Do not hang on exit if the twisted threadpool is used.

marienz · marienz · commit b17a7dc774fb · 2010-03-07T12:47:06.000+01:00
diff --git a/bpython/urwid.py b/bpython/urwid.py
@@ -105,6 +105,37 @@ def buildProtocol(self, addr):
             return EvalProtocol(self.repl)
 
 
+class TwistedEventLoop(urwid.TwistedEventLoop):
+
+    """TwistedEventLoop modified to properly stop the reactor.
+
+    urwid 0.9.9 and 0.9.9.1 crash the reactor on ExitMainLoop instead
+    of stopping it. One obvious way this breaks is if anything used
+    the reactor's thread pool: that thread pool is not shut down if
+    the reactor is not stopped, which means python hangs on exit
+    (joining the non-daemon threadpool threads that never exit). And
+    the default resolver is the ThreadedResolver, so if we looked up
+    any names we hang on exit. That is bad enough that we hack up
+    urwid a bit here to exit properly.
+    """
+
+    def handle_exit(self, f):
+        def wrapper(*args, **kwargs):
+            try:
+                return f(*args, **kwargs)
+            except urwid.ExitMainLoop:
+                # This is our change.
+                self.reactor.stop()
+            except:
+                # This is the same as in urwid.
+                # We are obviously not supposed to ever hit this.
+                import sys
+                print sys.exc_info()
+                self._exc_info = sys.exc_info()
+                self.reactor.crash()
+        return wrapper
+
+
 class Statusbar(object):
 
     """Statusbar object, ripped off from bpython.cli.
@@ -753,7 +784,7 @@ def main(args=None, locals_=None, banner=None):
             sys.stderr.write('Reactor %s does not exist\n' % (
                     options.reactor,))
             return
-        event_loop = urwid.TwistedEventLoop(reactor)
+        event_loop = TwistedEventLoop(reactor)
     else:
         # None, not urwid.SelectEventLoop(), to work with
         # screens that do not support external event loops.
