[Tracing] Fix runtime call stats tracing for GC.

src/heap/gc-tracer.cc

Index: src/heap/gc-tracer.cc
diff --git a/src/heap/gc-tracer.cc b/src/heap/gc-tracer.cc
index 706d3546a2c5d574d7224e118395ca5c81ff6691..f90988cc2aeaa1b2ed27e5192ceb4a7bc35efb27 100644
--- a/src/heap/gc-tracer.cc
+++ b/src/heap/gc-tracer.cc
@@ -24,24 +24,30 @@ static intptr_t CountTotalHolesSize(Heap* heap) {
 GCTracer::Scope::Scope(GCTracer* tracer, ScopeId scope)
     : tracer_(tracer), scope_(scope) {
   start_time_ = tracer_->heap_->MonotonicallyIncreasingTimeInMs();
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Enter(
+        tracer_->heap_->isolate()->counters()->tracing_runtime_call_stats(),

[ulan, 2016/09/08 12:03:37]

Naive question: why can't we use the same counter for tracing runtime calls and
ordinary runtime calls?

They seem to be mutually exclusive.

[Camillo Bruni, 2016/09/08 15:47:52]

You're right. Previously they weren't mutually exclusive which would have
justified the separate counter lists.

[lpy, 2016/09/08 18:23:53]

Done.

[lpy, 2016/09/08 18:23:53]

right, this is also what fmeawad@ is suggesting. Done.

+        &timer_, &RuntimeCallStats::GC);

[fmeawad, 2016/09/07 17:31:28]

This code is repeated 2 times, should we move it to counters?

[lpy, 2016/09/08 18:23:53]

I don't think we should make another enter and leave in counter.

+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Enter(
         tracer_->heap_->isolate()->counters()->runtime_call_stats(), &timer_,
         &RuntimeCallStats::GC);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }
 
 GCTracer::Scope::~Scope() {
   tracer_->AddScopeSample(
       scope_, tracer_->heap_->MonotonicallyIncreasingTimeInMs() - start_time_);
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Leave(
+        tracer_->heap_->isolate()->counters()->tracing_runtime_call_stats(),
+        &timer_);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Leave(
         tracer_->heap_->isolate()->counters()->runtime_call_stats(), &timer_);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }
 
 const char* GCTracer::Scope::Name(ScopeId id) {
@@ -216,12 +222,15 @@ void GCTracer::Start(GarbageCollector collector,
   counters->aggregated_memory_heap_committed()->AddSample(start_time,
                                                           committed_memory);
   counters->aggregated_memory_heap_used()->AddSample(start_time, used_memory);
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Enter(
+        heap_->isolate()->counters()->tracing_runtime_call_stats(), &timer_,
+        &RuntimeCallStats::GC);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Enter(heap_->isolate()->counters()->runtime_call_stats(),
                             &timer_, &RuntimeCallStats::GC);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }
 
 void GCTracer::MergeBaseline(const Event& baseline) {
@@ -322,12 +331,14 @@ void GCTracer::Stop(GarbageCollector collector) {
     heap_->PrintShortHeapStatistics();
   }
 
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Leave(
+        heap_->isolate()->counters()->tracing_runtime_call_stats(), &timer_);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Leave(heap_->isolate()->counters()->runtime_call_stats(),
                             &timer_);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }