Add support for allowing an embedder to get the V8 profile timer event logs.

Contributed by fmeawad@chromium.org

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/186163002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19745 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -3799,6 +3799,9 @@ typedef void (*FatalErrorCallback)(const char* location, const char* message);
 
 typedef void (*MessageCallback)(Handle<Message> message, Handle<Value> error);
 
+// --- Tracing ---
+
+typedef void (*LogEventCallback)(const char* name, int event);
 
 /**
  * Create new error objects by calling the corresponding error object
@@ -4185,6 +4188,11 @@ class V8_EXPORT Isolate {
    */
   void RequestGarbageCollectionForTesting(GarbageCollectionType type);
 
+  /**
+   * Set the callback to invoke for logging event.
+   */
+  void SetEventLogger(LogEventCallback that);
+
  private:
   Isolate();
   Isolate(const Isolate&);

src/api.cc

@@ -6381,6 +6381,11 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
 }
 
 
+void Isolate::SetEventLogger(LogEventCallback that) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->set_event_logger(that);
+}
+
 String::Utf8Value::Utf8Value(v8::Handle<v8::Value> obj)
     : str_(NULL), length_(0) {
   i::Isolate* isolate = i::Isolate::Current();

src/counters.cc

@@ -62,9 +62,7 @@ void HistogramTimer::Start() {
   if (Enabled()) {
     timer_.Start();
   }
-  if (FLAG_log_internal_timer_events) {
-    LOG(isolate(), TimerEvent(Logger::START, name()));
-  }
+  isolate()->event_logger()(name(), Logger::START);
 }
 
 
@@ -75,9 +73,7 @@ void HistogramTimer::Stop() {
     AddSample(static_cast<int>(timer_.Elapsed().InMilliseconds()));
     timer_.Stop();
   }
-  if (FLAG_log_internal_timer_events) {
-    LOG(isolate(), TimerEvent(Logger::END, name()));
-  }
+  isolate()->event_logger()(name(), Logger::END);
 }
 
 } }  // namespace v8::internal

src/isolate.cc

@@ -2016,6 +2016,12 @@ bool Isolate::Init(Deserializer* des) {
   bootstrapper_->Initialize(create_heap_objects);
   builtins_.SetUp(this, create_heap_objects);
 
+  if (FLAG_log_internal_timer_events) {
+    set_event_logger(Logger::LogInternalEvents);
+  } else {
+    set_event_logger(Logger::EmptyLogInternalEvents);
+  }
+
   // Set default value if not yet set.
   // TODO(yangguo): move this to ResourceConstraints::ConfigureDefaults
   // once ResourceConstraints becomes an argument to the Isolate constructor.

src/isolate.h

@@ -340,6 +340,7 @@ typedef List<HeapObject*> DebugObjectCache;
   /* A previously allocated buffer of kMinimalBufferSize bytes, or NULL. */    \
   V(byte*, assembler_spare_buffer, NULL)                                       \
   V(FatalErrorCallback, exception_behavior, NULL)                              \
+  V(LogEventCallback, event_logger, NULL)                                      \
   V(AllowCodeGenerationFromStringsCallback, allow_code_gen_callback, NULL)     \
   /* To distinguish the function templates, so that we can find them in the */ \
   /* function cache of the native context. */                                  \

src/log.cc

@@ -1124,8 +1124,14 @@ void Logger::LeaveExternal(Isolate* isolate) {
 }
 
 
+void Logger::LogInternalEvents(const char* name, int se) {
+  Isolate* isolate = Isolate::Current();
+  LOG(isolate, TimerEvent(static_cast<StartEnd>(se), name));
+}
+
+
 void Logger::TimerEventScope::LogTimerEvent(StartEnd se) {
-  LOG(isolate_, TimerEvent(se, name_));
+  isolate_->event_logger()(name_, se);
 }
 
 

src/log.h

@@ -316,15 +316,18 @@ class Logger {
   static void EnterExternal(Isolate* isolate);
   static void LeaveExternal(Isolate* isolate);
 
+  static void EmptyLogInternalEvents(const char* name, int se) { }
+  static void LogInternalEvents(const char* name, int se);
+
   class TimerEventScope {
    public:
     TimerEventScope(Isolate* isolate, const char* name)
         : isolate_(isolate), name_(name) {
-      if (FLAG_log_internal_timer_events) LogTimerEvent(START);
+      LogTimerEvent(START);
     }
 
     ~TimerEventScope() {
-      if (FLAG_log_internal_timer_events) LogTimerEvent(END);
+      LogTimerEvent(END);
     }
 
     void LogTimerEvent(StartEnd se);

test/cctest/test-api.cc

@@ -22116,3 +22116,27 @@ TEST(TestFunctionCallOptimization) {
   ApiCallOptimizationChecker checker;
   checker.RunAll();
 }
+
+
+static const char* last_event_message;
+static int last_event_status;
+void StoringEventLoggerCallback(const char* message, int status) {
+    last_event_message = message;
+    last_event_status = status;
+}
+
+
+TEST(EventLogging) {
+  v8::Isolate* isolate = CcTest::isolate();
+  isolate->SetEventLogger(StoringEventLoggerCallback);
+  v8::internal::HistogramTimer* histogramTimer =
+      new v8::internal::HistogramTimer(
+          "V8.Test", 0, 10000, 50,
+          reinterpret_cast<v8::internal::Isolate*>(isolate));
+  histogramTimer->Start();
+  CHECK_EQ("V8.Test", last_event_message);
+  CHECK_EQ(0, last_event_status);
+  histogramTimer->Stop();
+  CHECK_EQ("V8.Test", last_event_message);
+  CHECK_EQ(1, last_event_status);
+}