Re: [PATCH 01/13] PM: Add wake lock api.

Pavel Machek
2009-02-08T21:21:22Z

Hi!

> >> > If my understanding is correct, a wakelock is a mechanism that, if held, will
> >> > prevent the system from (automatically) entering a sleep state, but why do we
> >> > need a number of such wakelocks instead of just one reference counter with the
> >> > rule that (automatic) suspend can only happen if the counter is zero?
> >>
> >> Using wakelocks instead of a global reference count ensures that your
> >> request cannot be cleared by someone else.
> >
> > Decreasing the refcount without increasing it would have been a bug, IMO.
>
> Yes, but if all you have is a global reference count, you can't tell
> where the bug is.
...
> >> and detailed stats.
> >
> > Well, I'm not sure how this is useful in the long run.
>
> You may want to know which app drained your battery.

_If_ we want to allow userspace to hold wakelocks (better name could
be awakelock or nosleeplock?) then some way of displaying them is
required.
Pavel
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