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.
104 lines
3.6 KiB
104 lines
3.6 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 a custom tracing data source.
|
|
|
|
#include <perfetto.h>
|
|
|
|
#include <fstream>
|
|
#include <thread>
|
|
|
|
// The definition of our custom data source. Instances of this class will be
|
|
// automatically created and destroyed by Perfetto.
|
|
class CustomDataSource : public perfetto::DataSource<CustomDataSource> {
|
|
public:
|
|
void OnSetup(const SetupArgs&) override {
|
|
// Use this callback to apply any custom configuration to your data source
|
|
// based on the TraceConfig in SetupArgs.
|
|
}
|
|
|
|
// Optional callbacks for tracking the lifecycle of the data source.
|
|
void OnStart(const StartArgs&) override {}
|
|
void OnStop(const StopArgs&) override {}
|
|
};
|
|
|
|
PERFETTO_DECLARE_DATA_SOURCE_STATIC_MEMBERS(CustomDataSource);
|
|
PERFETTO_DEFINE_DATA_SOURCE_STATIC_MEMBERS(CustomDataSource);
|
|
|
|
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);
|
|
|
|
// Register our custom data source. Only the name is required, but other
|
|
// properties can be advertised too.
|
|
perfetto::DataSourceDescriptor dsd;
|
|
dsd.set_name("com.example.custom_data_source");
|
|
CustomDataSource::Register(dsd);
|
|
}
|
|
|
|
std::unique_ptr<perfetto::TracingSession> StartTracing() {
|
|
// The trace config defines which types of data sources are enabled for
|
|
// recording. In this example we enable the custom data source we registered
|
|
// above.
|
|
perfetto::TraceConfig cfg;
|
|
cfg.add_buffers()->set_size_kb(1024);
|
|
auto* ds_cfg = cfg.add_data_sources()->mutable_config();
|
|
ds_cfg->set_name("com.example.custom_data_source");
|
|
|
|
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) {
|
|
// Flush to make sure the last written event ends up in the trace.
|
|
CustomDataSource::Trace(
|
|
[](CustomDataSource::TraceContext ctx) { ctx.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_custom_data_source.pftrace",
|
|
std::ios::out | std::ios::binary);
|
|
output.write(&trace_data[0], trace_data.size());
|
|
output.close();
|
|
}
|
|
|
|
int main(int, const char**) {
|
|
InitializePerfetto();
|
|
auto tracing_session = StartTracing();
|
|
|
|
// Write an event using our custom data source.
|
|
CustomDataSource::Trace([](CustomDataSource::TraceContext ctx) {
|
|
auto packet = ctx.NewTracePacket();
|
|
packet->set_timestamp(42);
|
|
packet->set_for_testing()->set_str("Hello world!");
|
|
});
|
|
|
|
StopTracing(std::move(tracing_session));
|
|
return 0;
|
|
}
|