oop.hpp (original) (raw)

1 /* 2 * Copyright (c) 1997, 2015, 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 "utilities/top.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 void oop_store(T p, oop v); 44 template 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 private: 62 volatile markOop _mark; 63 union _metadata { 64 Klass* _klass; 65 narrowKlass _compressed_klass; 66 } _metadata; 67 68 // Fast access to barrier set. Must be initialized. 69 static BarrierSet* _bs; 70 71 public: 72 markOop mark() const { return _mark; } 73 markOop* mark_addr() const { return (markOop*) &_mark; } 74 75 void set_mark(volatile markOop m) { _mark = m; } 76 77 void release_set_mark(markOop m); 78 markOop cas_set_mark(markOop new_mark, markOop old_mark); 79 80 // Used only to re-initialize the mark word (e.g., of promoted 81 // objects during a GC) -- requires a valid klass pointer 82 void init_mark(); 83 84 Klass* klass() const; 85 Klass* klass_or_null() const volatile; 86 Klass** klass_addr(); 87 narrowKlass* compressed_klass_addr(); 88 89 void set_klass(Klass* k); 90 91 // For klass field compression 92 int klass_gap() const; 93 void set_klass_gap(int z); 94 // For when the klass pointer is being used as a linked list "next" field. 95 void set_klass_to_list_ptr(oop k); 96 oop list_ptr_from_klass(); 97 98 // size of object header, aligned to platform wordSize 99 static int header_size() { return sizeof(oopDesc)/HeapWordSize; } 100 101 // Returns whether this is an instance of k or an instance of a subclass of k 102 bool is_a(Klass* k) const; 103 104 // Returns the actual oop size of the object 105 int size(); 106 107 // Sometimes (for complicated concurrency-related reasons), it is useful 108 // to be able to figure out the size of an object knowing its klass. 109 int size_given_klass(Klass* klass); 110 111 // type test operations (inlined in oop.inline.hpp) 112 bool is_instance() const; 113 bool is_array() const; 114 bool is_objArray() const; 115 bool is_typeArray() const; 116 117 // type test operations that don't require inclusion of oop.inline.hpp. 118 bool is_instance_noinline() const; 119 bool is_array_noinline() const; 120 bool is_objArray_noinline() const; 121 bool is_typeArray_noinline() const; 122 123 private: 124 // field addresses in oop 125 void* field_base(int offset) const; 126 127 jbyte* byte_field_addr(int offset) const; 128 jchar* char_field_addr(int offset) const; 129 jboolean* bool_field_addr(int offset) const; 130 jint* int_field_addr(int offset) const; 131 jshort* short_field_addr(int offset) const; 132 jlong* long_field_addr(int offset) const; 133 jfloat* float_field_addr(int offset) const; 134 jdouble* double_field_addr(int offset) const; 135 Metadata** metadata_field_addr(int offset) const; 136 137 public: 138 // Need this as public for garbage collection. 139 template T* obj_field_addr(int offset) const; 140 141 // Needed for javaClasses 142 address* address_field_addr(int offset) const; 143 144 static bool is_null(oop obj); 145 static bool is_null(narrowOop obj); 146 147 // Decode an oop pointer from a narrowOop if compressed. 148 // These are overloaded for oop and narrowOop as are the other functions 149 // below so that they can be called in template functions. 150 static oop decode_heap_oop_not_null(oop v); 151 static oop decode_heap_oop_not_null(narrowOop v); 152 static oop decode_heap_oop(oop v); 153 static oop decode_heap_oop(narrowOop v); 154 155 // Encode an oop pointer to a narrow oop. The or_null versions accept 156 // null oop pointer, others do not in order to eliminate the 157 // null checking branches. 158 static narrowOop encode_heap_oop_not_null(oop v); 159 static narrowOop encode_heap_oop(oop v); 160 161 // Load an oop out of the Java heap 162 static narrowOop load_heap_oop(narrowOop* p); 163 static oop load_heap_oop(oop* p); 164 165 // Load an oop out of Java heap and decode it to an uncompressed oop. 166 static oop load_decode_heap_oop_not_null(narrowOop* p); 167 static oop load_decode_heap_oop_not_null(oop* p); 168 static oop load_decode_heap_oop(narrowOop* p); 169 static oop load_decode_heap_oop(oop* p); 170 171 // Store an oop into the heap. 172 static void store_heap_oop(narrowOop* p, narrowOop v); 173 static void store_heap_oop(oop* p, oop v); 174 175 // Encode oop if UseCompressedOops and store into the heap. 176 static void encode_store_heap_oop_not_null(narrowOop* p, oop v); 177 static void encode_store_heap_oop_not_null(oop* p, oop v); 178 static void encode_store_heap_oop(narrowOop* p, oop v); 179 static void encode_store_heap_oop(oop* p, oop v); 180 181 static void release_store_heap_oop(volatile narrowOop* p, narrowOop v); 182 static void release_store_heap_oop(volatile oop* p, oop v); 183 184 static void release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v); 185 static void release_encode_store_heap_oop_not_null(volatile oop* p, oop v); 186 static void release_encode_store_heap_oop(volatile narrowOop* p, oop v); 187 static void release_encode_store_heap_oop(volatile oop* p, oop v); 188 189 static oop atomic_exchange_oop(oop exchange_value, volatile HeapWord dest); 190 static oop atomic_compare_exchange_oop(oop exchange_value, 191 volatile HeapWord dest, 192 oop compare_value, 193 bool prebarrier = false); 194 195 // Access to fields in a instanceOop through these methods. 196 oop obj_field(int offset) const; 197 void obj_field_put(int offset, oop value); 198 void obj_field_put_raw(int offset, oop value); 199 void obj_field_put_volatile(int offset, oop value); 200 201 Metadata metadata_field(int offset) const; 202 void metadata_field_put(int offset, Metadata value); 203 204 jbyte byte_field(int offset) const; 205 void byte_field_put(int offset, jbyte contents); 206 207 jchar char_field(int offset) const; 208 void char_field_put(int offset, jchar contents); 209 210 jboolean bool_field(int offset) const; 211 void bool_field_put(int offset, jboolean contents); 212 213 jint int_field(int offset) const; 214 void int_field_put(int offset, jint contents); 215 216 jshort short_field(int offset) const; 217 void short_field_put(int offset, jshort contents); 218 219 jlong long_field(int offset) const; 220 void long_field_put(int offset, jlong contents); 221 222 jfloat float_field(int offset) const; 223 void float_field_put(int offset, jfloat contents); 224 225 jdouble double_field(int offset) const; 226 void double_field_put(int offset, jdouble contents); 227 228 address address_field(int offset) const; 229 void address_field_put(int offset, address contents); 230 231 oop obj_field_acquire(int offset) const; 232 void release_obj_field_put(int offset, oop value); 233 234 jbyte byte_field_acquire(int offset) const; 235 void release_byte_field_put(int offset, jbyte contents); 236 237 jchar char_field_acquire(int offset) const; 238 void release_char_field_put(int offset, jchar contents); 239 240 jboolean bool_field_acquire(int offset) const; 241 void release_bool_field_put(int offset, jboolean contents); 242 243 jint int_field_acquire(int offset) const; 244 void release_int_field_put(int offset, jint contents); 245 246 jshort short_field_acquire(int offset) const; 247 void release_short_field_put(int offset, jshort contents); 248 249 jlong long_field_acquire(int offset) const; 250 void release_long_field_put(int offset, jlong contents); 251 252 jfloat float_field_acquire(int offset) const; 253 void release_float_field_put(int offset, jfloat contents); 254 255 jdouble double_field_acquire(int offset) const; 256 void release_double_field_put(int offset, jdouble contents); 257 258 address address_field_acquire(int offset) const; 259 void release_address_field_put(int offset, address contents); 260 261 // printing functions for VM debugging 262 void print_on(outputStream* st) const; // First level print 263 void print_value_on(outputStream* st) const; // Second level print. 264 void print_address_on(outputStream* st) const; // Address printing 265 266 // printing on default output stream 267 void print(); 268 void print_value(); 269 void print_address(); 270 271 // return the print strings 272 char* print_string(); 273 char* print_value_string(); 274 275 // verification operations 276 void verify_on(outputStream* st); 277 void verify(); 278 279 // locking operations 280 bool is_locked() const; 281 bool is_unlocked() const; 282 bool has_bias_pattern() const; 283 284 // asserts 285 bool is_oop(bool ignore_mark_word = false) const; 286 bool is_oop_or_null(bool ignore_mark_word = false) const; 287 #ifndef PRODUCT 288 bool is_unlocked_oop() const; 289 #endif 290 291 // garbage collection 292 bool is_gc_marked() const; 293 294 bool is_scavengable() const; 295 296 // Forward pointer operations for scavenge 297 bool is_forwarded() const; 298 299 void forward_to(oop p); 300 bool cas_forward_to(oop p, markOop compare); 301 302 #if INCLUDE_ALL_GCS 303 // Like "forward_to", but inserts the forwarding pointer atomically. 304 // Exactly one thread succeeds in inserting the forwarding pointer, and 305 // this call returns "NULL" for that thread; any other thread has the 306 // value of the forwarding pointer returned and does not modify "this". 307 oop forward_to_atomic(oop p); 308 #endif // INCLUDE_ALL_GCS 309 310 oop forwardee() const; 311 312 // Age of object during scavenge 313 uint age() const; 314 void incr_age(); 315 316 317 // mark-sweep support 318 void follow_body(int begin, int end); 319 320 // Fast access to barrier set 321 static BarrierSet* bs() { return _bs; } 322 static void set_bs(BarrierSet* bs) { _bs = bs; } 323 324 // Garbage Collection support 325 326 // Mark Sweep 327 // Adjust all pointers in this object to point at it's forwarded location and 328 // return the size of this oop. This is used by the MarkSweep collector. 329 int ms_adjust_pointers(); 330 #if INCLUDE_ALL_GCS 331 // Parallel Compact 332 void pc_follow_contents(ParCompactionManager* pc); 333 void pc_update_contents(); 334 // Parallel Scavenge 335 void ps_push_contents(PSPromotionManager* pm); 336 #endif 337 338 339 // iterators, returns size of object 340 #define OOP_ITERATE_DECL(OopClosureType, nv_suffix)
341 void oop_iterate(OopClosureType* blk);
342 void oop_iterate(OopClosureType* blk, MemRegion mr); // Only in mr. 343 344 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DECL) 345 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DECL) 346 347 #define OOP_ITERATE_SIZE_DECL(OopClosureType, nv_suffix)
348 int oop_iterate_size(OopClosureType* blk);
349 int oop_iterate_size(OopClosureType* blk, MemRegion mr); // Only in mr. 350 351 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_SIZE_DECL) 352 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_SIZE_DECL) 353 354 355 #if INCLUDE_ALL_GCS 356 357 #define OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)
358 void oop_iterate_backwards(OopClosureType* blk); 359 360 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DECL) 361 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DECL) 362 #endif 363 364 int oop_iterate_no_header(OopClosure* bk); 365 int oop_iterate_no_header(OopClosure* bk, MemRegion mr); 366 367 // identity hash; returns the identity hash key (computes it if necessary) 368 // NOTE with the introduction of UseBiasedLocking that identity_hash() might reach a 369 // safepoint if called on a biased object. Calling code must be aware of that. 370 intptr_t identity_hash(); 371 intptr_t slow_identity_hash(); 372 373 // Alternate hashing code if string table is rehashed 374 unsigned int new_hash(juint seed); 375 376 // marks are forwarded to stack when object is locked 377 bool has_displaced_mark() const; 378 markOop displaced_mark() const; 379 void set_displaced_mark(markOop m); 380 381 static bool has_klass_gap(); 382 383 // for code generation 384 static int mark_offset_in_bytes() { return offset_of(oopDesc, _mark); } 385 static int klass_offset_in_bytes() { return offset_of(oopDesc, _metadata._klass); } 386 static int klass_gap_offset_in_bytes() { 387 assert(has_klass_gap(), "only applicable to compressed klass pointers"); 388 return klass_offset_in_bytes() + sizeof(narrowKlass); 389 } 390 }; 391 392 #endif // SHARE_VM_OOPS_OOP_HPP