Adds loop.call_soon and loop.run_forever

1 files changed, 58 insertions, 9 deletions

diff --git a/kombu/async/hub.py b/kombu/async/hub.py
index fe0ca376..e3e2924f 100644
--- a/kombu/async/hub.py
+++ b/kombu/async/hub.py
@@ -8,10 +8,13 @@ Event loop implementation.
 """
 from __future__ import absolute_import
 
+from collections import deque
 from contextlib import contextmanager
 from time import sleep
 from types import GeneratorType as generator
 
+from amqp import promise
+
 from kombu.five import Empty, items, range
 from kombu.log import get_logger
 from kombu.utils import cached_property, fileno, reprcall
@@ -25,6 +28,14 @@ logger = get_logger(__name__)
 _current_loop = None
 
 
+class Stop(BaseException):
+    """Stops the event loop."""
+
+
+def _raise_stop_error():
+    raise Stop()
+
+
 @contextmanager
 def _dummy_context(*args, **kwargs):
     yield
@@ -83,6 +94,10 @@ class Hub(object):
         self.writers = {}
         self.on_tick = set()
         self.on_close = set()
+        self._ready = deque()
+
+        self._running = False
+        self._loop = None
 
         # The eventloop (in celery.worker.loops)
         # will merge fds in this set and then instead of calling
@@ -94,6 +109,8 @@ class Hub(object):
         self.consolidate = set()
         self.consolidate_callback = None
 
+        self.propagate_errors = ()
+
         self._create_poller()
 
     def reset(self):
@@ -108,11 +125,9 @@ class Hub(object):
     def _close_poller(self):
         if self.poller is not None:
             self.poller.close()
-            self.poller = None
 
     def stop(self):
-        self._close_poller()
-        self.close()
+        self.call_soon(_raise_stop_error)
 
     def __repr__(self):
         return '<Hub@{0:#x}: R:{1} W:{2}>'.format(
@@ -132,6 +147,8 @@ class Hub(object):
                     entry()
                 except propagate:
                     raise
+                except MemoryError:
+                    raise
                 except Exception as exc:
                     logger.error('Error in timer: %r', exc, exc_info=1)
         return min(max(delay or 0, min_delay), max_delay)
@@ -154,6 +171,28 @@ class Hub(object):
         self._unregister(fd)
         self._discard(fd)
 
+    def run_forever(self):
+        self._running = True
+        try:
+            while 1:
+                try:
+                    self.run_once()
+                except Stop:
+                    break
+        finally:
+            self._running = False
+
+    def run_once(self):
+        try:
+            next(self.loop)
+        except StopIteration:
+            self._loop = None
+
+    def call_soon(self, callback, *args):
+        handle = promise(callback, args)
+        self._ready.append(handle)
+        return handle
+
     def call_later(self, delay, callback, *args):
         return self.timer.call_after(delay, callback, args)
 
@@ -198,6 +237,7 @@ class Hub(object):
             pass
 
     def close(self, *args):
+        self._close_poller()
         [self._unregister(fd) for fd in self.readers]
         self.readers.clear()
         [self._unregister(fd) for fd in self.writers]
@@ -212,10 +252,10 @@ class Hub(object):
         self.writers.pop(fd, None)
         self.consolidate.discard(fd)
 
-    def _loop(self, propagate=None,
-              generator=generator, sleep=sleep, min=min, next=next,
-              Empty=Empty, StopIteration=StopIteration, KeyError=KeyError,
-              READ=READ, WRITE=WRITE, ERR=ERR):
+    def create_loop(self,
+                    generator=generator, sleep=sleep, min=min, next=next,
+                    Empty=Empty, StopIteration=StopIteration,
+                    KeyError=KeyError, READ=READ, WRITE=WRITE, ERR=ERR):
         readers, writers = self.readers, self.writers
         poll = self.poller.poll
         fire_timers = self.fire_timers
@@ -225,6 +265,8 @@ class Hub(object):
         consolidate_callback = self.consolidate_callback
         on_tick = self.on_tick
         remove_ticks = on_tick.difference_update
+        todo = self._ready
+        propagate = self.propagate_errors
 
         while 1:
             outdated_ticks = set()
@@ -238,6 +280,11 @@ class Hub(object):
                     outdated_ticks.add(tick_callback)
             remove_ticks(outdated_ticks)
 
+            while todo:
+                item = todo.popleft()
+                if item:
+                    item()
+
             poll_timeout = fire_timers(propagate=propagate) if scheduled else 1
             #print('[[[HUB]]]: %s' % (self.repr_active(), ))
             if readers or writers:
@@ -323,6 +370,8 @@ class Hub(object):
     def scheduler(self):
         return iter(self.timer)
 
-    @cached_property
+    @property
     def loop(self):
-        self._loop()
+        if self._loop is None:
+            self._loop = self.create_loop()
+        return self._loop