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, InstanceKlass::ID) {
44 _adr_valueklass_fixed_block = valueklass_static_bloc();
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 *((int*)adr_default_value_offset()) = 0;
52 assert(Klass::ptr_is_value_type(this), "Value type klass ptr encoding");
53 set_prototype_header(markOopDesc::always_locked_prototype());
54 }
55
56 ValueKlassFixedBlock* valueklass_static_bloc() const {
57 address adr_jf = adr_value_fields_klasses();
58 if (adr_jf != NULL) {
59 return (ValueKlassFixedBlock*)(adr_jf + this->java_fields_count() * sizeof(Klass*));
60 }
61
62 address adr_fing = adr_fingerprint();
63 if (adr_fing != NULL) {
64 return (ValueKlassFixedBlock*)(adr_fingerprint() + sizeof(u8));
65 }
66
67 InstanceKlass** adr_host = adr_host_klass();
68 if (adr_host != NULL) {
69 return (ValueKlassFixedBlock*)(adr_host + 1);
70 }
71
72 Klass** adr_impl = adr_implementor();
73 if (adr_impl != NULL) {
74 return (ValueKlassFixedBlock*)(adr_impl + 1);
75 }
76
77 return (ValueKlassFixedBlock*)end_of_nonstatic_oop_maps();
78 }
79
80 address adr_extended_sig() const {
81 assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
82 return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _extended_sig));
83 }
84
85 address adr_return_regs() const {
86 ValueKlassFixedBlock* vkst = valueklass_static_bloc();
87 return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _return_regs));
88 }
89
90 // pack and unpack handlers for value types return
91 address adr_pack_handler() const {
92 assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
93 return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _pack_handler));
94 }
95
96 address adr_unpack_handler() const {
97 assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
98 return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _unpack_handler));
99 }
100
101 address pack_handler() const {
102 return *(address*)adr_pack_handler();
103 }
104
105 address unpack_handler() const {
106 return *(address*)adr_unpack_handler();
107 }
108
109 address adr_default_value_offset() const {
110 assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
111 return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _default_value_offset));
112 }
113
114 // static Klass* array_klass_impl(InstanceKlass* this_k, bool or_null, int n, TRAPS);
115
116 GrowableArray<SigEntry> collect_fields(int base_off = 0) const;
117
118 void cleanup_blobs();
119
120 protected:
121 // Returns the array class for the n'th dimension
122 Klass* array_klass_impl(bool or_null, int n, TRAPS);
123
124 // Returns the array class with this class as element type
125 Klass* array_klass_impl(bool or_null, TRAPS);
126
127 public:
128 // Type testing
129 bool is_value_slow() const { return true; }
130
131 // Casting from Klass*
132 static ValueKlass* cast(Klass* k) {
133 assert(k->is_value(), "cast to ValueKlass");
134 return (ValueKlass*) k;
135 }
136
137 // Use this to return the size of an instance in heap words
138 // Implementation is currently simple because all value types are allocated
139 // in Java heap like Java objects.
140 virtual int size_helper() const {
141 return layout_helper_to_size_helper(layout_helper());
142 }
143
144 // allocate_instance() allocates a stand alone value in the Java heap
145 instanceOop allocate_instance(TRAPS);
146 // allocate_buffered_or_heap_instance() tries to allocate a value in the
147 // thread local value buffer, if allocation fails, it allocates it in the
148 // Java heap
149 instanceOop allocate_buffered_or_heap_instance(bool* in_heap, TRAPS);
150
151 // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2
152 int raw_value_byte_size() const;
153
154 int first_field_offset() const;
155
156 address data_for_oop(oop o) const {
157 return ((address) (void*) o) + first_field_offset();
158 }
159
160 oop oop_for_data(address data) const {
161 oop o = (oop) (data - first_field_offset());
162 assert(oopDesc::is_oop(o, false), "Not an oop");
163 return o;
164 }
165
166 void set_if_bufferable() {
167 bool bufferable;
168
169 int size_in_heap_words = size_helper();
170 int base_offset = instanceOopDesc::base_offset_in_bytes();
171 size_t size_in_bytes = size_in_heap_words * HeapWordSize - base_offset;
172 bufferable = size_in_bytes <= BigValueTypeThreshold;
173 if (size_in_bytes > VTBufferChunk::max_alloc_size()) bufferable = false;
174 if (ValueTypesBufferMaxMemory == 0) bufferable = false;
175
176 if (bufferable) {
177 _extra_flags |= _extra_is_bufferable;
178 } else {
179 _extra_flags &= ~_extra_is_bufferable;
180 }
181 }
182
183 bool is_bufferable() const {
184 return (_extra_flags & _extra_is_bufferable) != 0;
185 }
186
187 // Query if h/w provides atomic load/store
188 bool is_atomic();
189
190 bool flatten_array();
191
192 bool contains_oops() const { return nonstatic_oop_map_count() > 0; }
193 int nonstatic_oop_count();
194
195 // Prototype general store methods...
196
197 // copy the fields, with no concern for GC barriers
198 void raw_field_copy(void* src, void* dst, size_t raw_byte_size);
199
200 void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) {
201 value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized);
202 }
203
204 // store the value of this klass contained with src into dst, raw data ptr
205 void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized);
206
207 // GC support...
208
209 void iterate_over_inside_oops(OopClosure* f, oop value);
210
211 // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element)
212 template <typename T, class OopClosureType>
213 inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure);
214
215 template <typename T, class OopClosureType>
216 inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi);
217
218 // calling convention support
219 void initialize_calling_convention();
220 Array<SigEntry>* extended_sig() const {
221 return *((Array<SigEntry>**)adr_extended_sig());
222 }
223 Array<VMRegPair>* return_regs() const {
224 return *((Array<VMRegPair>**)adr_return_regs());
225 }
226 bool can_be_returned_as_fields() const;
227 void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const;
228 void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const;
229 oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, bool buffered, TRAPS);
230 static ValueKlass* returned_value_klass(const RegisterMap& reg_map);
231
232 // pack and unpack handlers. Need to be loadable from generated code
233 // so at a fixed offset from the base of the klass pointer.
234 static ByteSize pack_handler_offset() {
235 fatal("Should be re-implemented using the ValueKlassStaticBlock indirection");
236 return in_ByteSize(InstanceKlass::header_size() * wordSize);
237 }
238
239 static ByteSize unpack_handler_offset() {
240 fatal("Should be re-implemented using the ValueKlassStaticBlock indirection");
241 return in_ByteSize((InstanceKlass::header_size()+1) * wordSize);
242 }
243
244 static ByteSize default_value_offset_offset() {
245 fatal("Should be re-implemented using the ValueKlassStaticBlock indirection");
246 return in_ByteSize((InstanceKlass::header_size()+2) * wordSize);
247 }
248
249 void set_default_value_offset(int offset) {
250 *((int*)adr_default_value_offset()) = offset;
251 }
252
253 int default_value_offset() {
254 int offset = *((int*)adr_default_value_offset());
255 assert(offset != 0, "must not be called if not initialized");
256 return offset;
257 }
258
259 void set_default_value(oop val) {
260 java_mirror()->obj_field_put(default_value_offset(), val);
261 }
262
263 oop default_value() {
264 oop val = java_mirror()->obj_field_acquire(default_value_offset());
265 assert(oopDesc::is_oop(val), "Sanity check");
266 assert(val->is_value(), "Sanity check");
267 assert(val->klass() == this, "sanity check");
268 return val;
269 }
270
271 void deallocate_contents(ClassLoaderData* loader_data);
272 static void cleanup(ValueKlass* ik) ;
273
274 // Verification
275 void verify_on(outputStream* st);
276 void oop_verify_on(oop obj, outputStream* st);
277
278 };
279
280 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */