On Wed, 25.02.09 11:45, Bu, Long (long.bu at intel.com) wrote: > Hi, > I am reading its code and wondering why the filter_cb is needed to handle ACLAdded > And ACLRemoved etc signals. Since there are > libhal_ctx_set_device_added(u->context, device_added_cb); > libhal_ctx_set_device_removed(u->context, device_removed_cb); > libhal_ctx_set_device_new_capability(u->context, new_capability_cb); > libhal_ctx_set_device_lost_capability(u->context, lost_capability_cb); > in pa__init, and the callbacks will handle for those signals. libhal does not provide a callback that is called whenever an ACL entry is removed/added to a device file. All it provides are callbacks for the devices themselves being added/removed. When the active session is switched HAL will make sure that the new active user acn access the audio devices and the old user can no longer. PA needs to know that so that it can suspend/resume its devices. Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net ICQ# 11060553 http://0pointer.net/lennart/ GnuPG 0x1A015CC4