[3.7] bpo-36794: Document that Lock.acquire is fair. (GH-13082)#13659

miss-islington merged 1 commit intopython:3.7python/cpython:3.7from

miss-islington:backport-34f4f5e-3.7miss-islington/cpython:backport-34f4f5e-3.7Copy head branch name to clipboard