source: webkit/trunk/JavaScriptCore/runtime/JSONObject.h@ 47304

Last change on this file since 47304 was 47267, checked in by [email protected], 16 years ago

Devirtualise marking
https://bugs.webkit.org/show_bug.cgi?id=28294

Reviewed by Maciej Stachowiak.

Add a bit to TypeInfo to indicate that an object uses the standard
JSObject::markChildren method. This allows us to devirtualise marking
of most objects (though a branch is still needed). We also add a branch
to identify arrays thus devirtualising marking in that case as well.

In order to make the best use of this devirtualisation I've also reworked
the MarkStack::drain() logic to make the iteration more efficient.

File size: 2.1 KB
Line 
1/*
2 * Copyright (C) 2009 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef JSONObject_h
27#define JSONObject_h
28
29#include "JSObject.h"
30
31namespace JSC {
32
33 class Stringifier;
34
35 class JSONObject : public JSObject {
36 public:
37 JSONObject(PassRefPtr<Structure> structure)
38 : JSObject(structure)
39 {
40 }
41
42 static PassRefPtr<Structure> createStructure(JSValue prototype)
43 {
44 return Structure::create(prototype, TypeInfo(ObjectType, HasDefaultMark));
45 }
46
47 static void markStringifiers(MarkStack&, Stringifier*);
48
49 private:
50 virtual bool getOwnPropertySlot(ExecState*, const Identifier&, PropertySlot&);
51
52 virtual const ClassInfo* classInfo() const { return &info; }
53 static const ClassInfo info;
54 };
55
56} // namespace JSC
57
58#endif // JSONObject_h
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