Re-enable Dart_Api Timeline tracing

runtime/vm/timeline.cc

Index: runtime/vm/timeline.cc
diff --git a/runtime/vm/timeline.cc b/runtime/vm/timeline.cc
index 64c71271d21da9075437233e745fdfb578907b47..76d4729f914ec100343022b0adae14bad41b8b7c 100644
--- a/runtime/vm/timeline.cc
+++ b/runtime/vm/timeline.cc
@@ -80,12 +80,10 @@ void Timeline::InitOnce() {
   } else if (use_ring_recorder) {
     recorder_ = new TimelineEventRingRecorder();
   }
-  vm_stream_ = new TimelineStream();
-  vm_stream_->Init("VM", EnableStreamByDefault("VM"), NULL);
-  vm_api_stream_ = new TimelineStream();
-  vm_api_stream_->Init("API",
-                       EnableStreamByDefault("API"),
-                       &stream_API_enabled_);
+  vm_stream_.Init("VM", EnableStreamByDefault("VM"), NULL);
+  vm_api_stream_.Init("API",
+                      EnableStreamByDefault("API"),
+                      &stream_API_enabled_);
   // Global overrides.
 #define ISOLATE_TIMELINE_STREAM_FLAG_DEFAULT(name, not_used)                   \
   stream_##name##_enabled_ = EnableStreamByDefault(#name);
@@ -99,12 +97,15 @@ void Timeline::Shutdown() {
   if (FLAG_timeline_dir != NULL) {
     recorder_->WriteTo(FLAG_timeline_dir);
   }
+  // Disable global streams.
+  vm_stream_.set_enabled(false);
+  vm_api_stream_.set_enabled(false);
+#define ISOLATE_TIMELINE_STREAM_DISABLE(name, not_used)                   \
+  stream_##name##_enabled_ = false;
+  ISOLATE_TIMELINE_STREAM_LIST(ISOLATE_TIMELINE_STREAM_DISABLE)
+#undef ISOLATE_TIMELINE_STREAM_DISABLE
   delete recorder_;

[Florian Schneider, 2016/01/15 15:48:26]

Make sure that the deletion of recorder_ safe here? Maybe it can also have
static lifetime?

[Cutch, 2016/01/15 17:35:49]

It can't have a static lifetime because there are multiple implementations of
it. Nothing will touch the recorder after the streams are disabled. Also, note
that all isolates have stopped running before this code runs.

   recorder_ = NULL;
-  delete vm_stream_;
-  vm_stream_ = NULL;
-  delete vm_api_stream_;
-  vm_api_stream_ = NULL;
 }
 
 
@@ -120,14 +121,12 @@ bool Timeline::EnableStreamByDefault(const char* stream_name) {
 
 
 TimelineStream* Timeline::GetVMStream() {
-  ASSERT(vm_stream_ != NULL);
-  return vm_stream_;
+  return &vm_stream_;
 }
 
 
 TimelineStream* Timeline::GetVMApiStream() {
-  ASSERT(vm_api_stream_ != NULL);
-  return vm_api_stream_;
+  return &vm_api_stream_;
 }
 
 
@@ -164,8 +163,8 @@ void Timeline::Clear() {
 
 
 TimelineEventRecorder* Timeline::recorder_ = NULL;
-TimelineStream* Timeline::vm_stream_ = NULL;
-TimelineStream* Timeline::vm_api_stream_ = NULL;
+TimelineStream Timeline::vm_stream_;
+TimelineStream Timeline::vm_api_stream_;
 
 #define ISOLATE_TIMELINE_STREAM_DEFINE_FLAG(name, enabled_by_default)          \
   bool Timeline::stream_##name##_enabled_ = enabled_by_default;