NanoClock: Yet another persistent clock

[NiLuJe]

There we go, released v0.9.9.

As mentioned above, minor logging & documentation tweaks to make the aforementioned "ninja sleep" behavior clearer .

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FWIW, I played a bit with *detecting* those and doing something (e.g., a tiny indicator that the clock is frozen), but it's mildly tricky, a lot race-y, somewhat intrusive, and the behavior is aggressive and predictable enough that it wouldn't serve much purpose anyway, as you can just assume that the device goes to bed ~5s after a page turn .

For curious people, all those experiments are in the public git history, and the final code was actually logically "sane", and actually achieved completely breaking the standby feature, thanks to the simple fact that the EPDC is itself a wakeup source, so catching the ninja in the act and sending a clock update right at that moment effectively *prevents* the suspend from succeeding. This isn't very nice though, and effectively launches Nickel into a repeated race with us to retry to suspend every 5s, which is why I dropped it .

[Phil_C]

OK, here is a log for 0.9.9 in case you need it.

And -- glad to help in my little way. You and a few others here give us a lot of good stuff. Thank you!

[NiLuJe]

Thanks, more data is always nice to have ;o).

(In particular, it confirms that the forced time adjustment on resume appears to be discarding nanosecond precision (and/or it's just a timing artifact, but the bottom line is essentially similar: subsecond drift, either backwards or forwards) on those older kernels, which effectively translates into time going ever so slightly backwards, so I'm glad I actually kept the discontinuity check (I was considering relaxing it severely, because the whole thing forces us to run a couple syscalls just to correct that small subsecond drift after every page turn), because it's technically more "correct" ^^).

Timekeeping is fun. It'll be even more fun in 2038 when all of this will self-destruct .

[Carmelocotonto]

Hi, now the clock is never updated in nickel and never in koreader. I tried version 0.9.9.
So I go back to version 0.9.7
With version 0.9.7 it is always updated except while reading with nickel. With nickel is updated when I touch the screen.

[NiLuJe]

@Carmelocotonto: Debug logs, please .

[Carmelocotonto]

Hi, now the clock is never updated in nickel and always in koreader. I tried version 0.9.9.

I said never in nickel and NEVER in koreader, but in koreader is updated.

This is de log
nanoclock.log.txt

Originally Posted by NiLuJe

@Carmelocotonto: Debug logs, please .

[NiLuJe]

AFAICT, it's behaving as expected.

You *appear* to have been modifying the *default* config (/usr/local/NanoClock/etc/nanoclock.ini) instead of the *user* config (/mnt/onboard/.adds/nanoclock/nanoclock.ini) though, and that *will* break a number of sanity checks.

[NiLuJe]

What you're seeing is a bad interaction between the autostandby, nickel's Homescreen clock, how it handles the refresh, and what happens after a resume on suspend.

* On views with a clock, before setting up the standby, Nickel programs a wake alarm to the first second of the next minute.
* Device wakes up according to said alarm.
* Standard "resume from suspend" operations happen, and that includes a hctosys (the system clock is reset based on the hardware clock).
* Nickel updates clock.

Now, NanoClock is setup to refresh *on the dot*, not on the first second.

So, resume from suspend triggers a discontinuous clock change (AFAICT, that one we can't do anything about, it's kernel related on platforms where nothing hardware ticks during suspend).
*Then*, the hctosys triggers a *second* discontinuous clock change.

Since those happen at :01, and we round *up*, latency means that we mostly never actually reach :00, which is what NanoClock expects for a clock tick induced refresh.

And I stopped forcing a clock refresh during those events, because they're not clock ticks per se, they're just the clock being *set*, and they're mostly duplicates of actual events that *do* already refresh the clock (page turns in the reader, and an actual tick here).

EDIT: I'm testing moving our ticks to :02 to ensure we always lose that race and get an actual actionable tick on our end.

[Carmelocotonto]

Oops!. I thought that I had to modify the default config with my user configuration.
I'm going to try to reinstall without modifying anything

Originally Posted by NiLuJe

AFAICT, it's behaving as expected.

You *appear* to have been modifying the *default* config (/usr/local/NanoClock/etc/nanoclock.ini) instead of the *user* config (/mnt/onboard/.adds/nanoclock/nanoclock.ini) though, and that *will* break a number of sanity checks.

[NiLuJe]

Released v0.9.10, which should now properly deal with the aforementioned interaction with Nickel's own clock on affected devices.

[Carmelocotonto]

Hello, these are the steps I have followed and the results:

1.- I install version 0.9.10
2.- clock is updated on the main screen but not reading
3.- I exit the reading and generate the log
4.- I connect via usb and copy the log to the pc
5.- I safely eject the kobo without disconnecting the cable
6.- the clock is updated on the main screen
8.- I open a book and I don't touch anything
7.- the clock is updated every minute without touching anything. I do not turn the page
8.- I remove the cable from the pc and the clock no longer updates with the book open
9.- I go to the main screen and the clock is updated

'log' has very little information:

EDIT: the correct log is into the next message

[Carmelocotonto]

Sorry, this is the correct log:

nanoclock.log.txt

Originally Posted by Carmelocotonto

Hello, these are the steps I have followed and the results:

1.- I install version 0.9.10
2.- clock is updated on the main screen but not reading
3.- I exit the reading and generate the log
4.- I connect via usb and copy the log to the pc
5.- I safely eject the kobo without disconnecting the cable
6.- the clock is updated on the main screen
8.- I open a book and I don't touch anything
7.- the clock is updated every minute without touching anything. I do not turn the page
8.- I remove the cable from the pc and the clock no longer updates with the book open
9.- I go to the main screen and the clock is updated

[NiLuJe]

Yep, that's the expected behavior on all counts .

[jamalau]

Hello, with v0.9.10 i cannot use my own config in .adds/nanoclock/nanoclick.ini
I think ther is a standard conf in use!
If i install v0.9.9 without to change anything, my own ini works fine!
What can i do?

[NiLuJe]

@jamalau: Any setting in particular?

(The only change between 0.9.9 and 0.9.10 is that truetype_format inherits the *default* format value instead of the user's. That was possibly somewhat ill-advised ^^).