1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "config.h"
6#include "bindings/core/v8/ScriptWrappable.h"
7
8#include "bindings/core/v8/DOMDataStore.h"
9#include "bindings/core/v8/V8DOMWrapper.h"
10
11namespace blink {
12
13#if COMPILER(MSVC)
14__declspec(align(4))
15#endif
16struct SameSizeAsScriptWrappableBase { };
17
18COMPILE_ASSERT(sizeof(ScriptWrappableBase) <= sizeof(SameSizeAsScriptWrappableBase), ScriptWrappableBase_should_stay_small);
19
20struct SameSizeAsScriptWrappable : public ScriptWrappableBase {
21    virtual ~SameSizeAsScriptWrappable() { }
22    v8::Object* m_wrapper;
23};
24
25COMPILE_ASSERT(sizeof(ScriptWrappable) <= sizeof(SameSizeAsScriptWrappable), ScriptWrappable_should_stay_small);
26
27namespace {
28
29class ScriptWrappableBaseProtector FINAL {
30    WTF_MAKE_NONCOPYABLE(ScriptWrappableBaseProtector);
31public:
32    ScriptWrappableBaseProtector(ScriptWrappableBase* scriptWrappableBase, const WrapperTypeInfo* wrapperTypeInfo)
33        : m_scriptWrappableBase(scriptWrappableBase), m_wrapperTypeInfo(wrapperTypeInfo)
34    {
35        m_wrapperTypeInfo->refObject(m_scriptWrappableBase);
36    }
37    ~ScriptWrappableBaseProtector()
38    {
39        m_wrapperTypeInfo->derefObject(m_scriptWrappableBase);
40    }
41
42private:
43    ScriptWrappableBase* m_scriptWrappableBase;
44    const WrapperTypeInfo* m_wrapperTypeInfo;
45};
46
47} // namespace
48
49v8::Handle<v8::Object> ScriptWrappable::wrap(v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
50{
51    const WrapperTypeInfo* wrapperTypeInfo = this->wrapperTypeInfo();
52
53    // It's possible that no one except for the new wrapper owns this object at
54    // this moment, so we have to prevent GC to collect this object until the
55    // object gets associated with the wrapper.
56    ScriptWrappableBaseProtector protect(this, wrapperTypeInfo);
57
58    ASSERT(!DOMDataStore::containsWrapperNonTemplate(this, isolate));
59
60    v8::Handle<v8::Object> wrapper = V8DOMWrapper::createWrapper(creationContext, wrapperTypeInfo, toScriptWrappableBase(), isolate);
61    if (UNLIKELY(wrapper.IsEmpty()))
62        return wrapper;
63
64    wrapperTypeInfo->installConditionallyEnabledProperties(wrapper, isolate);
65    return associateWithWrapper(wrapperTypeInfo, wrapper, isolate);
66}
67
68v8::Handle<v8::Object> ScriptWrappable::associateWithWrapper(const WrapperTypeInfo* wrapperTypeInfo, v8::Handle<v8::Object> wrapper, v8::Isolate* isolate)
69{
70    return V8DOMWrapper::associateObjectWithWrapperNonTemplate(this, wrapperTypeInfo, wrapper, isolate);
71}
72
73} // namespace blink
74