| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef ScriptWrappableVisitorVerifier_h |
| #define ScriptWrappableVisitorVerifier_h |
| |
| #include "platform/bindings/ScriptWrappableVisitor.h" |
| |
| namespace blink { |
| |
| // This visitor should be applied on wrapper members of each marked object |
| // after marking is complete. The Visit method checks that the given wrapper |
| // is also marked. |
| class ScriptWrappableVisitorVerifier final : public ScriptWrappableVisitor { |
| protected: |
| void Visit(const TraceWrapperV8Reference<v8::Value>&) const final {} |
| void Visit(const WrapperDescriptor& wrapper_descriptor) const final { |
| HeapObjectHeader* header = wrapper_descriptor.heap_object_header_callback( |
| wrapper_descriptor.traceable); |
| if (!header->IsWrapperHeaderMarked()) { |
| // If this branch is hit, it means that a white (not discovered by |
| // traceWrappers) object was assigned as a member to a black object |
| // (already processed by traceWrappers). Black object will not be |
| // processed anymore so White object will remain undetected and |
| // therefore its wrapper and all wrappers reachable from it would be |
| // collected. |
| |
| // This means there is a write barrier missing somewhere. Check the |
| // backtrace to see which types are causing this and review all the |
| // places where white object is set to a black object. |
| wrapper_descriptor.missed_write_barrier_callback(); |
| NOTREACHED(); |
| } |
| } |
| void Visit(DOMWrapperMap<ScriptWrappable>*, |
| const ScriptWrappable* key) const final {} |
| }; |
| } |
| #endif |
