1/*
2 * Copyright (C) 2017 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#pragma once
27
28#include "DisallowScope.h"
29#include <wtf/NeverDestroyed.h>
30#include <wtf/ThreadSpecific.h>
31
32namespace JSC {
33
34class DisallowVMReentry : public DisallowScope<DisallowVMReentry> {
35 WTF_MAKE_NONCOPYABLE(DisallowVMReentry);
36 typedef DisallowScope<DisallowVMReentry> Base;
37public:
38#ifdef NDEBUG
39
40 ALWAYS_INLINE DisallowVMReentry(bool = false) { }
41 ALWAYS_INLINE static void initialize() { }
42
43#else // not NDEBUG
44
45 DisallowVMReentry(bool enabled = true)
46 : Base(enabled)
47 { }
48
49 static void initialize()
50 {
51 s_scopeReentryCount.construct();
52 }
53
54private:
55 static unsigned scopeReentryCount()
56 {
57 return *s_scopeReentryCount.get();
58 }
59 static void setScopeReentryCount(unsigned value)
60 {
61 *s_scopeReentryCount.get() = value;
62 }
63
64 JS_EXPORT_PRIVATE static LazyNeverDestroyed<ThreadSpecific<unsigned, WTF::CanBeGCThread::True>> s_scopeReentryCount;
65
66#endif // NDEBUG
67
68 friend class DisallowScope<DisallowVMReentry>;
69};
70
71} // namespace JSC
72