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 // Addresses used for value type calling convention 46 *((Array<SigEntry>**)adr_extended_sig()) = NULL; 47 *((Array<VMRegPair>**)adr_return_regs()) = NULL; 48 *((address*)adr_pack_handler()) = NULL; 49 *((address*)adr_unpack_handler()) = NULL; 50 assert(pack_handler() == NULL, "pack handler not null"); 51 } 52 53 address adr_extended_sig() const { 54 address adr_vcc = adr_vcc_klass(); 55 if (adr_vcc == NULL) { 56 address adr_jf = adr_value_fields_klasses(); 57 if (adr_jf != NULL) { 58 return adr_jf + this->java_fields_count() * sizeof(Klass*); 59 } 60 61 address adr_fing = adr_fingerprint(); 62 if (adr_fing != NULL) { 63 return adr_fingerprint() + sizeof(u8); 64 } 65 66 InstanceKlass** adr_host = adr_host_klass(); 67 if (adr_host != NULL) { 68 return (address)(adr_host + 1); 69 } 70 71 Klass** adr_impl = adr_implementor(); 72 if (adr_impl != NULL) { 73 return (address)(adr_impl + 1); 74 } 75 76 return (address)end_of_nonstatic_oop_maps(); 77 } else { 78 return adr_vcc + sizeof(Klass*); 79 } 80 } 81 82 address adr_return_regs() const { 83 return adr_extended_sig() + sizeof(intptr_t); 84 } 85 86 // pack and unpack handlers for value types return 87 address adr_pack_handler() const { 88 return (address)this + in_bytes(pack_handler_offset()); 89 } 90 91 address adr_unpack_handler() const { 92 return (address)this + in_bytes(unpack_handler_offset()); 93 } 94 95 address pack_handler() const { 96 return *(address*)adr_pack_handler(); 97 } 98 99 address unpack_handler() const { 100 return *(address*)adr_unpack_handler(); 101 } 102 103 // static Klass* array_klass_impl(InstanceKlass* this_k, bool or_null, int n, TRAPS); 104 105 GrowableArray<SigEntry> collect_fields(int base_off = 0) const; 106 107 void cleanup_blobs(); 108 109 protected: 110 // Returns the array class for the n'th dimension 111 Klass* array_klass_impl(bool or_null, int n, TRAPS); 112 113 // Returns the array class with this class as element type 114 Klass* array_klass_impl(bool or_null, TRAPS); 115 116 public: 117 // Type testing 118 bool is_value_slow() const { return true; } 119 bool is__Value() const { return (this == SystemDictionary::___Value_klass()); } 120 121 // Casting from Klass* 122 static ValueKlass* cast(Klass* k) { 123 assert(k->is_value(), "cast to ValueKlass"); 124 return (ValueKlass*) k; 125 } 126 127 // Use this to return the size of an instance in heap words 128 // Implementation is currently simple because all value types are allocated 129 // in Java heap like Java objects. 130 virtual int size_helper() const { 131 return layout_helper_to_size_helper(layout_helper()); 132 } 133 134 // allocate_instance() allocates a stand alone value in the Java heap 135 instanceOop allocate_instance(TRAPS); 136 // allocate_buffered_or_heap_instance() tries to allocate a value in the 137 // thread local value buffer, if allocation fails, it allocates it in the 138 // Java heap 139 instanceOop allocate_buffered_or_heap_instance(bool* in_heap, TRAPS); 140 141 // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2 142 int raw_value_byte_size() const; 143 144 int first_field_offset() const; 145 146 address data_for_oop(oop o) const { 147 return ((address) (void*) o) + first_field_offset(); 148 } 149 150 oop oop_for_data(address data) const { 151 oop o = (oop) (data - first_field_offset()); 152 assert(oopDesc::is_oop(o, false), "Not an oop"); 153 return o; 154 } 155 156 void set_if_bufferable() { 157 bool bufferable; 158 if (contains_oops()) { 159 bufferable = false; 160 } else { 161 int size_in_heap_words = size_helper(); 162 int base_offset = instanceOopDesc::base_offset_in_bytes(); 163 size_t size_in_bytes = size_in_heap_words * HeapWordSize - base_offset; 164 bufferable = size_in_bytes <= BigValueTypeThreshold; 165 } 166 if (bufferable) { 167 _extra_flags |= _extra_is_bufferable; 168 } else { 169 _extra_flags &= ~_extra_is_bufferable; 170 } 171 } 172 173 bool is_bufferable() const { 174 return (_extra_flags & _extra_is_bufferable) != 0; 175 } 176 177 // Query if h/w provides atomic load/store 178 bool is_atomic(); 179 180 bool flatten_array(); 181 182 bool contains_oops() const { return nonstatic_oop_map_count() > 0; } 183 int nonstatic_oop_count(); 184 185 // Prototype general store methods... 186 187 // copy the fields, with no concern for GC barriers 188 void raw_field_copy(void* src, void* dst, size_t raw_byte_size); 189 190 void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) { 191 value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized); 192 } 193 194 // store the value of this klass contained with src into dst, raw data ptr 195 void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized); 196 197 oop unbox(Handle src, InstanceKlass* target_klass, TRAPS); 198 oop box(Handle src, InstanceKlass* target_klass, TRAPS); 199 200 // GC support... 201 202 // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element) 203 template <bool nv, typename T, class OopClosureType> 204 inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure); 205 206 template <bool nv, typename T, class OopClosureType> 207 inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi); 208 209 // calling convention support 210 void initialize_calling_convention(); 211 Array<SigEntry>* extended_sig() const { 212 assert(!is__Value(), "make no sense for __Value"); 213 return *((Array<SigEntry>**)adr_extended_sig()); 214 } 215 Array<VMRegPair>* return_regs() const { 216 assert(!is__Value(), "make no sense for __Value"); 217 return *((Array<VMRegPair>**)adr_return_regs()); 218 } 219 bool can_be_returned_as_fields() const; 220 void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const; 221 void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const; 222 oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, bool buffered, TRAPS); 223 static ValueKlass* returned_value_klass(const RegisterMap& reg_map); 224 225 // pack and unpack handlers. Need to be loadable from generated code 226 // so at a fixed offset from the base of the klass pointer. 227 static ByteSize pack_handler_offset() { 228 return in_ByteSize(InstanceKlass::header_size() * wordSize); 229 } 230 231 static ByteSize unpack_handler_offset() { 232 return in_ByteSize((InstanceKlass::header_size()+1) * wordSize); 233 } 234 235 void deallocate_contents(ClassLoaderData* loader_data); 236 static void cleanup(ValueKlass* ik) ; 237 }; 238 239 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */