Using spinOnce inside Services

Question

I would like to know whether it is safe or bad practice to spin ROS inside a while loop that exists inside a service callback. I am unable to use actions for this particular goal, and have confirmed that spinOnce inside the loop behaves as I expected, but before I go further I wanted to see if I was missing anything. Basically, there will be another process that will break the while loop and return either true or false based on the purpose of the break.

Edit: This question originally pertained to C++ packages, but has since also started to focus on python. Basically, I may have a service that is called, but should not respond until another action has finished (communications). I do not want this pause to effect other functions of the package, so I would like to find a way to have the service wait on responding, but spin ROS and let other callbacks react. I see that AsyncSpinner may be a good solution, but not sure of one for python.

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Originally posted by orion on ROS Answers with karma: 213 on 2014-01-16

Post score: 0

Answer 1

IIUC from the question, you need to service ROS callbacks during the execution of a service callback. Have you considered an asynchronous spinner as an alternative?. This wiki entry on Callbacks and Spinning is quite complete and might prove useful to your usecase.

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Originally posted by Adolfo Rodriguez T with karma: 3907 on 2014-01-16

This answer was ACCEPTED on the original site

Post score: 1

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Original comments

Comment by orion on 2014-01-24:
Example: I create a service. When the service callback begins, I initiate something. Until that something is finished, I do not send the response for the service. My thought was to have while loop on variable that the something would set to send the response. I will checkout the asynch spnner.