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author | danielsdeleo <dan@opscode.com> | 2013-09-11 08:30:34 -0700 |
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committer | danielsdeleo <dan@opscode.com> | 2013-09-11 08:30:34 -0700 |
commit | ebe7f8e87349655ba2601a3b18c4711fd95c6bf5 (patch) | |
tree | d332fb8ac53c3d14e8e8aae5bcaf115309630f1b /lib/mixlib | |
parent | 89f7f802e3bc5ab92c32eff7f065acdebff8492c (diff) | |
download | mixlib-shellout-ebe7f8e87349655ba2601a3b18c4711fd95c6bf5.tar.gz |
Use blocking waitpid only on ENOENT
This is a compromise that prevents us from leaving zombie processes
around after a failed exec raises ENOENT, but prevents us from blocking
(possibly forever) on timed-out commands. The latter case can cause
zombies, so this is not optimal for all cases. See MIXLIB-16 for a
proposed enhancement to solve that case.
Diffstat (limited to 'lib/mixlib')
-rw-r--r-- | lib/mixlib/shellout/unix.rb | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/lib/mixlib/shellout/unix.rb b/lib/mixlib/shellout/unix.rb index af3e421..d7b8b92 100644 --- a/lib/mixlib/shellout/unix.rb +++ b/lib/mixlib/shellout/unix.rb @@ -82,10 +82,18 @@ module Mixlib end end self - rescue Exception - # do our best to kill zombies + rescue Errno::ENOENT + # When ENOENT happens, we can be reasonably sure that the child process + # is going to exit quickly, so we use the blocking variant of waitpid2 Process.waitpid2(@child_pid) rescue nil raise + rescue Exception + # For exceptions other than ENOENT, such as timeout, we can't be sure + # how long the child process will live, so we use the non-blocking + # variant of waitpid2. This can result in zombie processes when the + # child later dies. See MIXLIB-16 for proposed enhancement. + Process.waitpid2(@child_pid, Process::WNOHANG) rescue nil + raise ensure # no matter what happens, turn the GC back on, and hope whatever busted # version of ruby we're on doesn't allocate some objects during the next |