1 /* 2 * Copyright (c) 1997, 2016, 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_OOP_HPP 26 #define SHARE_VM_OOPS_OOP_HPP 27 28 #include "gc/shared/specialized_oop_closures.hpp" 29 #include "memory/iterator.hpp" 30 #include "memory/memRegion.hpp" 31 #include "oops/metadata.hpp" 32 #include "utilities/macros.hpp" 33 #include "runtime/atomic.hpp" 34 35 // oopDesc is the top baseclass for objects classes. The {name}Desc classes describe 36 // the format of Java objects so the fields can be accessed from C++. 37 // oopDesc is abstract. 38 // (see oopHierarchy for complete oop class hierarchy) 39 // 40 // no virtual functions allowed 41 42 // store into oop with store check 43 template <class T> inline void oop_store(T* p, oop v); 44 template <class T> inline void oop_store(volatile T* p, oop v); 45 46 extern bool always_do_update_barrier; 47 48 // Forward declarations. 49 class OopClosure; 50 class ScanClosure; 51 class FastScanClosure; 52 class FilteringClosure; 53 class BarrierSet; 54 class CMSIsAliveClosure; 55 56 class PSPromotionManager; 57 class ParCompactionManager; 58 59 class oopDesc { 60 friend class VMStructs; 61 friend class JVMCIVMStructs; 62 private: 63 volatile markOop _mark; 64 union _metadata { 65 Klass* _klass; 66 narrowKlass _compressed_klass; 67 } _metadata; 68 69 // Fast access to barrier set. Must be initialized. 70 static BarrierSet* _bs; 71 72 public: 73 markOop mark() const { return _mark; } 74 markOop* mark_addr() const { return (markOop*) &_mark; } 75 76 void set_mark(volatile markOop m) { _mark = m; } 77 78 inline void release_set_mark(markOop m); 79 inline markOop cas_set_mark(markOop new_mark, markOop old_mark, cmpxchg_memory_order order = memory_order_conservative); 80 81 // Used only to re-initialize the mark word (e.g., of promoted 82 // objects during a GC) -- requires a valid klass pointer 83 inline void init_mark(); 84 85 inline Klass* klass() const; 86 inline Klass* klass_or_null() const volatile; 87 inline Klass** klass_addr(); 88 inline narrowKlass* compressed_klass_addr(); 89 90 inline void set_klass(Klass* k); 91 92 // For klass field compression 93 inline int klass_gap() const; 94 inline void set_klass_gap(int z); 95 // For when the klass pointer is being used as a linked list "next" field. 96 inline void set_klass_to_list_ptr(oop k); 97 inline oop list_ptr_from_klass(); 98 99 // size of object header, aligned to platform wordSize 100 static int header_size() { return sizeof(oopDesc)/HeapWordSize; } 101 102 // Returns whether this is an instance of k or an instance of a subclass of k 103 inline bool is_a(Klass* k) const; 104 105 // Returns the actual oop size of the object 106 inline int size(); 107 108 // Sometimes (for complicated concurrency-related reasons), it is useful 109 // to be able to figure out the size of an object knowing its klass. 110 inline int size_given_klass(Klass* klass); 111 112 // type test operations (inlined in oop.inline.hpp) 113 inline bool is_instance() const; 114 inline bool is_array() const; 115 inline bool is_objArray() const; 116 inline bool is_typeArray() const; 117 118 // type test operations that don't require inclusion of oop.inline.hpp. 119 bool is_instance_noinline() const; 120 bool is_array_noinline() const; 121 bool is_objArray_noinline() const; 122 bool is_typeArray_noinline() const; 123 124 private: 125 // field addresses in oop 126 inline void* field_base(int offset) const; 127 128 inline jbyte* byte_field_addr(int offset) const; 129 inline jchar* char_field_addr(int offset) const; 130 inline jboolean* bool_field_addr(int offset) const; 131 inline jint* int_field_addr(int offset) const; 132 inline jshort* short_field_addr(int offset) const; 133 inline jlong* long_field_addr(int offset) const; 134 inline jfloat* float_field_addr(int offset) const; 135 inline jdouble* double_field_addr(int offset) const; 136 inline Metadata** metadata_field_addr(int offset) const; 137 138 public: 139 // Need this as public for garbage collection. 140 template <class T> inline T* obj_field_addr(int offset) const; 141 142 // Needed for javaClasses 143 inline address* address_field_addr(int offset) const; 144 145 inline static bool is_null(oop obj) { return obj == NULL; } 146 inline static bool is_null(narrowOop obj) { return obj == 0; } 147 148 // Decode an oop pointer from a narrowOop if compressed. 149 // These are overloaded for oop and narrowOop as are the other functions 150 // below so that they can be called in template functions. 151 static inline oop decode_heap_oop_not_null(oop v) { return v; } 152 static inline oop decode_heap_oop_not_null(narrowOop v); 153 static inline oop decode_heap_oop(oop v) { return v; } 154 static inline oop decode_heap_oop(narrowOop v); 155 156 // Encode an oop pointer to a narrow oop. The or_null versions accept 157 // null oop pointer, others do not in order to eliminate the 158 // null checking branches. 159 static inline narrowOop encode_heap_oop_not_null(oop v); 160 static inline narrowOop encode_heap_oop(oop v); 161 162 // Load an oop out of the Java heap as is without decoding. 163 // Called by GC to check for null before decoding. 164 static inline narrowOop load_heap_oop(narrowOop* p) { return *p; } 165 static inline oop load_heap_oop(oop* p) { return *p; } 166 167 // Load an oop out of Java heap and decode it to an uncompressed oop. 168 static inline oop load_decode_heap_oop_not_null(narrowOop* p); 169 static inline oop load_decode_heap_oop_not_null(oop* p) { return *p; } 170 static inline oop load_decode_heap_oop(narrowOop* p); 171 static inline oop load_decode_heap_oop(oop* p) { return *p; } 172 173 // Store already encoded heap oop into the heap. 174 static inline void store_heap_oop(narrowOop* p, narrowOop v) { *p = v; } 175 static inline void store_heap_oop(oop* p, oop v) { *p = v; } 176 177 // Encode oop if UseCompressedOops and store into the heap. 178 static inline void encode_store_heap_oop_not_null(narrowOop* p, oop v); 179 static inline void encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; } 180 static inline void encode_store_heap_oop(narrowOop* p, oop v); 181 static inline void encode_store_heap_oop(oop* p, oop v) { *p = v; } 182 183 static inline void release_store_heap_oop(volatile narrowOop* p, narrowOop v); 184 static inline void release_store_heap_oop(volatile oop* p, oop v); 185 186 static inline void release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v); 187 static inline void release_encode_store_heap_oop_not_null(volatile oop* p, oop v); 188 static inline void release_encode_store_heap_oop(volatile narrowOop* p, oop v); 189 static inline void release_encode_store_heap_oop(volatile oop* p, oop v); 190 191 static inline oop atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest); 192 static inline oop atomic_compare_exchange_oop(oop exchange_value, 193 volatile HeapWord *dest, 194 oop compare_value, 195 bool prebarrier = false); 196 197 // Access to fields in a instanceOop through these methods. 198 inline oop obj_field(int offset) const; 199 inline void obj_field_put(int offset, oop value); 200 inline void obj_field_put_raw(int offset, oop value); 201 inline void obj_field_put_volatile(int offset, oop value); 202 203 inline Metadata* metadata_field(int offset) const; 204 inline void metadata_field_put(int offset, Metadata* value); 205 206 inline jbyte byte_field(int offset) const; 207 inline void byte_field_put(int offset, jbyte contents); 208 209 inline jchar char_field(int offset) const; 210 inline void char_field_put(int offset, jchar contents); 211 212 inline jboolean bool_field(int offset) const; 213 inline void bool_field_put(int offset, jboolean contents); 214 215 inline jint int_field(int offset) const; 216 inline void int_field_put(int offset, jint contents); 217 218 inline jshort short_field(int offset) const; 219 inline void short_field_put(int offset, jshort contents); 220 221 inline jlong long_field(int offset) const; 222 inline void long_field_put(int offset, jlong contents); 223 224 inline jfloat float_field(int offset) const; 225 inline void float_field_put(int offset, jfloat contents); 226 227 inline jdouble double_field(int offset) const; 228 inline void double_field_put(int offset, jdouble contents); 229 230 inline address address_field(int offset) const; 231 inline void address_field_put(int offset, address contents); 232 233 inline oop obj_field_acquire(int offset) const; 234 inline void release_obj_field_put(int offset, oop value); 235 236 inline jbyte byte_field_acquire(int offset) const; 237 inline void release_byte_field_put(int offset, jbyte contents); 238 239 inline jchar char_field_acquire(int offset) const; 240 inline void release_char_field_put(int offset, jchar contents); 241 242 inline jboolean bool_field_acquire(int offset) const; 243 inline void release_bool_field_put(int offset, jboolean contents); 244 245 inline jint int_field_acquire(int offset) const; 246 inline void release_int_field_put(int offset, jint contents); 247 248 inline jshort short_field_acquire(int offset) const; 249 inline void release_short_field_put(int offset, jshort contents); 250 251 inline jlong long_field_acquire(int offset) const; 252 inline void release_long_field_put(int offset, jlong contents); 253 254 inline jfloat float_field_acquire(int offset) const; 255 inline void release_float_field_put(int offset, jfloat contents); 256 257 inline jdouble double_field_acquire(int offset) const; 258 inline void release_double_field_put(int offset, jdouble contents); 259 260 inline address address_field_acquire(int offset) const; 261 inline void release_address_field_put(int offset, address contents); 262 263 // printing functions for VM debugging 264 void print_on(outputStream* st) const; // First level print 265 void print_value_on(outputStream* st) const; // Second level print. 266 void print_address_on(outputStream* st) const; // Address printing 267 268 // printing on default output stream 269 void print(); 270 void print_value(); 271 void print_address(); 272 273 // return the print strings 274 char* print_string(); 275 char* print_value_string(); 276 277 // verification operations 278 void verify_on(outputStream* st); 279 void verify(); 280 281 // locking operations 282 inline bool is_locked() const; 283 inline bool is_unlocked() const; 284 inline bool has_bias_pattern() const; 285 286 // asserts 287 inline bool is_oop(bool ignore_mark_word = false) const; 288 inline bool is_oop_or_null(bool ignore_mark_word = false) const; 289 #ifndef PRODUCT 290 inline bool is_unlocked_oop() const; 291 #endif 292 293 // garbage collection 294 inline bool is_gc_marked() const; 295 296 inline bool is_scavengable() const; 297 298 // Forward pointer operations for scavenge 299 inline bool is_forwarded() const; 300 301 inline void forward_to(oop p); 302 inline bool cas_forward_to(oop p, markOop compare, cmpxchg_memory_order order = memory_order_conservative); 303 304 #if INCLUDE_ALL_GCS 305 // Like "forward_to", but inserts the forwarding pointer atomically. 306 // Exactly one thread succeeds in inserting the forwarding pointer, and 307 // this call returns "NULL" for that thread; any other thread has the 308 // value of the forwarding pointer returned and does not modify "this". 309 inline oop forward_to_atomic(oop p); 310 #endif // INCLUDE_ALL_GCS 311 312 inline oop forwardee() const; 313 314 // Age of object during scavenge 315 inline uint age() const; 316 inline void incr_age(); 317 318 // mark-sweep support 319 void follow_body(int begin, int end); 320 321 // Fast access to barrier set 322 static BarrierSet* bs() { return _bs; } 323 static void set_bs(BarrierSet* bs) { _bs = bs; } 324 325 // Garbage Collection support 326 327 // Mark Sweep 328 // Adjust all pointers in this object to point at it's forwarded location and 329 // return the size of this oop. This is used by the MarkSweep collector. 330 inline int ms_adjust_pointers(); 331 #if INCLUDE_ALL_GCS 332 // Parallel Compact 333 inline void pc_follow_contents(ParCompactionManager* cm); 334 inline void pc_update_contents(ParCompactionManager* cm); 335 // Parallel Scavenge 336 inline void ps_push_contents(PSPromotionManager* pm); 337 #endif 338 339 340 // iterators, returns size of object 341 #define OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 342 inline void oop_iterate(OopClosureType* blk); \ 343 inline void oop_iterate(OopClosureType* blk, MemRegion mr); // Only in mr. 344 345 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DECL) 346 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DECL) 347 348 #define OOP_ITERATE_SIZE_DECL(OopClosureType, nv_suffix) \ 349 inline int oop_iterate_size(OopClosureType* blk); \ 350 inline int oop_iterate_size(OopClosureType* blk, MemRegion mr); // Only in mr. 351 352 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_SIZE_DECL) 353 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_SIZE_DECL) 354 355 356 #if INCLUDE_ALL_GCS 357 358 #define OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 359 inline void oop_iterate_backwards(OopClosureType* blk); 360 361 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DECL) 362 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DECL) 363 364 #endif // INCLUDE_ALL_GCS 365 366 inline int oop_iterate_no_header(OopClosure* bk); 367 inline int oop_iterate_no_header(OopClosure* bk, MemRegion mr); 368 369 // identity hash; returns the identity hash key (computes it if necessary) 370 // NOTE with the introduction of UseBiasedLocking that identity_hash() might reach a 371 // safepoint if called on a biased object. Calling code must be aware of that. 372 inline intptr_t identity_hash(); 373 intptr_t slow_identity_hash(); 374 375 // Alternate hashing code if string table is rehashed 376 unsigned int new_hash(juint seed); 377 378 // marks are forwarded to stack when object is locked 379 inline bool has_displaced_mark() const; 380 inline markOop displaced_mark() const; 381 inline void set_displaced_mark(markOop m); 382 383 static bool has_klass_gap(); 384 385 // for code generation 386 static int mark_offset_in_bytes() { return offset_of(oopDesc, _mark); } 387 static int klass_offset_in_bytes() { return offset_of(oopDesc, _metadata._klass); } 388 static int klass_gap_offset_in_bytes() { 389 assert(has_klass_gap(), "only applicable to compressed klass pointers"); 390 return klass_offset_in_bytes() + sizeof(narrowKlass); 391 } 392 }; 393 394 #endif // SHARE_VM_OOPS_OOP_HPP --- EOF ---