Activity restarts on Force Close
I have an Application with a single root Activity. I've recently had it brought to my attention that any kind of Force Close on my Activity results in it restarting and I have no idea why this might happen. If I force an uncaught exception or use the 'long back press to force close' option, they both result in the same.
My only guess would have been some form of quirk relating to retained references to some part of the Activity, only I don't have any outside of some WeakReference entries at the Application level.
Relevant logcat entries:
05-25 08:25:49.137: INFO/ActivityManager(18449): Displayed uk.co.randomicon.rstb/.TreeBuilderActivity: +8s82ms
05-25 08:25:54.222: DEBUG/dalvikvm(18546): GC_EXPLICIT freed 12K, 57% free 3640K/8327K, external 8323K/10136K, paused 72ms
05-25 08:25:55.373: WARN/InputManagerService(18449): Got RemoteException sending setActive(false) notification to pid 19122 uid 10069
05-25 08:25:59.217: DEBUG/dalvikvm(18646): GC_EXPLICIT freed 128K, 48% free 2980K/5703K, external 0K/0K, paused 67ms
05-25 08:26:00.238: DEBUG/dalvikvm(18991): GC_CONCURRENT freed 343K, 51% free 2794K/5639K, external 303K/532K, paused 3ms+3ms
05-25 08:26:02.950: INFO/Process(18449): Sending signal. PID: 19554 SIG: 9
05-25 08:26:02.980: INFO/ActivityManager(18449): Process uk.co.randomicon.rstb (pid 19554) has died.
05-25 08:26:02.990: ERROR/InputDispatcher(18449): channel '40a16ec8 uk.co.randomicon.rstb/uk.co.randomicon.rstb.TreeBuilderActivity (server)' ~ Consumer closed input channel or an error occurred. events=0x8
05-25 08:26:02.990: ERROR/InputDispatcher(18449): channel '40a16ec8 uk.co.randomicon.rstb/uk.co.randomicon.rstb.TreeBuilderActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
05-25 08:26:02.990: INFO/WindowManager(18449): WINDOW DIED Window{40a16ec8 uk.co.randomicon.rstb/uk.co.randomicon.rstb.TreeBuilderActivity paused=false}
05-25 08:26:03.010: WARN/WindowManager(18449): Failed looking up window
05-25 08:26:03.010: WARN/WindowManager(18449): java.lang.IllegalArgumentException: Requested window android.os.BinderProxy@40c774e0 does not exist
05-25 08:26:03.010: WARN/WindowManager(18449): at com.android.server.WindowManagerService.windowForClientLocked(WindowManagerService.java:8177)
05-25 08:26:03.010: WARN/WindowManager(18449): at com.android.server.WindowManagerService.windowForClientLocked(WindowManagerService.java:8168)
05-25 08:26:03.010: WARN/WindowManager(18449): at com.android.server.WindowManagerService$WindowState$DeathRecipient.binderDied(WindowManagerService.java:7026)
05-25 08:26:03.010: WARN/WindowManager(18449): at android.os.BinderProxy.sendDeathNotice(Binder.java:385)
05-25 08:26:03.010: WARN/WindowManager(18449): at dalvik.system.NativeStart.run(Native Method)
05-25 08:26:03.010: INFO/WindowManager(18449): WIN DEATH: null
05-25 08:26:03.020: INFO/ActivityManager(18449): Start proc uk.co.randomicon.rstb for activity uk.co.randomicon.rstb/.TreeBuilderActivity: pid=19565 uid=10069 gids={1015}
Any ideas where to even begin poking would be gratefully received!
EDIT: This was caused by me setting android:stateNotNeeded="true" in my Manifest. While I don't need the state, this caused Android to decide it was best to relaunch my app on the assumption the user would want that.
Answer
Here is some useful info:
As far as when an activity is restarted -- if the process running the foreground activity goes away, the system will throw away that activity if it does not have a valid saved state for it (typically meaning it is paused and has given the system the result of onSaveInstanceState from before the pause). Once it has decided whether or not to throw away that activity, it will resume whatever activity is now at the top of the stack. If this is one of your activities -- either because you have another behind the one that crashed, or the one that crashed was somehow it the settled pause state -- then it will start your process again to show that top activity.