tree 2c54aa7808e9654b8408fdc6a590f34b1e30aeb8
parent bb967aa0fe4419e32df9d180539bd7438aafa7dc
author mschaller <mschaller@google.com> 1499893703 +0200
committer László Csomor <laszlocsomor@google.com> 1499932601 +0200

Avoid races while deleting output directory ancestors

When an output file becomes a directory from one build to another, the
filesystem operations performed by several threads can race while they
prepare output directories. Without synchronization, these races can
cause failures. See the comments added in this CL for more detail.

This CL adds synchronization around these filsystem operations and gets
rid of the problematic races.

RELNOTES: None.
PiperOrigin-RevId: 161714702