openstack/nova
Code Issues Proposed changes

Remove unnecessary use of LoopingCall in nova/virt/xenapi/vm_utils.py

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The code synchronously blocks waiting on the LoopingCall to finish
anyway and the use of a maximum of number of attempts ends up being
awkwardly fit in.

Also, remove an out-of-date comment about future use of LoopingCall

Change-Id: Ife397e171f28fff5e73c70e6957cecdd09a42d68
This commit is contained in:
Johannes Erdfelt 2012-02-08 23:05:53 +00:00
parent e456d2b4e2
commit 1815aaf13a
1 changed files with 10 additions and 18 deletions
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28
nova/virt/xenapi/vm_utils.py
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@ -33,6 +33,8 @@ import uuid
from decimal import Decimal, InvalidOperation
from xml.dom import minidom
from eventlet import greenthread
from nova import exception
from nova import flags
from nova.image import glance
@ -1211,16 +1213,7 @@ def _wait_for_vhd_coalesce(session, instance, sr_ref, vdi_ref,
snapshot
"""
max_attempts = FLAGS.xenapi_vhd_coalesce_max_attempts
attempts = {'counter': 0}
def _poll_vhds():
attempts['counter'] += 1
if attempts['counter'] > max_attempts:
counter = attempts['counter']
msg = (_("VHD coalesce attempts exceeded (%(counter)d >"
" %(max_attempts)d), giving up...") % locals())
raise exception.Error(msg)
for i in xrange(max_attempts):
VMHelper.scan_sr(session, instance, sr_ref)
parent_uuid = get_vhd_parent_uuid(session, vdi_ref)
if original_parent_uuid and (parent_uuid != original_parent_uuid):
@ -1228,13 +1221,13 @@ def _wait_for_vhd_coalesce(session, instance, sr_ref, vdi_ref,
" %(original_parent_uuid)s, waiting for coalesce...")
% locals())
else:
# Breakout of the loop (normally) and return the parent_uuid
raise utils.LoopingCallDone(parent_uuid)
return parent_uuid
loop = utils.LoopingCall(_poll_vhds)
loop.start(FLAGS.xenapi_vhd_coalesce_poll_interval, now=True)
parent_uuid = loop.wait()
return parent_uuid
greenthread.sleep(FLAGS.xenapi_vhd_coalesce_poll_interval)
msg = (_("VHD coalesce attempts exceeded (%(max_attempts)d)"
", giving up...") % locals())
raise exception.Error(msg)
def remap_vbd_dev(dev):
@ -1319,7 +1312,6 @@ def vbd_unplug_with_retry(session, vbd_ref):
DEVICE_DETACH_REJECTED. For reasons which I don't understand, we're
seeing the device still in use, even when all processes using the device
should be dead."""
# FIXME(sirp): We can use LoopingCall here w/o blocking sleep()
while True:
try:
session.call_xenapi("VBD.unplug", vbd_ref)
@ -1329,7 +1321,7 @@ def vbd_unplug_with_retry(session, vbd_ref):
if (len(e.details) > 0 and
e.details[0] == 'DEVICE_DETACH_REJECTED'):
LOG.debug(_('VBD.unplug rejected: retrying...'))
time.sleep(1)
greenthread.sleep(1)
LOG.debug(_('Not sleeping anymore!'))
elif (len(e.details) > 0 and
e.details[0] == 'DEVICE_ALREADY_DETACHED'):