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I'm developing an application which needs to run small chunks of code frequently (once every two seconds, for example). I've tried to make it work using the simple Thread.sleep() (or android.os.SystemClock.sleep() to avoid interrupts, and finally I've tried with Timer and Handler), but the result is that the time that the program sleeps is random (or it simply doesn't run if I use Timer or Handler as the system discards they messages when the screen is off), as the system goes to a deep sleep mode during screen off.

For example the code works right if I have the phone plugged into the charger, or is playing music (that avoids the deep sleep mode), but when the phone isn't doing anything the time can grow from two seconds sleep up to minutes of sleep.

From https://groups.google.com/forum/#!topic/android-developers/Eqwp8Uiy2f0 seems that the only alternative is to use the AlarmManager to force the wake, but that way will probably cause too much battery drain.

Is there any alternative?

If not, is there any way to detect when the system goes into the deep sleep mode?

Fran
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1 Answers1

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It is too late but may be useful for somebody else. Yes, Timers does not work in deep sleep mode.I think there is no other better way than AlarmManager to run something periodically in deep sleep mode. Also, as your frequency is just 2 seconds I think you may have to go for exact alamrs (setExact() ) as the regular alarm may not serve you better if your requirement is critical in time. And sometimes even setExact might not capture the wake lock I observed. So you have to acquire your own (PARTIAL_..) wake lock and, do stuff and release the lock. But is it must that you have to run evvery 2 seconds ? If not continue using Timers which will continue working automatically after the device wake up. Take a look at Should I use AlarmManager or Handler?

Community
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cgr
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