1 /* 2 * Copyright (c) 2017, 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 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_OOPS_VALUEKLASS_HPP 26 #define SHARE_VM_OOPS_VALUEKLASS_HPP 27 28 #include "oops/instanceKlass.hpp" 29 #include "oops/method.hpp" 30 #include "oops/oop.inline.hpp" 31 32 // A ValueKlass is a specialized InstanceKlass for value types. 33 34 35 class ValueKlass: public InstanceKlass { 36 friend class VMStructs; 37 friend class InstanceKlass; 38 39 private: 40 41 // Constructor 42 ValueKlass(const ClassFileParser& parser) 43 : InstanceKlass(parser, InstanceKlass::_misc_kind_value_type) { 44 set_has_vcc_klass(); 45 } 46 47 // static Klass* array_klass_impl(InstanceKlass* this_k, bool or_null, int n, TRAPS); 48 protected: 49 // Returns the array class for the n'th dimension 50 Klass* array_klass_impl(bool or_null, int n, TRAPS); 51 52 // Returns the array class with this class as element type 53 Klass* array_klass_impl(bool or_null, TRAPS); 54 55 public: 56 // Type testing 57 bool is_value_slow() const { return true; } 58 59 // Casting from Klass* 60 static ValueKlass* cast(Klass* k) { 61 assert(k->is_value(), "cast to ValueKlass"); 62 return (ValueKlass*) k; 63 } 64 65 // Use this to return the size of an instance in heap words 66 // Implementation is currently simple because all value types are allocated 67 // in Java heap like Java objects. 68 virtual int size_helper() const { 69 return layout_helper_to_size_helper(layout_helper()); 70 } 71 72 // allocate_instance() allocates a stand alone value in the Java heap 73 instanceOop allocate_instance(TRAPS); 74 // allocate_buffered_or_heap_instance() tries to allocate a value in the 75 // thread local value buffer, if allocation fails, it allocates it in the 76 // Java heap 77 instanceOop allocate_buffered_or_heap_instance(bool* in_heap, TRAPS); 78 79 // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2 80 int raw_value_byte_size() const; 81 82 int first_field_offset() const; 83 84 address data_for_oop(oop o) const { 85 return ((address) (void*) o) + first_field_offset(); 86 } 87 88 oop oop_for_data(address data) const { 89 oop o = (oop) (data - first_field_offset()); 90 assert(o->is_oop(false), "Not an oop"); 91 return o; 92 } 93 94 void set_if_bufferable() { 95 bool bufferable; 96 if (contains_oops()) { 97 bufferable = false; 98 } else { 99 int size_in_heap_words = size_helper(); 100 int base_offset = instanceOopDesc::base_offset_in_bytes(); 101 size_t size_in_bytes = size_in_heap_words * HeapWordSize - base_offset; 102 bufferable = size_in_bytes <= BigValueTypeThreshold; 103 } 104 if (bufferable) { 105 _extra_flags |= _extra_is_bufferable; 106 } else { 107 _extra_flags &= ~_extra_is_bufferable; 108 } 109 } 110 111 bool is_bufferable() const { 112 return (_extra_flags & _extra_is_bufferable) != 0; 113 } 114 115 // Query if h/w provides atomic load/store 116 bool is_atomic(); 117 118 bool flatten_array(); 119 120 bool contains_oops() const { return nonstatic_oop_map_count() > 0; } 121 int nonstatic_oop_count(); 122 123 // Prototype general store methods... 124 125 // copy the fields, with no concern for GC barriers 126 void raw_field_copy(void* src, void* dst, size_t raw_byte_size); 127 128 void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) { 129 value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized); 130 } 131 132 // store the value of this klass contained with src into dst, raw data ptr 133 void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized); 134 135 oop unbox(Handle src, InstanceKlass* target_klass, TRAPS); 136 oop box(Handle src, InstanceKlass* target_klass, TRAPS); 137 138 // GC support... 139 140 // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element) 141 template <bool nv, typename T, class OopClosureType> 142 inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure); 143 144 template <bool nv, typename T, class OopClosureType> 145 inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi); 146 147 // calling convention support 148 GrowableArray<SigEntry> collect_fields(int base_off = 0) const; 149 GrowableArray<SigEntry> return_convention(VMRegPair*& regs, int& nb_fields) const; 150 void save_oop_fields(const GrowableArray<SigEntry>& sig_vk, RegisterMap& map, const VMRegPair* regs, GrowableArray<Handle>& handles, int nb_fields) const; 151 bool save_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const; 152 void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const; 153 oop realloc_result(const GrowableArray<SigEntry>& sig_vk, const RegisterMap& reg_map, const VMRegPair* regs, const GrowableArray<Handle>& handles, int nb_fields, TRAPS); 154 static ValueKlass* returned_value_type(const RegisterMap& reg_map); 155 }; 156 157 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */