Record Timeline to Android Systrace

runtime/vm/timeline.h

 // 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.
 
 #ifndef VM_TIMELINE_H_
 #define VM_TIMELINE_H_
 
 #include "include/dart_tools_api.h"
 
 #include "vm/allocation.h"
@@ skipping 324 matching lines @@
 
   bool Within(int64_t time_origin_micros,
               int64_t time_extent_micros);
 
   const char* GetSerializedJSON() const;
 
   void set_owns_label(bool owns_label) {
     state_ = OwnsLabelBit::update(owns_label, state_);
   }
 
+  // Returns the number of bytes written into |buffer|.
+  intptr_t PrintSystrace(char* buffer, intptr_t buffer_size);
+
  private:
   void FreeArguments();
 
   void StreamInit(TimelineStream* stream);
   void Init(EventType event_type, const char* label);
 
   void set_event_type(EventType event_type) {
     // We only reserve 4 bits to hold the event type.
     COMPILE_ASSERT(kNumEventTypes < 16);
     state_ = EventTypeField::update(event_type, state_);
@@ skipping 51 matching lines @@
   uword state_;
   const char* label_;
   const char* category_;
   ThreadId thread_;
   Dart_Port isolate_id_;
 
   friend class TimelineEventRecorder;
   friend class TimelineEventEndlessRecorder;
   friend class TimelineEventRingRecorder;
   friend class TimelineEventStartupRecorder;
+  friend class TimelineEventSystraceRecorder;
   friend class TimelineStream;
   friend class TimelineTestHelper;
   DISALLOW_COPY_AND_ASSIGN(TimelineEvent);
 };
 
 
 #ifndef PRODUCT
 #define TIMELINE_FUNCTION_COMPILATION_DURATION(thread, name, function)         \
   TimelineDurationScope tds(thread,                                            \
                             Timeline::GetCompilerStream(),                     \
@@ skipping 189 matching lines @@
   bool in_use_;
 
   void Open();
   void Finish();
 
   friend class Thread;
   friend class TimelineEventRecorder;
   friend class TimelineEventEndlessRecorder;
   friend class TimelineEventRingRecorder;
   friend class TimelineEventStartupRecorder;
+  friend class TimelineEventSystraceRecorder;
   friend class TimelineTestHelper;
   friend class JSONStream;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TimelineEventBlock);
 };
 
 
 class TimelineEventFilter : public ValueObject {
  public:
@@ skipping 144 matching lines @@
 
   const char* name() const {
     return "Ring";
   }
 
  protected:
   TimelineEventBlock* GetNewBlockLocked();
 };
 
 
+// A recorder that writes events to Android Systrace. Events are also stored in
+// a buffer of fixed capacity. When the buffer is full, new events overwrite
+// old events.
+class TimelineEventSystraceRecorder
+    : public TimelineEventFixedBufferRecorder {
+ public:
+  explicit TimelineEventSystraceRecorder(intptr_t capacity = kDefaultCapacity);
+
+  ~TimelineEventSystraceRecorder();
+
+  const char* name() const {
+    return "Systrace";
+  }
+
+ protected:
+  TimelineEventBlock* GetNewBlockLocked();
+  void CompleteEvent(TimelineEvent* event);
+
+  int systrace_fd_;

[Chinmay, 2016/09/08 17:58:11]

Should this be private? Along with the usual `DISALLOW_COPY_AND_ASSIGN`
decoration on the class.

[Cutch, 2016/09/08 18:06:10]

The base class has the decoration.

+};
+
+
 // A recorder that stores events in a buffer of fixed capacity. When the buffer
 // is full, new events are dropped.
 class TimelineEventStartupRecorder : public TimelineEventFixedBufferRecorder {
  public:
   explicit TimelineEventStartupRecorder(intptr_t capacity = kDefaultCapacity)
       : TimelineEventFixedBufferRecorder(capacity) {}
   ~TimelineEventStartupRecorder() {}
 
   const char* name() const {
     return "Startup";
@@ skipping 82 matching lines @@
 
  private:
   TimelineEventBlock* current_;
   TimelineEventRecorder* recorder_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_TIMELINE_H_