adding handling EINTR to poll to make it more robust

some system call and signal will interrupt poll,
making event loop stops and fails to react events and keepalive message
from libvirt.
adding handling EINTR to poll to make it more robust

Signed-off-by: Royce Lv <lvroyce@linux.vnet.ibm.com>
This commit is contained in:
Royce Lv 2012-07-19 09:49:41 +08:00 committed by Eric Blake
parent 5e21da5630
commit 5e62ba3428

View File

@ -178,48 +178,53 @@ class virEventLoopPure:
def run_once(self):
sleep = -1
self.runningPoll = True
next = self.next_timeout()
debug("Next timeout due at %d" % next)
if next > 0:
try:
next = self.next_timeout()
debug("Next timeout due at %d" % next)
if next > 0:
now = int(time.time() * 1000)
if now >= next:
sleep = 0
else:
sleep = (next - now) / 1000.0
debug("Poll with a sleep of %d" % sleep)
events = self.poll.poll(sleep)
# Dispatch any file handle events that occurred
for (fd, revents) in events:
# See if the events was from the self-pipe
# telling us to wakup. if so, then discard
# the data just continue
if fd == self.pipetrick[0]:
self.pendingWakeup = False
data = os.read(fd, 1)
continue
h = self.get_handle_by_fd(fd)
if h:
debug("Dispatch fd %d handle %d events %d" % (fd, h.get_id(), revents))
h.dispatch(self.events_from_poll(revents))
now = int(time.time() * 1000)
if now >= next:
sleep = 0
else:
sleep = (next - now) / 1000.0
for t in self.timers:
interval = t.get_interval()
if interval < 0:
continue
debug("Poll with a sleep of %d" % sleep)
events = self.poll.poll(sleep)
want = t.get_last_fired() + interval
# Deduct 20ms, since scheduler timeslice
# means we could be ever so slightly early
if now >= (want-20):
debug("Dispatch timer %d now %s want %s" % (t.get_id(), str(now), str(want)))
t.set_last_fired(now)
t.dispatch()
# Dispatch any file handle events that occurred
for (fd, revents) in events:
# See if the events was from the self-pipe
# telling us to wakup. if so, then discard
# the data just continue
if fd == self.pipetrick[0]:
self.pendingWakeup = False
data = os.read(fd, 1)
continue
h = self.get_handle_by_fd(fd)
if h:
debug("Dispatch fd %d handle %d events %d" % (fd, h.get_id(), revents))
h.dispatch(self.events_from_poll(revents))
now = int(time.time() * 1000)
for t in self.timers:
interval = t.get_interval()
if interval < 0:
continue
want = t.get_last_fired() + interval
# Deduct 20ms, since schedular timeslice
# means we could be ever so slightly early
if now >= (want-20):
debug("Dispatch timer %d now %s want %s" % (t.get_id(), str(now), str(want)))
t.set_last_fired(now)
t.dispatch()
self.runningPoll = False
except (os.error, select.error), e:
if e.args[0] != errno.EINTR:
raise
finally:
self.runningPoll = False
# Actually the event loop forever