polledTimeout: add option to use CPU count instead of millis()

[d-a-v]

No description provided.

[earlephilhower]

Is there some way to check for an overflow timeout when using CPU cycles?

[devyte]

As a general question: what is the use case? I see two slight advantages and one big disadvantage of the enhancement:
Pros:

• better precision for detection of expiration (1 cycle is a fraction of a ns, vs. 1ms for millis)
• faster polling (the code is lighter, so a for() or while() loop will run faster and hence poll at a higher frequency

Con:

• Rollover time is drastically reduced from something like several days to a minute or so for 80MHz, and half that for 160MHz.

Neither Pro nor Con:

• CPU busy waiting will be more or less the same
• Power usage will be more or less the same
• Usage is the same

[d-a-v]

Is there some way to check for an overflow timeout when using CPU cycles?

I'm afraid not.

rollover is 26 seconds @160Mhz. timeMax() is introduced, set to 13s. (or 26 @80Mhz)
comments added.

Misleading type names are removed (YieldOrSkip).
Unclear names *Cpu are renamed do *CycleMs so it now clearly needs milliseconds.

Con:

• Rollover time is drastically reduced from something like several days to a minute or so for 80MHz, and half that for 160MHz.

Yes, comments are added to use it only when it is known to be checked often

*Neither Pro nor Con:

• CPU busy waiting will be more or less the same
• Power usage will be more or less the same

Yes, it is not intended for busy waiting but for periodic testing only. Maybe I should remove oneShotCycleMs ?

• Usage is the same

This is a Pro :)

About performance, millis() uses 356 cpu cycles, while the other one only 3 or 4 cpu cycles.
I intend to extend ScheduleFunctions with periodic calls. Periodicity will also optionally be checked from inside yield() (only from cont stack of course). I could'nt resolve me to use phat millis() there, at every yield/loop. CycleMs does the same job about 100 times faster.

[devyte]

That off-by-one is the last thing, but I'm not sure how to fix it.

[devyte]

Done! Great job :)