Python decorator for exclusive methods

mutex_decorator.py

def one_at_a_time(message):
    ''' Decorator for exclusive methods
        Using like this:
            @one_at_a_time("Deployment or build already running")
            def deploy(self, msg, args)
    '''
    def mutex_decorator(func):
        @wraps(func)
        def wraper(self, *args, **kwargs):
            if not mutex.locked():
                # Not locked, call the function
                try:
                    mutex.acquire()
                    # return a generator if calling a generator
                    if inspect.isgeneratorfunction(func):
                        for res in func(self, *args, **kwargs):
                            yield res
                    else:
                        yield func(self, *args, **kwargs)
                finally:
                    mutex.release()
            else:
                # Locked, fire a message
                yield message
        return wraper
    return mutex_decorator