Comment 2 for bug 1355375

Reviewed: https://review.openstack.org/113343
Committed: https://git.openstack.org/cgit/openstack/ironic-python-agent/commit/?id=4f57590b2e41863770b764a8b84b8b81830ad577
Submitter: Jenkins
Branch: master

commit 4f57590b2e41863770b764a8b84b8b81830ad577
Author: Jim Rollenhagen <email address hidden>
Date: Mon Aug 11 11:45:28 2014 -0700

    Use poll instead of threading.Event in heartbeat thread

    poll() does not rely on absolute time.
    This fixes an issue where the system clock may be changed, and
    the heartbeat thread would stop heartbeating.

    This also gives us flexibility to force a heartbeat in a later
    change.

    Change-Id: Ifde7b53f59788addc43a5dac95c7b6519d87e834
    Closes-Bug: 1355375