1/*
2 * Copyright (C) 2013 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 "GCIncomingRefCounted.h"
29#include "Heap.h"
30
31namespace JSC {
32
33template<typename T>
34bool GCIncomingRefCounted<T>::addIncomingReference(JSCell* cell)
35{
36 if (!hasAnyIncoming()) {
37 m_encodedPointer = bitwise_cast<uintptr_t>(cell) | singletonFlag();
38 this->setIsDeferred(true);
39 ASSERT(hasSingleton());
40 return true;
41 }
42
43 ASSERT(Heap::heap(incomingReferenceAt(0)) == Heap::heap(cell));
44
45 if (hasSingleton()) {
46 Vector<JSCell*>* vector = new Vector<JSCell*>();
47 vector->append(singleton());
48 vector->append(cell);
49 m_encodedPointer = bitwise_cast<uintptr_t>(vector);
50 ASSERT(hasVectorOfCells());
51 return false;
52 }
53
54 vectorOfCells()->append(cell);
55 return false;
56}
57
58template<typename T>
59template<typename FilterFunctionType>
60bool GCIncomingRefCounted<T>::filterIncomingReferences(FilterFunctionType&& filterFunction)
61{
62 const bool verbose = false;
63
64 if (verbose)
65 dataLog("Filtering incoming references.\n");
66
67 if (!hasAnyIncoming()) {
68 ASSERT(!this->isDeferred());
69 ASSERT(this->refCount());
70 if (verbose)
71 dataLog(" Has no incoming.\n");
72 return false;
73 }
74
75 ASSERT(this->isDeferred());
76
77 if (hasSingleton()) {
78 if (filterFunction(singleton())) {
79 if (verbose)
80 dataLog(" Singleton passed.\n");
81 return false;
82 }
83
84 if (verbose)
85 dataLog(" Removing singleton.\n");
86 m_encodedPointer = 0;
87 ASSERT(!hasAnyIncoming());
88 this->setIsDeferred(false);
89 return true;
90 }
91
92 if (verbose)
93 dataLog(" Has ", vectorOfCells()->size(), " entries.\n");
94 for (size_t i = 0; i < vectorOfCells()->size(); ++i) {
95 if (filterFunction(vectorOfCells()->at(i)))
96 continue;
97 vectorOfCells()->at(i--) = vectorOfCells()->last();
98 vectorOfCells()->removeLast();
99 }
100
101 if (vectorOfCells()->size() >= 2) {
102 if (verbose)
103 dataLog(" Still has ", vectorOfCells()->size(), " entries.\n");
104 return false;
105 }
106
107 if (vectorOfCells()->isEmpty()) {
108 if (verbose)
109 dataLog(" Removing.\n");
110 delete vectorOfCells();
111 m_encodedPointer = 0;
112 ASSERT(!hasAnyIncoming());
113 this->setIsDeferred(false);
114 return true;
115 }
116
117 if (verbose)
118 dataLog(" Shrinking to singleton.\n");
119 JSCell* singleton = vectorOfCells()->at(0);
120 delete vectorOfCells();
121 m_encodedPointer = bitwise_cast<uintptr_t>(singleton) | singletonFlag();
122 ASSERT(hasSingleton());
123 return false;
124}
125
126} // namespace JSC
127