Hi Li, On Tue, Sep 01, 2015 at 06:56 AM CEST, eshark <eshar...@163.com> wrote: > I wonder why the sd_bus_slot_unref() always returns NULL? I expect > that I can check whether the slot->n_ref ==0 by checking its return > value.
It is my understanding that NULL is returned so that you can release the reference and nullify the pointer holding the reference in one line: ref = sd_bus_slot_unref(ref); This idiom prevents the access-after-release programming errors. Cheers, Jakub _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel