EventLoop: allow IO event handler re-entrance

IO event handlers may be re-entrant, in case something like
AbstractPollTask._wait_loop(), needs to be called inside a handler for
some reason.

diff --git a/pym/portage/util/_eventloop/EventLoop.py b/pym/portage/util/_eventloop/EventLoop.py
index 37839ab2d85dbdbef08a8273be135862c20ad1a4..af0c6a502a9e1ca28a132a5fe4d3711110ef1b94 100644 (file)
--- a/pym/portage/util/_eventloop/EventLoop.py
+++ b/pym/portage/util/_eventloop/EventLoop.py
@@ -20,7 +20,7 @@ class EventLoop(object):
                __slots__ = ("args", "callback", "calling", "source_id")
 
        class _io_handler_class(SlotObject):
-               __slots__ = ("args", "callback", "calling", "fd", "source_id")
+               __slots__ = ("args", "callback", "fd", "source_id")
 
        class _timeout_handler_class(SlotObject):
                __slots__ = ("args", "function", "calling", "interval", "source_id",
@@ -178,16 +178,11 @@ class EventLoop(object):
                        while event_handlers and self._poll_event_queue:
                                f, event = self._next_poll_event()
                                x = event_handlers[f]
-                               if x.calling:
-                                       # don't call it recursively
-                                       continue
-                               events_handled += 1
-                               x.calling = True
-                               try:
-                                       if not x.callback(f, event, *x.args):
-                                               self.source_remove(x.source_id)
-                               finally:
-                                       x.calling = False
+                               # NOTE: IO event handlers may be re-entrant, in case something
+                               # like AbstractPollTask._wait_loop(), needs to be called inside
+                               # a handler for some reason.
+                               if not x.callback(f, event, *x.args):
+                                       self.source_remove(x.source_id)
                except StopIteration:
                        events_handled += 1