1/*
2 * Copyright (C) 2012, 2015-2016 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 "StructureStubClearingWatchpoint.h"
28
29#if ENABLE(JIT)
30
31#include "CodeBlock.h"
32#include "JSCInlines.h"
33#include "StructureStubInfo.h"
34
35namespace JSC {
36
37void StructureTransitionStructureStubClearingWatchpoint::fireInternal(VM& vm, const FireDetail&)
38{
39 if (!m_holder->isValid())
40 return;
41
42 if (!m_key || !m_key.isWatchable(PropertyCondition::EnsureWatchability)) {
43 // This will implicitly cause my own demise: stub reset removes all watchpoints.
44 // That works, because deleting a watchpoint removes it from the set's list, and
45 // the set's list traversal for firing is robust against the set changing.
46 ConcurrentJSLocker locker(m_holder->codeBlock()->m_lock);
47 m_holder->stubInfo()->reset(m_holder->codeBlock());
48 return;
49 }
50
51 if (m_key.kind() == PropertyCondition::Presence) {
52 // If this was a presence condition, let's watch the property for replacements. This is profitable
53 // for the DFG, which will want the replacement set to be valid in order to do constant folding.
54 m_key.object()->structure(vm)->startWatchingPropertyForReplacements(vm, m_key.offset());
55 }
56
57 m_key.object()->structure(vm)->addTransitionWatchpoint(this);
58}
59
60inline bool WatchpointsOnStructureStubInfo::isValid() const
61{
62 return m_codeBlock->isLive();
63}
64
65WatchpointsOnStructureStubInfo::Node& WatchpointsOnStructureStubInfo::addWatchpoint(const ObjectPropertyCondition& key)
66{
67 if (!key || key.condition().kind() != PropertyCondition::Equivalence)
68 return *m_watchpoints.add(WTF::in_place<StructureTransitionStructureStubClearingWatchpoint>, key, *this);
69 ASSERT(key.condition().kind() == PropertyCondition::Equivalence);
70 return *m_watchpoints.add(WTF::in_place<AdaptiveValueStructureStubClearingWatchpoint>, key, *this);
71}
72
73void WatchpointsOnStructureStubInfo::ensureReferenceAndInstallWatchpoint(
74 std::unique_ptr<WatchpointsOnStructureStubInfo>& holderRef, CodeBlock* codeBlock,
75 StructureStubInfo* stubInfo, const ObjectPropertyCondition& key)
76{
77 if (!holderRef)
78 holderRef = makeUnique<WatchpointsOnStructureStubInfo>(codeBlock, stubInfo);
79 else {
80 ASSERT(holderRef->m_codeBlock == codeBlock);
81 ASSERT(holderRef->m_stubInfo == stubInfo);
82 }
83
84 ASSERT(!!key);
85 auto& watchpointVariant = holderRef->addWatchpoint(key);
86 if (key.kind() == PropertyCondition::Equivalence) {
87 auto& adaptiveWatchpoint = WTF::get<AdaptiveValueStructureStubClearingWatchpoint>(watchpointVariant);
88 adaptiveWatchpoint.install(codeBlock->vm());
89 } else {
90 auto* structureTransitionWatchpoint = &WTF::get<StructureTransitionStructureStubClearingWatchpoint>(watchpointVariant);
91 key.object()->structure()->addTransitionWatchpoint(structureTransitionWatchpoint);
92 }
93}
94
95Watchpoint* WatchpointsOnStructureStubInfo::ensureReferenceAndAddWatchpoint(
96 std::unique_ptr<WatchpointsOnStructureStubInfo>& holderRef, CodeBlock* codeBlock,
97 StructureStubInfo* stubInfo)
98{
99 if (!holderRef)
100 holderRef = makeUnique<WatchpointsOnStructureStubInfo>(codeBlock, stubInfo);
101 else {
102 ASSERT(holderRef->m_codeBlock == codeBlock);
103 ASSERT(holderRef->m_stubInfo == stubInfo);
104 }
105
106 return &WTF::get<StructureTransitionStructureStubClearingWatchpoint>(holderRef->addWatchpoint(ObjectPropertyCondition()));
107}
108
109void AdaptiveValueStructureStubClearingWatchpoint::handleFire(VM&, const FireDetail&)
110{
111 if (!m_holder->isValid())
112 return;
113
114 // This will implicitly cause my own demise: stub reset removes all watchpoints.
115 // That works, because deleting a watchpoint removes it from the set's list, and
116 // the set's list traversal for firing is robust against the set changing.
117 ConcurrentJSLocker locker(m_holder->codeBlock()->m_lock);
118 m_holder->stubInfo()->reset(m_holder->codeBlock());
119}
120
121} // namespace JSC
122
123#endif // ENABLE(JIT)
124
125