[Bug #1011606] Only check file descriptors for exceptional conditions if the fd is readable or writable
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
index f63a83e..a2387a1 100644
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -107,11 +107,14 @@
if map:
r = []; w = []; e = []
for fd, obj in map.items():
- e.append(fd)
- if obj.readable():
+ is_r = obj.readable()
+ is_w = obj.writable()
+ if is_r:
r.append(fd)
- if obj.writable():
+ if is_w:
w.append(fd)
+ if is_r or is_w:
+ e.append(fd)
if [] == r == w == e:
time.sleep(timeout)
else:
@@ -151,12 +154,15 @@
pollster = select.poll()
if map:
for fd, obj in map.items():
- flags = select.POLLERR | select.POLLHUP | select.POLLNVAL
+ flags = 0
if obj.readable():
flags |= select.POLLIN | select.POLLPRI
if obj.writable():
flags |= select.POLLOUT
if flags:
+ # Only check for exceptions if object was either readable
+ # or writable.
+ flags |= select.POLLERR | select.POLLHUP | select.POLLNVAL
pollster.register(fd, flags)
try:
r = pollster.poll(timeout)