Le 11 mars 2013 à 23:25, Jean Suisse <jean.li...@gmail.com> a écrit :
> Dear All, > > There may be several approaches to solve the issue I am about to describe, > either on the userland side or on the kernel side... or in-between, using a > daemon. > > Current situation > A bsd kernel extension communicates with a regular userland application > (called theApp). The kext gathers statistics, sends data to the user, takes > orders from the user, etc.. There are two-way communications initiated by > both sides using control sockets – There may be no market for such app, it is > more of investigation tool, but that's irrelevant. > > Goal > I would need to handle fast user switching, so that data sent by the kext are > directed towards the user that can actually handle them. This user is the one > "owning" the graphic interface (is there a technical word to say that?). > > Issue > When switching from user(A) to user(B) (using fast user switching for > instance), user(A) no longer owns the graphic interface and theApp(A) is no > longer able to interact with the user and give the required feedback to the > kext. User(B) starts theApp(B) and interacts normally with the kext. Then, > when switching from B to A, the same issue occurs in reverse. > > Solution > One approach would be to have theApp(A) launched by user(A) to be notified > when user(A) looses access to the graphic interface. > When switching back to user(A) theApp(A) and theApp(B) would also get > notified. > > I read this document > (https://developer.apple.com/library/mac/#documentation/MacOSX/Conceptual/BPMultipleUsers/Concepts/UserSwitchNotifications.html), > but it seems that there is some race condition occurring, maybe as a result > of interacting with the kernel (the kext must perform a few tasks before > allowing theApp(A) to disconnect and theApp(B) to connect). > > Are there any other alternatives, from the userland side ? There is an other way to track the current user: using the SystemConfiguration framework notification: http://developer.apple.com/library/mac/#qa/qa1133/_index.html -- Jean-Daniel _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
