| // Copyright 2023 The ChromiumOS Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef LIBBRILLO_BRILLO_TRACING_H_ |
| #define LIBBRILLO_BRILLO_TRACING_H_ |
| |
| #include <brillo/brillo_export.h> |
| |
| namespace brillo { |
| |
| // Enables Perfetto tracing by connecting to the system tracing service |
| // (traced). After this, track events (`TRACE_EVENT`) in the calling process |
| // will be recorded into future tracing sessions that have the track event data |
| // source enabled. Use https://ui.perfetto.dev to start tracing sessions and |
| // view recorded traces. Traces can also be recorded using the `perfetto` |
| // command line tool. |
| // |
| // By default, just built-in events from libchrome will be recorded. To add your |
| // own events: |
| // |
| // 1. Define tracing categories (in a header file): |
| // |
| // #include <perfetto/perfetto.h> |
| // |
| // PERFETTO_DEFINE_CATEGORIES_IN_NAMESPACE( |
| // my_namespace, |
| // perfetto::Category("foo") |
| // .SetDescription("Events from the Foo subsystem")); |
| // |
| // 2. Initialize tracing and register your categories (in a .cc file): |
| // |
| // PERFETTO_TRACK_EVENT_STATIC_STORAGE_IN_NAMESPACE(my_namespace); |
| // |
| // void Init() { |
| // brillo::InitPerfettoTracing(); |
| // my_namespace::TrackEvent::Register(); |
| // } |
| // |
| // 3. Instrument your code with events: |
| // |
| // namespace my_namespace { |
| // |
| // void FooOperation(int x, int y) { |
| // TRACE_EVENT("foo", "FooOperation", "x", x, "y", y); |
| // ... |
| // } |
| // |
| // } // namespace my_namespace |
| // |
| // See https://perfetto.dev/docs/instrumentation/track-events for more. |
| // |
| BRILLO_EXPORT void InitPerfettoTracing(); |
| |
| } // namespace brillo |
| |
| #endif // LIBBRILLO_BRILLO_TRACING_H_ |
