The exit path for the debugger client has always been a little odd. We'd call a shutdown function which would destroy the client, then later call a stop function which would first make a new client, then stop it, then that one would get destroyed later. Made it so we stop and destroy just one client.
This is an incremental step towards moving it all the way
to hphp/server. This flattens base but doesn't untangle
the server files from lib_hphp_runtime
Cleanup a lot of hangs with either the debugger client or server in a variety of error conditions, mostly related to communication errors or the client or server exiting unexpectedly. One of the biggest fixes is that all cases where the client was left in a state where Ctrl-C wouldn't work have been fixed.
Remove lots of little snippets of dead code. If you see a function (or small set of functions/fields) deleted then it was actually dead.
I debated whether to keep throwing DebuggerClientExitException on the server, and I decided to keep it. I think it's reasonable that if you've got the server stopped and you quit the debugger that the request gets terminated rather than continuing to run.
I also considered a big change to the way Ctrl-C works, but ended up staying with what was there with just a bit of cleanup. We need to guard against people banging on Ctrl-C, which is a reasonable behavior, and I think it feels pretty reasonable with the updated message.
Finally, added many comments about how this stuff works.