runtime/JSSymbolTableObject.h

   1 /*
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   3  *
   4  * Redistribution and use in source and binary forms, with or without
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   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
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  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef JSSymbolTableObject_h
  30 #define JSSymbolTableObject_h
  31
  32 #include "JSScope.h"
  33 #include "PropertyDescriptor.h"
  34 #include "SymbolTable.h"
  35 #include "VariableWriteFireDetail.h"
  36
  37 namespace JSC {
  38
  39 class JSSymbolTableObject;
  40
  41 class JSSymbolTableObject : public JSScope {
  42 public:
  43     typedef JSScope Base;
  44     static const unsigned StructureFlags = Base::StructureFlags | IsEnvironmentRecord | OverridesGetPropertyNames;
  45
  46     SymbolTable* symbolTable() const { return m_symbolTable.get(); }
  47
  48     JS_EXPORT_PRIVATE static bool deleteProperty(JSCell*, ExecState*, PropertyName);
  49     JS_EXPORT_PRIVATE static void getOwnNonIndexPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
  50
  51     static ptrdiff_t offsetOfSymbolTable() { return OBJECT_OFFSETOF(JSSymbolTableObject, m_symbolTable); }
  52
  53 protected:
  54     JSSymbolTableObject(VM& vm, Structure* structure, JSScope* scope)
  55         : Base(vm, structure, scope)
  56     {
  57     }
  58
  59     JSSymbolTableObject(VM& vm, Structure* structure, JSScope* scope, SymbolTable* symbolTable)
  60         : Base(vm, structure, scope)
  61     {
  62         ASSERT(symbolTable);
  63         setSymbolTable(vm, symbolTable);
  64     }
  65
  66     void setSymbolTable(VM& vm, SymbolTable* symbolTable)
  67     {
  68         ASSERT(!m_symbolTable);
  69         symbolTable->singletonScope()->notifyWrite(vm, this, "Allocated a scope");
  70         m_symbolTable.set(vm, this, symbolTable);
  71     }
  72
  73     static void visitChildren(JSCell*, SlotVisitor&);
  74
  75 private:
  76     WriteBarrier<SymbolTable> m_symbolTable;
  77 };
  78
  79 template<typename SymbolTableObjectType>
  80 inline bool symbolTableGet(
  81     SymbolTableObjectType* object, PropertyName propertyName, PropertySlot& slot)
  82 {
  83     SymbolTable& symbolTable = *object->symbolTable();
  84     ConcurrentJITLocker locker(symbolTable.m_lock);
  85     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
  86     if (iter == symbolTable.end(locker))
  87         return false;
  88     SymbolTableEntry::Fast entry = iter->value;
  89     ASSERT(!entry.isNull());
  90     slot.setValue(object, entry.getAttributes() | DontDelete, object->variableAt(entry.scopeOffset()).get());
  91     return true;
  92 }
  93
  94 template<typename SymbolTableObjectType>
  95 inline bool symbolTableGet(
  96     SymbolTableObjectType* object, PropertyName propertyName, PropertyDescriptor& descriptor)
  97 {
  98     SymbolTable& symbolTable = *object->symbolTable();
  99     ConcurrentJITLocker locker(symbolTable.m_lock);
 100     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 101     if (iter == symbolTable.end(locker))
 102         return false;
 103     SymbolTableEntry::Fast entry = iter->value;
 104     ASSERT(!entry.isNull());
 105     descriptor.setDescriptor(
 106         object->variableAt(entry.scopeOffset()).get(), entry.getAttributes() | DontDelete);
 107     return true;
 108 }
 109
 110 template<typename SymbolTableObjectType>
 111 inline bool symbolTableGet(
 112     SymbolTableObjectType* object, PropertyName propertyName, PropertySlot& slot,
 113     bool& slotIsWriteable)
 114 {
 115     SymbolTable& symbolTable = *object->symbolTable();
 116     ConcurrentJITLocker locker(symbolTable.m_lock);
 117     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 118     if (iter == symbolTable.end(locker))
 119         return false;
 120     SymbolTableEntry::Fast entry = iter->value;
 121     ASSERT(!entry.isNull());
 122     slot.setValue(object, entry.getAttributes() | DontDelete, object->variableAt(entry.scopeOffset()).get());
 123     slotIsWriteable = !entry.isReadOnly();
 124     return true;
 125 }
 126
 127 template<typename SymbolTableObjectType>
 128 inline bool symbolTablePut(
 129     SymbolTableObjectType* object, ExecState* exec, PropertyName propertyName, JSValue value,
 130     bool shouldThrow)
 131 {
 132     VM& vm = exec->vm();
 133     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(object));
 134
 135     WriteBarrierBase<Unknown>* reg;
 136     WatchpointSet* set;
 137     {
 138         SymbolTable& symbolTable = *object->symbolTable();
 139         // FIXME: This is very suspicious. We shouldn't need a GC-safe lock here.
 140         // https://bugs.webkit.org/show_bug.cgi?id=134601
 141         GCSafeConcurrentJITLocker locker(symbolTable.m_lock, exec->vm().heap);
 142         SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 143         if (iter == symbolTable.end(locker))
 144             return false;
 145         bool wasFat;
 146         SymbolTableEntry::Fast fastEntry = iter->value.getFast(wasFat);
 147         ASSERT(!fastEntry.isNull());
 148         if (fastEntry.isReadOnly()) {
 149             if (shouldThrow)
 150                 throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
 151             return true;
 152         }
 153         set = iter->value.watchpointSet();
 154         reg = &object->variableAt(fastEntry.scopeOffset());
 155     }
 156     // I'd prefer we not hold lock while executing barriers, since I prefer to reserve
 157     // the right for barriers to be able to trigger GC. And I don't want to hold VM
 158     // locks while GC'ing.
 159     reg->set(vm, object, value);
 160     if (set)
 161         VariableWriteFireDetail::touch(set, object, propertyName);
 162     return true;
 163 }
 164
 165 template<typename SymbolTableObjectType>
 166 inline bool symbolTablePutWithAttributes(
 167     SymbolTableObjectType* object, VM& vm, PropertyName propertyName,
 168     JSValue value, unsigned attributes)
 169 {
 170     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(object));
 171
 172     WriteBarrierBase<Unknown>* reg;
 173     WatchpointSet* set;
 174     {
 175         SymbolTable& symbolTable = *object->symbolTable();
 176         ConcurrentJITLocker locker(symbolTable.m_lock);
 177         SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 178         if (iter == symbolTable.end(locker))
 179             return false;
 180         SymbolTableEntry& entry = iter->value;
 181         ASSERT(!entry.isNull());
 182         set = entry.watchpointSet();
 183         entry.setAttributes(attributes);
 184         reg = &object->variableAt(entry.scopeOffset());
 185     }
 186     reg->set(vm, object, value);
 187     if (set)
 188         VariableWriteFireDetail::touch(set, object, propertyName);
 189     return true;
 190 }
 191
 192 } // namespace JSC
 193
 194 #endif // JSSymbolTableObject_h
 195