Have the parent wait for an exit code from the child during startup, when daemonizing #443
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| /* If we're daemonizing, we send an error code to the parent */ | ||
| if(daemonize) { | ||
| int code = 1; | ||
| write(pipefd[1], &code, sizeof(int)); |
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I'd surround the write with a do - while, which checks if the return code is == -1 and errno is EINTR.
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Good catch, thanks for noticing!
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This fix (checking POLLERR/POLLHUP) makes the parent aware also when the child crashes, and so fixes the last concern I had. This seems to be working fine for me, so merging as this has been around a while already: there will be time for improving it along the road. |
lminiero
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Feb 8, 2016
Have the parent wait for an exit code from the child during startup, when daemonizing
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A quick'n'dirty patch to allow for feedback on whether Janus started or not, when daemonizing. A pipe is created, and the parent waits on one end for an exit code before actually exiting: the child either writes a 0 when everything was started correctly, or a 1 when it didn't (currently done in
janus_termination_handler).The patch is much more basic than what @saghul proposed in #408 (no grandparents/grandchildren, for instance, but just the parent/child we already had), but seems to do the job. I'm just puzzled as to how to handle the cases where Janus crashes instead: I thought this would result in the child end of the pipe being closed, and so the poll to exit, but it didn't (the poll keeps waiting), meaning we should handle it accordingly. I guess there are some flags/controls that can be set on the pipe for that, I'll look into it.
Feedback welcome!