Note that these times are *uptime*. If the screen is off, and nobody is holding a wakelock, then the CPU will go to sleep, and uptime will stop counting until it wakes up again.
On Fri, Jul 13, 2012 at 9:24 AM, mapeters <mapet...@ideasave.com> wrote: > I have a thread (guts implemented as a subclass of Runnable) whose job is > to perform an operation on demand from other threads or automatically every > two minutes if no other thread invokes the operation. The run() method of > this Runnable calls Looper.prepare(), creates a Handler object in a member > variable, uses that to call sendEmptyMessageDelayed(1, 3000), then calls > Looper.loop(). > > Other threads use a method in this thread's public API to invoke its > operation. That method just calls the handler's sendEmptyMessage(0) method > to invoke it. When the handler's handleMessage(Message) method is called, > it acquires a lock (ReentrantLock), calls the handler's > removeCallbacksAndMessages(null) method and performs its operation (within > a try/catch block). The finally section of that block calls the handler's > sendEmptyMessageDelayed(1, 120000) method then releases the lock. > > This works fine on every device I have tested it on, and by everything I > know, it is a valid way to do this that ought to work on every version of > Android OS. Recently, however, somebody claimed it wasn't running every two > minutes as it should, and gave me the log file it produces to prove it > (which it does). That log shows that sendEmptyMessageDelayed(1, 120000) was > called, and then 11 minutes later, the handleMessage(Message) method was > called. I know this invocation of handleMessage() was in response to that > sendEmptyMessageDelayed(1, 120000) call because Message.what was 1 (a value > used only by the sendEmptyMessageDelayed() call). > > How is this possible? I could understand the timing being off by a few > seconds, but 11 minutes? In subsequent attempts to reproduce this, I have > seen that timing being off by 45 minutes and more. This problem has been > observed on an HTC One X running Android 4.0.3 and a Samsung Galaxy SII > running OS 2.3.6. > > Has anybody else seen this issue? Does anybody have a suggestion for what > might be causing this? My current position is that this is an OS bug, but I > am loathe to just accept that and call it a day. BTW - just for kicks, I > temporarily re-implemented this using a Timer object instead, and observed > exactly the same problem (using Handler is a better solution anyway). > > Thanks, > > Mark Peters > > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to android-developers@googlegroups.com > To unsubscribe from this group, send email to > android-developers+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- Dianne Hackborn Android framework engineer hack...@android.com Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails. All such questions should be posted on public forums, where I and others can see and answer them. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
