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   int collect_fields(GrowableArray<SigEntry>* sig, int base_off = 0) const;
 123 
 124   void cleanup_blobs();
 125 
 126  protected:
 127   // Returns the array class for the n'th dimension
 128   Klass* array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS);
 129 
 130   // Returns the array class with this class as element type
 131   Klass* array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS);
 132 
 133   // Specifically flat array klass
 134   Klass* value_array_klass(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS);
 135 
 136  public:
 137   // Type testing
 138   bool is_value_slow() const        { return true; }
 139 
 140   // value_mirror is the primary mirror
 141   oop value_mirror() const    { return java_lang_Class::inline_type_mirror(java_mirror()); }
 142   oop indirect_mirror() const { return java_lang_Class::indirect_type_mirror(java_mirror()); }
 143 
 144   // Casting from Klass*
 145   static ValueKlass* cast(Klass* k) {
 146     assert(k->is_value(), "cast to ValueKlass");
 147     return (ValueKlass*) k;
 148   }
 149 
 150   // Use this to return the size of an instance in heap words
 151   // Implementation is currently simple because all value types are allocated
 152   // in Java heap like Java objects.
 153   virtual int size_helper() const {
 154     return layout_helper_to_size_helper(layout_helper());
 155   }
 156 
 157   // Metadata iterators
 158   void array_klasses_do(void f(Klass* k));
 159 
 160   // allocate_instance() allocates a stand alone value in the Java heap
 161   instanceOop allocate_instance(TRAPS);
 162 
 163   // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2
 164   int raw_value_byte_size() const;
 165 
 166   int first_field_offset() const;
 167 
 168   address data_for_oop(oop o) const {
 169     return ((address) (void*) o) + first_field_offset();
 170   }
 171 
 172   oop oop_for_data(address data) const {
 173     oop o = (oop) (data - first_field_offset());
 174     assert(oopDesc::is_oop(o, false), "Not an oop");
 175     return o;
 176   }
 177 
 178   // Query if h/w provides atomic load/store
 179   bool is_atomic();
 180 
 181   bool flatten_array();
 182 
 183   bool contains_oops() const { return nonstatic_oop_map_count() > 0; }
 184   int nonstatic_oop_count();
 185 
 186   // Prototype general store methods...
 187 
 188   // copy the fields, with no concern for GC barriers
 189   void raw_field_copy(void* src, void* dst, size_t raw_byte_size);
 190 
 191   void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) {
 192     value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized);
 193   }
 194 
 195   // store the value of this klass contained with src into dst, raw data ptr
 196   void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized);
 197 
 198   // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element)
 199   template <typename T, class OopClosureType>
 200   inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure);
 201 
 202   template <typename T, class OopClosureType>
 203   inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi);
 204 
 205   // calling convention support
 206   void initialize_calling_convention(TRAPS);
 207   Array<SigEntry>* extended_sig() const {
 208     return *((Array<SigEntry>**)adr_extended_sig());
 209   }
 210   Array<VMRegPair>* return_regs() const {
 211     return *((Array<VMRegPair>**)adr_return_regs());
 212   }
 213   bool is_scalarizable() const;
 214   bool can_be_returned_as_fields() const;
 215   void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const;
 216   void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const;
 217   oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS);
 218   static ValueKlass* returned_value_klass(const RegisterMap& reg_map);
 219 
 220   address pack_handler() const {
 221     return *(address*)adr_pack_handler();
 222   }
 223 
 224   address unpack_handler() const {
 225     return *(address*)adr_unpack_handler();
 226   }
 227 
 228   // pack and unpack handlers. Need to be loadable from generated code
 229   // so at a fixed offset from the base of the klass pointer.
 230   static ByteSize pack_handler_offset() {
 231     return byte_offset_of(ValueKlassFixedBlock, _pack_handler);
 232   }
 233 
 234   static ByteSize unpack_handler_offset() {
 235     return byte_offset_of(ValueKlassFixedBlock, _unpack_handler);
 236   }
 237 
 238   static ByteSize default_value_offset_offset() {
 239     return byte_offset_of(ValueKlassFixedBlock, _default_value_offset);
 240   }
 241 
 242   void set_default_value_offset(int offset) {
 243     *((int*)adr_default_value_offset()) = offset;
 244   }
 245 
 246   int default_value_offset() {
 247     int offset = *((int*)adr_default_value_offset());
 248     assert(offset != 0, "must not be called if not initialized");
 249     return offset;
 250   }
 251 
 252   void set_default_value(oop val) {
 253     java_mirror()->obj_field_put(default_value_offset(), val);
 254     indirect_mirror()->obj_field_put(default_value_offset(), val);
 255   }
 256 
 257   oop default_value() {
 258     oop val = java_mirror()->obj_field_acquire(default_value_offset());
 259     assert(oopDesc::is_oop(val), "Sanity check");
 260     assert(val->is_value(), "Sanity check");
 261     assert(val->klass() == this, "sanity check");
 262     return val;
 263   }
 264 
 265   void deallocate_contents(ClassLoaderData* loader_data);
 266   static void cleanup(ValueKlass* ik) ;
 267 
 268   // Verification
 269   void verify_on(outputStream* st);
 270   void oop_verify_on(oop obj, outputStream* st);
 271 
 272 };
 273 
 274 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */
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