[libvirt] [PATCH] add handling EINTR to test example of event loop
From: lvroyce <lvroyce@linux.vnet.ibm.com> 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: lvroyce <lvroyce@linux.vnet.ibm.com> --- examples/domain-events/events-python/event-test.py | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/examples/domain-events/events-python/event-test.py b/examples/domain-events/events-python/event-test.py index 96dc268..b446c21 100644 --- a/examples/domain-events/events-python/event-test.py +++ b/examples/domain-events/events-python/event-test.py @@ -188,7 +188,13 @@ class virEventLoopPure: sleep = (next - now) / 1000.0 debug("Poll with a sleep of %d" % sleep) - events = self.poll.poll(sleep) + try: + events = self.poll.poll(sleep) + except select.error, e: + self.runningPoll = False + if not e.errno in (errno.EINTR, errno.EAGAIN): + raise + return # Dispatch any file handle events that occurred for (fd, revents) in events: -- 1.7.7.6
On Mon, Jun 18, 2012 at 05:43:55PM +0800, lvroyce@linux.vnet.ibm.com wrote:
From: lvroyce <lvroyce@linux.vnet.ibm.com>
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: lvroyce <lvroyce@linux.vnet.ibm.com> --- examples/domain-events/events-python/event-test.py | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/examples/domain-events/events-python/event-test.py b/examples/domain-events/events-python/event-test.py index 96dc268..b446c21 100644 --- a/examples/domain-events/events-python/event-test.py +++ b/examples/domain-events/events-python/event-test.py @@ -188,7 +188,13 @@ class virEventLoopPure: sleep = (next - now) / 1000.0
debug("Poll with a sleep of %d" % sleep) - events = self.poll.poll(sleep) + try: + events = self.poll.poll(sleep) + except select.error, e: + self.runningPoll = False + if not e.errno in (errno.EINTR, errno.EAGAIN): + raise + return
It isn't possible for poll() to return EAGAIN according to the manpage. If you remove that errno, then the patch would be ok. Also the indentation in the except: block is too deep - line it up with the try: block Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On Mon, Jun 18, 2012 at 10:56:26AM +0100, Daniel P. Berrange wrote:
On Mon, Jun 18, 2012 at 05:43:55PM +0800, lvroyce@linux.vnet.ibm.com wrote:
From: lvroyce <lvroyce@linux.vnet.ibm.com>
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: lvroyce <lvroyce@linux.vnet.ibm.com> --- examples/domain-events/events-python/event-test.py | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/examples/domain-events/events-python/event-test.py b/examples/domain-events/events-python/event-test.py index 96dc268..b446c21 100644 --- a/examples/domain-events/events-python/event-test.py +++ b/examples/domain-events/events-python/event-test.py @@ -188,7 +188,13 @@ class virEventLoopPure: sleep = (next - now) / 1000.0
debug("Poll with a sleep of %d" % sleep) - events = self.poll.poll(sleep) + try: + events = self.poll.poll(sleep) + except select.error, e: + self.runningPoll = False + if not e.errno in (errno.EINTR, errno.EAGAIN): + raise + return
It isn't possible for poll() to return EAGAIN according to the manpage.
If you remove that errno, then the patch would be ok. Also the indentation in the except: block is too deep - line it up with the try: block
The same function has another possible exception-raiser: os.read() few lines below, and probably others. How about putting self.runningPoll = False in a "finally" clause opened right after the first self.runningPoll assignment? Dan
On Mon, Jun 18, 2012 at 10:17:53PM +0300, Dan Kenigsberg wrote:
On Mon, Jun 18, 2012 at 10:56:26AM +0100, Daniel P. Berrange wrote:
On Mon, Jun 18, 2012 at 05:43:55PM +0800, lvroyce@linux.vnet.ibm.com wrote:
From: lvroyce <lvroyce@linux.vnet.ibm.com>
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: lvroyce <lvroyce@linux.vnet.ibm.com> --- examples/domain-events/events-python/event-test.py | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/examples/domain-events/events-python/event-test.py b/examples/domain-events/events-python/event-test.py index 96dc268..b446c21 100644 --- a/examples/domain-events/events-python/event-test.py +++ b/examples/domain-events/events-python/event-test.py @@ -188,7 +188,13 @@ class virEventLoopPure: sleep = (next - now) / 1000.0
debug("Poll with a sleep of %d" % sleep) - events = self.poll.poll(sleep) + try: + events = self.poll.poll(sleep) + except select.error, e: + self.runningPoll = False + if not e.errno in (errno.EINTR, errno.EAGAIN): + raise + return
It isn't possible for poll() to return EAGAIN according to the manpage.
If you remove that errno, then the patch would be ok. Also the indentation in the except: block is too deep - line it up with the try: block
The same function has another possible exception-raiser: os.read() few lines below, and probably others. How about putting
self.runningPoll = False
in a "finally" clause opened right after the first self.runningPoll assignment?
Sounds like a reasonable idea. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
participants (3)
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Dan Kenigsberg -
Daniel P. Berrange -
lvroyce＠linux.vnet.ibm.com