assassin.rb
no zombies ever, not even on exit! or kill -9
pipe = IO.popen 'some-program-that-must-not-be-zombied'
Assassin.at_exit_kill(pipe.pid)also see lib/assassin.rb and test/assassin_test.rb
assassin.rb is a small (~ 60 loc), simple, reliable methodology of ensuring that child processes are always cleaned up, regardless of the manner in which the parent program is shut down.
the basic concept it to generate, start, and detach another script that monitors the parent process and, when that process no longer exists, ensures through escalation of signals that a child process is shut down and does not become a zombie.
this becomes espcially important for libraries which spawn processes, such
as via IO.popen that need to ensure those children are cleaned up, but
which cannot control whether client code may call exit!. this approach
also handles being kill -9d - something no at_exit{} handler can
promise.
gem install assassin
http://github.com/ahoward/assassin
- 0.4.2. initial release