1/*
2 * Copyright (C) 2013-2018 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#include "config.h"
27#include "VMEntryScope.h"
28
29#include "DisallowVMReentry.h"
30#include "JSGlobalObject.h"
31#include "Options.h"
32#include "SamplingProfiler.h"
33#include "VM.h"
34#include "Watchdog.h"
35#include <wtf/StackBounds.h>
36#include <wtf/SystemTracing.h>
37
38namespace JSC {
39
40VMEntryScope::VMEntryScope(VM& vm, JSGlobalObject* globalObject)
41 : m_vm(vm)
42 , m_globalObject(globalObject)
43{
44 ASSERT(!DisallowVMReentry::isInEffectOnCurrentThread());
45 ASSERT(Thread::current().stack().isGrowingDownward());
46 if (!vm.entryScope) {
47 vm.entryScope = this;
48
49 // Reset the date cache between JS invocations to force the VM to
50 // observe time zone changes.
51 vm.resetDateCache();
52
53 if (vm.watchdog())
54 vm.watchdog()->enteredVM();
55
56#if ENABLE(SAMPLING_PROFILER)
57 if (SamplingProfiler* samplingProfiler = vm.samplingProfiler())
58 samplingProfiler->noticeVMEntry();
59#endif
60 if (Options::useTracePoints())
61 tracePoint(VMEntryScopeStart);
62 }
63
64 vm.clearLastException();
65}
66
67void VMEntryScope::addDidPopListener(Function<void ()>&& listener)
68{
69 m_didPopListeners.append(WTFMove(listener));
70}
71
72VMEntryScope::~VMEntryScope()
73{
74 if (m_vm.entryScope != this)
75 return;
76
77 if (Options::useTracePoints())
78 tracePoint(VMEntryScopeEnd);
79
80 if (m_vm.watchdog())
81 m_vm.watchdog()->exitedVM();
82
83 m_vm.entryScope = nullptr;
84
85 for (auto& listener : m_didPopListeners)
86 listener();
87
88 m_vm.clearScratchBuffers();
89}
90
91} // namespace JSC
92