renamed coros.async_result to coros.AsyncJob; added poll, kill_after, __nonzero__ methods; made it access greenlet via weakref

eventlet/coros.py

@@ -26,6 +26,7 @@ import collections
 import sys
 import time
 import traceback
+import weakref
 
 
 from eventlet import api
@@ -236,36 +237,83 @@ class event(object):
         # the arguments and the same as for greenlet.throw
         return self.send(None, args)
 
+class _AsyncJobPollError(Exception):
+    pass
 
-class async_result(object):
+class AsyncJob(object):
 
-    def __init__(self, greenlet, event):
-        self.greenlet = greenlet
+    def __init__(self, greenlet_ref, event):
+        self.greenlet_ref = greenlet_ref
         self.event = event
 
-    def __bool__(self):
-        return not self.greenlet.dead
+    @property
+    def greenlet(self):
+        return self.greenlet_ref()
+
+    def __nonzero__(self):
+        greenlet = self.greenlet_ref()
+        if greenlet is not None and not greenlet.dead:
+            return True
+        return False
+
+    def __repr__(self):
+        klass = type(self).__name__
+        if self.greenlet is not None and self.greenlet.dead:
+            dead = '(dead)'
+        else:
+            dead = ''
+        return '<%s greenlet=%r%s event=%s>' % (klass, self.greenlet, dead, self.event)
 
     def wait(self):
         return self.event.wait()
 
-    def kill(self):
-        return api.kill(self.greenlet)
+    def poll(self, marker=None):
+        error = _AsyncJobPollError()
+        timer = api.exc_after(0, error)
+        try:
+            return self.wait()
+        except _AsyncJobPollError, ex:
+            if ex is error:
+                return marker
+            raise
+        finally:
+            timer.cancel()
 
-def _wrap_result_in_event(event, func, *args, **kwargs):
+    def kill(self):
+        greenlet = self.greenlet_ref()
+        if greenlet is not None:
+            return api.kill(greenlet)
+
+    def kill_after(self, seconds):
+        api.call_after_global(seconds, _kill_by_ref, weakref.ref(self))
+
+def _kill_by_ref(async_job_ref):
+    async_job = async_job_ref()
+    if async_job is not None:
+        async_job.kill()
+
+def _wrap_result_in_event(event_ref, func, *args, **kwargs):
     try:
         result = func(*args, **kwargs)
     except api.GreenletExit, ex:
-        event.send(ex)
+        event = event_ref()
+        if event is not None:
+            event.send(ex)
     except:
-        event.send_exception(*sys.exc_info())
+        event = event_ref()
+        if event is not None:
+            event.send_exception(*sys.exc_info())
+        else:
+            raise # let hub log the exception
     else:
-        event.send(result)
+        event = event_ref()
+        if event is not None:
+            event.send(result)
 
 def spawn_link(func, *args, **kwargs):
     result = event()
-    g = api.spawn(_wrap_result_in_event, result, func, *args, **kwargs)
-    return async_result(g, result)
+    g = api.spawn(_wrap_result_in_event, weakref.ref(result), func, *args, **kwargs)
+    return AsyncJob(weakref.ref(g), result)
 
 
 class multievent(object):

greentest/test__event.py

@@ -1,7 +1,7 @@
 import unittest
 import sys
 from eventlet.coros import event, spawn_link
-from eventlet.api import spawn, sleep, GreenletExit
+from eventlet.api import spawn, sleep, GreenletExit, exc_after
 
 class TestEvent(unittest.TestCase):
     
@@ -41,12 +41,14 @@ class TestSpawnLink(unittest.TestCase):
             sleep(0.1)
             return 101
         res = spawn_link(func)
+        assert res
         if sync:
             res.kill()
         else:
             spawn(res.kill)
         wait_result = res.wait()
-        assert isinstance(wait_result, GreenletExit), `wait_result`
+        assert not res, repr(res)
+        assert isinstance(wait_result, GreenletExit), repr(wait_result)
 
     def test_kill_sync(self):
         return self._test_kill(True)
@@ -54,9 +56,39 @@ class TestSpawnLink(unittest.TestCase):
     def test_kill_async(self):
         return self._test_kill(False)
 
+    def test_poll(self):
+        def func():
+            sleep(0.1)
+            return 25
+        job = spawn_link(func)
+        self.assertEqual(job.poll(), None)
+        assert job, repr(job)
+        self.assertEqual(job.wait(), 25)
+        self.assertEqual(job.poll(), 25)
+        assert not job, repr(job)
+
+        job = spawn_link(func)
+        self.assertEqual(job.poll(5), 5)
+        assert job, repr(job)
+        self.assertEqual(job.wait(), 25)
+        self.assertEqual(job.poll(5), 25)
+        assert not job, repr(job)
+
+    def test_kill_after(self):
+        def func():
+            sleep(0.1)
+            return 25
+        job = spawn_link(func)
+        job.kill_after(0.05)
+        result = job.wait()
+        assert isinstance(result, GreenletExit), repr(result)
+
+        job = spawn_link(func)
+        job.kill_after(0.2)
+        self.assertEqual(job.wait(), 25)
+        sleep(0.2)
+        self.assertEqual(job.wait(), 25)
+
 
 if __name__=='__main__':
     unittest.main()
-
-
-