pr2_mechanism/spawner should wait for the services it calls. (ros ticket #4879)

[ahendrix]

I recently made a mechanism controller manager for our robot rosie, which I want to start in the same launch file as the spawner that loads the controllers themselves.

However, there is a race condition: The spawner calls 3 services which it assumes to be up. The spawner crashes if the controller manager starts later. The attached patch makes the spawner wait for these services.

trac data:

• Owner: wim
• Reporter: kresse
• Reported at: Thu Nov 4 09:07:45 2010
• URL: https://code.ros.org/trac/wg-ros-pkg/ticket/4879

[ahendrix]

[wim] What version of pr2_mechanism are you using? The cturtle version of spawner already has the wait_for_service methods (lines 92-94). I can run this version of spawner without the services being available; it just waits and does not crash.

[ahendrix]

[kresse] Oops, found the lines. I searched my logs (no success, this output went to screen), and tried to reproduce it a dozen times under several user accounts - it's all okay. The only explanation that remains for me is that there was an interfering zombie process.

Anyway, thanks for the quick reply!

And never mind!