Hello,
On 27.04.17 04:18, Cody Herzog wrote: > > Hello. > > > > I'm running Kamailio 4.3.5 on Ubuntu Server 14.04. > > > > I just started using the app_python module together with the OpenTok > Python SDK, described here: > > > > https://tokbox.com/developer/sdks/python/ > > > > My basic Python test script works fine, but when I add an import > statement in the Python script to bring in a package from the OpenTok > Python SDK, Kamailio terminates right after launch with the following > log message: > > > > "terminating due to SIGCHLD" > > > > I was surprised to not find any extra log messages indicating which > child process was causing the signal. > > > > I hacked the code in the handle_sigs() function in main.c.c to NOT > terminate in response to SIGCHLD, and was surprised to see that my > Python script was working fine, and was able to properly use the > OpenTok Python SDK. > > > > I then started adding more debugging log statements and discovered > that the call to waitpid() was returning 0, which apparently indicates > that no child process has changed state. > > > > It's very strange, because it seems that SIGCHLD is being sent and > handled, but waitpid() is indicating that no child process has changed > state. > > > > I'm not sure if that is valid situation which needs to be handled. > Perhaps SIGCHLD is sometimes sent for spurious or harmless reasons > which should be ignored, and not result in total Kamailio termination. > > > > My current workaround is to NOT terminate when SIGCHLD is received and > waitpid() indicates that no child process has changed state. In other > words, I only terminate when the waitpid() while() loop has been > entered at least once due to a return value greater than 0. > > > > Does that seem like a change that might make sense in the master > branch going forward, or does it seem dangerous somehow? > > > > I'm not sure if this is helpful, but the waitid() system call > (available since Linux 2.6.9) provides more precise control over which > child state changes to wait for. > > > > http://manpages.ubuntu.com/manpages/trusty/man2/wait.2.html > > > this can happen because your python script (or the libs used there) creates new processes and they terminate. Kamailio has a strict policy on watching the children and terminating if one disappears. I think we can relax that based on your suggestion. Can you make a pull request on github.com/kamailio/kamailio with your proposed changes? Ideally with a new parameter to control this behaviour, but don't worry if it is not straightforward for you to look at flex/bison files, I will do it on top of your patch. Cheers, Daniel -- Daniel-Constantin Mierla www.twitter.com/miconda -- www.linkedin.com/in/miconda Kamailio Advanced Training - May 22-24 (USA) - www.asipto.com Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com
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