add BGP daemon feature

Currently, the BGP code can work as an daemon (IOW, not RyuApp).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 140 insertions, 0 deletions

diff --git a/ryu/services/protocols/bgp/utils/evtlet.py b/ryu/services/protocols/bgp/utils/evtlet.py
new file mode 100644
index 00000000..4dc8a943
--- /dev/null
+++ b/ryu/services/protocols/bgp/utils/evtlet.py
@@ -0,0 +1,140 @@
+# Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+#
+# 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.
+
+"""
+ Concurrent networking library - Eventlet, based utilities classes.
+"""
+import eventlet
+from eventlet import event
+import logging
+
+LOG = logging.getLogger('utils.evtlet')
+
+
+class EventletIOFactory(object):
+
+    @staticmethod
+    def create_custom_event():
+        LOG.debug('Create CustomEvent called')
+        return CustomEvent()
+
+    @staticmethod
+    def create_looping_call(funct, *args, **kwargs):
+        LOG.debug('create_looping_call called')
+        return LoopingCall(funct, *args, **kwargs)
+
+
+class CustomEvent(object):
+    """Encapsulates eventlet event to provide a event which can recur.
+
+    It has the same interface as threading.Event but works for eventlet.
+    """
+    def __init__(self,):
+        self._event = event.Event()
+        self._is_set = False
+
+    def is_set(self):
+        """Return true if and only if the internal flag is true."""
+        return self._is_set
+
+    def set(self):
+        """Set the internal flag to true.
+
+         All threads waiting for it to become true are awakened.
+         Threads that call wait() once the flag is true will not block at all.
+        """
+        if self._event and not self._event.ready():
+            self._event.send()
+        self._is_set = True
+
+    def clear(self):
+        """Reset the internal flag to false.
+
+        Subsequently, threads calling wait() will block until set() is called
+        to set the internal flag to true again.
+        """
+        if self._is_set:
+            self._is_set = False
+            self._event = event.Event()
+
+    def wait(self):
+        """Block until the internal flag is true.
+
+        If the internal flag is true on entry, return immediately. Otherwise,
+        block until another thread calls set() to set the flag to true, or
+        until the optional timeout occurs.
+        """
+        if not self._is_set:
+            self._event.wait()
+
+
+class LoopingCall(object):
+    """Call a function repeatedly.
+    """
+    def __init__(self, funct, *args, **kwargs):
+        self._funct = funct
+        self._args = args
+        self._kwargs = kwargs
+        self._running = False
+        self._interval = 0
+        self._self_thread = None
+
+    @property
+    def running(self):
+        return self._running
+
+    @property
+    def interval(self):
+        return self._interval
+
+    def __call__(self):
+        if self._running:
+            # Schedule next iteration of the call.
+            self._self_thread = eventlet.spawn_after(self._interval, self)
+        self._funct(*self._args, **self._kwargs)
+
+    def start(self, interval, now=True):
+        """Start running pre-set function every interval seconds.
+        """
+        if interval < 0:
+            raise ValueError('interval must be >= 0')
+
+        if self._running:
+            self.stop()
+
+        self._running = True
+        self._interval = interval
+        if now:
+            self._self_thread = eventlet.spawn_after(0, self)
+        else:
+            self._self_thread = eventlet.spawn_after(self._interval, self)
+
+    def stop(self):
+        """Stop running scheduled function.
+        """
+        self._running = False
+        if self._self_thread is not None:
+            self._self_thread.cancel()
+            self._self_thread = None
+
+    def reset(self):
+        """Skip the next iteration and reset timer.
+        """
+        if self._self_thread is not None:
+            # Cancel currently scheduled call
+            self._self_thread.cancel()
+            self._self_thread = None
+        # Schedule a new call
+        self._self_thread = eventlet.spawn_after(self._interval, self)