SSL wrapped socket is not set to non-blocking

[jpwsutton]

migrated from Bugzilla #465625
status UNCONFIRMED severity normal in component MQTT-Python for 1.1
Reported in version 1.1 on platform PC
Assigned to: Roger Light

Original attachment names and IDs:

• ssl-blocking-test.py (ID 259120)

On 2015-04-27 16:13:31 -0400, Jeff Jasper wrote:

When using SSL enabled Paho and publishing a large number (~ 1000) of messages in rapid succession I noticed a behavior where 50-100 messages would be sent and then a period of 1 minute would elapse before the remaining messages were sent. I tracked the delay down to the ssl.read(1) (line 1405) method in _packet_read. It appears that the socket may be getting disconnected causing the read to block for a minute before returning an empty byte.

I noticed that the ssl wrapped socket (generated in the reconnect method) is not explicitly set to non-blocking like it is for a non-SSL socket. After setting the ssl wrapped socket to non-blocking the delay when publishing a large burst of messages appears to be gone. I guess this isn't necessarily a bug, but rather a performance issue.

On 2015-05-23 17:21:11 -0400, Roger Light wrote:

Hi Jeff,

Thanks for this, but I'm a bit confused. The socket gets set to be non-blocking around line 756, regardless of whether it is SSL or not. The ssl.wrap_socket() call is blocking, but everything afterwards should be non-blocking.

On 2016-01-12 05:21:16 -0500, Pierre Fersing wrote:

Created attachment 259120
script to test SSL blocking status

I confirm what Jeff seen, SSL is blocking... but only with Python 3 :(

Python 2 works well, but not Python 3 (tested 2.7.10 and 3.4.3)

With Python 2 calling setblocking(0) on either raw-socket or ssl-socket is enough.

With Python 3 calling setblocking(0) on raw-socket change nothing on ssl-socket. We need to call setblocking(0) on ssl-socket to make ssl socket non-blocking.

I've attached a basic script that I used to test the blocking status of ssl socket.