On Wed, Nov 01, 2017 at 09:45:06PM +0100, Martin Ågren wrote: > With --recurse-submodules, we add each submodule that we encounter to > the list of alternate object databases. With threading, our changes to > the list are not protected against races. Indeed, ThreadSanitizer > reports a race when we call `add_to_alternates_memory()` around the same > time that another thread is reading in the list through > `read_sha1_file()`. > > Take the grep read-lock while adding the submodule. The lock is used to > serialize uses of non-thread-safe parts of Git's API, including > `read_sha1_file()`. > > Helped-by: Brandon Williams <bmwill@xxxxxxxxxx> > Signed-off-by: Martin Ågren <martin.agren@xxxxxxxxx> This looks good to me. -Peff
