From 9a7bbc246ba53e07370dab1aae0b3f00bca9c54f Mon Sep 17 00:00:00 2001
From: Royce Lv <lvroyce@linux.vnet.ibm.com>
Date: Thu, 19 Jul 2012 09:49:41 +0800
Subject: [PATCH] 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>
(cherry picked from commit 5e62ba3428b377d47f5ddbee705ee33027354824)
---
 .../domain-events/events-python/event-test.py | 83 ++++++++++---------
 1 file changed, 44 insertions(+), 39 deletions(-)

diff --git a/examples/domain-events/events-python/event-test.py b/examples/domain-events/events-python/event-test.py
index 96dc2684fe..6b655cdd33 100644
--- a/examples/domain-events/events-python/event-test.py
+++ b/examples/domain-events/events-python/event-test.py
@@ -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