# Xlib.support.lock -- allocate a lock
#
#    Copyright (C) 2000 Peter Liljenberg <petli@ctrl-c.liu.se>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public License
# as published by the Free Software Foundation; either version 2.1
# of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
#    Free Software Foundation, Inc.,
#    59 Temple Place,
#    Suite 330,
#    Boston, MA 02111-1307 USA

class _DummyLock(object):
    def __init__(self):

        # This might be nerdy, but by assigning methods like this
        # instead of defining them all, we create a single bound
        # method object once instead of one each time one of the
        # methods is called.

        # This gives some speed improvements which should reduce the
        # impact of the threading infrastructure in the regular code,
        # when not using threading.

        self.acquire = self.release = self.locked = self.__noop

    def __noop(self, *args):
        return


# More optimisations: we use a single lock for all lock instances
_dummy_lock = _DummyLock()

def allocate_lock():
    return _dummy_lock