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