Cron Lock
=========

The ``fussy.cronlock`` module provides a simple mechanism to prevent 
runaway cron jobs.  A lock can be used to protect a piece of code that 
should only ever have a single running instance:

.. code-block:: python

    from fussy import cronlock
    lock = cronlock.Lock( 'test.lock' )
    
    with lock:
        do_something()

It can also be used to prevent a piece of code from running for too long
(note: the lock does not need to be held for this to work):

.. code-block:: python

    from fussy import cronlock
    lock = cronlock.Lock( 'test.lock' )
    
    lock.set_timeout( 20 ) # from this moment
    do_something_that_might_take_a_while()

A decorator is provided to create and hold the lock for a given function,
normally the main function of your cron-lock:

.. code-block:: python

    from fussy import with_lock
    
    @with_lock( 'test.lock', timeout=20 )
    def main():
        """Your cron job main-loop"""
    

Module: fussy.cronlock
----------------------

.. automodule:: fussy.cronlock
    :members:
    :special-members: