On 10/10/06, Segin segin2005@gmail.com wrote:
It took some good hydro from Holland and about 6 hours of trying to write a program that could syncronize multiple instances of itself using IPC and signals (so it could run on Minix 3, where pthreads sadly doesn't exist, so it was a threading hack of sorts) to come up with a possible fix for the cross-process problem with NtProtectVirtualMemory.
The solution: Use signals.
It's really simple to explain (I wouldn't know where to begin with actually coding it, pointers would help). Since the NtProtectVirtualMemory call is only supported by the current process, use wineserver and software signals to allow a bit of a cross-process hack.
When the individual Win32 process client recieves a certain signal (ohh, for now, say SIGUSR2), the client would break the Win32 code, call up wineserver for the parameters (and silently ignore if it's a false signal, e.g. lame user trying to use `kill -USR2'), preform the required operations itself, and then resume executing the Win32 process.
Does this sound like a good hack or what?
I was wrestling with this over the summer, but alas, school got in the way before it got "good enough." Check out http://wiki.winehq.org/RemoteProcessOperations (the page history might be useful--Dan recently removed some info.)
Basically, Wine already uses signals for some things, and piggy-backing these operations on the current mechanism is doable should be done in the coming months.
Best,
Tommy