HHVM reads file too early when uploading/updating?

### HHVM Version

HipHop VM 3.12.0 (rel) & HipHop VM 3.14.1 (rel)
### Standalone code, or other way to reproduce the problem

**Problem occurs very rarely on high traffic sites.**
When someone uploads files via FTP or when many files are updated by PHP itself (self-updates) sometimes the HHVM's cache gets corrupted. I sometimes see errors in the hhvm error log which hint that the HHVM read only a partial file while it was being uploaded or updated but when I check the file via vim the error reported by HHVM should not occur.. If we upload the same file again the error goes away (I guess this is based on the same probability of HHVM reading a partially uploaded file.)

Has anyone else experienced this before?