Simplify IdleEvent.

- Return False when a ping has been sent, so current instance isn't trashed
  and replaced by ping's internal expectPacket.
- Make current idleEvent instance handle ping's timeout, to avoid creating
  a new event for each ping sent in relation to an existing event.
- Don't call expectPacket from ping when given a msg_id, meaning it is
  related to an existing event.
- Add a minimal delay of 5 seconds between 2 pings.
- Update event tests

git-svn-id: https://svn.erp5.org/repos/neo/trunk@1713 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/connection.py

@@ -290,13 +290,17 @@ class Connection(BaseConnection):
                 return
             self.read_buf = self.read_buf[len(packet):]
 
+            packet_type = packet.getType()
             # Remove idle events, if appropriate packets were received.
             for msg_id in (None, packet.getId()):
                 event = self.event_dict.pop(msg_id, None)
                 if event is not None:
-                    self.em.removeIdleEvent(event)
+                    if packet_type == Packets.Pong:
+                        self.em.refreshIdleEvent(event)
+                        self.event_dict[msg_id] = event
+                    else:
+                        self.em.removeIdleEvent(event)
 
-            packet_type = packet.getType()
             if packet_type == Packets.Ping:
                 # Send a pong notification
                 self.answer(Packets.Pong(), packet.getId())
@@ -474,12 +478,13 @@ class Connection(BaseConnection):
         assert packet.isResponse(), packet
         self._addPacket(packet)
 
-    def ping(self, timeout=5):
+    def ping(self, timeout=5, msg_id=None):
         """ Send a ping and expect to receive a pong notification """
         packet = Packets.Ping()
-        msg_id = self._getNextId()
+        if msg_id is None:
+            msg_id = self._getNextId()
+            self.expectMessage(msg_id, timeout, 0)
         packet.setId(msg_id)
-        self.expectMessage(msg_id, timeout, 0)
         self._addPacket(packet)
 
 

neo/event.py

@@ -21,6 +21,9 @@ from time import time
 
 from neo.epoll import Epoll
 
+PING_DELAY = 5
+PING_TIMEOUT = 5
+
 class IdleEvent(object):
     """
     This class represents an event called when a connection is waiting for
@@ -33,7 +36,7 @@ class IdleEvent(object):
         t = time()
         self._time = t + timeout
         self._critical_time = t + timeout + additional_timeout
-        self._additional_timeout = additional_timeout
+        self.refresh()
 
     def getId(self):
         return self._id
@@ -44,9 +47,12 @@ class IdleEvent(object):
     def getCriticalTime(self):
         return self._critical_time
 
+    def refresh(self):
+        self._next_critical_time = self._critical_time
+
     def __call__(self, t):
         conn = self._conn
-        if t > self._critical_time:
+        if t > self._next_critical_time:
             # No answer after _critical_time, close connection.
             # This means that remote peer is processing the request for too
             # long, although being responsive at network level.
@@ -62,31 +68,20 @@ class IdleEvent(object):
         elif t > self._time:
             # Still no answer after _time, send a ping to see if connection is
             # broken.
-            # Sending a ping triggers a new IdleEvent for the ping (hard timeout
-            # after 5 seconds, see part on additional_timeout above).
-            # XXX: Here, we return True, which causes the current IdleEvent
-            # instance to be discarded, and a new instance is created with
-            # reduced additional_timeout. It must be possible to avoid
-            # recreating a new instance just to keep waiting for the same
-            # response.
             # XXX: This code has no meaning if the remote peer is single-
             # threaded. Nevertheless, it should be kept in case it gets
             # multithreaded, someday (master & storage are the only candidates
             # for using this code, as other don't receive requests).
             conn.lock()
             try:
-                if self._additional_timeout > 5:
-                    # XXX this line is misleading: we modify self, but this
-                    # instance is doomed anyway: we will return True, causing
-                    # it to be discarded.
-                    self._additional_timeout -= 5
-                    conn.expectMessage(self._id, 5, self._additional_timeout)
-                    conn.ping()
-                else:
-                    conn.expectMessage(self._id, self._additional_timeout, 0)
-                return True
+                conn.ping()
             finally:
                 conn.unlock()
+            # Don't retry pinging after at least PING_DELAY seconds have
+            # passed.
+            self._time = t + PING_DELAY
+            self._next_critical_time = min(self._critical_time,
+                t + PING_TIMEOUT)
         return False
 
 class EpollEventManager(object):
@@ -231,6 +226,9 @@ class EpollEventManager(object):
         except ValueError:
             pass
 
+    def refreshIdleEvent(self, event):
+        event.refresh()
+
     def addReader(self, conn):
         connector = conn.getConnector()
         assert connector is not None, conn.whoSetConnector()

neo/tests/testEvent.py

@@ -157,7 +157,6 @@ class EventTests(NeoTestBase):
         self.assertEquals(len(conn.mockGetNamedCalls("getHandler")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("close")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("unlock")), 0)
-        self.assertEquals(len(conn.mockGetNamedCalls("expectMessage")), 0)
         self.checkNoPacketSent(conn)
         self.assertEquals(len(handler.mockGetNamedCalls("timeoutExpired")), 0)
 
@@ -165,13 +164,12 @@ class EventTests(NeoTestBase):
         t = time + 5
         self.assertTrue(t < critical_time)
         r = event(t)
-        self.assertTrue(r)
+        self.assertFalse(r)
         self.assertEquals(len(conn.mockGetNamedCalls("lock")), 1)
         self.assertEquals(len(conn.mockGetNamedCalls("getHandler")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("close")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("unlock")), 1)
         self.assertEquals(len(conn.mockGetNamedCalls("ping")), 1)
-        self.assertEquals(len(conn.mockGetNamedCalls("expectMessage")), 1)
         self.assertEquals(len(handler.mockGetNamedCalls("timeoutExpired")), 0)
 
         # call with time < critical_time < t
@@ -184,7 +182,6 @@ class EventTests(NeoTestBase):
         self.assertEquals(len(conn.mockGetNamedCalls("close")), 1)
         self.assertEquals(len(conn.mockGetNamedCalls("unlock")), 2)
         self.assertEquals(len(conn.mockGetNamedCalls("ping")), 1)
-        self.assertEquals(len(conn.mockGetNamedCalls("expectMessage")), 1)
         self.assertEquals(len(handler.mockGetNamedCalls("timeoutExpired")), 1)
 
         # same test with additional time < 5
@@ -208,7 +205,6 @@ class EventTests(NeoTestBase):
         self.assertEquals(len(conn.mockGetNamedCalls("getHandler")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("close")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("unlock")), 0)
-        self.assertEquals(len(conn.mockGetNamedCalls("expectMessage")), 0)
         self.checkNoPacketSent(conn)
         self.assertEquals(len(handler.mockGetNamedCalls("timeoutExpired")), 0)
 
@@ -216,12 +212,11 @@ class EventTests(NeoTestBase):
         t = time + 1
         self.assertTrue(t < critical_time)
         r = event(t)
-        self.assertTrue(r)
+        self.assertFalse(r)
         self.assertEquals(len(conn.mockGetNamedCalls("lock")), 1)
         self.assertEquals(len(conn.mockGetNamedCalls("getHandler")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("close")), 0)
         self.assertEquals(len(conn.mockGetNamedCalls("unlock")), 1)
-        self.assertEquals(len(conn.mockGetNamedCalls("expectMessage")), 1)
         self.checkNoPacketSent(conn)
         self.assertEquals(len(handler.mockGetNamedCalls("timeoutExpired")), 0)
 
@@ -234,7 +229,6 @@ class EventTests(NeoTestBase):
         self.assertEquals(len(conn.mockGetNamedCalls("getHandler")), 1)
         self.assertEquals(len(conn.mockGetNamedCalls("close")), 1)
         self.assertEquals(len(conn.mockGetNamedCalls("unlock")), 2)
-        self.assertEquals(len(conn.mockGetNamedCalls("expectMessage")), 1)
         self.checkNoPacketSent(conn)
         self.assertEquals(len(handler.mockGetNamedCalls("timeoutExpired")), 1)