StartActivity intent fails when certain apps are running

I am running into a critical conflict of sorts. My app is a remote service which essentially starts an activity when the screen goes to sleep. How it does this is very simple via screen off broadcast receiver and then an explicit intent to start the activity as a new task. The activity is basically in charge of responding to key events and displaying some simple text.

Thanks to a few window flags added in 2.0, activities can do开发者_运维问答 this. They can be created in a way that either puts them on top of the lockscreen, or completely dismiss the lockscreen. This way they basically have focus without the lockscreen having to be dismissed by user. The alarm clock in 2.0 uses the flags to wake up the device and show the alarm dialog. I use them to place my activity when the screen sleeps so the user sees a custom wakeup lockscreen. The reason we create it at screen off is to get rid of lag the user experiences at wakeup involving first seeing the lockscreen, then seeing the activity appear. Also doing it immediately at sleep allows it to have focus so it can handle key events effectively.

The process works perfectly except in certain apps. So far, it seems the bug is consistent while browser (and even dolphin browser) as well as the facebook app are running. The bug never happens in GTalk or Launcher. It is rare but can still be duplicated in the messaging app every so often. I can't figure out why my activity doesn't get created at sleep while these apps are active. My remote service still gets the screen off broadcast and does the startActivity for the explicit intent, and that's all I get in the log. My onCreate is not being called. Instead it gets called when we wake the screen up again.

I have tried, as a control, to hold the partial wakelock starting when my remote service gets created, and the issue persists. So I don't believe it is a problem that the CPU has gone to sleep. Since only these particular apps cause the issue to duplicate, I can't imagine why the activity start fails. What could those apps be doing to interfere with another app's ability to get created? I use singleInstance as the launch mode so that I can ensure that the activity will never be able to be recalled by user process. I want it to go away when user unlocks and it is working fine like this, as long as it is able to be created. The singleInstance ensures I can have the same lockscreen handle an intent to do something specific based on user actions that the remote service monitors.

my source code can be viewed on my project page. http://code.google.com/p/mylockforandroid/source/browse/#svn/trunk/myLock/src/i4nc4mp/myLock

the issue happens to both my CustomLockService and NoLockService variations. These two services will start Lockscreen or ShowWhenLockedActivity and the bug is witnessed. The build illustrating the bug's end result-- user has to try to unlock 3 times due to the bug because on wakeup when the oncreate finally succeeds, user is seeing the activity when normally it would have auto-dismissed thanks to key event logic that also isn't seeming to happen due to the delayed onCreate, so they have to send it to sleep again. Now that the activity is properly done being started, and screen is asleep, the expected functionality happens at next wakeup-- can be downloaded also from the downloads tab.

This seems like an extremely irrational thing to be caused only by specific apps. I am quite baffled and out of ideas for a solution unless I've made some critical mistake in my activity definitions.

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The answer is actually a bug in android that has been in review for a while. It has to do with the home key. For some reason start activity calls as new tasks are getting stopped after the home key has recently been launched. I never noticed the connection during the testing of this. The bug was not consistent and the factor of consistency was whether home button had been used during the wake in question

Here is the bug report: http://code.google.com/p/android/issues/detail?id=4536