31
32 class Klass;
33
34 // An objArrayOop is an array containing oops.
35 // Evaluating "String arg[10]" will create an objArrayOop.
36
37 class objArrayOopDesc : public arrayOopDesc {
38 friend class ObjArrayKlass;
39 friend class Runtime1;
40 friend class psPromotionManager;
41 friend class CSetMarkWordClosure;
42
43 template <class T> T* obj_at_addr(int index) const;
44
45 template <class T>
46 static ptrdiff_t obj_at_offset(int index) {
47 return base_offset_in_bytes() + sizeof(T) * index;
48 }
49
50 private:
51 // Give size of objArrayOop in HeapWords minus the header
52 static int array_size(int length) {
53 const uint OopsPerHeapWord = HeapWordSize/heapOopSize;
54 assert(OopsPerHeapWord >= 1 && (HeapWordSize % heapOopSize == 0),
55 "Else the following (new) computation would be in error");
56 uint res = ((uint)length + OopsPerHeapWord - 1)/OopsPerHeapWord;
57 #ifdef ASSERT
58 // The old code is left in for sanity-checking; it'll
59 // go away pretty soon. XXX
60 // Without UseCompressedOops, this is simply:
61 // oop->length() * HeapWordsPerOop;
62 // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer.
63 // The oop elements are aligned up to wordSize
64 const uint HeapWordsPerOop = heapOopSize/HeapWordSize;
65 uint old_res;
66 if (HeapWordsPerOop > 0) {
67 old_res = length * HeapWordsPerOop;
68 } else {
69 old_res = align_up((uint)length, OopsPerHeapWord)/OopsPerHeapWord;
70 }
71 assert(res == old_res, "Inconsistency between old and new.");
72 #endif // ASSERT
73 return res;
74 }
75
76 public:
77 // Returns the offset of the first element.
78 static int base_offset_in_bytes() {
79 return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
80 }
81
82 // base is the address following the header.
83 HeapWord* base() const;
84
85 // Accessing
86 oop obj_at(int index) const;
87
88 void obj_at_put(int index, oop value);
89
90 oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value);
91
92 // Sizing
93 static int header_size() { return arrayOopDesc::header_size(T_OBJECT); }
94 size_t object_size() { return object_size(length()); }
95
96 static size_t object_size(int length) {
97 // This returns the object size in HeapWords.
98 uint asz = array_size(length);
99 uint osz = align_object_size(header_size() + asz);
100 assert(osz >= asz, "no overflow");
101 assert((int)osz > 0, "no overflow");
102 return (size_t)osz;
103 }
104
105 Klass* element_klass();
106
107 public:
108 // special iterators for index ranges, returns size of object
109 template <typename OopClosureType>
110 void oop_iterate_range(OopClosureType* blk, int start, int end);
111 };
112
113 // See similar requirement for oopDesc.
114 static_assert(std::is_trivially_default_constructible<objArrayOopDesc>::value, "required");
115
116 #endif // SHARE_OOPS_OBJARRAYOOP_HPP
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31
32 class Klass;
33
34 // An objArrayOop is an array containing oops.
35 // Evaluating "String arg[10]" will create an objArrayOop.
36
37 class objArrayOopDesc : public arrayOopDesc {
38 friend class ObjArrayKlass;
39 friend class Runtime1;
40 friend class psPromotionManager;
41 friend class CSetMarkWordClosure;
42
43 template <class T> T* obj_at_addr(int index) const;
44
45 template <class T>
46 static ptrdiff_t obj_at_offset(int index) {
47 return base_offset_in_bytes() + sizeof(T) * index;
48 }
49
50 private:
51 // Give size of objArrayOop in bytes minus the header
52 static size_t array_size_in_bytes(int length) {
53 return (size_t)length * heapOopSize;
54 }
55
56 public:
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 HeapWord* base() const;
64
65 // Accessing
66 oop obj_at(int index) const;
67
68 void obj_at_put(int index, oop value);
69
70 oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value);
71
72 // Sizing
73 size_t object_size() { return object_size(length()); }
74
75 static size_t object_size(int length) {
76 // This returns the object size in HeapWords.
77 size_t asz = array_size_in_bytes(length);
78 size_t size_words = align_up(base_offset_in_bytes() + asz, HeapWordSize) / HeapWordSize;
79 size_t osz = align_object_size(size_words);
80 assert(osz < max_jint, "no overflow");
81 return osz;
82 }
83
84 Klass* element_klass();
85
86 public:
87 // special iterators for index ranges, returns size of object
88 template <typename OopClosureType>
89 void oop_iterate_range(OopClosureType* blk, int start, int end);
90 };
91
92 // See similar requirement for oopDesc.
93 static_assert(std::is_trivially_default_constructible<objArrayOopDesc>::value, "required");
94
95 #endif // SHARE_OOPS_OBJARRAYOOP_HPP
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