1 /*
 2  * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
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24 
25 #ifndef SHARE_VM_OOPS_FLATARRAYOOP_HPP
26 #define SHARE_VM_OOPS_FLATARRAYOOP_HPP
27 
28 #include "oops/arrayOop.hpp"
29 #include "oops/inlineKlass.hpp"
30 #include "oops/klass.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "runtime/handles.hpp"
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 
39  public:
40   void*  base() const;
41   void* value_at_addr(int index, jint lh) const;
42 
43   inline oop obj_at(int index) const;
44   inline oop obj_at(int index, TRAPS) const;
45   inline void obj_at_put(int index, oop value);
46   inline void obj_at_put(int index, oop value, TRAPS);
47 
48   // Sizing
49   static size_t element_size(int lh, int nof_elements) {
50     size_t sz = (size_t) nof_elements;
51     return sz << Klass::layout_helper_log2_element_size(lh);
52   }
53 
54   static int object_size(int lh, int length) {
55     julong size_in_bytes = arrayOopDesc::base_offset_in_bytes(Klass::layout_helper_element_type(lh));
56     size_in_bytes += element_size(lh, length);
57     julong size_in_words = ((size_in_bytes + (HeapWordSize-1)) >> LogHeapWordSize);
58     assert(size_in_words <= (julong)max_jint, "no overflow");
59     return align_object_size((intptr_t)size_in_words);
60   }
61 
62   int object_size(int lh) const;
63 
64 };
65 
66 // See similar requirement for oopDesc.
67 static_assert(std::is_trivially_default_constructible<flatArrayOopDesc>::value, "required");
68 
69 #endif // SHARE_VM_OOPS_FLATARRAYOOP_HPP