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#ifndef PolymorphicAccessStructureList_h 27#define PolymorphicAccessStructureList_h 28 29#include "JITStubRoutine.h" 30#include "Structure.h" 31#include "StructureChain.h" 32#include <wtf/Platform.h> 33 34#define POLYMORPHIC_LIST_CACHE_SIZE 8 35 36namespace JSC { 37 38// *Sigh*, If the JIT is enabled we need to track the stubRountine (of type CodeLocationLabel), 39// If the JIT is not in use we don't actually need the variable (that said, if the JIT is not in use we don't 40// curently actually use PolymorphicAccessStructureLists, which we should). Anyway, this seems like the best 41// solution for now - will need to something smarter if/when we actually want mixed-mode operation. 42 43#if ENABLE(JIT) 44// Structure used by op_get_by_id_self_list and op_get_by_id_proto_list instruction to hold data off the main opcode stream. 45struct PolymorphicAccessStructureList { 46 WTF_MAKE_FAST_ALLOCATED; 47public: 48 struct PolymorphicStubInfo { 49 bool isChain; 50 bool isDirect; 51 RefPtr<JITStubRoutine> stubRoutine; 52 WriteBarrier<Structure> base; 53 union { 54 WriteBarrierBase<Structure> proto; 55 WriteBarrierBase<StructureChain> chain; 56 } u; 57 58 PolymorphicStubInfo() 59 { 60 u.proto.clear(); 61 } 62 63 void set(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> _stubRoutine, Structure* _base, bool isDirect) 64 { 65 stubRoutine = _stubRoutine; 66 base.set(vm, owner, _base); 67 u.proto.clear(); 68 isChain = false; 69 this->isDirect = isDirect; 70 } 71 72 void set(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> _stubRoutine, Structure* _base, Structure* _proto, bool isDirect) 73 { 74 stubRoutine = _stubRoutine; 75 base.set(vm, owner, _base); 76 u.proto.set(vm, owner, _proto); 77 isChain = false; 78 this->isDirect = isDirect; 79 } 80 81 void set(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> _stubRoutine, Structure* _base, StructureChain* _chain, bool isDirect) 82 { 83 stubRoutine = _stubRoutine; 84 base.set(vm, owner, _base); 85 u.chain.set(vm, owner, _chain); 86 isChain = true; 87 this->isDirect = isDirect; 88 } 89 } list[POLYMORPHIC_LIST_CACHE_SIZE]; 90 91 PolymorphicAccessStructureList() 92 { 93 } 94 95 PolymorphicAccessStructureList(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> stubRoutine, Structure* firstBase, bool isDirect) 96 { 97 list[0].set(vm, owner, stubRoutine, firstBase, isDirect); 98 } 99 100 PolymorphicAccessStructureList(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> stubRoutine, Structure* firstBase, Structure* firstProto, bool isDirect) 101 { 102 list[0].set(vm, owner, stubRoutine, firstBase, firstProto, isDirect); 103 } 104 105 PolymorphicAccessStructureList(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> stubRoutine, Structure* firstBase, StructureChain* firstChain, bool isDirect) 106 { 107 list[0].set(vm, owner, stubRoutine, firstBase, firstChain, isDirect); 108 } 109 110 bool visitWeak(int count) 111 { 112 for (int i = 0; i < count; ++i) { 113 PolymorphicStubInfo& info = list[i]; 114 if (!info.base) { 115 // We're being marked during initialisation of an entry 116 ASSERT(!info.u.proto); 117 continue; 118 } 119 120 if (!Heap::isMarked(info.base.get())) 121 return false; 122 if (info.u.proto && !info.isChain 123 && !Heap::isMarked(info.u.proto.get())) 124 return false; 125 if (info.u.chain && info.isChain 126 && !Heap::isMarked(info.u.chain.get())) 127 return false; 128 } 129 130 return true; 131 } 132}; 133 134#endif // ENABLE(JIT) 135 136} // namespace JSC 137 138#endif // PolymorphicAccessStructureList_h 139 140