set queue_size=1 on publishers

[ibaranov-cp]

hey,

In hydro, queue size is an optional parameter, but is suggested to be used.
I suggest size of 1, but anything would do.

Specifically, lines:
self.descr_topic = rospy.Publisher('~parameter_descriptions', ConfigDescrMsg, latch=True, queue_size=1)

and

self.update_topic = rospy.Publisher('~parameter_updates', ConfigMsg, latch=True, queue_size=1 )

in

/opt/ros/indigo/lib/python2.7/dist-packages/dynamic_reconfigure/server.py

[BennyRe]

+1

First I thought a queue size of 1 is a bit unsafe but after looking at the code nothing speaks against it.

[dirk-thomas]

WIth a queue_size of 1 when the dynamic reconfigure Server is going to send multiple parameter updates shortly after each other the chances are very high that only the latest publish call will happen. The previous ones will just vanish / be overwritten in the queue before sending. I don't think that this is desired and would therefore not recommend to choose a queue_size of 1.

[ibaranov-cp]

Perhaps a reasonable middle ground then? Say 10?