Alexandre Julliard:
It would certainly be nice if we could convince dosvm to stop using SIGUSR2, there are lots of other things that could make better use of it. I don't really have a good solution to offer though (except maybe getting rid of dosvm altogether ;-)
Well, I'm not going to comment about dosvm usefulness, but I guess there are quite a few types of asynchronous requests Windows processes make to each other, so some kind of multiplexing system is going to be needed, anyway, and dosvm notification signal probably could use the same system without adding any extra complexity.
I was myself thinking about using a single signal whose handler just pulls asynchronous requests from wineserver as an implementation of the multiplexing system. Locking issues could be fixed using worker threads, signal safe critical section implementation or explicit signal blocking in protected code paths. But since there are quite a few ways for implementing multiplexing and fixing the resulting locking issues I probably just wait and see what the implementation turns out to be.