Track live instance and allocation counts for classes

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index 63d0c9d75758c49981b45c49dd23f1813fd5e43c..ca05ed41e368dbd16d1f7a09927007c1b488a958 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -160,6 +160,7 @@ void Heap::CollectGarbage(Space space, ApiCallbacks api_callbacks) {
   switch (space) {
     case kNew: {
       RecordBeforeGC(kNew, kNewSpace);
+      UpdateClassHeapStatsBeforeGC(kNew);
       new_space_->Scavenge(invoke_api_callbacks);
       RecordAfterGC();
       PrintStats();
@@ -173,6 +174,7 @@ void Heap::CollectGarbage(Space space, ApiCallbacks api_callbacks) {
     case kCode: {
       bool promotion_failure = new_space_->HadPromotionFailure();
       RecordBeforeGC(kOld, promotion_failure ? kPromotionFailure : kOldSpace);
+      UpdateClassHeapStatsBeforeGC(kOld);
       old_space_->MarkSweep(invoke_api_callbacks);
       RecordAfterGC();
       PrintStats();
@@ -192,6 +194,17 @@ void Heap::UpdateObjectHistogram() {
 }
 
 
+void Heap::UpdateClassHeapStatsBeforeGC(Heap::Space space) {
+  Isolate* isolate = Isolate::Current();
+  ClassTable* class_table = isolate->class_table();
+  if (space == kNew) {
+    class_table->ResetCountersNew();
+  } else {
+    class_table->ResetCountersOld();
+  }
+}
+
+
 void Heap::CollectGarbage(Space space) {
   ApiCallbacks api_callbacks;
   if (space == kOld) {
@@ -205,10 +218,12 @@ void Heap::CollectGarbage(Space space) {
 
 void Heap::CollectAllGarbage() {
   RecordBeforeGC(kNew, kFull);
+  UpdateClassHeapStatsBeforeGC(kNew);
   new_space_->Scavenge(kInvokeApiCallbacks);
   RecordAfterGC();
   PrintStats();
   RecordBeforeGC(kOld, kFull);
+  UpdateClassHeapStatsBeforeGC(kOld);
   old_space_->MarkSweep(kInvokeApiCallbacks);
   RecordAfterGC();
   PrintStats();