def run(self):
        ''' xfer & run module on all matched hosts '''

        # find hosts that match the pattern
        hosts = self.inventory.list_hosts(self.pattern)
        if len(hosts) == 0:
            self.callbacks.on_no_hosts()
            return dict(contacted={}, dark={})

        global multiprocessing_runner
        multiprocessing_runner = self
        results = None

        # Check if this is an action plugin. Some of them are designed
        # to be ran once per group of hosts. Example module: pause,
        # run once per hostgroup, rather than pausing once per each
        # host.
        p = utils.plugins.action_loader.get(self.module_name, self)
        if p and getattr(p, 'BYPASS_HOST_LOOP', None):
            # Expose the current hostgroup to the bypassing plugins
            self.host_set = hosts
            # We aren't iterating over all the hosts in this
            # group. So, just pick the first host in our group to
            # construct the conn object with.
            result_data = self._executor(hosts[0]).result
            # Create a ResultData item for each host in this group
            # using the returned result. If we didn't do this we would
            # get false reports of dark hosts.
            results = [ ReturnData(host=h, result=result_data, comm_ok=True) \
                           for h in hosts ]
            del self.host_set
        elif self.forks > 1:
            try:
                results = self._parallel_exec(hosts)
            except IOError, ie:
                print ie.errno
                if ie.errno == 32:
                    # broken pipe from Ctrl+C
                    raise errors.AnsibleError("interupted")
                raise
        else:
            results = [ self._executor(h) for h in hosts ]
        return self._partition_results(results)
xfer & run module on all matched hosts