tree 2591a6639da2b8b039f953190432dae004a6cebf
parent e8843ab060ace3825760ba24e55164440e58c93e
author Sami Kyostila <skyostil@google.com> 1571934975 +0100
committer Sami Kyostila <skyostil@google.com> 1571934975 +0100

TrackEvent: Add support for dynamically enabled tracing categories

This patch introduces support for annotating track events with named
tracing categories. Each category can be individually enabled or
disabled using a trace config.

The set of categories is defined at compile time using a macro:

  PERFETTO_DEFINE_CATEGORIES(
      PERFETTO_CATEGORY(cat1),
      PERFETTO_CATEGORY(cat2),
      PERFETTO_CATEGORY(cat3));

We also introduce a set of macros for efficiently emitting track events
with category annotation:

  TRACE_EVENT_BEGIN("cat1", "EventName");
  TRACE_EVENT_END();

The trace point implementation replaces the per-data source instance
enable bitmap with a per-category bitmap in order to avoid doing any
extra work for categories that aren't enabled for tracing.

Bug: 132678367
Change-Id: I84cdb13fc2608a23f311f49a3402640c92199909