Add eventlet_backdoor and threadgroup from openstack-common

In addition to this the list of imports is now in an alphabetical order.

Change-Id: I34517ce3f740f63094d21b3cbebb542cc40661a2

openstack-common.conf

@@ -1,5 +1,5 @@
 [DEFAULT]
 # The list of modules to copy from openstack-common
-modules=cfg,exception,importutils,iniparser,jsonutils,policy,setup,network_utils,notifier,timeutils,log,context,local,rpc,gettextutils,excutils,uuidutils,service,loopingcall
+modules=cfg,context,eventlet_backdoor,exception,excutils,gettextutils,importutils,iniparser,jsonutils,local,log,loopingcall,network_utils,notifier,policy,rpc,service,setup,threadgroup,timeutils,uuidutils
 # The base module to hold the copy of openstack.common
 base=quantum

quantum/openstack/common/eventlet_backdoor.py

@@ -0,0 +1,78 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2012 Openstack, LLC.
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import gc
+import pprint
+import sys
+import traceback
+
+import eventlet
+import eventlet.backdoor
+import greenlet
+
+from quantum.openstack.common import cfg
+
+eventlet_backdoor_opts = [
+    cfg.IntOpt('backdoor_port',
+               default=None,
+               help='port for eventlet backdoor to listen')
+]
+
+CONF = cfg.CONF
+CONF.register_opts(eventlet_backdoor_opts)
+
+
+def _dont_use_this():
+    print "Don't use this, just disconnect instead"
+
+
+def _find_objects(t):
+    return filter(lambda o: isinstance(o, t), gc.get_objects())
+
+
+def _print_greenthreads():
+    for i, gt in enumerate(find_objects(greenlet.greenlet)):
+        print i, gt
+        traceback.print_stack(gt.gr_frame)
+        print
+
+
+def initialize_if_enabled():
+    backdoor_locals = {
+        'exit': _dont_use_this,      # So we don't exit the entire process
+        'quit': _dont_use_this,      # So we don't exit the entire process
+        'fo': _find_objects,
+        'pgt': _print_greenthreads,
+    }
+
+    if CONF.backdoor_port is None:
+        return
+
+    # NOTE(johannes): The standard sys.displayhook will print the value of
+    # the last expression and set it to __builtin__._, which overwrites
+    # the __builtin__._ that gettext sets. Let's switch to using pprint
+    # since it won't interact poorly with gettext, and it's easier to
+    # read the output too.
+    def displayhook(val):
+        if val is not None:
+            pprint.pprint(val)
+    sys.displayhook = displayhook
+
+    eventlet.spawn_n(eventlet.backdoor.backdoor_server,
+                     eventlet.listen(('localhost', CONF.backdoor_port)),
+                     locals=backdoor_locals)

quantum/openstack/common/threadgroup.py

@@ -0,0 +1,119 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2012 Red Hat, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from eventlet import greenlet
+from eventlet import greenpool
+from eventlet import greenthread
+
+from quantum.openstack.common.gettextutils import _
+from quantum.openstack.common import log as logging
+from quantum.openstack.common import loopingcall
+
+
+LOG = logging.getLogger(__name__)
+
+
+def _thread_done(gt, *args, **kwargs):
+    '''
+    Callback function to be passed to GreenThread.link() when we spawn()
+    Calls the ThreadGroup to notify if.
+    '''
+    kwargs['group'].thread_done(kwargs['thread'])
+
+
+class Thread(object):
+    """
+    Wrapper around a greenthread, that holds a reference to
+    the ThreadGroup. The Thread will notify the ThreadGroup
+    when it has done so it can be removed from the threads
+    list.
+    """
+    def __init__(self, name, thread, group):
+        self.name = name
+        self.thread = thread
+        self.thread.link(_thread_done, group=group, thread=self)
+
+    def stop(self):
+        self.thread.cancel()
+
+    def wait(self):
+        return self.thread.wait()
+
+
+class ThreadGroup(object):
+    """
+    The point of this class is to:
+    - keep track of timers and greenthreads (making it easier to stop them
+      when need be).
+    - provide an easy API to add timers.
+    """
+    def __init__(self, name, thread_pool_size=10):
+        self.name = name
+        self.pool = greenpool.GreenPool(thread_pool_size)
+        self.threads = []
+        self.timers = []
+
+    def add_timer(self, interval, callback, initial_delay=None,
+                  *args, **kwargs):
+        pulse = loopingcall.LoopingCall(callback, *args, **kwargs)
+        pulse.start(interval=interval,
+                    initial_delay=initial_delay)
+        self.timers.append(pulse)
+
+    def add_thread(self, callback, *args, **kwargs):
+        gt = self.pool.spawn(callback, *args, **kwargs)
+        th = Thread(callback.__name__, gt, self)
+        self.threads.append(th)
+
+    def thread_done(self, thread):
+        self.threads.remove(thread)
+
+    def stop(self):
+        current = greenthread.getcurrent()
+        for x in self.threads:
+            if x is current:
+                # don't kill the current thread.
+                continue
+            try:
+                x.stop()
+            except Exception as ex:
+                LOG.exception(ex)
+
+        for x in self.timers:
+            try:
+                x.stop()
+            except Exception as ex:
+                LOG.exception(ex)
+        self.timers = []
+
+    def wait(self):
+        for x in self.timers:
+            try:
+                x.wait()
+            except greenlet.GreenletExit:
+                pass
+            except Exception as ex:
+                LOG.exception(ex)
+        current = greenthread.getcurrent()
+        for x in self.threads:
+            if x is current:
+                continue
+            try:
+                x.wait()
+            except greenlet.GreenletExit:
+                pass
+            except Exception as ex:
+                LOG.exception(ex)