+ def _LockAndExecLU(self, lu, level):
+ """Execute a Logical Unit, with the needed locks.
+
+ This is a recursive function that starts locking the given level, and
+ proceeds up, till there are no more locks to acquire. Then it executes the
+ given LU and its opcodes.
+
+ """
+ if level in lu.needed_locks:
+ # This is always safe to do, as we can't acquire more/less locks than
+ # what was requested.
+ lu.needed_locks[level] = self.context.glm.acquire(level,
+ lu.needed_locks[level])
+ try:
+ result = self._LockAndExecLU(lu, level + 1)
+ finally:
+ if lu.needed_locks[level]:
+ self.context.glm.release(level)
+ else:
+ result = self._ExecLU(lu)
+
+ return result
+