplish the same thing. It certainly wouldn't make the kernel less bloated, nor application programming much simpler, so I can only assume it's for performance reasons (cut down number of threads, perhaps since windows has limited resources and is a lousy multitasker or something).

So far, Wine does not support overlapped I/O. Several ways of implementing it have been discussed. The easiest one is simply not to handle the request in the background (but to do it inside ReadFile or WriteFile), signal the caller within ReadFile/WriteFile and have GetOverlappedResult always return TRUE.

Some more complicated implementation would require threading (or service thread support). Anyway, it also turns out that Windows 9x only supports overlapped I/O for the serial line or socket, but not on disk files. Win NT also supports overlapped I/O for disk files. So the first and easy implementation shall do for a first round.

Patches for this implementation circulated, but it just helped CodeBase crash a little farther. No success story yet.

After some fights with Microsoft documentation, some fixes on VirtualAlloc, things went better (read: it ran further before crashing) until some explanation from Ulrich Weigand boiled the thing down to bad news: some tricky Bleem! code calls MapLS/UnMapLS in a certain way to get back the LDT base address, and then modify it for getting access to ring-0, and then create its own threads inside the VMM. This is certainly a very bad way of writing applications, and a sign of Windows 9x not being protected (as an OS).

The conclusion is that it will be nearly impossible to let Bleem! (and other badly written applications) run under Wine.

This type of behavior will not be permitted under NT, and some discussion went on for implementation of type of direct LDT access under Wine, but did not go very far.