[Help-smalltalk] committed reorganization of Win32 event handling

[Paolo Bonzini]

I finally finished the reorganization of sysdep code I started last weekend:

1) last weekend I separated the sysdep code into various pieces in the 
sysdep/ directory, organized by "topic" and OS, and duplicated events.c 
(previously considered non-system-dependent, but actually relying 
heavily on POSIX features) into sysdep/posix/events.c and 
sysdep/win32/events.c.

2) now I rewrote sysdep/win32/events.c to use native Win32 APIs; so I 
was also able to figure out the common parts, and move them back to 
libgst/events.c.

The Win32 code is still not very commented and not very readable; the 
approach is totally different from POSIX because it signals Smalltalk 
semaphores from a separate thread rather than from signal handlers.  In 
the future, however, this may turn out to be the way to go even for 
POSIX (via libevent)!

While I wrote the code independently, after the fact I noticed that 
putty uses the same approach.  This cannot be bad.

3) at the same time, sockets became a bit more intertwined with the 
event handling machinery, so I moved socket code into the main DLL.  You 
will still have to load the Sockets.star package (it's just the C module 
that is no more).

The good news are threefolded.  First, the POSIX code sees just 
functions moving around; the actually code is basically untouched.  This 
is good for stability.  Second, some very ugly code for Win32 (the 
emulation of poll, and signalx.*) goes away: the net effect is like -600 
lines of code.  Third, despite extremely light testing, it is less buggy 
than before---at least "Sockets.Socket microTest" works.

Besides including VisualGST, I think we're now feature-complete for 3.2.

Paolo