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>
Adds the BinarySemaphore, CountingSemaphore, and Mutex to the
pw_sync module along with an STL backend for each.
Change-Id: I54a3a64e702202a319ed2c9068bf37412d3fd240
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/24241
Reviewed-by: Ewout van Bekkum <ewout@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
Reviewed-by: Keir Mierle <keir@google.com>
Commit-Queue: Ewout van Bekkum <ewout@google.com>
