Comment 12 for bug 1928794

Reviewed: https://review.opendev.org/c/openstack/neutron/+/805768
Committed: https://opendev.org/openstack/neutron/commit/3139bbcbe6b3747ce432901a5a316d93f8f168fb
Submitter: "Zuul (22348)"
Branch: stable/wallaby

commit 3139bbcbe6b3747ce432901a5a316d93f8f168fb
Author: Terry Wilson <email address hidden>
Date: Thu Mar 18 15:01:07 2021 -0500

    Add wait for the post-fork event to nb/sb objects

    It is possible for events from the nb/sb to fire before the opposite
    db connection is made. These events can call back into driver code
    which tries to access the other db before it is connected.

    Conflicts:
            neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py
            neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py
            neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
            neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovn_db_sync.py
            neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
            neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py

    Closes-Bug: #1929197
    Closes-Bug: #1928794
    Closes-Bug: #1929633
    Change-Id: If947581b90ced42981c4611c32de8f428a052c69
    (cherry picked from commit 90980f496cfa3cc5df1c93cf834a44f33d3f1f6f)