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 address adr_extended_sig() const { 48 address adr_vcc = adr_vcc_klass(); 49 if (adr_vcc == NULL) { 50 address adr_jf = adr_value_fields_klasses(); 51 if (adr_jf != NULL) { 52 return adr_jf + this->java_fields_count() * sizeof(Klass*); 53 } 54 55 address adr_fing = adr_fingerprint(); 56 if (adr_fing != NULL) { 57 return adr_fingerprint() + sizeof(u8); 58 } 59 60 InstanceKlass** adr_host = adr_host_klass(); 61 if (adr_host != NULL) { 62 return (address)(adr_host + 1); 63 } 64 65 Klass** adr_impl = adr_implementor(); 66 if (adr_impl != NULL) { 67 return (address)(adr_impl + 1); 68 } 69 70 return (address)end_of_nonstatic_oop_maps(); 71 } else { 72 return adr_vcc + sizeof(Klass*); 73 } 74 } 75 76 address adr_return_regs() const { 77 return adr_extended_sig() + sizeof(intptr_t); 78 } 79 80 // pack and unpack handlers for value types return 81 address adr_pack_handler() const { 82 return (address)this + in_bytes(pack_handler_offset()); 83 } 84 85 address adr_unpack_handler() const { 86 return (address)this + in_bytes(unpack_handler_offset()); 87 } 88 89 address pack_handler() const { 90 return *(address*)adr_pack_handler(); 91 } 92 93 address unpack_handler() const { 94 return *(address*)adr_unpack_handler(); 95 } 96 97 // static Klass* array_klass_impl(InstanceKlass* this_k, bool or_null, int n, TRAPS); 98 99 GrowableArray<SigEntry> collect_fields(int base_off = 0) const; 100 101 void cleanup_blobs(); 102 103 protected: 104 // Returns the array class for the n'th dimension 105 Klass* array_klass_impl(bool or_null, int n, TRAPS); 106 107 // Returns the array class with this class as element type 108 Klass* array_klass_impl(bool or_null, TRAPS); 109 110 public: 111 // Type testing 112 bool is_value_slow() const { return true; } 113 114 // Casting from Klass* 115 static ValueKlass* cast(Klass* k) { 116 assert(k->is_value(), "cast to ValueKlass"); 117 return (ValueKlass*) k; 118 } 119 120 // Use this to return the size of an instance in heap words 121 // Implementation is currently simple because all value types are allocated 122 // in Java heap like Java objects. 123 virtual int size_helper() const { 124 return layout_helper_to_size_helper(layout_helper()); 125 } 126 127 // allocate_instance() allocates a stand alone value in the Java heap 128 instanceOop allocate_instance(TRAPS); 129 // allocate_buffered_or_heap_instance() tries to allocate a value in the 130 // thread local value buffer, if allocation fails, it allocates it in the 131 // Java heap 132 instanceOop allocate_buffered_or_heap_instance(bool* in_heap, TRAPS); 133 134 // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2 135 int raw_value_byte_size() const; 136 137 int first_field_offset() const; 138 139 address data_for_oop(oop o) const { 140 return ((address) (void*) o) + first_field_offset(); 141 } 142 143 oop oop_for_data(address data) const { 144 oop o = (oop) (data - first_field_offset()); 145 assert(o->is_oop(false), "Not an oop"); 146 return o; 147 } 148 149 void set_if_bufferable() { 150 bool bufferable; 151 if (contains_oops()) { 152 bufferable = false; 153 } else { 154 int size_in_heap_words = size_helper(); 155 int base_offset = instanceOopDesc::base_offset_in_bytes(); 156 size_t size_in_bytes = size_in_heap_words * HeapWordSize - base_offset; 157 bufferable = size_in_bytes <= BigValueTypeThreshold; 158 } 159 if (bufferable) { 160 _extra_flags |= _extra_is_bufferable; 161 } else { 162 _extra_flags &= ~_extra_is_bufferable; 163 } 164 } 165 166 bool is_bufferable() const { 167 return (_extra_flags & _extra_is_bufferable) != 0; 168 } 169 170 // Query if h/w provides atomic load/store 171 bool is_atomic(); 172 173 bool flatten_array(); 174 175 bool contains_oops() const { return nonstatic_oop_map_count() > 0; } 176 int nonstatic_oop_count(); 177 178 // Prototype general store methods... 179 180 // copy the fields, with no concern for GC barriers 181 void raw_field_copy(void* src, void* dst, size_t raw_byte_size); 182 183 void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) { 184 value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized); 185 } 186 187 // store the value of this klass contained with src into dst, raw data ptr 188 void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized); 189 190 oop unbox(Handle src, InstanceKlass* target_klass, TRAPS); 191 oop box(Handle src, InstanceKlass* target_klass, TRAPS); 192 193 // GC support... 194 195 // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element) 196 template <bool nv, typename T, class OopClosureType> 197 inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure); 198 199 template <bool nv, typename T, class OopClosureType> 200 inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi); 201 202 // calling convention support 203 void initialize_calling_convention(); 204 Array<SigEntry>* extended_sig() const { 205 assert(this != SystemDictionary::___Value_klass(), "make no sense for __Value"); 206 return *((Array<SigEntry>**)adr_extended_sig()); 207 } 208 Array<VMRegPair>* return_regs() const { 209 assert(this != SystemDictionary::___Value_klass(), "make no sense for __Value"); 210 return *((Array<VMRegPair>**)adr_return_regs()); 211 } 212 void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const; 213 bool save_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const; 214 void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const; 215 oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, bool buffered, TRAPS); 216 static ValueKlass* returned_value_type(const RegisterMap& reg_map); 217 218 // pack and unpack handlers. Need to be loadable from generated code 219 // so at a fixed offset from the base of the klass pointer. 220 static ByteSize pack_handler_offset() { 221 return in_ByteSize(InstanceKlass::header_size() * wordSize); 222 } 223 224 static ByteSize unpack_handler_offset() { 225 return in_ByteSize((InstanceKlass::header_size()+1) * wordSize); 226 } 227 228 void deallocate_contents(ClassLoaderData* loader_data); 229 static void cleanup(ValueKlass* ik) ; 230 }; 231 232 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */