Acquire thread and file locks.  Re-opening log for 'degraded' mode.

def acquire(self):
        """ Acquire thread and file locks.  Re-opening log for 'degraded' mode.
        """
        # handle thread lock
        if Handler:
            # under some tests Handler ends up being null due to instantiation
            # order
            Handler.acquire(self)

        # Issue a file lock.  (This is inefficient for multiple active threads
        # within a single process. But if you're worried about high-performance,
        # you probably aren't using this log handler.)
        if self.stream_lock:
            # If stream_lock=None, then assume close() was called or something
            # else weird and ignore all file-level locks.
            if self.stream_lock.closed:
                # Daemonization can close all open file descriptors, see
                # https://bugzilla.redhat.com/show_bug.cgi?id=952929
                # Try opening the lock file again.  Should we warn() here?!?
                try:
                    self._open_lockfile()
                except Exception:
                    self.handleError(NullLogRecord())
                    # Don't try to open the stream lock again
                    self.stream_lock = None
                    return
            lock(self.stream_lock, LOCK_EX)