runtime/JSSymbolTableObject.h

   1 /*
   2  * Copyright (C) 2012, 2014 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  *
   8  * 1.  Redistributions of source code must retain the above copyright
   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.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  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 "VariableWatchpointSetInlines.h"
  36
  37 namespace JSC {
  38
  39 class JSSymbolTableObject : public JSScope {
  40 public:
  41     typedef JSScope Base;
  42
  43     SymbolTable* symbolTable() const { return m_symbolTable.get(); }
  44
  45     JS_EXPORT_PRIVATE static bool deleteProperty(JSCell*, ExecState*, PropertyName);
  46     JS_EXPORT_PRIVATE static void getOwnNonIndexPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
  47
  48 protected:
  49     static const unsigned StructureFlags = IsEnvironmentRecord | OverridesVisitChildren | OverridesGetPropertyNames | Base::StructureFlags;
  50
  51     JSSymbolTableObject(VM& vm, Structure* structure, JSScope* scope, SymbolTable* symbolTable = 0)
  52         : Base(vm, structure, scope)
  53     {
  54         if (symbolTable)
  55             m_symbolTable.set(vm, this, symbolTable);
  56     }
  57
  58     void finishCreation(VM& vm)
  59     {
  60         Base::finishCreation(vm);
  61         if (!m_symbolTable)
  62             m_symbolTable.set(vm, this, SymbolTable::create(vm));
  63     }
  64
  65     static void visitChildren(JSCell*, SlotVisitor&);
  66
  67     WriteBarrier<SymbolTable> m_symbolTable;
  68 };
  69
  70 template<typename SymbolTableObjectType>
  71 inline bool symbolTableGet(
  72     SymbolTableObjectType* object, PropertyName propertyName, PropertySlot& slot)
  73 {
  74     SymbolTable& symbolTable = *object->symbolTable();
  75     ConcurrentJITLocker locker(symbolTable.m_lock);
  76     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
  77     if (iter == symbolTable.end(locker))
  78         return false;
  79     SymbolTableEntry::Fast entry = iter->value;
  80     ASSERT(!entry.isNull());
  81     slot.setValue(object, entry.getAttributes() | DontDelete, object->registerAt(entry.getIndex()).get());
  82     return true;
  83 }
  84
  85 template<typename SymbolTableObjectType>
  86 inline bool symbolTableGet(
  87     SymbolTableObjectType* object, PropertyName propertyName, PropertyDescriptor& descriptor)
  88 {
  89     SymbolTable& symbolTable = *object->symbolTable();
  90     ConcurrentJITLocker locker(symbolTable.m_lock);
  91     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
  92     if (iter == symbolTable.end(locker))
  93         return false;
  94     SymbolTableEntry::Fast entry = iter->value;
  95     ASSERT(!entry.isNull());
  96     descriptor.setDescriptor(
  97         object->registerAt(entry.getIndex()).get(), entry.getAttributes() | DontDelete);
  98     return true;
  99 }
 100
 101 template<typename SymbolTableObjectType>
 102 inline bool symbolTableGet(
 103     SymbolTableObjectType* object, PropertyName propertyName, PropertySlot& slot,
 104     bool& slotIsWriteable)
 105 {
 106     SymbolTable& symbolTable = *object->symbolTable();
 107     ConcurrentJITLocker locker(symbolTable.m_lock);
 108     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 109     if (iter == symbolTable.end(locker))
 110         return false;
 111     SymbolTableEntry::Fast entry = iter->value;
 112     ASSERT(!entry.isNull());
 113     slot.setValue(object, entry.getAttributes() | DontDelete, object->registerAt(entry.getIndex()).get());
 114     slotIsWriteable = !entry.isReadOnly();
 115     return true;
 116 }
 117
 118 template<typename SymbolTableObjectType>
 119 inline bool symbolTablePut(
 120     SymbolTableObjectType* object, ExecState* exec, PropertyName propertyName, JSValue value,
 121     bool shouldThrow)
 122 {
 123     VM& vm = exec->vm();
 124     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(object));
 125
 126     WriteBarrierBase<Unknown>* reg;
 127     {
 128         SymbolTable& symbolTable = *object->symbolTable();
 129         // FIXME: This is very suspicious. We shouldn't need a GC-safe lock here.
 130         // https://bugs.webkit.org/show_bug.cgi?id=134601
 131         GCSafeConcurrentJITLocker locker(symbolTable.m_lock, exec->vm().heap);
 132         SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 133         if (iter == symbolTable.end(locker))
 134             return false;
 135         bool wasFat;
 136         SymbolTableEntry::Fast fastEntry = iter->value.getFast(wasFat);
 137         ASSERT(!fastEntry.isNull());
 138         if (fastEntry.isReadOnly()) {
 139             if (shouldThrow)
 140                 throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
 141             return true;
 142         }
 143         if (VariableWatchpointSet* set = iter->value.watchpointSet()) {
 144             // FIXME: It's strange that we're doing this while holding the symbol table's lock.
 145             // https://bugs.webkit.org/show_bug.cgi?id=134601
 146             set->notifyWrite(vm, value);
 147         }
 148         reg = &object->registerAt(fastEntry.getIndex());
 149     }
 150     // I'd prefer we not hold lock while executing barriers, since I prefer to reserve
 151     // the right for barriers to be able to trigger GC. And I don't want to hold VM
 152     // locks while GC'ing.
 153     reg->set(vm, object, value);
 154     return true;
 155 }
 156
 157 template<typename SymbolTableObjectType>
 158 inline bool symbolTablePutWithAttributes(
 159     SymbolTableObjectType* object, VM& vm, PropertyName propertyName,
 160     JSValue value, unsigned attributes)
 161 {
 162     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(object));
 163
 164     WriteBarrierBase<Unknown>* reg;
 165     {
 166         SymbolTable& symbolTable = *object->symbolTable();
 167         ConcurrentJITLocker locker(symbolTable.m_lock);
 168         SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
 169         if (iter == symbolTable.end(locker))
 170             return false;
 171         SymbolTableEntry& entry = iter->value;
 172         ASSERT(!entry.isNull());
 173         if (VariableWatchpointSet* set = entry.watchpointSet())
 174             set->notifyWrite(vm, value);
 175         entry.setAttributes(attributes);
 176         reg = &object->registerAt(entry.getIndex());
 177     }
 178     reg->set(vm, object, value);
 179     return true;
 180 }
 181
 182 } // namespace JSC
 183
 184 #endif // JSSymbolTableObject_h
 185