Add a PollScheduler._next_poll_event() method to maintain a central event

queue between _poll_loop() and _schedule_wait(). This solves an intermittent
KeyError from _poll_loop() which occured when an event handler called
_schedule_wait() which unregistered an event handler for an event that
_poll_loop() had already recieved but hadn't processed yet.

svn path=/main/trunk/; revision=11051

1 files changed, 25 insertions, 11 deletions

diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index a2c7b19e7..ef16f477c 100644
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -8085,6 +8085,7 @@ class PollScheduler(object):
 		self._max_jobs = 1
 		self._max_load = None
 		self._jobs = 0
+		self._poll_event_queue = []
 		self._poll_event_handlers = {}
 		self._poll_event_handler_ids = {}
 		# Increment id for each new handler.
@@ -8132,19 +8133,29 @@ class PollScheduler(object):
 
 		return True
 
+	def _next_poll_event(self):
+		"""
+		Since the _schedule_wait() loop is called by event
+		handlers from _poll_loop(), maintain a central event
+		queue for both of them to share events from a single
+		poll() call.
+		"""
+		if not self._poll_event_queue:
+			self._poll_event_queue.extend(self._poll.poll())
+		return self._poll_event_queue.pop()
+
 	def _poll_loop(self):
 
 		event_handlers = self._poll_event_handlers
-		poll = self._poll.poll
-		state_change = 0
+		event_handled = False
 
 		while event_handlers:
-			for f, event in poll():
-				handler, reg_id = event_handlers[f]
-				if not handler(f, event):
-					state_change += 1
+			f, event = self._next_poll_event()
+			handler, reg_id = event_handlers[f]
+			handler(f, event)
+			event_handled = True
 
-		if not state_change:
+		if not event_handled:
 			raise AssertionError("tight loop")
 
 	def _register(self, f, eventmask, handler):
@@ -8177,15 +8188,18 @@ class PollScheduler(object):
 		"""
 		event_handlers = self._poll_event_handlers
 		handler_ids = self._poll_event_handler_ids
-		poll = self._poll.poll
+		event_handled = False
 
 		if isinstance(wait_ids, int):
 			wait_ids = frozenset([wait_ids])
 
 		while wait_ids.intersection(handler_ids):
-			for f, event in poll():
-				handler, reg_id = event_handlers[f]
-				handler(f, event)
+			f, event = self._next_poll_event()
+			handler, reg_id = event_handlers[f]
+			handler(f, event)
+			event_handled = True
+
+		return event_handled
 
 class QueueScheduler(PollScheduler):