[Libevent-users] event_base_loop_break()?

[Scott Lamb]

While playing with pyevent, I saw this code:

def abort():
     """Abort event dispatch loop."""
     cdef extern int event_gotsig
     cdef extern int (*event_sigcb)()
     event_sigcb = __event_sigcb
     event_gotsig = 1

This is used in exception handling - if a callback throws an exception, 
it does this to propogate the exception through immediately (breaking 
out of the loop without running any more callbacks).

This off-label use of a deprecated libevent interface is confusing, and 
I suspect it can interact badly with the more modern signal handling 
interface.

I propose instead that libevent have a event_base_loop_break() and 
event_loop_break(). (Or whatever you want them called.) They'd differ 
from event_{base_,}loop_exit() in that they would *immediately* abort 
the loop without finishing the iteration (i.e., sooner than 
event_base_loop_exit({.tv_sec=0, .tv_usec=0})). They'd be analogous to 
the C "break;" statement. Like event_loop_exit(), the next dispatch 
would be unaffected.

Feelings? I'd be happy to work up a patch and unit test.

Best regards,
Scott

[1] - Well, not quite, because there's a bug. 
<http://code.google.com/p/pyevent/issues/detail?id=6> But it's clearly 
intended to, and with a small patch it does.

-- 
Scott Lamb <http://www.slamb.org/>