Reload length of retained_maps array after GC.

src/objects.cc

 // Copyright 2013 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 <iomanip>
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 8259 matching lines @@
     }
     casted_result->set_last_used_index(target_index - 1 - kFirstIndex);
     for (; target_index < result->length(); ++target_index) {
       result->set(target_index, Smi::FromInt(0));
     }
   }
   return casted_result;
 }
 
 
-Handle<ArrayList> ArrayList::Add(Handle<ArrayList> array, Handle<Object> obj) {
+Handle<ArrayList> ArrayList::Add(Handle<ArrayList> array, Handle<Object> obj,
+                                 AddMode mode) {
   int length = array->Length();
   array = EnsureSpace(array, length + 1);
+  if (mode == kReloadLengthAfterAllocation) {
+    DCHECK(array->Length() <= length);
+    length = array->Length();
+  }
   array->Set(length, *obj);
   array->SetLength(length + 1);
   return array;
 }
 
 
 Handle<ArrayList> ArrayList::Add(Handle<ArrayList> array, Handle<Object> obj1,
-                                 Handle<Object> obj2) {
+                                 Handle<Object> obj2, AddMode mode) {
   int length = array->Length();
   array = EnsureSpace(array, length + 2);
+  if (mode == kReloadLengthAfterAllocation) {
+    length = array->Length();

[Erik Corry, 2015/03/25 09:53:07]

Missing DCHECK from the single-argument version.

Did you try just doing this unconditionally, and was it too slow?  It looks a
bit like a trap for the unwary now.

+  }
   array->Set(length, *obj1);
   array->Set(length + 1, *obj2);
   array->SetLength(length + 2);
   return array;
 }
 
 
 Handle<ArrayList> ArrayList::EnsureSpace(Handle<ArrayList> array, int length) {
   int capacity = array->length();

[Erik Corry, 2015/03/25 09:53:07]

// This is the length of the FixedArray

+  bool empty = (capacity == 0);
   if (capacity < kFirstIndex + length) {
     capacity = kFirstIndex + length;
     capacity = capacity + Max(capacity / 2, 2);

[Erik Corry, 2015/03/25 09:53:07]

Division by 2 of a signed value can be an expensive operation.  Consider either
making it unsigned or using shift.

     array = Handle<ArrayList>::cast(FixedArray::CopySize(array, capacity));
+    if (empty) array->SetLength(0);

[Erik Corry, 2015/03/25 09:53:06]

// This sets the length of the ArrayList, using the first entry in the fixed
array

   }
   return array;
 }
 
 
 Handle<DescriptorArray> DescriptorArray::Allocate(Isolate* isolate,
                                                   int number_of_descriptors,
                                                   int slack) {
   DCHECK(0 <= number_of_descriptors);
   Factory* factory = isolate->factory();
@@ skipping 8790 matching lines @@
                                                CompilationInfo* info) {
   Handle<DependentCode> codes = DependentCode::InsertCompilationInfo(
       handle(cell->dependent_code(), info->isolate()),
       DependentCode::kPropertyCellChangedGroup, info->object_wrapper());
   if (*codes != cell->dependent_code()) cell->set_dependent_code(*codes);
   info->dependencies(DependentCode::kPropertyCellChangedGroup)->Add(
       cell, info->zone());
 }
 
 } }  // namespace v8::internal