Print out how many AllocationMementos were found on a scavenge of new space

src/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 68 matching lines @@
 // ConfigureHeap (survived_since_last_expansion_, external_allocation_limit_)
 // Will be 4 * reserved_semispace_size_ to ensure that young
 // generation can be aligned to its size.
       survived_since_last_expansion_(0),
       sweep_generation_(0),
       always_allocate_scope_depth_(0),
       linear_allocation_scope_depth_(0),
       contexts_disposed_(0),
       global_ic_age_(0),
       flush_monomorphic_ics_(false),
+      allocation_mementos_found_on_scavenge_(0),
       scan_on_scavenge_pages_(0),
       new_space_(this),
       old_pointer_space_(NULL),
       old_data_space_(NULL),
       code_space_(NULL),
       map_space_(NULL),
       cell_space_(NULL),
       property_cell_space_(NULL),
       lo_space_(NULL),
       gc_state_(NOT_IN_GC),
@@ skipping 1222 matching lines @@
   }
 
  private:
   Heap* heap_;
 };
 
 
 void Heap::Scavenge() {
   RelocationLock relocation_lock(this);
 
+  allocation_mementos_found_on_scavenge_ = 0;
+
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) VerifyNonPointerSpacePointers(this);
 #endif
 
   gc_state_ = SCAVENGE;
 
   // Implements Cheney's copying algorithm
   LOG(isolate_, ResourceEvent("scavenge", "begin"));
 
   // Clear descriptor cache.
@@ skipping 127 matching lines @@
 
   // Update how much has survived scavenge.
   IncrementYoungSurvivorsCounter(static_cast<int>(
       (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size()));
 
   LOG(isolate_, ResourceEvent("scavenge", "end"));
 
   gc_state_ = NOT_IN_GC;
 
   scavenges_since_last_idle_round_++;
+
+  if (FLAG_trace_track_allocation_sites &&
+      allocation_mementos_found_on_scavenge_ > 0) {
+    PrintF("AllocationMementos found during scavenge = %d\n",
+           allocation_mementos_found_on_scavenge_);
+  }
 }
 
 
 String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap,
                                                                 Object** p) {
   MapWord first_word = HeapObject::cast(*p)->map_word();
 
   if (!first_word.IsForwardingAddress()) {
     // Unreachable external string can be finalized.
     heap->FinalizeExternalString(String::cast(*p));
@@ skipping 6377 matching lines @@
   if (FLAG_concurrent_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal