Relaunch in my case isn't about crash recovery, its about preventing user waits and preventing crashes in the first place.
Examples of situations where auto relaunch is desirable: - user changes a preference which essentially invalidates every object in every nib - color preferences - resetting prefs ( clearing NSUserDefaults, deleting all cached files ) - making the user wait for timeouts is unacceptable In my app, only one NSDocument is open at a time, because it specifies a network of servers. It is ok to interrupt any threaded transaction in progress, but it is time consuming to synchronize the deletion of those threads. For example, if a background threaded NSURLRequest has a 5-second timeout, then the user might have to wait 5 seconds to close the current NSDocument and open the new one. Either that or I have to write special unmaintainable code for every imaginable edge-case. Annoying for the user, and wasted development resources on my part. If I call execve() when switching to a different NSDocument, cleanup happens in 5 milliseconds (once save to disk is done), and relaunch happens in less than 2 seconds. Why make the user wait for longer? While I admire apps that have the budget to reconfigure on the fly, it typically takes a long time for them to be stable. Take for example, the apple usb-ethernet driver... https://discussions.apple.com/thread/3957141?start=0&tstart=0 Keith Knauber Senior Software Engineer Production Resource Group 8617 Ambassador Row, Suite 120 Dallas, Texas 75247 214-819-3145 Phone 214-477-3928 Mobile 214-630-5867 Fax kknau...@prg.com www.prg.com On Dec 18, 2012, at 11:47 AM, Kyle Sluder wrote: On Dec 18, 2012, at 9:27 AM, Keith Knauber <kknau...@prg.com> wrote: > Automatic relaunch of your app is such a basic software requirement, It is? > and apple has never published a clean method for accomplishing this. Ape's crash reporter offers to relaunch the app. > There are situations when a relaunch of an app is much safer, faster, and > fault tolerant than an approach which kills every background thread, > deletes all your NSDocument objects, and open a new NSDocument. The desired user experience is that after a relaunch NSDocumentController reopens all the documents that were open at the time of the crash. > > - (void) applicationWillTerminate:(NSNotification *)notification > { > … do clean-up tasks like NSUserDefaults synchronize, etc. … > > if ( ! userWantsRelaunch ) > return; This won't be executed if you crash, and you certainly shouldn't trap all exceptions and go through the normal quit process to make it do so. Are you trying to auto relaunch for reasons other than a crash? If so, why? If it's for software update reasons, then self-exec is not a good idea because the old version app will likely remain mapped and will be relaunched. Better to have a helper script that waits for the process to quit and the file to be replaced before actually doing the launching. I can't really think of any reason other than crash or self-update where relaunching the app is the correct user experience. --Kyle Sluder _______________________________________________ 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
