Re: Merge of nickrob-async-20060513 to mainline?

[Nick Roberts <nickrob@snap.net.nz>]

 > Yes, this should work, though it seems cumbersome.  When you've got
 > a single thread, you don't need to pass actual data around an fd,
 > just a marker "yes i'm ready now".

I don't quite follow, that's how the event loop works.  Even user input
requires an fd through stdin_event_handler.  There is a provision for other
events but currently only file events are used.

 > Moving the call to waitpid out of linux-nat.c, and to a target
 > independent file, is a mistake - presumably that's just how you got it
 > to work quickly?  That's related to why it doesn't work for threads.
 > The vital line is "options ^= __WCLONE" in the loop in linux_nat_wait.
 > Without __WCLONE, you'll never see a wait status from a thread; with
 > it you'll never see a wait status from the main program.

Perhaps I can use __WALL as a catch all.

 > Ideally you'd be able to reuse the signal handler logic (see the calls
 > to sigprocmask and sigsuspend) and thus not have a millisecond latency
 > and excessive spinning.  That's actually a pretty important feature,
 > because context switching to gdb every millisecond or so is going to
 > really hurt performance of the debuggee.

OK, a bit more homework then.

Thanks

-- 
Nick                                           http://www.inet.net.nz/~nickrob