1 /*
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 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24 
25 #ifndef SHARE_OOPS_REFARRAYOOP_HPP
26 #define SHARE_OOPS_REFARRAYOOP_HPP
27 
28 #include "oops/objArrayOop.hpp"
29 #include "utilities/align.hpp"
30 
31 class RefArrayKlass;
32 
33 // A refArrayOop is an array containing references (oops).
34 // Evaluating "String arg[10]" will create a refArrayOop.
35 
36 class refArrayOopDesc : public objArrayOopDesc {
37   friend class ArchiveHeapWriter;
38   friend class RefArrayKlass;
39   friend class Runtime1;
40   friend class psPromotionManager;
41   friend class CSetMarkWordClosure;
42   friend class Continuation;
43   template <typename T>
44   friend class RawOopWriter;
45   friend class AOTMapLogger;
46 
47   template <class T> T* obj_at_addr(int index) const;
48 
49   template <class T>
50   static ptrdiff_t obj_at_offset(int index) {
51     return base_offset_in_bytes() + sizeof(T) * index;
52   }
53 
54  public:
55   inline RefArrayKlass* klass() const;
56 
57   // Returns the offset of the first element.
58   static int base_offset_in_bytes() {
59     return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
60   }
61 
62   // base is the address following the header.
63   inline HeapWord* base() const;
64 
65   // Accessing
66   oop obj_at(int index) const;
67 
68   void obj_at_put(int index, oop value);
69   void obj_at_put(int index, oop value, TRAPS);
70 
71   oop replace_if_null(int index, oop exchange_value);
72 
73   // Sizing
74   size_t object_size() { return object_size(length()); }
75 
76   static size_t object_size(int length) {
77     // This returns the object size in HeapWords.
78     size_t asz = (size_t)length * heapOopSize;
79     size_t size_words = heap_word_size(base_offset_in_bytes() + asz);
80     size_t osz = align_object_size(size_words);
81     assert(osz < max_jint, "no overflow");
82     return osz;
83   }
84 
85   // special iterators for index ranges, returns size of object
86   template <typename OopClosureType>
87   void oop_iterate_elements_range(OopClosureType* blk, int start, int end);
88 };
89 
90 // See similar requirement for oopDesc.
91 static_assert(std::is_trivially_default_constructible<refArrayOopDesc>::value, "required");
92 
93 #endif // SHARE_OOPS_REFARRAYOOP_HPP