Re-enable Dart_Api Timeline tracing

runtime/vm/timeline.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <cstdlib>
 
 #include "vm/atomic.h"
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/lockers.h"
@@ skipping 62 matching lines @@
   // Default to ring recorder being enabled.
   const bool use_ring_recorder = true;
   // Some flags require that we use the endless recorder.
   const bool use_endless_recorder =
       (FLAG_timeline_dir != NULL) || FLAG_timing || FLAG_complete_timeline;
   if (use_endless_recorder) {
     recorder_ = new TimelineEventEndlessRecorder();
   } 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);
   ISOLATE_TIMELINE_STREAM_LIST(ISOLATE_TIMELINE_STREAM_FLAG_DEFAULT)
 #undef ISOLATE_TIMELINE_STREAM_FLAG_DEFAULT
 }
 
 
 void Timeline::Shutdown() {
   ASSERT(recorder_ != NULL);
   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;
 }
 
 
 TimelineEventRecorder* Timeline::recorder() {
   return recorder_;
 }
 
 
 bool Timeline::EnableStreamByDefault(const char* stream_name) {
   // TODO(johnmccutchan): Allow for command line control over streams.
   return (FLAG_timeline_dir != NULL) || FLAG_timing || FLAG_complete_timeline;
 }
 
 
 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_;
 }
 
 
 void Timeline::ReclaimCachedBlocksFromThreads() {
   TimelineEventRecorder* recorder = Timeline::recorder();
   if (recorder == NULL) {
     return;
   }
 
   // Iterate over threads.
@@ skipping 16 matching lines @@
   TimelineEventRecorder* recorder = Timeline::recorder();
   if (recorder == NULL) {
     return;
   }
   ReclaimCachedBlocksFromThreads();
   recorder->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;
   ISOLATE_TIMELINE_STREAM_LIST(ISOLATE_TIMELINE_STREAM_DEFINE_FLAG)
 #undef ISOLATE_TIMELINE_STREAM_DEFINE_FLAG
 
 TimelineEvent::TimelineEvent()
     : timestamp0_(0),
       timestamp1_(0),
       arguments_(NULL),
@@ skipping 1140 matching lines @@
 
 
 TimelineEventBlock* TimelineEventBlockIterator::Next() {
   ASSERT(current_ != NULL);
   TimelineEventBlock* r = current_;
   current_ = current_->next();
   return r;
 }
 
 }  // namespace dart