1 /* 2 * Copyright (c) 1997, 2014, 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 #include "precompiled.hpp" 26 #include "classfile/javaClasses.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "gc_implementation/shared/markSweep.inline.hpp" 29 #include "gc_interface/collectedHeap.hpp" 30 #include "gc_interface/collectedHeap.inline.hpp" 31 #include "memory/genCollectedHeap.hpp" 32 #include "memory/genOopClosures.inline.hpp" 33 #include "oops/instanceRefKlass.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "utilities/preserveException.hpp" 36 #include "utilities/macros.hpp" 37 #if INCLUDE_ALL_GCS 38 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 39 #include "gc_implementation/g1/g1OopClosures.inline.hpp" 40 #include "gc_implementation/g1/g1RemSet.inline.hpp" 41 #include "gc_implementation/g1/heapRegionManager.inline.hpp" 42 #include "gc_implementation/parNew/parOopClosures.inline.hpp" 43 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp" 44 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp" 45 #include "oops/oop.pcgc.inline.hpp" 46 #endif // INCLUDE_ALL_GCS 47 48 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 49 50 template <class T> 51 void specialized_oop_follow_contents(InstanceRefKlass* ref, oop obj) { 52 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 53 T heap_oop = oopDesc::load_heap_oop(referent_addr); 54 debug_only( 55 if(TraceReferenceGC && PrintGCDetails) { 56 gclog_or_tty->print_cr("InstanceRefKlass::oop_follow_contents " INTPTR_FORMAT, (void *)obj); 57 } 58 ) 59 if (!oopDesc::is_null(heap_oop)) { 60 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); 61 if (!referent->is_gc_marked() && 62 MarkSweep::ref_processor()->discover_reference(obj, ref->reference_type())) { 63 // reference was discovered, referent will be traversed later 64 ref->InstanceKlass::oop_follow_contents(obj); 65 debug_only( 66 if(TraceReferenceGC && PrintGCDetails) { 67 gclog_or_tty->print_cr(" Non NULL enqueued " INTPTR_FORMAT, (void *)obj); 68 } 69 ) 70 return; 71 } else { 72 // treat referent as normal oop 73 debug_only( 74 if(TraceReferenceGC && PrintGCDetails) { 75 gclog_or_tty->print_cr(" Non NULL normal " INTPTR_FORMAT, (void *)obj); 76 } 77 ) 78 MarkSweep::mark_and_push(referent_addr); 79 } 80 } 81 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 82 if (ReferenceProcessor::pending_list_uses_discovered_field()) { 83 // Treat discovered as normal oop, if ref is not "active", 84 // i.e. if next is non-NULL. 85 T next_oop = oopDesc::load_heap_oop(next_addr); 86 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 87 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 88 debug_only( 89 if(TraceReferenceGC && PrintGCDetails) { 90 gclog_or_tty->print_cr(" Process discovered as normal " 91 INTPTR_FORMAT, discovered_addr); 92 } 93 ) 94 MarkSweep::mark_and_push(discovered_addr); 95 } 96 } else { 97 #ifdef ASSERT 98 // In the case of older JDKs which do not use the discovered 99 // field for the pending list, an inactive ref (next != NULL) 100 // must always have a NULL discovered field. 101 oop next = oopDesc::load_decode_heap_oop(next_addr); 102 oop discovered = java_lang_ref_Reference::discovered(obj); 103 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered), 104 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", 105 (oopDesc*)obj)); 106 #endif 107 } 108 // treat next as normal oop. next is a link in the reference queue. 109 debug_only( 110 if(TraceReferenceGC && PrintGCDetails) { 111 gclog_or_tty->print_cr(" Process next as normal " INTPTR_FORMAT, next_addr); 112 } 113 ) 114 MarkSweep::mark_and_push(next_addr); 115 ref->InstanceKlass::oop_follow_contents(obj); 116 } 117 118 void InstanceRefKlass::oop_follow_contents(oop obj) { 119 if (UseCompressedOops) { 120 specialized_oop_follow_contents<narrowOop>(this, obj); 121 } else { 122 specialized_oop_follow_contents<oop>(this, obj); 123 } 124 } 125 126 #if INCLUDE_ALL_GCS 127 template <class T> 128 void specialized_oop_follow_contents(InstanceRefKlass* ref, 129 ParCompactionManager* cm, 130 oop obj) { 131 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 132 T heap_oop = oopDesc::load_heap_oop(referent_addr); 133 debug_only( 134 if(TraceReferenceGC && PrintGCDetails) { 135 gclog_or_tty->print_cr("InstanceRefKlass::oop_follow_contents " INTPTR_FORMAT, (void *)obj); 136 } 137 ) 138 if (!oopDesc::is_null(heap_oop)) { 139 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); 140 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) && 141 PSParallelCompact::ref_processor()-> 142 discover_reference(obj, ref->reference_type())) { 143 // reference already enqueued, referent will be traversed later 144 ref->InstanceKlass::oop_follow_contents(cm, obj); 145 debug_only( 146 if(TraceReferenceGC && PrintGCDetails) { 147 gclog_or_tty->print_cr(" Non NULL enqueued " INTPTR_FORMAT, (void *)obj); 148 } 149 ) 150 return; 151 } else { 152 // treat referent as normal oop 153 debug_only( 154 if(TraceReferenceGC && PrintGCDetails) { 155 gclog_or_tty->print_cr(" Non NULL normal " INTPTR_FORMAT, (void *)obj); 156 } 157 ) 158 PSParallelCompact::mark_and_push(cm, referent_addr); 159 } 160 } 161 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 162 if (ReferenceProcessor::pending_list_uses_discovered_field()) { 163 // Treat discovered as normal oop, if ref is not "active", 164 // i.e. if next is non-NULL. 165 T next_oop = oopDesc::load_heap_oop(next_addr); 166 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 167 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 168 debug_only( 169 if(TraceReferenceGC && PrintGCDetails) { 170 gclog_or_tty->print_cr(" Process discovered as normal " 171 INTPTR_FORMAT, discovered_addr); 172 } 173 ) 174 PSParallelCompact::mark_and_push(cm, discovered_addr); 175 } 176 } else { 177 #ifdef ASSERT 178 // In the case of older JDKs which do not use the discovered 179 // field for the pending list, an inactive ref (next != NULL) 180 // must always have a NULL discovered field. 181 T next = oopDesc::load_heap_oop(next_addr); 182 oop discovered = java_lang_ref_Reference::discovered(obj); 183 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered), 184 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", 185 (oopDesc*)obj)); 186 #endif 187 } 188 PSParallelCompact::mark_and_push(cm, next_addr); 189 ref->InstanceKlass::oop_follow_contents(cm, obj); 190 } 191 192 void InstanceRefKlass::oop_follow_contents(ParCompactionManager* cm, 193 oop obj) { 194 if (UseCompressedOops) { 195 specialized_oop_follow_contents<narrowOop>(this, cm, obj); 196 } else { 197 specialized_oop_follow_contents<oop>(this, cm, obj); 198 } 199 } 200 #endif // INCLUDE_ALL_GCS 201 202 #ifdef ASSERT 203 template <class T> void trace_reference_gc(const char *s, oop obj, 204 T* referent_addr, 205 T* next_addr, 206 T* discovered_addr) { 207 if(TraceReferenceGC && PrintGCDetails) { 208 gclog_or_tty->print_cr("%s obj " INTPTR_FORMAT, s, (address)obj); 209 gclog_or_tty->print_cr(" referent_addr/* " INTPTR_FORMAT " / " 210 INTPTR_FORMAT, referent_addr, 211 referent_addr ? 212 (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL); 213 gclog_or_tty->print_cr(" next_addr/* " INTPTR_FORMAT " / " 214 INTPTR_FORMAT, next_addr, 215 next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL); 216 gclog_or_tty->print_cr(" discovered_addr/* " INTPTR_FORMAT " / " 217 INTPTR_FORMAT, discovered_addr, 218 discovered_addr ? 219 (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL); 220 } 221 } 222 #endif 223 224 template <class T> void specialized_oop_adjust_pointers(InstanceRefKlass *ref, oop obj) { 225 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 226 MarkSweep::adjust_pointer(referent_addr); 227 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 228 MarkSweep::adjust_pointer(next_addr); 229 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 230 MarkSweep::adjust_pointer(discovered_addr); 231 debug_only(trace_reference_gc("InstanceRefKlass::oop_adjust_pointers", obj, 232 referent_addr, next_addr, discovered_addr);) 233 } 234 235 int InstanceRefKlass::oop_adjust_pointers(oop obj) { 236 int size = size_helper(); 237 InstanceKlass::oop_adjust_pointers(obj); 238 239 if (UseCompressedOops) { 240 specialized_oop_adjust_pointers<narrowOop>(this, obj); 241 } else { 242 specialized_oop_adjust_pointers<oop>(this, obj); 243 } 244 return size; 245 } 246 247 #define InstanceRefKlass_SPECIALIZED_OOP_ITERATE(T, nv_suffix, contains) \ 248 T* disc_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); \ 249 if (closure->apply_to_weak_ref_discovered_field()) { \ 250 closure->do_oop##nv_suffix(disc_addr); \ 251 } \ 252 \ 253 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); \ 254 T heap_oop = oopDesc::load_heap_oop(referent_addr); \ 255 ReferenceProcessor* rp = closure->_ref_processor; \ 256 if (!oopDesc::is_null(heap_oop)) { \ 257 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); \ 258 if (!referent->is_gc_marked() && (rp != NULL) && \ 259 rp->discover_reference(obj, reference_type())) { \ 260 return size; \ 261 } else if (contains(referent_addr)) { \ 262 /* treat referent as normal oop */ \ 263 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\ 264 closure->do_oop##nv_suffix(referent_addr); \ 265 } \ 266 } \ 267 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); \ 268 if (ReferenceProcessor::pending_list_uses_discovered_field()) { \ 269 T next_oop = oopDesc::load_heap_oop(next_addr); \ 270 /* Treat discovered as normal oop, if ref is not "active" (next non-NULL) */\ 271 if (!oopDesc::is_null(next_oop) && contains(disc_addr)) { \ 272 /* i.e. ref is not "active" */ \ 273 debug_only( \ 274 if(TraceReferenceGC && PrintGCDetails) { \ 275 gclog_or_tty->print_cr(" Process discovered as normal " \ 276 INTPTR_FORMAT, disc_addr); \ 277 } \ 278 ) \ 279 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\ 280 closure->do_oop##nv_suffix(disc_addr); \ 281 } \ 282 } else { \ 283 /* In the case of older JDKs which do not use the discovered field for */ \ 284 /* the pending list, an inactive ref (next != NULL) must always have a */ \ 285 /* NULL discovered field. */ \ 286 debug_only( \ 287 T next_oop = oopDesc::load_heap_oop(next_addr); \ 288 T disc_oop = oopDesc::load_heap_oop(disc_addr); \ 289 assert(oopDesc::is_null(next_oop) || oopDesc::is_null(disc_oop), \ 290 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL" \ 291 "discovered field", (oopDesc*)obj)); \ 292 ) \ 293 } \ 294 /* treat next as normal oop */ \ 295 if (contains(next_addr)) { \ 296 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk); \ 297 closure->do_oop##nv_suffix(next_addr); \ 298 } \ 299 return size; \ 300 301 302 template <class T> bool contains(T *t) { return true; } 303 304 // Macro to define InstanceRefKlass::oop_oop_iterate for virtual/nonvirtual for 305 // all closures. Macros calling macros above for each oop size. 306 307 #define InstanceRefKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 308 \ 309 int InstanceRefKlass:: \ 310 oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \ 311 /* Get size before changing pointers */ \ 312 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\ 313 \ 314 int size = InstanceKlass::oop_oop_iterate##nv_suffix(obj, closure); \ 315 \ 316 if (UseCompressedOops) { \ 317 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains); \ 318 } else { \ 319 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains); \ 320 } \ 321 } 322 323 #if INCLUDE_ALL_GCS 324 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 325 \ 326 int InstanceRefKlass:: \ 327 oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \ 328 /* Get size before changing pointers */ \ 329 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\ 330 \ 331 int size = InstanceKlass::oop_oop_iterate_backwards##nv_suffix(obj, closure); \ 332 \ 333 if (UseCompressedOops) { \ 334 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains); \ 335 } else { \ 336 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains); \ 337 } \ 338 } 339 #endif // INCLUDE_ALL_GCS 340 341 342 #define InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \ 343 \ 344 int InstanceRefKlass:: \ 345 oop_oop_iterate##nv_suffix##_m(oop obj, \ 346 OopClosureType* closure, \ 347 MemRegion mr) { \ 348 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\ 349 \ 350 int size = InstanceKlass::oop_oop_iterate##nv_suffix##_m(obj, closure, mr); \ 351 if (UseCompressedOops) { \ 352 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, mr.contains); \ 353 } else { \ 354 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, mr.contains); \ 355 } \ 356 } 357 358 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN) 359 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN) 360 #if INCLUDE_ALL_GCS 361 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN) 362 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN) 363 #endif // INCLUDE_ALL_GCS 364 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m) 365 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m) 366 367 #if INCLUDE_ALL_GCS 368 template <class T> 369 void specialized_oop_push_contents(InstanceRefKlass *ref, 370 PSPromotionManager* pm, oop obj) { 371 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 372 if (PSScavenge::should_scavenge(referent_addr)) { 373 ReferenceProcessor* rp = PSScavenge::reference_processor(); 374 if (rp->discover_reference(obj, ref->reference_type())) { 375 // reference already enqueued, referent and next will be traversed later 376 ref->InstanceKlass::oop_push_contents(pm, obj); 377 return; 378 } else { 379 // treat referent as normal oop 380 pm->claim_or_forward_depth(referent_addr); 381 } 382 } 383 // Treat discovered as normal oop, if ref is not "active", 384 // i.e. if next is non-NULL. 385 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 386 if (ReferenceProcessor::pending_list_uses_discovered_field()) { 387 T next_oop = oopDesc::load_heap_oop(next_addr); 388 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 389 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 390 debug_only( 391 if(TraceReferenceGC && PrintGCDetails) { 392 gclog_or_tty->print_cr(" Process discovered as normal " 393 INTPTR_FORMAT, discovered_addr); 394 } 395 ) 396 if (PSScavenge::should_scavenge(discovered_addr)) { 397 pm->claim_or_forward_depth(discovered_addr); 398 } 399 } 400 } else { 401 #ifdef ASSERT 402 // In the case of older JDKs which do not use the discovered 403 // field for the pending list, an inactive ref (next != NULL) 404 // must always have a NULL discovered field. 405 oop next = oopDesc::load_decode_heap_oop(next_addr); 406 oop discovered = java_lang_ref_Reference::discovered(obj); 407 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered), 408 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", 409 (oopDesc*)obj)); 410 #endif 411 } 412 413 // Treat next as normal oop; next is a link in the reference queue. 414 if (PSScavenge::should_scavenge(next_addr)) { 415 pm->claim_or_forward_depth(next_addr); 416 } 417 ref->InstanceKlass::oop_push_contents(pm, obj); 418 } 419 420 void InstanceRefKlass::oop_push_contents(PSPromotionManager* pm, oop obj) { 421 if (UseCompressedOops) { 422 specialized_oop_push_contents<narrowOop>(this, pm, obj); 423 } else { 424 specialized_oop_push_contents<oop>(this, pm, obj); 425 } 426 } 427 428 template <class T> 429 void specialized_oop_update_pointers(InstanceRefKlass *ref, 430 ParCompactionManager* cm, oop obj) { 431 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 432 PSParallelCompact::adjust_pointer(referent_addr); 433 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 434 PSParallelCompact::adjust_pointer(next_addr); 435 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 436 PSParallelCompact::adjust_pointer(discovered_addr); 437 debug_only(trace_reference_gc("InstanceRefKlass::oop_update_ptrs", obj, 438 referent_addr, next_addr, discovered_addr);) 439 } 440 441 int InstanceRefKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) { 442 InstanceKlass::oop_update_pointers(cm, obj); 443 if (UseCompressedOops) { 444 specialized_oop_update_pointers<narrowOop>(this, cm, obj); 445 } else { 446 specialized_oop_update_pointers<oop>(this, cm, obj); 447 } 448 return size_helper(); 449 } 450 #endif // INCLUDE_ALL_GCS 451 452 void InstanceRefKlass::update_nonstatic_oop_maps(Klass* k) { 453 // Clear the nonstatic oop-map entries corresponding to referent 454 // and nextPending field. They are treated specially by the 455 // garbage collector. 456 // The discovered field is used only by the garbage collector 457 // and is also treated specially. 458 InstanceKlass* ik = InstanceKlass::cast(k); 459 460 // Check that we have the right class 461 debug_only(static bool first_time = true); 462 assert(k == SystemDictionary::Reference_klass() && first_time, 463 "Invalid update of maps"); 464 debug_only(first_time = false); 465 assert(ik->nonstatic_oop_map_count() == 1, "just checking"); 466 467 OopMapBlock* map = ik->start_of_nonstatic_oop_maps(); 468 469 // Check that the current map is (2,4) - currently points at field with 470 // offset 2 (words) and has 4 map entries. 471 debug_only(int offset = java_lang_ref_Reference::referent_offset); 472 debug_only(unsigned int count = ((java_lang_ref_Reference::discovered_offset - 473 java_lang_ref_Reference::referent_offset)/heapOopSize) + 1); 474 475 if (UseSharedSpaces) { 476 assert(map->offset() == java_lang_ref_Reference::queue_offset && 477 map->count() == 1, "just checking"); 478 } else { 479 assert(map->offset() == offset && map->count() == count, 480 "just checking"); 481 482 // Update map to (3,1) - point to offset of 3 (words) with 1 map entry. 483 map->set_offset(java_lang_ref_Reference::queue_offset); 484 map->set_count(1); 485 } 486 } 487 488 489 // Verification 490 491 void InstanceRefKlass::oop_verify_on(oop obj, outputStream* st) { 492 InstanceKlass::oop_verify_on(obj, st); 493 // Verify referent field 494 oop referent = java_lang_ref_Reference::referent(obj); 495 496 // We should make this general to all heaps 497 GenCollectedHeap* gch = NULL; 498 if (Universe::heap()->kind() == CollectedHeap::GenCollectedHeap) 499 gch = GenCollectedHeap::heap(); 500 501 if (referent != NULL) { 502 guarantee(referent->is_oop(), "referent field heap failed"); 503 } 504 // Verify next field 505 oop next = java_lang_ref_Reference::next(obj); 506 if (next != NULL) { 507 guarantee(next->is_oop(), "next field verify failed"); 508 guarantee(next->is_instanceRef(), "next field verify failed"); 509 } 510 } 511 512 bool InstanceRefKlass::owns_pending_list_lock(JavaThread* thread) { 513 if (java_lang_ref_Reference::pending_list_lock() == NULL) return false; 514 Handle h_lock(thread, java_lang_ref_Reference::pending_list_lock()); 515 return ObjectSynchronizer::current_thread_holds_lock(thread, h_lock); 516 } 517 518 void InstanceRefKlass::acquire_pending_list_lock(BasicLock *pending_list_basic_lock) { 519 // we may enter this with pending exception set 520 PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument 521 522 // Create a HandleMark in case we retry a GC multiple times. 523 // Each time we attempt the GC, we allocate the handle below 524 // to hold the pending list lock. We want to free this handle. 525 HandleMark hm; 526 527 Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock()); 528 ObjectSynchronizer::fast_enter(h_lock, pending_list_basic_lock, false, THREAD); 529 assert(ObjectSynchronizer::current_thread_holds_lock( 530 JavaThread::current(), h_lock), 531 "Locking should have succeeded"); 532 if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION; 533 } 534 535 void InstanceRefKlass::release_and_notify_pending_list_lock( 536 BasicLock *pending_list_basic_lock) { 537 // we may enter this with pending exception set 538 PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument 539 540 // Create a HandleMark in case we retry a GC multiple times. 541 // Each time we attempt the GC, we allocate the handle below 542 // to hold the pending list lock. We want to free this handle. 543 HandleMark hm; 544 545 Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock()); 546 assert(ObjectSynchronizer::current_thread_holds_lock( 547 JavaThread::current(), h_lock), 548 "Lock should be held"); 549 // Notify waiters on pending lists lock if there is any reference. 550 if (java_lang_ref_Reference::pending_list() != NULL) { 551 ObjectSynchronizer::notifyall(h_lock, THREAD); 552 } 553 ObjectSynchronizer::fast_exit(h_lock(), pending_list_basic_lock, THREAD); 554 if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION; 555 }