Reland "[tracing] Add a configurable output stream for perfetto tracing"

This is a reland of a03ed626

Removed the added test which was failing on win32. The test was unrelated
to the CL; we can add it later.

Original change's description:
> [tracing] Add a configurable output stream for perfetto tracing
>
> Add the ability to provide perfetto with an output stream for the JSON
> consumer rather than hardcode it. D8 will use this interface exclusively
> once the old trace controller is removed.
>
> Also add a test for scope-managed trace events and their duration - this
> was leftover from a previous CL.
>
> Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
> Bug: v8:8339
> Change-Id: I1c45e17e528b549a4cfdaecabd33c7ac4ab4af77
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1611801
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Peter Marshall <petermarshall@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61753}

TBR=jgruber@chromium.org, ulan@chromium.org

Bug: v8:8339
Change-Id: I3442a4d111e12947c107e7d0c226ae934acd06e4
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627334Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61780}

include/libplatform/v8-tracing.h

@@ -240,6 +240,11 @@ class V8_PLATFORM_EXPORT TracingController
   TracingController();
   ~TracingController() override;
   void Initialize(TraceBuffer* trace_buffer);
+#ifdef V8_USE_PERFETTO
+  // Must be called before StartTracing() if V8_USE_PERFETTO is true. Provides
+  // the output stream for the JSON trace data.
+  void InitializeForPerfetto(std::ostream* output_stream);
+#endif
 
   // v8::TracingController implementation.
   const uint8_t* GetCategoryGroupEnabled(const char* category_group) override;
@@ -285,6 +290,7 @@ class V8_PLATFORM_EXPORT TracingController
 #ifdef V8_USE_PERFETTO
   std::atomic_bool perfetto_recording_{false};
   std::unique_ptr<PerfettoTracingController> perfetto_tracing_controller_;
+  std::ostream* output_stream_ = nullptr;
 #endif
 
   // Disallow copy and assign

src/d8/d8.cc

@@ -3323,7 +3323,6 @@ void Shell::CleanupWorkers() {
 }
 
 int Shell::Main(int argc, char* argv[]) {
-  std::ofstream trace_file;
   v8::base::EnsureConsoleOutput();
   if (!SetOptions(argc, argv)) return 1;
   v8::V8::InitializeICUDefaultLocation(argv[0], options.icu_data_file);
@@ -3334,15 +3333,26 @@ int Shell::Main(int argc, char* argv[]) {
           : v8::platform::InProcessStackDumping::kEnabled;
 
   std::unique_ptr<platform::tracing::TracingController> tracing;
+  std::ofstream trace_file;
+#ifdef V8_USE_PERFETTO
+  std::ofstream perfetto_trace_file;
+#endif  // V8_USE_PERFETTO
   if (options.trace_enabled && !i::FLAG_verify_predictable) {
     tracing = base::make_unique<platform::tracing::TracingController>();
 
     trace_file.open(options.trace_path ? options.trace_path : "v8_trace.json");
+    DCHECK(trace_file.good());
     platform::tracing::TraceBuffer* trace_buffer =
         platform::tracing::TraceBuffer::CreateTraceBufferRingBuffer(
             platform::tracing::TraceBuffer::kRingBufferChunks,
             platform::tracing::TraceWriter::CreateJSONTraceWriter(trace_file));
     tracing->Initialize(trace_buffer);
+
+#ifdef V8_USE_PERFETTO
+    perfetto_trace_file.open("v8_perfetto_trace.json");
+    DCHECK(trace_file.good());
+    tracing->InitializeForPerfetto(&perfetto_trace_file);
+#endif  // V8_USE_PERFETTO
   }
 
   platform::tracing::TracingController* tracing_controller = tracing.get();
@@ -3529,6 +3539,9 @@ int Shell::Main(int argc, char* argv[]) {
 
   // Delete the platform explicitly here to write the tracing output to the
   // tracing file.
+  if (options.trace_enabled) {
+    tracing_controller->StopTracing();
+  }
   g_platform.reset();
   return result;
 }

src/libplatform/tracing/perfetto-tracing-controller.cc

@@ -22,16 +22,15 @@ PerfettoTracingController::PerfettoTracingController()
       consumer_finished_semaphore_(0) {}
 
 void PerfettoTracingController::StartTracing(
-    const ::perfetto::TraceConfig& trace_config) {
-  DCHECK(!trace_file_.is_open());
-  trace_file_.open("v8_perfetto_trace.json");
-  CHECK(trace_file_.good());
+    const ::perfetto::TraceConfig& trace_config, std::ostream* output_stream) {
+  DCHECK_NOT_NULL(output_stream);
+  DCHECK(output_stream->good());
 
   DCHECK(!task_runner_);
   task_runner_ = base::make_unique<PerfettoTaskRunner>();
   // The Perfetto service expects calls on the task runner thread which is why
   // the setup below occurs in posted tasks.
-  task_runner_->PostTask([&trace_config, this] {
+  task_runner_->PostTask([&trace_config, output_stream, this] {
     std::unique_ptr<::perfetto::SharedMemory::Factory> shmem_factory =
         base::make_unique<PerfettoSharedMemoryFactory>();
 
@@ -46,7 +45,7 @@ void PerfettoTracingController::StartTracing(
     service_->SetSMBScrapingEnabled(true);
     producer_ = base::make_unique<PerfettoProducer>(this);
     consumer_ = base::make_unique<PerfettoJSONConsumer>(
-        &trace_file_, &consumer_finished_semaphore_);
+        output_stream, &consumer_finished_semaphore_);
 
     producer_->set_service_endpoint(service_->ConnectProducer(
         producer_.get(), 0, "v8.perfetto-producer", 0, true));
@@ -90,9 +89,6 @@ void PerfettoTracingController::StopTracing() {
   // Finish the above task, and any callbacks that were triggered.
   task_runner_->FinishImmediateTasks();
   task_runner_.reset();
-
-  DCHECK(trace_file_.is_open());
-  trace_file_.close();
 }
 
 PerfettoTracingController::~PerfettoTracingController() {

src/libplatform/tracing/perfetto-tracing-controller.h

@@ -37,8 +37,10 @@ class PerfettoTracingController {
 
   // Blocks and sets up all required data structures for tracing. It is safe to
   // call GetOrCreateThreadLocalWriter() to obtain thread-local TraceWriters for
-  // writing trace events once this call returns.
-  void StartTracing(const ::perfetto::TraceConfig& trace_config);
+  // writing trace events once this call returns. Tracing output will be sent in
+  // JSON format to |output_stream|.
+  void StartTracing(const ::perfetto::TraceConfig& trace_config,
+                    std::ostream* output_stream);
 
   // Blocks and finishes all existing AddTraceEvent tasks. Stops the tracing
   // thread.
@@ -68,9 +70,6 @@ class PerfettoTracingController {
   base::Semaphore producer_ready_semaphore_;
   base::Semaphore consumer_finished_semaphore_;
 
-  // TODO(petermarshall): pass this in instead.
-  std::ofstream trace_file_;
-
   DISALLOW_COPY_AND_ASSIGN(PerfettoTracingController);
 };
 

src/libplatform/tracing/tracing-controller.cc

@@ -73,6 +73,14 @@ void TracingController::Initialize(TraceBuffer* trace_buffer) {
   mutex_.reset(new base::Mutex());
 }
 
+#ifdef V8_USE_PERFETTO
+void TracingController::InitializeForPerfetto(std::ostream* output_stream) {
+  output_stream_ = output_stream;
+  DCHECK_NOT_NULL(output_stream);
+  DCHECK(output_stream->good());
+}
+#endif
+
 int64_t TracingController::CurrentTimestampMicroseconds() {
   return base::TimeTicks::HighResolutionNow().ToInternalValue();
 }
@@ -271,8 +279,12 @@ void TracingController::StartTracing(TraceConfig* trace_config) {
   auto* ds_config = perfetto_trace_config.add_data_sources()->mutable_config();
   ds_config->set_name("v8.trace_events");
 
+  DCHECK_NOT_NULL(output_stream_);
+  DCHECK(output_stream_->good());
+
   // TODO(petermarshall): Set all the params from |perfetto_trace_config|.
-  perfetto_tracing_controller_->StartTracing(perfetto_trace_config);
+  perfetto_tracing_controller_->StartTracing(perfetto_trace_config,
+                                             output_stream_);
   perfetto_recording_.store(true);
 #endif  // V8_USE_PERFETTO
 

test/cctest/test-cpu-profiler.cc

@@ -2665,6 +2665,11 @@ TEST(TracingCpuProfiler) {
           i::V8::GetCurrentPlatform()->GetTracingController());
   tracing_controller->Initialize(ring_buffer);
 
+#ifdef V8_USE_PERFETTO
+  std::ostringstream perfetto_output;
+  tracing_controller->InitializeForPerfetto(&perfetto_output);
+#endif
+
   bool result = false;
   for (int run_duration = 50; !result; run_duration += 50) {
     TraceConfig* trace_config = new TraceConfig();