tree 3b8aaaa1c2eddfdda141d86ad261383c4c54a416
parent cddc5cda875b2eea7dc3fbf0a2be0c1a9edd2b3a
author Ewout van Bekkum <ewout@google.com> 1611889083 -0800
committer CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com> 1611971288 +0000

pw_chrono: Improve SystemClock C API

Changes the SystemClock C Api to:
1) Use a pw_chrono_SystemClock_Duration struct instead of aliasing
   an int64_t under pw_chrono_SystemClock_TickCount which could
   accidentally permit direct tick usage.
2) Add PW_SYSTEM_CLOCK_{MS,S,MIN,H} and
   PW_SYSTEM_CLOCK_{MS,S,MIN,H}_CEIL to permit C API users to
   create durations which round up to the nearest tick for deadlines
   and timeouts, mirroring std::chrono::ceil.
3) Add PW_SYSTEM_CLOCK_{MS,S,MIN,H}_FLOOR to permit C API users to
   create durations which round down to the nearest tick for oddball
   corner cases, mirroring std::chrono::floor.
4) In order to enable said macros, the system_clock_config.h backend
   config was changed to require the clock period as a preprocessor
   defines instead of a std::ratio<>.
5) Renames pw_chrono_SystemClock_TimeDelta to
   pw_chrono_SystemClock_TimeElapsed to make the argument ordering
   make more sense.
6) Changes existing std::chrono::duration_cast usage to
   std::chrono::ceil and std::chrono:floor to set a good example
   to be explicit on rounding.
7) Renames pw_chrono_SystemClock_TickCountsToNsTruncate accordingly to
   pw_chrono_SystemClock_DurationToNsFloor.

Requires: pigweed-internal:9340
Change-Id: Ia628dceac53f964eda7c4aacd3d790b8b0e92207
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/31280
Commit-Queue: Ewout van Bekkum <ewout@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>