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src/hotspot/share/oops/objArrayOop.hpp

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 30 
 31 class Klass;
 32 
 33 // An objArrayOop is an array containing oops.
 34 // Evaluating "String arg[10]" will create an objArrayOop.
 35 
 36 class objArrayOopDesc : public arrayOopDesc {
 37   friend class ObjArrayKlass;
 38   friend class Runtime1;
 39   friend class psPromotionManager;
 40   friend class CSetMarkWordClosure;
 41 
 42   template <class T> T* obj_at_addr(int index) const;
 43 
 44   template <class T>
 45   static ptrdiff_t obj_at_offset(int index) {
 46     return base_offset_in_bytes() + sizeof(T) * index;
 47   }
 48 
 49 private:
 50   // Give size of objArrayOop in HeapWords minus the header
 51   static int array_size(int length) {
 52     const uint OopsPerHeapWord = HeapWordSize/heapOopSize;
 53     assert(OopsPerHeapWord >= 1 && (HeapWordSize % heapOopSize == 0),
 54            "Else the following (new) computation would be in error");
 55     uint res = ((uint)length + OopsPerHeapWord - 1)/OopsPerHeapWord;
 56 #ifdef ASSERT
 57     // The old code is left in for sanity-checking; it'll
 58     // go away pretty soon. XXX
 59     // Without UseCompressedOops, this is simply:
 60     // oop->length() * HeapWordsPerOop;
 61     // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer.
 62     // The oop elements are aligned up to wordSize
 63     const uint HeapWordsPerOop = heapOopSize/HeapWordSize;
 64     uint old_res;
 65     if (HeapWordsPerOop > 0) {
 66       old_res = length * HeapWordsPerOop;
 67     } else {
 68       old_res = align_up((uint)length, OopsPerHeapWord)/OopsPerHeapWord;
 69     }
 70     assert(res == old_res, "Inconsistency between old and new.");
 71 #endif  // ASSERT
 72     return res;
 73   }
 74 
 75  public:
 76   // Returns the offset of the first element.
 77   static int base_offset_in_bytes() {
 78     return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
 79   }
 80 
 81   // base is the address following the header.
 82   HeapWord* base() const;
 83 
 84   // Accessing
 85   oop obj_at(int index) const;
 86 
 87   void obj_at_put(int index, oop value);
 88 
 89   oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value);
 90 
 91   // Sizing
 92   static int header_size()    { return arrayOopDesc::header_size(T_OBJECT); }
 93   int object_size()           { return object_size(length()); }
 94 
 95   static int object_size(int length) {
 96     // This returns the object size in HeapWords.
 97     uint asz = array_size(length);
 98     uint osz = align_object_size(header_size() + asz);
 99     assert(osz >= asz,   "no overflow");
100     assert((int)osz > 0, "no overflow");
101     return (int)osz;
102   }
103 
104   Klass* element_klass();
105 
106 public:
107   // special iterators for index ranges, returns size of object
108   template <typename OopClosureType>
109   void oop_iterate_range(OopClosureType* blk, int start, int end);
110 };
111 
112 #endif // SHARE_OOPS_OBJARRAYOOP_HPP

 30 
 31 class Klass;
 32 
 33 // An objArrayOop is an array containing oops.
 34 // Evaluating "String arg[10]" will create an objArrayOop.
 35 
 36 class objArrayOopDesc : public arrayOopDesc {
 37   friend class ObjArrayKlass;
 38   friend class Runtime1;
 39   friend class psPromotionManager;
 40   friend class CSetMarkWordClosure;
 41 
 42   template <class T> T* obj_at_addr(int index) const;
 43 
 44   template <class T>
 45   static ptrdiff_t obj_at_offset(int index) {
 46     return base_offset_in_bytes() + sizeof(T) * index;
 47   }
 48 
 49 private:
 50   // Give size of objArrayOop in bytes minus the header
 51   static size_t array_size_in_bytes(int length) {
 52     return (size_t)length * heapOopSize;




















 53   }
 54 
 55  public:
 56   // Returns the offset of the first element.
 57   static int base_offset_in_bytes() {
 58     return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
 59   }
 60 
 61   // base is the address following the header.
 62   HeapWord* base() const;
 63 
 64   // Accessing
 65   oop obj_at(int index) const;
 66 
 67   void obj_at_put(int index, oop value);
 68 
 69   oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value);
 70 
 71   // Sizing

 72   int object_size()           { return object_size(length()); }
 73 
 74   static int object_size(int length) {
 75     // This returns the object size in HeapWords.
 76     size_t asz = array_size_in_bytes(length);
 77     size_t size_words = align_up(base_offset_in_bytes() + asz, HeapWordSize) / HeapWordSize;
 78     size_t osz = align_object_size(size_words);
 79     assert(osz < max_jint, "no overflow");
 80     return checked_cast<int>(osz);
 81   }
 82 
 83   Klass* element_klass();
 84 
 85 public:
 86   // special iterators for index ranges, returns size of object
 87   template <typename OopClosureType>
 88   void oop_iterate_range(OopClosureType* blk, int start, int end);
 89 };
 90 
 91 #endif // SHARE_OOPS_OBJARRAYOOP_HPP
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