1  /*
 2   * Copyright (C) 2015-2017 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  #include "config.h"
27  #include "AdaptiveInferredPropertyValueWatchpointBase.h"
28  
29  #include "JSCInlines.h"
30  
31  namespace JSC {
32  
33  AdaptiveInferredPropertyValueWatchpointBase::AdaptiveInferredPropertyValueWatchpointBase(const ObjectPropertyCondition& key)
34      : m_key(key)
35  {
36      RELEASE_ASSERT(key.kind() == PropertyCondition::Equivalence);
37  }
38  
39  void AdaptiveInferredPropertyValueWatchpointBase::install(VM& vm)
40  {
41      RELEASE_ASSERT(m_key.isWatchable());
42  
43      Structure* structure = m_key.object()->structure(vm);
44  
45      structure->addTransitionWatchpoint(&m_structureWatchpoint);
46  
47      PropertyOffset offset = structure->getConcurrently(m_key.uid());
48      WatchpointSet* set = structure->propertyReplacementWatchpointSet(offset);
49      set->add(&m_propertyWatchpoint);
50  }
51  
52  void AdaptiveInferredPropertyValueWatchpointBase::fire(VM& vm, const FireDetail& detail)
53  {
54      // One of the watchpoints fired, but the other one didn't. Make sure that neither of them are
55      // in any set anymore. This simplifies things by allowing us to reinstall the watchpoints
56      // wherever from scratch.
57      if (m_structureWatchpoint.isOnList())
58          m_structureWatchpoint.remove();
59      if (m_propertyWatchpoint.isOnList())
60          m_propertyWatchpoint.remove();
61  
62      if (!isValid())
63          return;
64  
65      if (m_key.isWatchable(PropertyCondition::EnsureWatchability)) {
66          install(vm);
67          return;
68      }
69  
70      handleFire(vm, detail);
71  }
72  
73  bool AdaptiveInferredPropertyValueWatchpointBase::isValid() const
74  {
75      return true;
76  }
77  
78  void AdaptiveInferredPropertyValueWatchpointBase::StructureWatchpoint::fireInternal(VM& vm, const FireDetail& detail)
79  {
80      ptrdiff_t myOffset = OBJECT_OFFSETOF(AdaptiveInferredPropertyValueWatchpointBase, m_structureWatchpoint);
81  
82      AdaptiveInferredPropertyValueWatchpointBase* parent = bitwise_cast<AdaptiveInferredPropertyValueWatchpointBase*>(bitwise_cast<char*>(this) - myOffset);
83  
84      parent->fire(vm, detail);
85  }
86  
87  void AdaptiveInferredPropertyValueWatchpointBase::PropertyWatchpoint::fireInternal(VM& vm, const FireDetail& detail)
88  {
89      ptrdiff_t myOffset = OBJECT_OFFSETOF(AdaptiveInferredPropertyValueWatchpointBase, m_propertyWatchpoint);
90  
91      AdaptiveInferredPropertyValueWatchpointBase* parent = bitwise_cast<AdaptiveInferredPropertyValueWatchpointBase*>(bitwise_cast<char*>(this) - myOffset);
92      
93      parent->fire(vm, detail);
94  }
95      
96  } // namespace JSC