Do porcelain command require lock management?

[Konstantin Ryabitsev <konstantin@xxxxxxxxxxxxxxxxxxx>]

Hello:

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?

-K