1 /*
   2  * Copyright (c) 2017, 2019, 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 "classfile/javaClasses.hpp"
  29 #include "oops/instanceKlass.hpp"
  30 #include "oops/method.hpp"
  31 #include "oops/oop.inline.hpp"
  32 
  33 // A ValueKlass is a specialized InstanceKlass for value types.
  34 
  35 
  36 class ValueKlass: public InstanceKlass {
  37   friend class VMStructs;
  38   friend class InstanceKlass;
  39 
  40  private:
  41 
  42   // Constructor
  43   ValueKlass(const ClassFileParser& parser)
  44     : InstanceKlass(parser, InstanceKlass::_misc_kind_value_type, InstanceKlass::ID) {
  45     _adr_valueklass_fixed_block = valueklass_static_block();
  46     // Addresses used for value type calling convention
  47     *((Array<SigEntry>**)adr_extended_sig()) = NULL;
  48     *((Array<VMRegPair>**)adr_return_regs()) = NULL;
  49     *((address*)adr_pack_handler()) = NULL;
  50     *((address*)adr_unpack_handler()) = NULL;
  51     assert(pack_handler() == NULL, "pack handler not null");
  52     *((int*)adr_default_value_offset()) = 0;
  53     *((Klass**)adr_value_array_klass()) = NULL;
  54     set_prototype_header(markOopDesc::always_locked_prototype());
  55   }
  56 
  57   ValueKlassFixedBlock* valueklass_static_block() const {
  58     address adr_jf = adr_value_fields_klasses();
  59     if (adr_jf != NULL) {
  60       return (ValueKlassFixedBlock*)(adr_jf + this->java_fields_count() * sizeof(Klass*));
  61     }
  62 
  63     address adr_fing = adr_fingerprint();
  64     if (adr_fing != NULL) {
  65       return (ValueKlassFixedBlock*)(adr_fingerprint() + sizeof(u8));
  66     }
  67 
  68     InstanceKlass** adr_host = adr_unsafe_anonymous_host();
  69     if (adr_host != NULL) {
  70       return (ValueKlassFixedBlock*)(adr_host + 1);
  71     }
  72 
  73     Klass* volatile* adr_impl = adr_implementor();
  74     if (adr_impl != NULL) {
  75       return (ValueKlassFixedBlock*)(adr_impl + 1);
  76     }
  77 
  78     return (ValueKlassFixedBlock*)end_of_nonstatic_oop_maps();
  79   }
  80 
  81   address adr_extended_sig() const {
  82     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
  83     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _extended_sig));
  84   }
  85 
  86   address adr_return_regs() const {
  87     ValueKlassFixedBlock* vkst = valueklass_static_block();
  88     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _return_regs));
  89   }
  90 
  91   // pack and unpack handlers for value types return
  92   address adr_pack_handler() const {
  93     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
  94     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _pack_handler));
  95   }
  96 
  97   address adr_unpack_handler() const {
  98     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
  99     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _unpack_handler));
 100   }
 101 
 102   address adr_default_value_offset() const {
 103     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 104     return ((address)_adr_valueklass_fixed_block) + in_bytes(default_value_offset_offset());
 105   }
 106 
 107   address adr_value_array_klass() const {
 108     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 109     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _value_array_klass));
 110   }
 111 
 112   Klass* get_value_array_klass() const {
 113     return *(Klass**)adr_value_array_klass();
 114   }
 115 
 116   Klass* acquire_value_array_klass() const {
 117     return OrderAccess::load_acquire((Klass**)adr_value_array_klass());
 118   }
 119 
 120   Klass* allocate_value_array_klass(TRAPS);
 121 
 122   address adr_alignment() const {
 123     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 124     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _alignment));
 125   }
 126 
 127   address adr_first_field_offset() const {
 128     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 129     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _first_field_offset));
 130   }
 131 
 132   address adr_exact_size_in_bytes() const {
 133     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 134     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _exact_size_in_bytes));
 135   }
 136 
 137  public:
 138   int get_alignment() const {
 139     return *(int*)adr_alignment();
 140   }
 141 
 142   void set_alignment(int alignment) {
 143     *(int*)adr_alignment() = alignment;
 144   }
 145 
 146   int get_first_field_offset() const {
 147     int offset = *(int*)adr_first_field_offset();
 148     assert(offset != 0, "Must be initialized before use");
 149     return *(int*)adr_first_field_offset();
 150   }
 151 
 152   void set_first_field_offset(int offset) {
 153     *(int*)adr_first_field_offset() = offset;
 154   }
 155 
 156   int get_exact_size_in_bytes() {
 157     return *(int*)adr_exact_size_in_bytes();
 158   }
 159 
 160   void set_exact_size_in_bytes(int exact_size) {
 161     *(int*)adr_exact_size_in_bytes() = exact_size;
 162   }
 163 
 164  private:
 165   int collect_fields(GrowableArray<SigEntry>* sig, int base_off = 0) const;
 166 
 167   void cleanup_blobs();
 168 
 169   int first_field_offset_old() const;
 170 
 171  protected:
 172   // Returns the array class for the n'th dimension
 173   Klass* array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS);
 174 
 175   // Returns the array class with this class as element type
 176   Klass* array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS);
 177 
 178   // Specifically flat array klass
 179   Klass* value_array_klass(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS);
 180 
 181  public:
 182   // Type testing
 183   bool is_value_slow() const        { return true; }
 184 
 185   // value_mirror is the primary mirror
 186   oop value_mirror() const    { return java_lang_Class::inline_type_mirror(java_mirror()); }
 187   oop indirect_mirror() const { return java_lang_Class::indirect_type_mirror(java_mirror()); }
 188 
 189   // Casting from Klass*
 190   static ValueKlass* cast(Klass* k) {
 191     assert(k->is_value(), "cast to ValueKlass");
 192     return (ValueKlass*) k;
 193   }
 194 
 195   // Use this to return the size of an instance in heap words
 196   // Implementation is currently simple because all value types are allocated
 197   // in Java heap like Java objects.
 198   virtual int size_helper() const {
 199     return layout_helper_to_size_helper(layout_helper());
 200   }
 201 
 202   // Metadata iterators
 203   void array_klasses_do(void f(Klass* k));
 204 
 205   // allocate_instance() allocates a stand alone value in the Java heap
 206   instanceOop allocate_instance(TRAPS);
 207 
 208   // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2
 209   int raw_value_byte_size() const;
 210 
 211   int first_field_offset() const {
 212     // To be refactored/simplified once old layout code and UseNewLayout are removed
 213     if (UseNewLayout) {
 214       return get_first_field_offset();
 215     } else {
 216       return first_field_offset_old();
 217     }
 218   };
 219 
 220   address data_for_oop(oop o) const {
 221     return ((address) (void*) o) + first_field_offset();
 222   }
 223 
 224   oop oop_for_data(address data) const {
 225     oop o = (oop) (data - first_field_offset());
 226     assert(oopDesc::is_oop(o, false), "Not an oop");
 227     return o;
 228   }
 229 
 230   // Query if h/w provides atomic load/store
 231   bool is_atomic();
 232 
 233   bool flatten_array();
 234 
 235   bool contains_oops() const { return nonstatic_oop_map_count() > 0; }
 236   int nonstatic_oop_count();
 237 
 238   // Prototype general store methods...
 239 
 240   // copy the fields, with no concern for GC barriers
 241   void raw_field_copy(void* src, void* dst, size_t raw_byte_size);
 242 
 243   void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) {
 244     value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized);
 245   }
 246 
 247   // store the value of this klass contained with src into dst, raw data ptr
 248   void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized);
 249 
 250   // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element)
 251   template <typename T, class OopClosureType>
 252   inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure);
 253 
 254   template <typename T, class OopClosureType>
 255   inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi);
 256 
 257   // calling convention support
 258   void initialize_calling_convention(TRAPS);
 259   Array<SigEntry>* extended_sig() const {
 260     return *((Array<SigEntry>**)adr_extended_sig());
 261   }
 262   Array<VMRegPair>* return_regs() const {
 263     return *((Array<VMRegPair>**)adr_return_regs());
 264   }
 265   bool is_scalarizable() const;
 266   bool can_be_returned_as_fields() const;
 267   void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const;
 268   void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const;
 269   oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS);
 270   static ValueKlass* returned_value_klass(const RegisterMap& reg_map);
 271 
 272   address pack_handler() const {
 273     return *(address*)adr_pack_handler();
 274   }
 275 
 276   address unpack_handler() const {
 277     return *(address*)adr_unpack_handler();
 278   }
 279 
 280   // pack and unpack handlers. Need to be loadable from generated code
 281   // so at a fixed offset from the base of the klass pointer.
 282   static ByteSize pack_handler_offset() {
 283     return byte_offset_of(ValueKlassFixedBlock, _pack_handler);
 284   }
 285 
 286   static ByteSize unpack_handler_offset() {
 287     return byte_offset_of(ValueKlassFixedBlock, _unpack_handler);
 288   }
 289 
 290   static ByteSize default_value_offset_offset() {
 291     return byte_offset_of(ValueKlassFixedBlock, _default_value_offset);
 292   }
 293 
 294   void set_default_value_offset(int offset) {
 295     *((int*)adr_default_value_offset()) = offset;
 296   }
 297 
 298   int default_value_offset() {
 299     int offset = *((int*)adr_default_value_offset());
 300     assert(offset != 0, "must not be called if not initialized");
 301     return offset;
 302   }
 303 
 304   void set_default_value(oop val) {
 305     java_mirror()->obj_field_put(default_value_offset(), val);
 306     indirect_mirror()->obj_field_put(default_value_offset(), val);
 307   }
 308 
 309   oop default_value() {
 310     oop val = java_mirror()->obj_field_acquire(default_value_offset());
 311     assert(oopDesc::is_oop(val), "Sanity check");
 312     assert(val->is_value(), "Sanity check");
 313     assert(val->klass() == this, "sanity check");
 314     return val;
 315   }
 316 
 317   void deallocate_contents(ClassLoaderData* loader_data);
 318   static void cleanup(ValueKlass* ik) ;
 319 
 320   // Verification
 321   void verify_on(outputStream* st);
 322   void oop_verify_on(oop obj, outputStream* st);
 323 
 324 };
 325 
 326 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */