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_VM_OOPS_FLATARRAYOOP_HPP
26 #define SHARE_VM_OOPS_FLATARRAYOOP_HPP
27 
28 #include "oops/klass.hpp"
29 #include "oops/objArrayOop.hpp"
30 #include "utilities/globalDefinitions.hpp"
31 
32 class FlatArrayKlass;
33 
34 // A flatArrayOop points to a flat array containing inline types (no indirection).
35 // It may include embedded oops in its elements.
36 
37 class flatArrayOopDesc : public objArrayOopDesc {
38  public:
39   inline FlatArrayKlass* klass() const;
40 
41   void* base() const;
42   static size_t base_offset_in_bytes();
43   void* value_at_addr(int index, jint lh) const;
44   size_t value_offset(int index, jint lh) const;
45   size_t value_offset_from_base(int index, jint lh) const;
46 
47   // oop obj_at(...) must always allocate when reading a non-null flat element,
48   // as such only obj_at(int, TRAPS) is provided. To null-check element without
49   // allocating use obj_at_is_null(int);
50   inline oop obj_at(int index) const = delete;
51   inline oop obj_at(int index, TRAPS) const;
52   inline bool obj_at_is_null(int index) const;
53   inline jboolean null_marker_of_obj_at(int index) const;
54   inline jboolean null_marker_of_obj_at(int index, TRAPS) const;
55   inline void obj_at_put(int index, oop value);
56   inline void obj_at_put(int index, oop value, TRAPS);
57 
58   // Sizing
59   static size_t element_size(int lh, int nof_elements) {
60     size_t sz = (size_t) nof_elements;
61     return sz << Klass::layout_helper_log2_element_size(lh);
62   }
63 
64   static int object_size(int lh, int length) {
65     julong size_in_bytes = arrayOopDesc::base_offset_in_bytes(Klass::layout_helper_element_type(lh));
66     size_in_bytes += element_size(lh, length);
67     julong size_in_words = ((size_in_bytes + (HeapWordSize-1)) >> LogHeapWordSize);
68     assert(size_in_words <= (julong)max_jint, "no overflow");
69     return align_object_size((intptr_t)size_in_words);
70   }
71 
72   int object_size(int lh) const;
73 
74   // Special iterators for an element index range.
75   template <typename OopClosureType>
76   void oop_iterate_elements_range(OopClosureType* blk, int start, int end);
77 
78 };
79 
80 // See similar requirement for oopDesc.
81 static_assert(std::is_trivially_default_constructible<flatArrayOopDesc>::value, "required");
82 
83 #endif // SHARE_VM_OOPS_FLATARRAYOOP_HPP