i have an application w/ several threads, one of which is exclusively
dedicated to catching signals (everything is blocked in the other thread).
all of the worker threads execute in-step to a SIGALRM. this application
used to work fine prior to 3.3. this is the first time i've used tried in
3.3, and it appears that when the signal handler is executing and SIGALRM is
fired, the application dies (from a SIGALRM, according to zsh).