Fix hang when using eventlet and ssl

sigmunau · sigmunau · commit 252b52c27ff4 · 2016-02-24T13:50:26.000+01:00
The eventlet read loop runs select before each recv call. This will
fail because recv() on an ssl socket might read more data than
requested from the underlying socket in order to have enough context
for decryption. These extra bytes would be returned by the next recv
on the ssl socket, but are not known to underlying socket so select
will hang.

It is my understanding that eventlet implements blocking IO by using
poll under the hood and yielding, so the select should not be
necessary at all
diff --git a/cassandra/io/eventletreactor.py b/cassandra/io/eventletreactor.py
@@ -18,9 +18,9 @@
 
 from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, EINVAL
 import eventlet
-from eventlet.green import select, socket
+from eventlet.green import socket
+import ssl
 from eventlet.queue import Queue
-from functools import partial
 import logging
 import os
 from threading import Event
@@ -37,7 +37,8 @@
 def is_timeout(err):
     return (
         err in (EINPROGRESS, EALREADY, EWOULDBLOCK) or
-        (err == EINVAL and os.name in ('nt', 'ce'))
+        (err == EINVAL and os.name in ('nt', 'ce')) or
+        (isinstance(err, ssl.SSLError) and err.args[0] == 'timed out')
     )
 
 
@@ -138,26 +139,17 @@ def handle_write(self):
                 return  # Leave the write loop
 
     def handle_read(self):
-        run_select = partial(select.select, (self._socket,), (), ())
         while True:
-            try:
-                run_select()
-            except Exception as exc:
-                if not self.is_closed:
-                    log.debug("Exception during read select() for %s: %s",
-                              self, exc)
-                    self.defunct(exc)
-                return
-
             try:
                 buf = self._socket.recv(self.in_buffer_size)
                 self._iobuf.write(buf)
             except socket.error as err:
-                if not is_timeout(err):
-                    log.debug("Exception during socket recv for %s: %s",
-                              self, err)
-                    self.defunct(err)
-                    return  # leave the read loop
+                if is_timeout(err):
+                    continue
+                log.debug("Exception during socket recv for %s: %s",
+                          self, err)
+                self.defunct(err)
+                return  # leave the read loop
 
             if self._iobuf.tell():
                 self.process_io_buffer()
