guard / rb-inotify / 83

80%

push

travis-ci

Prevent race condition in Notifier#run / #stop

There is a potential race condition when a notifier is run in a new
thread and then immediately stopped in the original thread.  If
`Notifier#stop` sets `@stop = true` before `Notifier#run` sets
`@stop = false`, then `Notifier#run` will loop until `Notifier#stop` is
called again.  Furthermore, if `Notifier#run` acquires the `@running`
mutex before `Notifier#stop` does (but after `Notifier#stop` sets
`@stop = true`), then `Notifier#stop` will get stuck waiting for the
mutex while `Notifier#run` infinitely loops.

This commit modifies `Notifier#run` to assume `@stop == false` when it
begins, and to reset `@stop = false` only after its loop terminates,
thus eliminating the race.

2 of 2 new or added lines in 1 file covered. (100.0%)

172 of 214 relevant lines covered (80.37%)

9.26 hits per line