Monkey patch original current_thread _active

Monkey patch the original current_thread to use the up-to-date _active
global variable. This solution is based on that documented at:
eventlet/eventlet#592

Change-Id: Ida548b4bec00530418fd3d7ab254e971af77d3fe
Closes-Bug: #1863021

cinder/cmd/api.py

@@ -22,6 +22,13 @@
 
 import eventlet  # noqa
 eventlet.monkey_patch()
+# Monkey patch the original current_thread to use the up-to-date _active
+# global variable. See https://bugs.launchpad.net/bugs/1863021 and
+# https://github.com/eventlet/eventlet/issues/592
+import __original_module_threading as orig_threading
+import threading # noqa
+orig_threading.current_thread.__globals__['_active'] = threading._active
+
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_reports import guru_meditation_report as gmr

cinder/cmd/backup.py

@@ -26,6 +26,13 @@
 # share the same context.
 import eventlet
 eventlet.monkey_patch()
+# Monkey patch the original current_thread to use the up-to-date _active
+# global variable. See https://bugs.launchpad.net/bugs/1863021 and
+# https://github.com/eventlet/eventlet/issues/592
+import __original_module_threading as orig_threading
+import threading # noqa
+orig_threading.current_thread.__globals__['_active'] = threading._active
+
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_log import log as logging

cinder/cmd/scheduler.py

@@ -22,6 +22,13 @@
 
 import eventlet
 eventlet.monkey_patch()
+# Monkey patch the original current_thread to use the up-to-date _active
+# global variable. See https://bugs.launchpad.net/bugs/1863021 and
+# https://github.com/eventlet/eventlet/issues/592
+import __original_module_threading as orig_threading
+import threading # noqa
+orig_threading.current_thread.__globals__['_active'] = threading._active
+
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_reports import guru_meditation_report as gmr

cinder/cmd/volume.py

@@ -33,6 +33,13 @@
     eventlet.monkey_patch(os=False)
 else:
     eventlet.monkey_patch()
+# Monkey patch the original current_thread to use the up-to-date _active
+# global variable. See https://bugs.launchpad.net/bugs/1863021 and
+# https://github.com/eventlet/eventlet/issues/592
+import __original_module_threading as orig_threading
+import threading # noqa
+orig_threading.current_thread.__globals__['_active'] = threading._active
+
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_privsep import priv_context