From: A. Jesse Jiryu Davis <jesse@mongodb.com>
Date: Tue, 17 Feb 2015 18:09:09 +0000 (-0500)
Subject: Event.wait raises TimeoutError instead of returning False.
X-Git-Tag: v4.2.0b1~103^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=17598514ec5be9af97887cae6421ab89d58af865;p=thirdparty%2Ftornado.git

Event.wait raises TimeoutError instead of returning False.
---

diff --git a/tornado/locks.py b/tornado/locks.py
index 823204079..62d962b81 100644
--- a/tornado/locks.py
+++ b/tornado/locks.py
@@ -18,7 +18,7 @@ __all__ = ['Condition', 'Event']
 
 import collections
 
-from tornado import ioloop
+from tornado import gen, ioloop
 from tornado.concurrent import Future
 
 
@@ -80,9 +80,6 @@ class Condition(object):
             self._waiters = collections.deque(
                 w for w in self._waiters if not w.done())
 
-_true_future = Future()
-_true_future.set_result(True)
-
 
 class Event(object):
     """An event blocks coroutines until its internal flag is set to True.
@@ -90,39 +87,38 @@ class Event(object):
     Similar to `threading.Event`.
     """
     def __init__(self):
-        self._condition = Condition()
-        self._flag = False
+        self._future = Future()
 
     def __str__(self):
         return '<%s %s>' % (
-            self.__class__.__name__, 'set' if self._flag else 'clear')
+            self.__class__.__name__, 'set' if self.is_set() else 'clear')
 
     def is_set(self):
         """Return ``True`` if the internal flag is true."""
-        return self._flag
+        return self._future.done()
 
     def set(self):
         """Set the internal flag to ``True``. All waiters are awakened.
 
         Calling `.wait` once the flag is set will not block.
         """
-        self._flag = True
-        self._condition.notify_all()
+        if not self._future.done():
+            self._future.set_result(None)
 
     def clear(self):
         """Reset the internal flag to ``False``.
         
         Calls to `.wait` will block until `.set` is called.
         """
-        self._flag = False
+        self._future = Future()
 
-    def wait(self, deadline=None):
+    def wait(self, timeout=None):
         """Block until the internal flag is true.
 
-        Returns a `.Future` that resolves ``True`` if the condition is notified,
-        or ``False`` after a timeout.
+        Returns a Future, which raises :exc:`~tornado.gen.TimeoutError` after a
+        timeout.
         """
-        if self._flag:
-            return _true_future
+        if timeout is None:
+            return self._future
         else:
-            return self._condition.wait(deadline)
+            return gen.with_timeout(timeout, self._future)
diff --git a/tornado/test/event_test.py b/tornado/test/event_test.py
index a51e0502a..78fe36683 100644
--- a/tornado/test/event_test.py
+++ b/tornado/test/event_test.py
@@ -14,6 +14,7 @@ from datetime import timedelta
 import unittest
 
 from tornado import gen, locks
+from tornado.gen import TimeoutError
 from tornado.testing import gen_test, AsyncTestCase
 
 
@@ -26,40 +27,33 @@ class TestEvent(AsyncTestCase):
         self.assertFalse('clear' in str(event))
         self.assertTrue('set' in str(event))
 
-    @gen.coroutine
-    def _test_event(self, n):
+    def test_event(self):
         e = locks.Event()
-        futures = [e.wait() for _ in range(n)]
+        future_0 = e.wait()
         e.set()
+        future_1 = e.wait()
         e.clear()
-        results = yield futures
-        self.assertTrue(all(results))
+        future_2 = e.wait()
 
-    @gen_test
-    def test_event_1(self):
-        yield self._test_event(1)
-
-    @gen_test
-    def test_event_200(self):
-        yield self._test_event(200)
+        self.assertTrue(future_0.done())
+        self.assertTrue(future_1.done())
+        self.assertFalse(future_2.done())
 
     @gen_test
     def test_event_timeout(self):
         e = locks.Event()
-        result = yield e.wait(deadline=timedelta(seconds=0.01))
-        self.assertEqual(False, result)
+        with self.assertRaises(TimeoutError):
+            yield e.wait(timedelta(seconds=0.01))
 
         # After a timed-out waiter, normal operation works.
         self.io_loop.add_timeout(timedelta(seconds=0.01), e.set)
-        result = yield e.wait(deadline=timedelta(seconds=1))
-        self.assertTrue(result)
+        yield e.wait(timedelta(seconds=1))
 
-    @gen_test
-    def test_event_nowait(self):
+    def test_event_set_multiple(self):
         e = locks.Event()
         e.set()
-        self.assertEqual(True, e.is_set())
-        self.assertTrue(e.wait().result())
+        e.set()
+        self.assertTrue(e.is_set())
 
 
 if __name__ == '__main__':