third_party/perfetto/examples/sdk/example_console.cc

/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// This example shows how to log trace events to the console using the console
// interceptor.

#include "trace_categories.h"

#include <chrono>
#include <thread>

void InitializePerfetto() {
  perfetto::TracingInitArgs args;
  args.backends = perfetto::kInProcessBackend;
  perfetto::Tracing::Initialize(args);
  perfetto::TrackEvent::Register();
  perfetto::ConsoleInterceptor::Register();
}

std::unique_ptr<perfetto::TracingSession> StartTracing() {
  perfetto::TraceConfig cfg;
  cfg.add_buffers()->set_size_kb(1024);
  auto* ds_cfg = cfg.add_data_sources()->mutable_config();
  ds_cfg->set_name("track_event");

  // Enable the console interceptor.
  ds_cfg->mutable_interceptor_config()->set_name("console");

  auto tracing_session = perfetto::Tracing::NewTrace();
  tracing_session->Setup(cfg);
  tracing_session->StartBlocking();
  return tracing_session;
}

void DrawPlayer(int player_number) {
  TRACE_EVENT("rendering", "DrawPlayer", "player_number", player_number);
  // Sleep to simulate a long computation.
  std::this_thread::sleep_for(std::chrono::milliseconds(500));
}

void DrawGame() {
  // This is an example of an unscoped slice, which begins and ends at specific
  // points (instead of at the end of the current block scope).
  TRACE_EVENT_BEGIN("rendering", "DrawGame");
  DrawPlayer(1);
  DrawPlayer(2);
  TRACE_EVENT_END("rendering");
}

int main(int, const char**) {
  InitializePerfetto();
  auto tracing_session = StartTracing();

  // Simulate some work that emits trace events.
  DrawGame();

  tracing_session->StopBlocking();
  return 0;
}