Re: Do porcelain command require lock management?

[Konstantin Ryabitsev <konstantin@linuxfoundation.org>]

On Sun, Oct 25, 2020 at 11:02:03PM +0000, brian m. carlson wrote:
> > A script I'm writing performs a succession of porcelain commands to
> > create a commit in a bare git repository:
> > 
> > git hash-object
> > git mktree
> > git commit-tree
> > git update-ref
> > 
> > Do I need to manage external locking around these commands to avoid any
> > concurrency problems, or will git take care of that?
> 
> I'm almost certain that Git will do the same locking and object creation
> semantics that it does in porcelain commands as in the plumbing commands
> you're using.  For example, I happen to know that all loose object
> creation goes through one function, which should gracefully handle
> concurrent accesses.  Git is in general safe against concurrent accesses
> and is designed not to lose or corrupt data in this case.
> 
> However, I will point out that ref updates may conflict and if so, Git
> will fail instead of waiting.  So while your repository will remain
> consistent and won't experience corruption, that doesn't mean that all
> operations will complete successfully.  Some sort of retry mechanism or
> other error handling will probably be warranted.

Thanks for your advice. I think in this case it's easier to just use 
simple locking to make sure that concurrent processes don't step on 
each-other's toes.

Best regards,
-K