https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=21872
--- Comment #59 from David Cook <[email protected]> --- (In reply to Martin Renvoize from comment #57) > 1) The 'die' on fork failure isn't cleaning up after itself.. imagine a case > where we want to sporn 5 subprocesses, it we get to process 4 and then run > out of memory for example. The parent script will die and leave behind > zombie child processes. I don't think that this is an actual problem. I think that this happens all the time. The parent dies, the init process (ie 1) becomes the new parent, and it reaps the children when they complete. I don't even think they actually do become zombie child processes in this process. This is also the same process used to daemonize a process. Where you run into a problem with zombie child processes is when the parent lives, the child exits, and the parent doesn't reap the child, which means that you have zombie child processes filling up your process table. That's a real problem. > 2) It doesn't look like there's any form of signal handling here and as such > a CTRL+C for example could end up leaving zombie processes too. > You don't need any signal handling. If you do a CTRL+C on the parent process, it'll cascade down through the child processes, because they'll share the same process group ID. So a CTRL+C won't leave zombie child processes. Even if the CTRL+C just killed the parent and not the children (e.g. the children had set their own process group ID after forking), then they'd just be inherited by init and cleaned up anyway. > I'm also wrapping my head around the use of wait vs waitpid here.. I > remember tripping myself up using them before, but can't remember the > details well enough right now to be confident I've not missed something. > I think wait() and waitpid(-1) are roughly equivalent? They could probably be more rigorous in checking that the PID returned by wait() actually matches the child PIDs, but not the end of the world. Even if the parent forgot to wait and exited early, the child processes would be cleaned up once they completed. -- You are receiving this mail because: You are watching all bug changes. _______________________________________________ Koha-bugs mailing list [email protected] http://lists.koha-community.org/cgi-bin/mailman/listinfo/koha-bugs website : http://www.koha-community.org/ git : http://git.koha-community.org/ bugs : http://bugs.koha-community.org/
