Commit Graph

11 Commits

Author SHA1 Message Date
Tom Collins 145796f037 py,extmod: Some casts and minor refactors to quiet compiler warnings. 2017-07-07 11:32:22 +10:00
Damien George 2e3fc77809 extmod/utime_mphal: Don't exit/enter the GIL in generic sleep functions.
GIL behaviour should be handled by the port.  And ports probably want to
define sleep_us so that it doesn't release the GIL, to improve timing
accuracy.
2017-03-22 12:49:21 +11:00
Paul Sokolovsky 9b345a9e48 extmod/utime_mphal: ticks_diff/ticks_add: Don't hardcode 32-bit types.
Use normal mp_int_t/mp_uint_t types, algorithms (hm, formulas) can work
with any type width.
2016-11-03 23:54:16 +03:00
Paul Sokolovsky 10bde6933e extmod/utime_mphal: ticks_diff(): Optimize to avoid if conditions. 2016-11-02 02:50:48 +03:00
Paul Sokolovsky e429daa572 extmod/utime_mphal: Fix implementation of new semantics of ticks_diff().
Now the function properly uses ring arithmetic to return signed value
in range (inclusive):
[-MICROPY_PY_UTIME_TICKS_PERIOD/2, MICROPY_PY_UTIME_TICKS_PERIOD/2-1].

That means that function can properly process 2 time values away from
each other within MICROPY_PY_UTIME_TICKS_PERIOD/2 ticks, but away in
both directions. For example, if tick value 'a' predates tick value 'b',
ticks_diff(a, b) will return negative value, and positive value otherwise.
But at positive value of MICROPY_PY_UTIME_TICKS_PERIOD/2-1, the result
of the function will wrap around to negative -MICROPY_PY_UTIME_TICKS_PERIOD/2,
in other words, if a follows b in more than MICROPY_PY_UTIME_TICKS_PERIOD/2 - 1
ticks, the function will "consider" a to actually predate b.
2016-10-30 03:07:22 +03:00
Paul Sokolovsky 76146b3d9a extmod/utime_mphal: Allow ticks functions period be configurable by a port.
Using MICROPY_PY_UTIME_TICKS_PERIOD config var.
2016-10-30 03:02:07 +03:00
Paul Sokolovsky d86cac4b82 extmod/utime_mphal: Implement ticks_add(), add to all maintained ports. 2016-10-29 17:30:05 +03:00
Paul Sokolovsky 6a87084019 extmod/utime_mphal: Add MP_THREAD_GIL_EXIT/ENTER warppers for sleep functions.
Ported from unix port.
2016-10-29 13:42:36 +03:00
Paul Sokolovsky 6ed5583f8c extmod/utime_mphal: ticks_diff(): switch arg order, return signed value.
Based on the earlier discussed RFC. Practice showed that the most natural
order for arguments corresponds to mathematical subtraction:

ticks_diff(x, y) <=> x - y

Also, practice showed that in real life, it's hard to order events by time
of occurance a priori, events tend to miss deadlines, etc. and the expected
order breaks. And then there's a need to detect such cases. And ticks_diff
can be used exactly for this purpose, if it returns a signed, instead of
unsigned, value. E.g. if x is scheduled time for event, and y is the current
time, then if ticks_diff(x, y) < 0 then event has missed a deadline (and e.g.
needs to executed ASAP or skipped). Returning in this case a large unsigned
number (like ticks_diff behaved previously) doesn't make sense, and such
"large unsigned number" can't be reliably detected per our definition of
ticks_* function (we don't expose to user level maximum value, it can be
anything, relatively small or relatively large).
2016-10-29 05:02:24 +03:00
Paul Sokolovsky 36f97f19b4 extmod/utime_mphal: sleep_us/ms(): Don't wait on negative argument. 2016-10-14 22:19:45 +03:00
Paul Sokolovsky a97284423e extmod/utime_mphal: Factor out implementations in terms of mp_hal_* for reuse.
As long as a port implement mp_hal_sleep_ms(), mp_hal_ticks_ms(), etc.
functions, it can just use standard implementations of utime.sleel_ms(),
utime.ticks_ms(), etc. Python-level functions.
2016-10-14 20:14:01 +03:00