Initial Timeline Events

runtime/vm/timeline.h

Index: runtime/vm/timeline.h
diff --git a/runtime/vm/timeline.h b/runtime/vm/timeline.h
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+++ b/runtime/vm/timeline.h
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+// 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 "vm/bitfield.h"
+
+namespace dart {
+
+class JSONStream;
+class Object;
+class RawArray;
+class Thread;
+class TimelineEvent;
+class TimelineEventBuffer;
+class TimelineStream;
+
+class TimelineEvent {
+ public:
+  // Keep in sync with StateBits below.
+  enum EventType {
+    kNone = 0,
+    kDuration = 1,
+    kInstant = 2,
+  };
+
+  void Reset();
+
+  bool IsValid() const {
+    return (event_type() >= kDuration) && (event_type() <= kInstant);
+  }
+
+  void DurationBegin(TimelineStream* stream, const char* label);
+  void DurationEnd();
+  void Instant(TimelineStream* stream, const char* label);
+
+  void SetArgument(const char* name, const char* value);
+
+  EventType event_type() const {
+    return EventTypeField::decode(state_);
+  }
+
+  void PrintJSON(JSONStream* stream);
+
+ private:
+  int64_t timestamp0_;
+  int64_t timestamp1_;
+  uword state_;
+  const char* label_;
+  TimelineStream* stream_;
+  Thread* thread_;
+  const char* arg_name_;
+  const char* arg_value_;
+
+  void Init(EventType event_type, TimelineStream* stream, const char* label);
+
+  void set_event_type(EventType event_type) {
+    state_ = EventTypeField::update(event_type, state_);
+  }
+
+  enum StateBits {
+    kEventTypeBit = 0,
+    // reserve 4 bits for type.
+    kNextBit = 4,
+  };
+
+  class EventTypeField : public BitField<EventType, kEventTypeBit, 4> {};
+
+  DISALLOW_COPY_AND_ASSIGN(TimelineEvent);
+};
+
+
+// A stream of timeline events. A stream has a name and can be enabled or
+// disabled individually.
+class TimelineStream {
+ public:
+  TimelineStream();
+
+  void Init(const char* name, bool enabled);
+
+  const char* name() const {
+    return name_;
+  }
+
+  bool enabled() const {
+    return enabled_;
+  }
+
+  void set_enabled(bool enabled) {
+    enabled_ = enabled;
+  }
+
+  TimelineEventBuffer* buffer() const {
+    return buffer_;
+  }
+
+  void set_buffer(TimelineEventBuffer* buffer) {
+    buffer_ = buffer;
+  }
+
+  // Records an event. Will return |NULL| if not enabled. The returned
+  // |TimelineEvent| is in an undefined state and must be initialized.
+  // |obj| is associated with the returned |TimelineEvent|.
+  TimelineEvent* RecordEvent(const Object& obj);
+
+  // Records an event. Will return |NULL| if not enabled. The returned
+  // |TimelineEvent| is in an undefined state and must be initialized.
+  TimelineEvent* RecordEvent();
+
+ private:
+  // Buffer of TimelineEvents.
+  TimelineEventBuffer* buffer_;
+  const char* name_;
+  bool enabled_;
+};
+
+
+// name, enabled by default.
+#define ISOLATE_TIMELINE_STREAM_LIST(V)                                        \
+  V(API, true)                                                                 \
+  V(Compiler, true)                                                            \
+  V(GC, true)                                                                  \
+
+
+class TimelineDurationScope : public ValueObject {
+ public:
+  TimelineDurationScope(TimelineStream* stream, const char* label) {
+    event_ = stream->RecordEvent();
+    if (event_ == NULL) {
+      return;
+    }
+    event_->DurationBegin(stream, label);
+  }
+
+  void SetArgument(const char* arg_name, const char* arg_value) {
+    if (event_ == NULL) {
+      return;
+    }
+    event_->SetArgument(arg_name, arg_value);
+  }
+
+  ~TimelineDurationScope() {
+    if (event_ == NULL) {
+      return;
+    }
+    event_->DurationEnd();
+  }
+
+ private:
+  TimelineEvent* event_;
+};
+
+
+class TimelineEventBuffer {
+ public:
+  static const intptr_t kDefaultCapacity = 8192;
+
+  static intptr_t SizeForCapacity(intptr_t capacity);
+
+  explicit TimelineEventBuffer(intptr_t capacity = kDefaultCapacity);
+  ~TimelineEventBuffer();
+
+  void Dump();
+
+ private:
+  // events_[i] and event_objects_[i] are indexed together.
+  TimelineEvent* events_;
+  RawArray* event_objects_;
+  uintptr_t cursor_;
+  intptr_t capacity_;
+
+  void DumpMeta(JSONArray* array);
+  void DumpEvents(JSONArray* array);
+
+  intptr_t GetNextIndex();
+  void VisitObjectPointers(ObjectPointerVisitor* visitor);
+  TimelineEvent* RecordEvent(const Object& obj);
+  TimelineEvent* RecordEvent();
+
+  friend class TimelineStream;
+  friend class Isolate;
+  DISALLOW_COPY_AND_ASSIGN(TimelineEventBuffer);
+};
+
+}  // namespace dart
+
+#endif  // VM_TIMELINE_H_