http: Catch an occasional error not handled in standard library.

caucase/http.py

@@ -22,6 +22,7 @@ from __future__ import absolute_import, print_function
 import argparse
 from collections import defaultdict
 import datetime
+import errno
 from getpass import getpass
 import glob
 import itertools
@@ -95,6 +96,40 @@ class ThreadingWSGIServer(ThreadingMixIn, WSGIServer):
       self.socket.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, 1)
     WSGIServer.server_bind(self)
 
+  # pylint: disable=arguments-differ
+  def serve_forever(self, *args, **kw):
+    """
+    Handle one request at a time until shutdown.
+
+    In addition to python's version:
+    - intercept EBADF on shutdown if select is interrupted:
+    """
+    try:
+      return WSGIServer.serve_forever(self, *args, **kw)
+    except socket.error as exception:
+      # Workaround for the following unhandled error:
+      # Traceback (most recent call last):
+      #   File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
+      #     self.run()
+      #   File "/usr/lib/python2.7/threading.py", line 754, in run
+      #     self.__target(*self.__args, **self.__kwargs)
+      #   File "/usr/lib/python2.7/SocketServer.py", line 231, in serve_forever
+      #     poll_interval)
+      #   File "/usr/lib/python2.7/SocketServer.py", line 150, in _eintr_retry
+      #     return func(*args)
+      #   File "/usr/lib/python2.7/SocketServer.py", line 459, in fileno
+      #     return self.socket.fileno()
+      #   File "/usr/lib/python2.7/socket.py", line 228, in meth
+      #     return getattr(self._sock,name)(*args)
+      #   File "/usr/lib/python2.7/socket.py", line 174, in _dummy
+      #     raise error(EBADF, 'Bad file descriptor')
+      # error: [Errno 9] Bad file descriptor
+      # Sadly, self.__shutdown_request is not accessible from here, so do not
+      # check any further.
+      if exception.errno != errno.EBADF:
+        raise
+  # pylint: enable=arguments-differ
+
 def _buildQuoteCharList():
   # All chars considered guilty
   result = ['\\x%02x' % x for x in xrange(256)]