Hi Pierre-Yves, >>> It seems that once a friendly name has been cached to /var/lib/ >>> bluetooth/*/names, RemoteNameUpdated signals contain this cached >>> name forever, and user is never informed of a name change unless >>> those "names" files are deleted. >> >> the names are never updated once retrieved. At least not via an >> inquiry run. If you connect to a remote device, it will update the >> name. Another option is Extended Inquiry support if you have the >> hardware for it. >> >> The reason behind this is that the remote name operation is too >> expensive if you don't have an ACL link between two devices. And a >> lot >> of times the name doesn't change so often or it is unimportant >> anyway. > > It makes a lot of sense, at least for the python example I submitted, > which was only performing calls to "DiscoverDevices". > > But I've encountered another situation, where bluez' caching behaviour > produces some nonsense. I have no simple test application to provide, > but it is quite simple to explain and understand. > > I've an application which performs a continuous inquiry (eg when it > gets > DiscoveryCompleted, it calls DiscoverDevices() and so on). In the > meantime, this application does also perform sdp extraction and rfcomm > connections to the detected devices. Here is a record of all > RemoteNameUpdated signals from a particular device: > > I delete /var/lib/bluetooth/*/names, set my device's name to "Name 1", > and start my application > > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > > So far so good. At this point I set my device's name to "Name2": I > start > to get mixed values (I understand that "Name1" are sent out from the > discovery, and thus use the cached value as you explainded above, and > "Name2" are from the other operations, which are actually getting the > current name, because they do connect to the device) > > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name1 > > At this point I delete /var/lib/bluetooth/*/names. As cache is > recreated > with the current value (Name2) everything looks good again > > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > > At this point, I change my device's name to "Name3". Things get > mixed up > again. > > RemoteNameUpdated signal received: 006057BB4D92 - Name3 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name3 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name3 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > RemoteNameUpdated signal received: 006057BB4D92 - Name3 > RemoteNameUpdated signal received: 006057BB4D92 - Name2 > > So, shouldn't the cached value get updated when bluez gets a different > name later on? this indeed looks like a bug. Seems like the new name is not written to disk. Can you re-produce this with bluez-utils-3.29? Regards Marcel ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Bluez-devel mailing list Bluez-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/bluez-devel
