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It appears that if a service's process dies in the middle of handling a request, the service call on the client side will hang forever.
Is there any way around this besides putting the service call in its own thread and killing the thread after a timeout?
Based on the client code attached in the ticket, I added the line:
if(!client.waitForExistence(ros::Duration(5.0))) continue;
before the service call (line 21). This allows the client to carry on and make service calls once the server comes up again.
Retried the code again after Lorenz's comment. It seems this worked only when the server was killed at specific points in time (just before the service call I presume). Though I still don't understand why it worked previously when the "Failed to call service" line wasn't printed.
It is true that particular service call (when server dies) does not return (I do not get the message "Failed to call service add_two_ints"). But the client does continue to run its next loop until waitForExistence and until the server comes up again. ie the client does not hang
Asked: 2012-09-18 16:02:21 -0500
Seen: 1,524 times
Last updated: Sep 19 '12
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How long did you wait? I think the sockets should die at some point, maybe after 2 minutes or so. Does the service client not throw an exception in that case? (I believe in roslisp, it does :))
Wow. I just tested your code and it really seems like the service call blocks forever...