[Pkg-bitcoin-commits] [python-quamash] 203/269: Add strict test for scheduling of callbacks

[Jonas Smedegaard]

This is an automated email from the git hooks/post-receive script.

js pushed a commit to branch master
in repository python-quamash.

commit 4529200a571e1405b395608f987e820e7c364820
Author: Jonas Wielicki <j.wielicki at sotecware.net>
Date:   Thu Jan 15 19:20:21 2015 +0100

    Add strict test for scheduling of callbacks
    
    This test shows a difference to stock asyncio event loop. In stock
    asyncio, writer_cb is called exactly once, due to fut_cb being called
    before writer_cb gets a second chance. writer_cb gets thus removed and
    is not called again.
    
    This may be critical. The asyncio implementation shipping with Python
    3.4.2 relies on this in the implementation of sock_connect (c.f.
    selector_events.py:352--389 from that version), and not adhering to this
    yields to odd results up to infinite loops of callbacks.
---
 tests/test_qeventloop.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/test_qeventloop.py b/tests/test_qeventloop.py
index ce68239..8425ab4 100644
--- a/tests/test_qeventloop.py
+++ b/tests/test_qeventloop.py
@@ -645,3 +645,25 @@ def test_remove_writer_idempotence(loop, sock_pair):
 	assert not removed0
 	assert removed1
 	assert not removed2
+
+
+def test_scheduling(loop, sock_pair):
+	s1, s2 = sock_pair
+	fd = s1.fileno()
+	cb_called = asyncio.Future()
+
+	def writer_cb(fut):
+		if fut.done():
+			cb_called.set_exception(
+				ValueError("writer_cb called twice")
+			)
+		fut.set_result(None)
+
+	def fut_cb(fut):
+		loop.remove_writer(fd)
+		cb_called.set_result(None)
+
+	fut = asyncio.Future()
+	fut.add_done_callback(fut_cb)
+	loop.add_writer(fd, writer_cb, fut)
+	loop.run_until_complete(cb_called)

-- 
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/pkg-bitcoin/python-quamash.git