ProcessReaper: single thread reaper (original) (raw)

Martin Buchholz martinrb at google.com
Wed Apr 16 19:15:17 UTC 2014

On Mon, Apr 14, 2014 at 1:57 PM, Peter Levart <peter.levart at gmail.com>wrote:

There's already such a race in current implementation of Process.terminate(). It admittedly only concerns a small window between process exiting and the reaper thread managing to signal this state to the other threads wishing to terminate it at the same time, so it could happen that a KILL/TERM signal is sent to an already deceased PID which was re-used, but it doesn't happen in practice since PIDs are not re-used very soon typically. But I agree, waiting between listing children and sending them signals increases the chance of hitting a reused PID.

We do rely on the OS not reusing a PID immediately. We used to have bugs in this area where Process.destroy would send a signal to a pid that may have deceased arbitrarily long ago.

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