You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
102 lines
3.4 KiB
102 lines
3.4 KiB
/*
|
|
* 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 demonstrates in-process tracing with Perfetto.
|
|
|
|
#include "trace_categories.h"
|
|
|
|
#include <chrono>
|
|
#include <fstream>
|
|
#include <thread>
|
|
|
|
void InitializePerfetto() {
|
|
perfetto::TracingInitArgs args;
|
|
// The backends determine where trace events are recorded. For this example we
|
|
// are going to use the in-process tracing service, which only includes in-app
|
|
// events.
|
|
args.backends = perfetto::kInProcessBackend;
|
|
|
|
perfetto::Tracing::Initialize(args);
|
|
perfetto::TrackEvent::Register();
|
|
}
|
|
|
|
std::unique_ptr<perfetto::TracingSession> StartTracing() {
|
|
// The trace config defines which types of data sources are enabled for
|
|
// recording. In this example we just need the "track_event" data source,
|
|
// which corresponds to the TRACE_EVENT trace points.
|
|
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");
|
|
|
|
auto tracing_session = perfetto::Tracing::NewTrace();
|
|
tracing_session->Setup(cfg);
|
|
tracing_session->StartBlocking();
|
|
return tracing_session;
|
|
}
|
|
|
|
void StopTracing(std::unique_ptr<perfetto::TracingSession> tracing_session) {
|
|
// Make sure the last event is closed for this example.
|
|
perfetto::TrackEvent::Flush();
|
|
|
|
// Stop tracing and read the trace data.
|
|
tracing_session->StopBlocking();
|
|
std::vector<char> trace_data(tracing_session->ReadTraceBlocking());
|
|
|
|
// Write the result into a file.
|
|
// Note: To save memory with longer traces, you can tell Perfetto to write
|
|
// directly into a file by passing a file descriptor into Setup() above.
|
|
std::ofstream output;
|
|
output.open("example.pftrace", std::ios::out | std::ios::binary);
|
|
output.write(&trace_data[0], trace_data.size());
|
|
output.close();
|
|
}
|
|
|
|
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");
|
|
|
|
// Record the rendering framerate as a counter sample.
|
|
TRACE_COUNTER("rendering", "Framerate", 120);
|
|
}
|
|
|
|
int main(int, const char**) {
|
|
InitializePerfetto();
|
|
auto tracing_session = StartTracing();
|
|
|
|
// Give a custom name for the traced process.
|
|
perfetto::ProcessTrack process_track = perfetto::ProcessTrack::Current();
|
|
perfetto::protos::gen::TrackDescriptor desc = process_track.Serialize();
|
|
desc.mutable_process()->set_process_name("Example");
|
|
perfetto::TrackEvent::SetTrackDescriptor(process_track, desc);
|
|
|
|
// Simulate some work that emits trace events.
|
|
DrawGame();
|
|
|
|
StopTracing(std::move(tracing_session));
|
|
return 0;
|
|
}
|