Mahdi ramezaan zaadeandAlexander Medvednikov
eb973b8757
* trace: add span tracer with aggregates and Chrome export (fixes #30343) * Address independent review edge cases for #30416 * Complete validation and formatting for #30416 --------- Co-authored-by: Alexander Medvednikov <alexander@medvednikov.com>
Description
trace records manual spans using the monotonic clock. Create a tracer with new_tracer(),
open a span with tracer.span(name), and call span.end() when the operation finishes.
The same span instance ignores repeated end() calls; copies have independent completion state
and should not both be ended. A span records the thread where it started, even if ended elsewhere.
report() returns per-name counts and total, average, and maximum durations in nanoseconds,
sorted by total duration. to_chrome_trace() exports completed spans as Chrome trace-event JSON
for Perfetto or Chrome tracing, with microsecond timestamps and durations.
event_count() counts completed spans. reset() clears recorded events and aggregates; spans
that remain open can still record when ended.
The tracer synchronizes its shared aggregates and event log. A span instance itself must be ended by one caller at a time. The log retains every completed event until reset and does not perform sampling or allocation tracking.