Avoid race condition between indexing threads

When more than one thread try to index a change in the target instance,
it could be possible that, because of a race condition, the last thread
writes an outdated status to the index.

Synchronize the threads indexing the same change while still allowing
parallelization between threads indexing different changes.

Change-Id: Ic47c9d220f124c096e5e66bb46d13a9a7b0f51e7
1 file changed
tree: bf2d14b0cb5e96c9fb165da6fe54d7be71f1e7ba
  1. .buckconfig
  2. .gitignore
  3. BUCK
  4. lib/
  5. src/