Commit 93ec6ced authored by Jim Fulton's avatar Jim Fulton Committed by GitHub

Merge pull request #78 from zopefoundation/avoid-future-timeouts

Avoid waiting on futures using timeouts -> major performance win on Python 2
parents e5318884 38c09539
......@@ -4,8 +4,11 @@ Changelog
5.0.2 (unreleased)
------------------
- Provide much better performance on Python 2.
- Provide better error messages when pip tries to install ZEO on an
unsupported Python version. See `issue 75 <https://github.com/zopefoundation/ZEO/issues/75>`_.
unsupported Python version. See `issue 75
<https://github.com/zopefoundation/ZEO/issues/75>`_.
5.0.1 (2016-09-06)
------------------
......
......@@ -547,7 +547,7 @@ class Client(object):
def get_peername(self):
return self.protocol.get_peername()
def call_async_threadsafe(self, future, method, args):
def call_async_threadsafe(self, future, wait_ready, method, args):
if self.ready:
self.protocol.call_async(method, args)
future.set_result(None)
......@@ -557,7 +557,7 @@ class Client(object):
def call_async_from_same_thread(self, method, *args):
return self.protocol.call_async(method, args)
def call_async_iter_threadsafe(self, future, it):
def call_async_iter_threadsafe(self, future, wait_ready, it):
if self.ready:
self.protocol.call_async_iter(it)
future.set_result(None)
......@@ -581,16 +581,19 @@ class Client(object):
else:
self._when_ready(func, result_future, *args)
def call_threadsafe(self, future, method, args):
def call_threadsafe(self, future, wait_ready, method, args):
if self.ready:
self.protocol.call(future, method, args)
elif wait_ready:
self._when_ready(
self.call_threadsafe, future, wait_ready, method, args)
else:
self._when_ready(self.call_threadsafe, future, method, args)
future.set_exception(ClientDisconnected())
# Special methods because they update the cache.
@future_generator
def load_before_threadsafe(self, future, oid, tid):
def load_before_threadsafe(self, future, wait_ready, oid, tid):
data = self.cache.loadBefore(oid, tid)
if data is not None:
future.set_result(data)
......@@ -604,8 +607,11 @@ class Client(object):
if data:
data, start, end = data
self.cache.store(oid, start, end, data)
elif wait_ready:
self._when_ready(
self.load_before_threadsafe, future, wait_ready, oid, tid)
else:
self._when_ready(self.load_before_threadsafe, future, oid, tid)
future.set_exception(ClientDisconnected())
@future_generator
def _prefetch(self, oid, tid):
......@@ -617,7 +623,7 @@ class Client(object):
except Exception:
logger.exception("prefetch %r %r" % (oid, tid))
def prefetch(self, future, oids, tid):
def prefetch(self, future, wait_ready, oids, tid):
if self.ready:
for oid in oids:
if self.cache.loadBefore(oid, tid) is None:
......@@ -628,7 +634,7 @@ class Client(object):
future.set_exception(ClientDisconnected())
@future_generator
def tpc_finish_threadsafe(self, future, tid, updates, f):
def tpc_finish_threadsafe(self, future, wait_ready, tid, updates, f):
if self.ready:
try:
tid = yield self.protocol.fut('tpc_finish', tid)
......@@ -652,7 +658,7 @@ class Client(object):
else:
future.set_exception(ClientDisconnected())
def close_threadsafe(self, future):
def close_threadsafe(self, future, _):
self.close()
future.set_result(None)
......@@ -720,15 +726,30 @@ class ClientRunner(object):
def call(meth, *args, **kw):
timeout = kw.pop('timeout', None)
assert not kw
# Some explanation of the code below.
# Timeouts on Python 2 are expensive, so we try to avoid
# them if we're connected. The 3rd argument below is a
# wait flag. If false, and we're disconnected, we fail
# immediately. If that happens, then we try again with the
# wait flag set to True and wait with the default timeout.
result = Future()
call_soon_threadsafe(meth, result, *args)
call_soon_threadsafe(meth, result, timeout is not None, *args)
try:
return self.wait_for_result(result, timeout)
except ClientDisconnected:
if timeout is None:
result = Future()
call_soon_threadsafe(meth, result, True, *args)
return self.wait_for_result(result, self.timeout)
else:
raise
self.__call = call
def wait_for_result(self, future, timeout):
try:
return future.result(self.timeout if timeout is None else timeout)
return future.result(timeout)
except concurrent.futures.TimeoutError:
if not self.client.ready:
raise ClientDisconnected("timed out waiting for connection")
......@@ -742,7 +763,7 @@ class ClientRunner(object):
# for tests
result = concurrent.futures.Future()
self.loop.call_soon_threadsafe(
self.call_threadsafe, result, method, args)
self.call_threadsafe, result, True, method, args)
return result
def async(self, method, *args):
......@@ -783,7 +804,7 @@ class ClientRunner(object):
self.__call = call_closed
def apply_threadsafe(self, future, func, *args):
def apply_threadsafe(self, future, wait_ready, func, *args):
try:
future.set_result(func(*args))
except Exception as exc:
......
......@@ -113,6 +113,8 @@ class ClientTests(Base, setupstack.TestCase, ClientRunner):
sized(self.encode(message_id, False, '.reply', result)))
def wait_for_result(self, future, timeout):
if future.done() and future.exception() is not None:
raise future.exception()
return future
def testClientBasics(self):
......@@ -145,8 +147,7 @@ class ClientTests(Base, setupstack.TestCase, ClientRunner):
# connecting, we get an error. This is because some dufus
# decided to create a client storage without waiting for it to
# connect.
f1 = self.call('foo', 1, 2)
self.assertTrue(isinstance(f1.exception(), ClientDisconnected))
self.assertRaises(ClientDisconnected, self.call, 'foo', 1, 2)
# When the client is reconnecting, it's ready flag is set to False and
# it queues calls:
......@@ -155,8 +156,7 @@ class ClientTests(Base, setupstack.TestCase, ClientRunner):
self.assertFalse(f1.done())
# If we try to make an async call, we get an immediate error:
f2 = self.async('bar', 3, 4)
self.assert_(isinstance(f2.exception(), ClientDisconnected))
self.assertRaises(ClientDisconnected, self.async, 'bar', 3, 4)
# The wrapper object (ClientStorage) hasn't been notified:
self.assertFalse(wrapper.notify_connected.called)
......
......@@ -114,9 +114,6 @@ If we access the root object, it'll be loaded from the server:
>>> conn.root()[1].x
6
>>> len(db.storage._cache)
2
Similarly, if we simply disconnect the client, and write data from
another client:
......@@ -138,8 +135,8 @@ another client:
- Drops or clears it's client cache. (The end result is that the cache
is working but empty.)
>>> len(db.storage._cache)
1
>>> len(db.storage._cache) <= 1
True
(When a database is created, it checks to make sure the root object is
in the database, which is why we get 1, rather than 0 objects in the cache.)
......
......@@ -971,8 +971,8 @@ def test_prefetch(self):
>>> conn.close()
>>> conn = ZEO.connection(addr)
>>> storage = conn.db().storage
>>> len(storage._cache)
1
>>> len(storage._cache) <= 1
True
>>> storage.prefetch(oids, conn._storage._start)
The prefetch returns before the cache is filled:
......
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