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 "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 pack_handler() const {
 103     return *(address*)adr_pack_handler();
 104   }
 105 
 106   address unpack_handler() const {
 107     return *(address*)adr_unpack_handler();
 108   }
 109 
 110   address adr_default_value_offset() const {
 111     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 112     return ((address)_adr_valueklass_fixed_block) + in_bytes(default_value_offset_offset());
 113   }
 114 
 115   address adr_value_array_klass() const {
 116     assert(_adr_valueklass_fixed_block != NULL, "Should have been initialized");
 117     return ((address)_adr_valueklass_fixed_block) + in_bytes(byte_offset_of(ValueKlassFixedBlock, _value_array_klass));
 118   }
 119 
 120   Klass* get_value_array_klass() const {
 121     return *(Klass**)adr_value_array_klass();
 122   }
 123 
 124   Klass* acquire_value_array_klass() const {
 125     return OrderAccess::load_acquire((Klass**)adr_value_array_klass());
 126   }
 127 
 128   Klass* allocate_value_array_klass(TRAPS);
 129 
 130   int collect_fields(GrowableArray<SigEntry>* sig, int base_off = 0) const;
 131 
 132   void cleanup_blobs();
 133 
 134  protected:
 135   // Returns the array class for the n'th dimension
 136   Klass* array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS);
 137 
 138   // Returns the array class with this class as element type
 139   Klass* array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS);
 140 
 141   // Specifically flat array klass
 142   Klass* value_array_klass(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS);
 143 
 144  public:
 145   // Type testing
 146   bool is_value_slow() const        { return true; }
 147 
 148   oop value_mirror() const {
 149     return java_lang_Class::value_mirror(java_mirror());
 150   }
 151 
 152   // Casting from Klass*
 153   static ValueKlass* cast(Klass* k) {
 154     assert(k->is_value(), "cast to ValueKlass");
 155     return (ValueKlass*) k;
 156   }
 157 
 158   // Use this to return the size of an instance in heap words
 159   // Implementation is currently simple because all value types are allocated
 160   // in Java heap like Java objects.
 161   virtual int size_helper() const {
 162     return layout_helper_to_size_helper(layout_helper());
 163   }
 164 
 165   // Metadata iterators
 166   void array_klasses_do(void f(Klass* k));
 167 
 168   // allocate_instance() allocates a stand alone value in the Java heap
 169   instanceOop allocate_instance(TRAPS);
 170 
 171   // minimum number of bytes occupied by nonstatic fields, HeapWord aligned or pow2
 172   int raw_value_byte_size() const;
 173 
 174   int first_field_offset() const;
 175 
 176   address data_for_oop(oop o) const {
 177     return ((address) (void*) o) + first_field_offset();
 178   }
 179 
 180   oop oop_for_data(address data) const {
 181     oop o = (oop) (data - first_field_offset());
 182     assert(oopDesc::is_oop(o, false), "Not an oop");
 183     return o;
 184   }
 185 
 186   // Query if h/w provides atomic load/store
 187   bool is_atomic();
 188 
 189   bool flatten_array();
 190 
 191   bool contains_oops() const { return nonstatic_oop_map_count() > 0; }
 192   int nonstatic_oop_count();
 193 
 194   // Prototype general store methods...
 195 
 196   // copy the fields, with no concern for GC barriers
 197   void raw_field_copy(void* src, void* dst, size_t raw_byte_size);
 198 
 199   void value_store(void* src, void* dst, bool dst_is_heap, bool dst_uninitialized) {
 200     value_store(src, dst, nonstatic_field_size() << LogBytesPerHeapOop, dst_is_heap, dst_uninitialized);
 201   }
 202 
 203   // store the value of this klass contained with src into dst, raw data ptr
 204   void value_store(void* src, void* dst, size_t raw_byte_size, bool dst_is_heap, bool dst_uninitialized);
 205 
 206   // GC support...
 207   void iterate_over_inside_oops(OopClosure* f, oop value);
 208 
 209   // oop iterate raw value type data pointer (where oop_addr may not be an oop, but backing/array-element)
 210   template <typename T, class OopClosureType>
 211   inline void oop_iterate_specialized(const address oop_addr, OopClosureType* closure);
 212 
 213   template <typename T, class OopClosureType>
 214   inline void oop_iterate_specialized_bounded(const address oop_addr, OopClosureType* closure, void* lo, void* hi);
 215 
 216   // calling convention support
 217   void initialize_calling_convention(TRAPS);
 218   Array<SigEntry>* extended_sig() const {
 219     return *((Array<SigEntry>**)adr_extended_sig());
 220   }
 221   Array<VMRegPair>* return_regs() const {
 222     return *((Array<VMRegPair>**)adr_return_regs());
 223   }
 224   bool can_be_returned_as_fields() const;
 225   void save_oop_fields(const RegisterMap& map, GrowableArray<Handle>& handles) const;
 226   void restore_oop_results(RegisterMap& map, GrowableArray<Handle>& handles) const;
 227   oop realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS);
 228   static ValueKlass* returned_value_klass(const RegisterMap& reg_map);
 229 
 230   // pack and unpack handlers. Need to be loadable from generated code
 231   // so at a fixed offset from the base of the klass pointer.
 232   static ByteSize pack_handler_offset() {
 233     return byte_offset_of(ValueKlassFixedBlock, _pack_handler);
 234   }
 235 
 236   static ByteSize unpack_handler_offset() {
 237     return byte_offset_of(ValueKlassFixedBlock, _unpack_handler);
 238   }
 239 
 240   static ByteSize default_value_offset_offset() {
 241     return byte_offset_of(ValueKlassFixedBlock, _default_value_offset);
 242   }
 243 
 244   void set_default_value_offset(int offset) {
 245     *((int*)adr_default_value_offset()) = offset;
 246   }
 247 
 248   int default_value_offset() {
 249     int offset = *((int*)adr_default_value_offset());
 250     assert(offset != 0, "must not be called if not initialized");
 251     return offset;
 252   }
 253 
 254   void set_default_value(oop val) {
 255     java_mirror()->obj_field_put(default_value_offset(), val);
 256   }
 257 
 258   oop default_value() {
 259     oop val = java_mirror()->obj_field_acquire(default_value_offset());
 260     assert(oopDesc::is_oop(val), "Sanity check");
 261     assert(val->is_value(), "Sanity check");
 262     assert(val->klass() == this, "sanity check");
 263     return val;
 264   }
 265 
 266   void deallocate_contents(ClassLoaderData* loader_data);
 267   static void cleanup(ValueKlass* ik) ;
 268 
 269   // Verification
 270   void verify_on(outputStream* st);
 271   void oop_verify_on(oop obj, outputStream* st);
 272 
 273 };
 274 
 275 #endif /* SHARE_VM_OOPS_VALUEKLASS_HPP */