Merge lp://staging/~mbp/bzr/2.5-client-reconnect-819604 into lp://staging/bzr

Focusing on ./bzr selftest -s bzrlib.tests.test_bundle.TestReadMergeableFromUrl.test_smart_server_connection_reset.

Running this command repeatedly shows that either the test succeeds in ~50ms OR ~10.000ms. I.e. the select timeout triggers.

With this patch:

   modified bzrlib/tests/servers.py

=== modified file 'bzrlib/tests/servers.py'
--- bzrlib/tests/servers.py 2011-11-28 07:52:49 +0000
+++ bzrlib/tests/servers.py 2011-11-28 09:33:09 +0000
@@ -40,10 +40,6 @@
         self.sock.setblocking(False)
         while not self._please_stop:
             try:
- # We can't just accept here, because accept is not interrupted
- # by the listen socket being asynchronously closed by
- # stop_server. However, select will be interrupted.
- select.select([fd], [fd], [fd], 10)
                 conn, addr = self.sock.accept()
             except (select.error, socket.error), e:
                 en = getattr(e, 'errno') or e[0]
@@ -68,6 +64,7 @@
             # just in case the test failed to do so.
             conn = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             conn.connect(self.sock.getsockname())
+ conn.shutdown(socket.SHUT_RDWR)
             conn.close()
         except socket.error:
             pass

Running the same command 1.000 times reliably succeeds in ~50ms.

I don't think the select is worth it, what matters is to shutdown() the socket instead of just close()'ing it.

More precisely, on top of jelmer's branch, the following patch also resists the 1.000 stress test. (note that I wrongly tested it with TestingThreadingTCPServer instead of TestingTCPServer in DisconnectingServer at first, for even more stress tests).

   modified bzrlib/tests/test_bundle.py

=== modified file 'bzrlib/tests/test_bundle.py'
--- bzrlib/tests/test_bundle.py 2011-10-05 12:16:17 +0000
+++ bzrlib/tests/test_bundle.py 2011-11-28 10:57:48 +0000
@@ -17,6 +17,7 @@
 from cStringIO import StringIO
 import os
 import socket
+import SocketServer
 import sys
 import threading

@@ -41,13 +42,12 @@
 from bzrlib.bundle.serializer.v4 import BundleSerializerV4
 from bzrlib.repofmt import knitrepo
 from bzrlib.tests import (
+ features,
+ test_commit,
     test_read_bundle,
- test_commit,
+ test_server,
     )
 from bzrlib.transform import TreeTransform
-from bzrlib.tests import (
- features,
- )

 def get_text(vf, key):
@@ -1836,7 +1836,7 @@
         bundle, then the ConnectionReset error should be propagated.
         """
         # Instantiate a server that will provoke a ConnectionReset
- sock_server = _DisconnectingTCPServer()
+ sock_server = DisconnectingServer()
         self.start_server(sock_server)
         # We don't really care what the url is since the server will close the
         # connection without interpreting it
@@ -1844,35 +1844,21 @@
         self.assertRaises(errors.ConnectionReset, read_mergeable_from_url, url)

-class _DisconnectingTCPServer(object):
- """A TCP server that immediately closes any connection made to it."""
-
- def start_server(self):
- self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
- self.sock.bind(('127.0.0.1', 0))
- self.sock.listen(1)
- self.port = self.sock.getsockname()[1]
- self.thread = threading.Thread(
- name='%s (port %d)' % (self.__class__.__name__, self.port),
- target=self.accept_and_close)
- self.thread.start()
-
- def accept_and_close(self):
- conn, addr = self.sock.accept()
- conn.shutdown(socket.SHUT_RDWR)
- conn.close()
+class DisconnectingHandler(SocketServer.BaseRequestHandler):
+ """A request handler that immediately closes any connection made to it."""
+
+ def handle(self):
+ self.request.close()
+
+
+class DisconnectingServer(test_server.TestingTCPServerInAThread):
+
+ def __init__(self):
+ super(DisconnectingServer, self).__init__(
+ ('127.0.0.1', 0),
+ test_server.TestingTCPServer,
+ DisconnectingHandler)

     def get_url(self):
- return 'bzr://127.0.0.1:%d/' % (self.port,)
-
- def stop_server(self):
- try:
- # make sure the thread dies by connecting to the listening socket,
- # just in case the test failed to do so.
- conn = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
- conn.connect(self.sock.getsockname())
- conn.close()
- except socket.error:
- pass
- self.sock.close()
- self.thread.join()
+ ...

I guess this is superseded by https://code.launchpad.net/~bzr/bzr/2.5-client-reconnect-819604/+merge/83575