[Checkins] [zopefoundation/ZODB] 3d5ad1: Use same lock for DB & MVCCAdapter

[Julien Muchembled]

  Branch: refs/heads/issue290
  Home:   https://github.com/zopefoundation/ZODB
  Commit: 3d5ad164b3c90bce60d38cee2160149760c42638
      https://github.com/zopefoundation/ZODB/commit/3d5ad164b3c90bce60d38cee2160149760c42638
  Author: Julien Muchembled <jm at nexedi.com>
  Date:   2019-10-04 (Fri, 04 Oct 2019)

  Changed paths:
    M src/ZODB/DB.py
    M src/ZODB/mvccadapter.py
    M src/ZODB/tests/testConnection.py

  Log Message:
  -----------
  Use same lock for DB & MVCCAdapter