RFC: Try to be much more careful with where we skip the write barrier by:...

src/builtins.cc

 // Copyright 2006-2008 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 229 matching lines @@
   // Optimize the case where there are no parameters passed.
   if (args.length() == 1) {
     return array->Initialize(JSArray::kPreallocatedArrayElements);
   }
 
   // Take the arguments as elements.
   int number_of_elements = args.length() - 1;
   Smi* len = Smi::FromInt(number_of_elements);
   Object* obj = Heap::AllocateFixedArrayWithHoles(len->value());
   if (obj->IsFailure()) return obj;
+
+  AssertNoAllocation no_gc;
   FixedArray* elms = FixedArray::cast(obj);
-  WriteBarrierMode mode = elms->GetWriteBarrierMode();
+  WriteBarrierMode mode = elms->GetWriteBarrierMode(no_gc);
   // Fill in the content
   for (int index = 0; index < number_of_elements; index++) {
     elms->set(index, args[index+1], mode);
   }
 
   // Set length and elements on the array.
   array->set_elements(FixedArray::cast(obj));
-  array->set_length(len, SKIP_WRITE_BARRIER);
+  array->set_length(len);
 
   return array;
 }
 
 
 BUILTIN(ArrayPush) {
   JSArray* array = JSArray::cast(*args.receiver());
   ASSERT(array->HasFastElements());
 
   // Make sure we have space for the elements.
   int len = Smi::cast(array->length())->value();
 
   // Set new length.
   int new_length = len + args.length() - 1;
   FixedArray* elms = FixedArray::cast(array->elements());
 
   if (new_length <= elms->length()) {
     // Backing storage has extra space for the provided values.
     for (int index = 0; index < args.length() - 1; index++) {
       elms->set(index + len, args[index+1]);
     }
   } else {
     // New backing storage is needed.
     int capacity = new_length + (new_length >> 1) + 16;
     Object* obj = Heap::AllocateFixedArrayWithHoles(capacity);
     if (obj->IsFailure()) return obj;
+
+    AssertNoAllocation no_gc;
     FixedArray* new_elms = FixedArray::cast(obj);
-    WriteBarrierMode mode = new_elms->GetWriteBarrierMode();
+    WriteBarrierMode mode = new_elms->GetWriteBarrierMode(no_gc);
     // Fill out the new array with old elements.
     for (int i = 0; i < len; i++) new_elms->set(i, elms->get(i), mode);
     // Add the provided values.
     for (int index = 0; index < args.length() - 1; index++) {
       new_elms->set(index + len, args[index+1], mode);
     }
     // Set the new backing storage.
     array->set_elements(new_elms);
   }
   // Set the length.
-  array->set_length(Smi::FromInt(new_length), SKIP_WRITE_BARRIER);
+  array->set_length(Smi::FromInt(new_length));
   return array->length();
 }
 
 
 BUILTIN(ArrayPop) {
   JSArray* array = JSArray::cast(*args.receiver());
   ASSERT(array->HasFastElements());
   Object* undefined = Heap::undefined_value();
 
   int len = Smi::cast(array->length())->value();
   if (len == 0) return undefined;
 
   // Get top element
   FixedArray* elms = FixedArray::cast(array->elements());
   Object* top = elms->get(len - 1);
 
   // Set the length.
-  array->set_length(Smi::FromInt(len - 1), SKIP_WRITE_BARRIER);
+  array->set_length(Smi::FromInt(len - 1));
 
   if (!top->IsTheHole()) {
     // Delete the top element.
     elms->set_the_hole(len - 1);
     return top;
   }
 
   // Remember to check the prototype chain.
   JSFunction* array_function =
       Top::context()->global_context()->array_function();
@@ skipping 581 matching lines @@
       if (entry->contains(pc)) {
         return names_[i];
       }
     }
   }
   return NULL;
 }
 
 
 } }  // namespace v8::internal