js/src/jit/TemplateObject.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set ts=8 sts=2 et sw=2 tw=80:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef jit_TemplateObject_h
   8 #define jit_TemplateObject_h
   9
  10 #include "vm/NativeObject.h"
  11 #include "vm/Shape.h"
  12
  13 namespace js {
  14 namespace jit {
  15
  16 class TemplateNativeObject;
  17
  18 // Wrapper for template objects. This should only expose methods that can be
  19 // safely called off-thread without racing with the main thread.
  20 class TemplateObject {
  21  protected:
  22   JSObject* obj_;
  23
  24  public:
  25   explicit TemplateObject(JSObject* obj) : obj_(obj) {}
  26
  27   inline gc::AllocKind getAllocKind() const;
  28
  29   // The following methods rely on the object's group->clasp. This is safe
  30   // to read off-thread for template objects.
  31   inline bool isNativeObject() const;
  32   inline const TemplateNativeObject& asTemplateNativeObject() const;
  33   inline bool isArrayObject() const;
  34   inline bool isArgumentsObject() const;
  35   inline bool isTypedArrayObject() const;
  36   inline bool isRegExpObject() const;
  37   inline bool isCallObject() const;
  38   inline bool isBlockLexicalEnvironmentObject() const;
  39   inline bool isPlainObject() const;
  40
  41   // The shape should not change. This is true for template objects because
  42   // they're never exposed to arbitrary script.
  43   inline gc::Cell* shape() const;
  44 };
  45
  46 class TemplateNativeObject : public TemplateObject {
  47  protected:
  48   NativeObject& asNativeObject() const { return obj_->as<NativeObject>(); }
  49
  50  public:
  51   // Reading slot counts and object slots is safe, as long as we don't touch
  52   // the BaseShape (it can change when we create a ShapeTable for the shape).
  53   inline bool hasDynamicSlots() const;
  54   inline uint32_t numDynamicSlots() const;
  55   inline uint32_t numUsedFixedSlots() const;
  56   inline uint32_t numFixedSlots() const;
  57   inline uint32_t slotSpan() const;
  58   inline Value getSlot(uint32_t i) const;
  59
  60   // Reading ObjectElements fields is safe, except for the flags.
  61   // isSharedMemory is an exception: it's debug-only and not called on arrays.
  62 #ifdef DEBUG
  63   inline bool isSharedMemory() const;
  64 #endif
  65   inline uint32_t getDenseCapacity() const;
  66   inline uint32_t getDenseInitializedLength() const;
  67   inline uint32_t getArrayLength() const;
  68   inline bool hasDynamicElements() const;
  69   inline const Value* getDenseElements() const;
  70
  71   inline gc::Cell* regExpShared() const;
  72 };
  73
  74 }  // namespace jit
  75 }  // namespace js
  76
  77 #endif /* jit_TemplateObject_h */