1 /*
  2  * Copyright (c) 2017, 2020, 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_INLINEKLASS_HPP
 26 #define SHARE_VM_OOPS_INLINEKLASS_HPP
 27 
 28 #include "classfile/classFileParser.hpp"
 29 #include "classfile/javaClasses.hpp"
 30 #include "oops/instanceKlass.hpp"
 31 #include "oops/method.hpp"
 32 #include "runtime/registerMap.hpp"
 33 //#include "oops/oop.inline.hpp"
 34 
 35 // An InlineKlass is a specialized InstanceKlass for inline types.
 36 
 37 
 38 class InlineKlass: public InstanceKlass {
 39   friend class VMStructs;
 40   friend class InstanceKlass;
 41   friend class ClassFileParser;
 42 
 43  public:
 44   static const KlassKind Kind = InlineKlassKind;
 45 
 46   InlineKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 47 
 48  private:
 49 
 50   // Constructor
 51   InlineKlass(const ClassFileParser& parser);
 52 
 53   void init_fixed_block();
 54   inline InlineKlassFixedBlock* inlineklass_static_block() const;
 55   inline address adr_return_regs() const;
 56 
 57   address adr_extended_sig() const {
 58     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 59     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _extended_sig));
 60   }
 61 
 62   // pack and unpack handlers for inline types return
 63   address adr_pack_handler() const {
 64     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 65     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _pack_handler));
 66   }
 67 
 68   address adr_pack_handler_jobject() const {
 69     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 70     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _pack_handler_jobject));
 71   }
 72 
 73   address adr_unpack_handler() const {
 74     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 75     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _unpack_handler));
 76   }
 77 
 78   address adr_default_value_offset() const {
 79     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 80     return ((address)_adr_inlineklass_fixed_block) + in_bytes(default_value_offset_offset());
 81   }
 82 
 83   ArrayKlass* volatile* adr_value_array_klasses() const {
 84     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 85     return (ArrayKlass* volatile*) ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _null_free_inline_array_klasses));
 86   }
 87 
 88   ArrayKlass* value_array_klasses() const {
 89     return *adr_value_array_klasses();
 90   }
 91 
 92   address adr_alignment() const {
 93     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 94     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _alignment));
 95   }
 96 
 97   address adr_first_field_offset() const {
 98     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
 99     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _first_field_offset));
100   }
101 
102   address adr_exact_size_in_bytes() const {
103     assert(_adr_inlineklass_fixed_block != nullptr, "Should have been initialized");
104     return ((address)_adr_inlineklass_fixed_block) + in_bytes(byte_offset_of(InlineKlassFixedBlock, _exact_size_in_bytes));
105   }
106 
107  public:
108   int get_alignment() const {
109     return *(int*)adr_alignment();
110   }
111 
112   void set_alignment(int alignment) {
113     *(int*)adr_alignment() = alignment;
114   }
115 
116   int first_field_offset() const {
117     int offset = *(int*)adr_first_field_offset();
118     assert(offset != 0, "Must be initialized before use");
119     return *(int*)adr_first_field_offset();
120   }
121 
122   void set_first_field_offset(int offset) {
123     *(int*)adr_first_field_offset() = offset;
124   }
125 
126   int get_exact_size_in_bytes() const {
127     return *(int*)adr_exact_size_in_bytes();
128   }
129 
130   void set_exact_size_in_bytes(int exact_size) {
131     *(int*)adr_exact_size_in_bytes() = exact_size;
132   }
133 
134   int first_field_offset_old();
135 
136   virtual void remove_unshareable_info();
137   virtual void remove_java_mirror();
138   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
139   virtual void metaspace_pointers_do(MetaspaceClosure* it);
140 
141  private:
142   int collect_fields(GrowableArray<SigEntry>* sig, int base_off = 0);
143 
144   void cleanup_blobs();
145 
146  public:
147   // Type testing
148   bool is_inline_klass_slow() const        { return true; }
149   bool is_null_free() const { return access_flags().is_primitive_class(); }
150 
151   // ref and val mirror
152   oop ref_mirror() const { return java_mirror(); }
153   oop val_mirror() const { return java_lang_Class::secondary_mirror(java_mirror()); }
154 
155   // naming
156   const char* ref_signature_name() const {
157     return InstanceKlass::signature_name_of_carrier(JVM_SIGNATURE_CLASS);
158   }
159   const char* val_signature_name() const {
160     return InstanceKlass::signature_name_of_carrier(JVM_SIGNATURE_PRIMITIVE_OBJECT);
161   }
162 
163   // Casting from Klass*
164   static InlineKlass* cast(Klass* k);
165 
166   // Use this to return the size of an instance in heap words.
167   // Note that this size only applies to heap allocated stand-alone instances.
168   virtual int size_helper() const {
169     return layout_helper_to_size_helper(layout_helper());
170   }
171 
172   // allocate_instance() allocates a stand alone value in the Java heap
173   // initialized to default value (cleared memory)
174   instanceOop allocate_instance(TRAPS);
175   // allocates a stand alone inline buffer in the Java heap
176   // DOES NOT have memory cleared, user MUST initialize payload before
177   // returning to Java (i.e.: inline_copy)
178   instanceOop allocate_instance_buffer(TRAPS);
179 
180   address data_for_oop(oop o) const;
181 
182   // Query if this class promises atomicity one way or another
183   bool is_atomic() { return is_naturally_atomic() || is_declared_atomic(); }
184 
185   bool flat_array();
186 
187   bool contains_oops() const { return nonstatic_oop_map_count() > 0; }
188   int nonstatic_oop_count();
189 
190   // null free inline arrays...
191   //
192 
193   // null free inline array klass, akin to InstanceKlass::array_klass()
194   // Returns the array class for the n'th dimension
195   Klass* value_array_klass(int n, TRAPS);
196   Klass* value_array_klass_or_null(int n);
197 
198   // Returns the array class with this class as element type
199   Klass* value_array_klass(TRAPS);
200   Klass* value_array_klass_or_null();
201 
202 
203   // General store methods
204   //
205   // Normally loads and store methods would be found in *Oops classes, but since values can be
206   // "in-lined" (flat layout) into containing oops, these methods reside here in InlineKlass.
207   //
208   // "inline_copy_*_to_new_*" assume new memory (i.e. IS_DEST_UNINITIALIZED for write barriers)
209 
210   void inline_copy_payload_to_new_oop(void* src, oop dst);
211   void inline_copy_oop_to_new_oop(oop src, oop dst);
212   void inline_copy_oop_to_new_payload(oop src, void* dst);
213   void inline_copy_oop_to_payload(oop src, void* dst);
214 
215   oop read_flat_field(oop obj, int offset, TRAPS);
216   void write_flat_field(oop obj, int offset, oop value, TRAPS);
217 
218   // oop iterate raw inline type data pointer (where oop_addr may not be an oop, but backing/array-element)
219   template <typename T, class OopClosureType>
220   inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure);
221 
222   template <typename T, class OopClosureType>
223   inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi);
224 
225   // calling convention support
226   void initialize_calling_convention(TRAPS);
227   Array<SigEntry>* extended_sig() const {
228     return *((Array<SigEntry>**)adr_extended_sig());
229   }
230   inline Array<VMRegPair>* return_regs() const;
231   bool can_be_passed_as_fields() const;
232   bool can_be_returned_as_fields(bool init = false) const;
233   void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const;
234   void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const;
235   oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS);
236   static InlineKlass* returned_inline_klass(const RegisterMap& reg_map);
237 
238   address pack_handler() const {
239     return *(address*)adr_pack_handler();
240   }
241 
242   address unpack_handler() const {
243     return *(address*)adr_unpack_handler();
244   }
245 
246   // pack and unpack handlers. Need to be loadable from generated code
247   // so at a fixed offset from the base of the klass pointer.
248   static ByteSize pack_handler_offset() {
249     return byte_offset_of(InlineKlassFixedBlock, _pack_handler);
250   }
251 
252   static ByteSize pack_handler_jobject_offset() {
253     return byte_offset_of(InlineKlassFixedBlock, _pack_handler_jobject);
254   }
255 
256   static ByteSize unpack_handler_offset() {
257     return byte_offset_of(InlineKlassFixedBlock, _unpack_handler);
258   }
259 
260   static ByteSize default_value_offset_offset() {
261     return byte_offset_of(InlineKlassFixedBlock, _default_value_offset);
262   }
263 
264   static ByteSize first_field_offset_offset() {
265     return byte_offset_of(InlineKlassFixedBlock, _first_field_offset);
266   }
267 
268   void set_default_value_offset(int offset) {
269     *((int*)adr_default_value_offset()) = offset;
270   }
271 
272   int default_value_offset() {
273     int offset = *((int*)adr_default_value_offset());
274     assert(offset != 0, "must not be called if not initialized");
275     return offset;
276   }
277 
278   void set_default_value(oop val) {
279     java_mirror()->obj_field_put(default_value_offset(), val);
280   }
281 
282   oop default_value();
283   void deallocate_contents(ClassLoaderData* loader_data);
284   static void cleanup(InlineKlass* ik) ;
285 
286   // Verification
287   void verify_on(outputStream* st);
288   void oop_verify_on(oop obj, outputStream* st);
289 
290 };
291 
292 #endif /* SHARE_VM_OOPS_INLINEKLASS_HPP */