Pull tracing related methods out of Platform

This will allow for embedders to easily implement their own Platform
without duplicating the tracing controller code.

BUG=v8:6511
R=fmeawad@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I7c64933d12b2cf53f0636fbc87f6ad5d22019f5c
Reviewed-on: https://chromium-review.googlesource.com/543015
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Fadi Meawad <fmeawad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46118}

include/libplatform/v8-tracing.h

@@ -209,7 +209,15 @@ class V8_PLATFORM_EXPORT TraceConfig {
   void operator=(const TraceConfig&) = delete;
 };
 
-class V8_PLATFORM_EXPORT TracingController {
+#if defined(_MSC_VER)
+#define V8_PLATFORM_NON_EXPORTED_BASE(code) \
+  __pragma(warning(suppress : 4275)) code
+#else
+#define V8_PLATFORM_NON_EXPORTED_BASE(code) code
+#endif  // defined(_MSC_VER)
+
+class V8_PLATFORM_EXPORT TracingController
+    : public V8_PLATFORM_NON_EXPORTED_BASE(v8::TracingController) {
  public:
   enum Mode { DISABLED = 0, RECORDING_MODE };
 
@@ -227,25 +235,29 @@ class V8_PLATFORM_EXPORT TracingController {
   };
 
   TracingController();
-  ~TracingController();
+  ~TracingController() override;
   void Initialize(TraceBuffer* trace_buffer);
-  const uint8_t* GetCategoryGroupEnabled(const char* category_group);
-  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
+
+  // v8::TracingController implementation.
+  const uint8_t* GetCategoryGroupEnabled(const char* category_group) override;
   uint64_t AddTraceEvent(
       char phase, const uint8_t* category_enabled_flag, const char* name,
       const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
       const char** arg_names, const uint8_t* arg_types,
       const uint64_t* arg_values,
       std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
-      unsigned int flags);
+      unsigned int flags) override;
   void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
-                                const char* name, uint64_t handle);
+                                const char* name, uint64_t handle) override;
+  void AddTraceStateObserver(
+      v8::TracingController::TraceStateObserver* observer) override;
+  void RemoveTraceStateObserver(
+      v8::TracingController::TraceStateObserver* observer) override;
 
   void StartTracing(TraceConfig* trace_config);
   void StopTracing();
 
-  void AddTraceStateObserver(Platform::TraceStateObserver* observer);
-  void RemoveTraceStateObserver(Platform::TraceStateObserver* observer);
+  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
 
  private:
   const uint8_t* GetCategoryGroupEnabledInternal(const char* category_group);
@@ -255,7 +267,7 @@ class V8_PLATFORM_EXPORT TracingController {
   std::unique_ptr<TraceBuffer> trace_buffer_;
   std::unique_ptr<TraceConfig> trace_config_;
   std::unique_ptr<base::Mutex> mutex_;
-  std::unordered_set<Platform::TraceStateObserver*> observers_;
+  std::unordered_set<v8::TracingController::TraceStateObserver*> observers_;
   Mode mode_ = DISABLED;
 
   // Disallow copy and assign
@@ -263,6 +275,8 @@ class V8_PLATFORM_EXPORT TracingController {
   void operator=(const TracingController&) = delete;
 };
 
+#undef V8_PLATFORM_NON_EXPORTED_BASE
+
 }  // namespace tracing
 }  // namespace platform
 }  // namespace v8

include/v8-platform.h

@@ -52,6 +52,66 @@ class ConvertableToTraceFormat {
   virtual void AppendAsTraceFormat(std::string* out) const = 0;
 };
 
+/**
+ * V8 Tracing controller.
+ *
+ * Can be implemented by an embedder to record trace events from V8.
+ */
+class TracingController {
+ public:
+  virtual ~TracingController() = default;
+
+  /**
+   * Called by TRACE_EVENT* macros, don't call this directly.
+   * The name parameter is a category group for example:
+   * TRACE_EVENT0("v8,parse", "V8.Parse")
+   * The pointer returned points to a value with zero or more of the bits
+   * defined in CategoryGroupEnabledFlags.
+   **/
+  virtual const uint8_t* GetCategoryGroupEnabled(const char* name) {
+    static uint8_t no = 0;
+    return &no;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags) {
+    return 0;
+  }
+
+  /**
+   * Sets the duration field of a COMPLETE trace event. It must be called with
+   * the handle returned from AddTraceEvent().
+   **/
+  virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                        const char* name, uint64_t handle) {}
+
+  class TraceStateObserver {
+   public:
+    virtual ~TraceStateObserver() = default;
+    virtual void OnTraceEnabled() = 0;
+    virtual void OnTraceDisabled() = 0;
+  };
+
+  /** Adds tracing state change observer. */
+  virtual void AddTraceStateObserver(TraceStateObserver*) {}
+
+  /** Removes tracing state change observer. */
+  virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
+};
+
 /**
  * V8 Platform abstraction layer.
  *
@@ -135,6 +195,20 @@ class Platform {
    * the epoch.
    **/
   virtual double MonotonicallyIncreasingTime() = 0;
+  typedef void (*StackTracePrinter)();
+
+  /**
+   * Returns a function pointer that print a stack trace of the current stack
+   * on invocation. Disables printing of the stack trace if nullptr.
+   */
+  virtual StackTracePrinter GetStackTracePrinter() { return nullptr; }
+
+  /**
+   * Returns an instance of a v8::TracingController. This must be non-nullptr.
+   */
+  virtual TracingController* GetTracingController() { return nullptr; }
+
+  // DEPRECATED methods, use TracingController interface instead.
 
   /**
    * Called by TRACE_EVENT* macros, don't call this directly.
@@ -200,26 +274,13 @@ class Platform {
   virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
                                         const char* name, uint64_t handle) {}
 
-  class TraceStateObserver {
-   public:
-    virtual ~TraceStateObserver() = default;
-    virtual void OnTraceEnabled() = 0;
-    virtual void OnTraceDisabled() = 0;
-  };
+  typedef v8::TracingController::TraceStateObserver TraceStateObserver;
 
   /** Adds tracing state change observer. */
   virtual void AddTraceStateObserver(TraceStateObserver*) {}
 
   /** Removes tracing state change observer. */
   virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
-
-  typedef void (*StackTracePrinter)();
-
-  /**
-   * Returns a function pointer that print a stack trace of the current stack
-   * on invocation. Disables printing of the stack trace if nullptr.
-   */
-  virtual StackTracePrinter GetStackTracePrinter() { return nullptr; }
 };
 
 }  // namespace v8

src/libplatform/default-platform.cc

@@ -272,6 +272,10 @@ double DefaultPlatform::MonotonicallyIncreasingTime() {
          static_cast<double>(base::Time::kMicrosecondsPerSecond);
 }
 
+TracingController* DefaultPlatform::GetTracingController() {
+  return tracing_controller_.get();
+}
+
 uint64_t DefaultPlatform::AddTraceEvent(
     char phase, const uint8_t* category_enabled_flag, const char* name,
     const char* scope, uint64_t id, uint64_t bind_id, int num_args,

src/libplatform/default-platform.h

@@ -58,6 +58,7 @@ class V8_PLATFORM_EXPORT DefaultPlatform : public NON_EXPORTED_BASE(Platform) {
   void CallIdleOnForegroundThread(Isolate* isolate, IdleTask* task) override;
   bool IdleTasksEnabled(Isolate* isolate) override;
   double MonotonicallyIncreasingTime() override;
+  TracingController* GetTracingController() override;
   const uint8_t* GetCategoryGroupEnabled(const char* name) override;
   const char* GetCategoryGroupName(
       const uint8_t* category_enabled_flag) override;

src/libplatform/tracing/tracing-controller.cc

@@ -98,7 +98,7 @@ const char* TracingController::GetCategoryGroupName(
 
 void TracingController::StartTracing(TraceConfig* trace_config) {
   trace_config_.reset(trace_config);
-  std::unordered_set<Platform::TraceStateObserver*> observers_copy;
+  std::unordered_set<v8::TracingController::TraceStateObserver*> observers_copy;
   {
     base::LockGuard<base::Mutex> lock(mutex_.get());
     mode_ = RECORDING_MODE;
@@ -113,7 +113,7 @@ void TracingController::StartTracing(TraceConfig* trace_config) {
 void TracingController::StopTracing() {
   mode_ = DISABLED;
   UpdateCategoryGroupEnabledFlags();
-  std::unordered_set<Platform::TraceStateObserver*> observers_copy;
+  std::unordered_set<v8::TracingController::TraceStateObserver*> observers_copy;
   {
     base::LockGuard<base::Mutex> lock(mutex_.get());
     observers_copy = observers_;
@@ -196,7 +196,7 @@ const uint8_t* TracingController::GetCategoryGroupEnabledInternal(
 }
 
 void TracingController::AddTraceStateObserver(
-    Platform::TraceStateObserver* observer) {
+    v8::TracingController::TraceStateObserver* observer) {
   {
     base::LockGuard<base::Mutex> lock(mutex_.get());
     observers_.insert(observer);
@@ -207,7 +207,7 @@ void TracingController::AddTraceStateObserver(
 }
 
 void TracingController::RemoveTraceStateObserver(
-    Platform::TraceStateObserver* observer) {
+    v8::TracingController::TraceStateObserver* observer) {
   base::LockGuard<base::Mutex> lock(mutex_.get());
   DCHECK(observers_.find(observer) != observers_.end());
   observers_.erase(observer);

test/cctest/heap/test-incremental-marking.cc

@@ -71,29 +71,6 @@ class MockPlatform : public v8::Platform {
     delete task;
   }
 
-  using Platform::AddTraceEvent;
-  uint64_t AddTraceEvent(char phase, const uint8_t* categoryEnabledFlag,
-                         const char* name, const char* scope, uint64_t id,
-                         uint64_t bind_id, int numArgs, const char** argNames,
-                         const uint8_t* argTypes, const uint64_t* argValues,
-                         unsigned int flags) override {
-    return 0;
-  }
-
-  void UpdateTraceEventDuration(const uint8_t* categoryEnabledFlag,
-                                const char* name, uint64_t handle) override {}
-
-  const uint8_t* GetCategoryGroupEnabled(const char* name) override {
-    static uint8_t no = 0;
-    return &no;
-  }
-
-  const char* GetCategoryGroupName(
-      const uint8_t* categoryEnabledFlag) override {
-    static const char* dummy = "dummy";
-    return dummy;
-  }
-
  private:
   v8::Platform* platform_;
   Task* task_;