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 friend class Continuation;
43 template <typename T>
44 friend class RawOopWriter;
45
46 template <class T> T* obj_at_addr(int index) const;
47
48 template <class T>
49 static ptrdiff_t obj_at_offset(int index) {
50 return base_offset_in_bytes() + sizeof(T) * index;
51 }
52
53 private:
54 // Give size of objArrayOop in HeapWords minus the header
55 static int array_size(int length) {
56 const uint OopsPerHeapWord = HeapWordSize/heapOopSize;
57 assert(OopsPerHeapWord >= 1 && (HeapWordSize % heapOopSize == 0),
58 "Else the following (new) computation would be in error");
59 uint res = ((uint)length + OopsPerHeapWord - 1)/OopsPerHeapWord;
60 #ifdef ASSERT
61 // The old code is left in for sanity-checking; it'll
62 // go away pretty soon. XXX
63 // Without UseCompressedOops, this is simply:
64 // oop->length() * HeapWordsPerOop;
65 // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer.
66 // The oop elements are aligned up to wordSize
67 const uint HeapWordsPerOop = heapOopSize/HeapWordSize;
68 uint old_res;
69 if (HeapWordsPerOop > 0) {
70 old_res = length * HeapWordsPerOop;
71 } else {
72 old_res = align_up((uint)length, OopsPerHeapWord)/OopsPerHeapWord;
73 }
74 assert(res == old_res, "Inconsistency between old and new.");
75 #endif // ASSERT
76 return res;
77 }
78
79 public:
80 // Returns the offset of the first element.
81 static int base_offset_in_bytes() {
82 return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
83 }
84
85 // base is the address following the header.
86 HeapWord* base() const;
87
88 // Accessing
89 oop obj_at(int index) const;
90
91 void obj_at_put(int index, oop value);
92
93 oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value);
94
95 // Sizing
96 static int header_size() { return arrayOopDesc::header_size(T_OBJECT); }
97 size_t object_size() { return object_size(length()); }
98
99 static size_t object_size(int length) {
100 // This returns the object size in HeapWords.
101 uint asz = array_size(length);
102 uint osz = align_object_size(header_size() + asz);
103 assert(osz >= asz, "no overflow");
104 assert((int)osz > 0, "no overflow");
105 return (size_t)osz;
106 }
107
108 Klass* element_klass();
109
110 public:
111 // special iterators for index ranges, returns size of object
112 template <typename OopClosureType>
113 void oop_iterate_range(OopClosureType* blk, int start, int end);
114 };
115
116 // See similar requirement for oopDesc.
117 static_assert(std::is_trivially_default_constructible<objArrayOopDesc>::value, "required");
118
119 #endif // SHARE_OOPS_OBJARRAYOOP_HPP
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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 friend class Continuation;
43 template <typename T>
44 friend class RawOopWriter;
45
46 template <class T> T* obj_at_addr(int index) const;
47
48 template <class T>
49 static ptrdiff_t obj_at_offset(int index) {
50 return base_offset_in_bytes() + sizeof(T) * index;
51 }
52
53 private:
54 // Give size of objArrayOop in bytes minus the header
55 static size_t array_size_in_bytes(int length) {
56 return (size_t)length * heapOopSize;
57 }
58
59 public:
60 // Returns the offset of the first element.
61 static int base_offset_in_bytes() {
62 return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
63 }
64
65 // base is the address following the header.
66 HeapWord* base() const;
67
68 // Accessing
69 oop obj_at(int index) const;
70
71 void obj_at_put(int index, oop value);
72
73 oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value);
74
75 // Sizing
76 size_t object_size() { return object_size(length()); }
77
78 static size_t object_size(int length) {
79 // This returns the object size in HeapWords.
80 size_t asz = array_size_in_bytes(length);
81 size_t size_words = align_up(base_offset_in_bytes() + asz, HeapWordSize) / HeapWordSize;
82 size_t osz = align_object_size(size_words);
83 assert(osz < max_jint, "no overflow");
84 return osz;
85 }
86
87 Klass* element_klass();
88
89 public:
90 // special iterators for index ranges, returns size of object
91 template <typename OopClosureType>
92 void oop_iterate_range(OopClosureType* blk, int start, int end);
93 };
94
95 // See similar requirement for oopDesc.
96 static_assert(std::is_trivially_default_constructible<objArrayOopDesc>::value, "required");
97
98 #endif // SHARE_OOPS_OBJARRAYOOP_HPP
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