Reland: Fix JSON parser Handle leak (previous CL 1041483004)

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 600 matching lines @@
 #endif
 
   AllowHeapAllocation for_the_rest_of_the_epilogue;
 
 #ifdef DEBUG
   if (FLAG_print_global_handles) isolate_->global_handles()->Print();
   if (FLAG_print_handles) PrintHandles();
   if (FLAG_gc_verbose) Print();
   if (FLAG_code_stats) ReportCodeStatistics("After GC");
 #endif
+  if (FLAG_check_handle_count) CheckHandleCount();
   if (FLAG_deopt_every_n_garbage_collections > 0) {
     // TODO(jkummerow/ulan/jarin): This is not safe! We can't assume that
     // the topmost optimized frame can be deoptimized safely, because it
     // might not have a lazy bailout point right after its current PC.
     if (++gcs_since_last_deopt_ == FLAG_deopt_every_n_garbage_collections) {
       Deoptimizer::DeoptimizeAll(isolate());
       gcs_since_last_deopt_ = 0;
     }
   }
 
@@ skipping 5014 matching lines @@
 
 
 void Heap::PrintHandles() {
   PrintF("Handles:\n");
   PrintHandleVisitor v;
   isolate_->handle_scope_implementer()->Iterate(&v);
 }
 
 #endif
 
+class CheckHandleCountVisitor : public ObjectVisitor {
+ public:
+  CheckHandleCountVisitor() : handle_count_(0) {}
+  ~CheckHandleCountVisitor() { CHECK(handle_count_ < 2000); }
+  void VisitPointers(Object** start, Object** end) {
+    handle_count_ += end - start;
+  }
+
+ private:
+  ptrdiff_t handle_count_;
+};
+
+
+void Heap::CheckHandleCount() {
+  CheckHandleCountVisitor v;
+  isolate_->handle_scope_implementer()->Iterate(&v);
+}
+
 
 Space* AllSpaces::next() {
   switch (counter_++) {
     case NEW_SPACE:
       return heap_->new_space();
     case OLD_POINTER_SPACE:
       return heap_->old_pointer_space();
     case OLD_DATA_SPACE:
       return heap_->old_data_space();
     case CODE_SPACE:
@@ skipping 732 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal