runtime/StructureInlines.h

   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 StructureInlines_h
  27 #define StructureInlines_h
  28
  29 #include "JSArrayBufferView.h"
  30 #include "PropertyMapHashTable.h"
  31 #include "Structure.h"
  32
  33 namespace JSC {
  34
  35 inline Structure* Structure::create(VM& vm, JSGlobalObject* globalObject, JSValue prototype, const TypeInfo& typeInfo, const ClassInfo* classInfo, IndexingType indexingType, unsigned inlineCapacity)
  36 {
  37     ASSERT(vm.structureStructure);
  38     ASSERT(classInfo);
  39     Structure* structure = new (NotNull, allocateCell<Structure>(vm.heap)) Structure(vm, globalObject, prototype, typeInfo, classInfo, indexingType, inlineCapacity);
  40     structure->finishCreation(vm);
  41     return structure;
  42 }
  43
  44 inline Structure* Structure::createStructure(VM& vm)
  45 {
  46     ASSERT(!vm.structureStructure);
  47     Structure* structure = new (NotNull, allocateCell<Structure>(vm.heap)) Structure(vm);
  48     structure->finishCreation(vm, CreatingEarlyCell);
  49     return structure;
  50 }
  51
  52 inline Structure* Structure::create(VM& vm, Structure* structure)
  53 {
  54     ASSERT(vm.structureStructure);
  55     Structure* newStructure = new (NotNull, allocateCell<Structure>(vm.heap)) Structure(vm, structure);
  56     newStructure->finishCreation(vm);
  57     return newStructure;
  58 }
  59
  60 inline JSObject* Structure::storedPrototypeObject() const
  61 {
  62     JSValue value = m_prototype.get();
  63     if (value.isNull())
  64         return 0;
  65     return asObject(value);
  66 }
  67
  68 inline Structure* Structure::storedPrototypeStructure() const
  69 {
  70     JSObject* object = storedPrototypeObject();
  71     if (!object)
  72         return 0;
  73     return object->structure();
  74 }
  75
  76 ALWAYS_INLINE PropertyOffset Structure::get(VM& vm, PropertyName propertyName)
  77 {
  78     ASSERT(!isCompilationThread());
  79     ASSERT(structure()->classInfo() == info());
  80     PropertyTable* propertyTable;
  81     materializePropertyMapIfNecessary(vm, propertyTable);
  82     if (!propertyTable)
  83         return invalidOffset;
  84
  85     PropertyMapEntry* entry = propertyTable->get(propertyName.uid());
  86     return entry ? entry->offset : invalidOffset;
  87 }
  88
  89 ALWAYS_INLINE PropertyOffset Structure::get(VM& vm, const WTF::String& name)
  90 {
  91     ASSERT(!isCompilationThread());
  92     ASSERT(structure()->classInfo() == info());
  93     PropertyTable* propertyTable;
  94     materializePropertyMapIfNecessary(vm, propertyTable);
  95     if (!propertyTable)
  96         return invalidOffset;
  97
  98     PropertyMapEntry* entry = propertyTable->findWithString(name.impl()).first;
  99     return entry ? entry->offset : invalidOffset;
 100 }
 101
 102 ALWAYS_INLINE PropertyOffset Structure::get(VM& vm, PropertyName propertyName, unsigned& attributes, JSCell*& specificValue)
 103 {
 104     ASSERT(!isCompilationThread());
 105     ASSERT(structure()->classInfo() == info());
 106
 107     PropertyTable* propertyTable;
 108     materializePropertyMapIfNecessary(vm, propertyTable);
 109     if (!propertyTable)
 110         return invalidOffset;
 111
 112     PropertyMapEntry* entry = propertyTable->get(propertyName.uid());
 113     if (!entry)
 114         return invalidOffset;
 115
 116     attributes = entry->attributes;
 117     specificValue = entry->specificValue.get();
 118     return entry->offset;
 119 }
 120
 121 inline PropertyOffset Structure::getConcurrently(VM& vm, StringImpl* uid)
 122 {
 123     unsigned attributesIgnored;
 124     JSCell* specificValueIgnored;
 125     return getConcurrently(
 126         vm, uid, attributesIgnored, specificValueIgnored);
 127 }
 128
 129 inline bool Structure::hasIndexingHeader(const JSCell* cell) const
 130 {
 131     if (hasIndexedProperties(indexingType()))
 132         return true;
 133
 134     if (!isTypedView(m_classInfo->typedArrayStorageType))
 135         return false;
 136
 137     return jsCast<const JSArrayBufferView*>(cell)->mode() == WastefulTypedArray;
 138 }
 139
 140 inline bool Structure::masqueradesAsUndefined(JSGlobalObject* lexicalGlobalObject)
 141 {
 142     return typeInfo().masqueradesAsUndefined() && globalObject() == lexicalGlobalObject;
 143 }
 144
 145 inline bool Structure::transitivelyTransitionedFrom(Structure* structureToFind)
 146 {
 147     for (Structure* current = this; current; current = current->previousID()) {
 148         if (current == structureToFind)
 149             return true;
 150     }
 151     return false;
 152 }
 153
 154 inline void Structure::setEnumerationCache(VM& vm, JSPropertyNameIterator* enumerationCache)
 155 {
 156     ASSERT(!isDictionary());
 157     if (!m_hasRareData)
 158         allocateRareData(vm);
 159     rareData()->setEnumerationCache(vm, enumerationCache);
 160 }
 161
 162 inline JSPropertyNameIterator* Structure::enumerationCache()
 163 {
 164     if (!m_hasRareData)
 165         return 0;
 166     return rareData()->enumerationCache();
 167 }
 168
 169 inline JSValue Structure::prototypeForLookup(JSGlobalObject* globalObject) const
 170 {
 171     if (isObject())
 172         return m_prototype.get();
 173
 174     ASSERT(typeInfo().type() == StringType);
 175     return globalObject->stringPrototype();
 176 }
 177
 178 inline JSValue Structure::prototypeForLookup(ExecState* exec) const
 179 {
 180     return prototypeForLookup(exec->lexicalGlobalObject());
 181 }
 182
 183 inline StructureChain* Structure::prototypeChain(VM& vm, JSGlobalObject* globalObject) const
 184 {
 185     // We cache our prototype chain so our clients can share it.
 186     if (!isValid(globalObject, m_cachedPrototypeChain.get())) {
 187         JSValue prototype = prototypeForLookup(globalObject);
 188         m_cachedPrototypeChain.set(vm, this, StructureChain::create(vm, prototype.isNull() ? 0 : asObject(prototype)->structure()));
 189     }
 190     return m_cachedPrototypeChain.get();
 191 }
 192
 193 inline StructureChain* Structure::prototypeChain(ExecState* exec) const
 194 {
 195     return prototypeChain(exec->vm(), exec->lexicalGlobalObject());
 196 }
 197
 198 inline bool Structure::isValid(JSGlobalObject* globalObject, StructureChain* cachedPrototypeChain) const
 199 {
 200     if (!cachedPrototypeChain)
 201         return false;
 202
 203     JSValue prototype = prototypeForLookup(globalObject);
 204     WriteBarrier<Structure>* cachedStructure = cachedPrototypeChain->head();
 205     while (*cachedStructure && !prototype.isNull()) {
 206         if (asObject(prototype)->structure() != cachedStructure->get())
 207             return false;
 208         ++cachedStructure;
 209         prototype = asObject(prototype)->prototype();
 210     }
 211     return prototype.isNull() && !*cachedStructure;
 212 }
 213
 214 inline bool Structure::isValid(ExecState* exec, StructureChain* cachedPrototypeChain) const
 215 {
 216     return isValid(exec->lexicalGlobalObject(), cachedPrototypeChain);
 217 }
 218
 219 inline bool Structure::putWillGrowOutOfLineStorage()
 220 {
 221     checkOffsetConsistency();
 222
 223     ASSERT(outOfLineCapacity() >= outOfLineSize());
 224
 225     if (!propertyTable()) {
 226         unsigned currentSize = numberOfOutOfLineSlotsForLastOffset(m_offset);
 227         ASSERT(outOfLineCapacity() >= currentSize);
 228         return currentSize == outOfLineCapacity();
 229     }
 230
 231     ASSERT(totalStorageCapacity() >= propertyTable()->propertyStorageSize());
 232     if (propertyTable()->hasDeletedOffset())
 233         return false;
 234
 235     ASSERT(totalStorageCapacity() >= propertyTable()->size());
 236     return propertyTable()->size() == totalStorageCapacity();
 237 }
 238
 239 ALWAYS_INLINE WriteBarrier<PropertyTable>& Structure::propertyTable()
 240 {
 241     ASSERT(!globalObject() || !globalObject()->vm().heap.isCollecting());
 242     return m_propertyTableUnsafe;
 243 }
 244
 245 ALWAYS_INLINE bool Structure::checkOffsetConsistency() const
 246 {
 247     PropertyTable* propertyTable = m_propertyTableUnsafe.get();
 248
 249     if (!propertyTable) {
 250         ASSERT(!m_isPinnedPropertyTable);
 251         return true;
 252     }
 253
 254     // We cannot reliably assert things about the property table in the concurrent
 255     // compilation thread. It is possible for the table to be stolen and then have
 256     // things added to it, which leads to the offsets being all messed up. We could
 257     // get around this by grabbing a lock here, but I think that would be overkill.
 258     if (isCompilationThread())
 259         return true;
 260
 261     RELEASE_ASSERT(numberOfSlotsForLastOffset(m_offset, m_inlineCapacity) == propertyTable->propertyStorageSize());
 262     unsigned totalSize = propertyTable->propertyStorageSize();
 263     RELEASE_ASSERT((totalSize < inlineCapacity() ? 0 : totalSize - inlineCapacity()) == numberOfOutOfLineSlotsForLastOffset(m_offset));
 264
 265     return true;
 266 }
 267
 268 inline size_t nextOutOfLineStorageCapacity(size_t currentCapacity)
 269 {
 270     if (!currentCapacity)
 271         return initialOutOfLineCapacity;
 272     return currentCapacity * outOfLineGrowthFactor;
 273 }
 274
 275 inline size_t Structure::suggestedNewOutOfLineStorageCapacity()
 276 {
 277     return nextOutOfLineStorageCapacity(outOfLineCapacity());
 278 }
 279
 280 } // namespace JSC
 281
 282 #endif // StructureInlines_h
 283