instanceRefKlass.cpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 1997, 2012, 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#ifndef SERIALGC 37#include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 38#include "gc_implementation/g1/g1OopClosures.inline.hpp" 39#include "gc_implementation/g1/g1RemSet.inline.hpp" 40#include "gc_implementation/g1/heapRegionSeq.inline.hpp" 41#include "gc_implementation/parNew/parOopClosures.inline.hpp" 42#include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp" 43#include "gc_implementation/parallelScavenge/psScavenge.inline.hpp" 44#include "oops/oop.pcgc.inline.hpp" 45#endif 46 47template <class T> 48void specialized_oop_follow_contents(instanceRefKlass* ref, oop obj) { 49 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 50 T heap_oop = oopDesc::load_heap_oop(referent_addr); 51 debug_only( 52 if(TraceReferenceGC && PrintGCDetails) { 53 gclog_or_tty->print_cr("instanceRefKlass::oop_follow_contents " INTPTR_FORMAT, obj); 54 } 55 ) 56 if (!oopDesc::is_null(heap_oop)) { 57 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); 58 if (!referent->is_gc_marked() && 59 MarkSweep::ref_processor()->discover_reference(obj, ref->reference_type())) { 60 // reference was discovered, referent will be traversed later 61 ref->InstanceKlass::oop_follow_contents(obj); 62 debug_only( 63 if(TraceReferenceGC && PrintGCDetails) { 64 gclog_or_tty->print_cr(" Non NULL enqueued " INTPTR_FORMAT, obj); 65 } 66 ) 67 return; 68 } else { 69 // treat referent as normal oop 70 debug_only( 71 if(TraceReferenceGC && PrintGCDetails) { 72 gclog_or_tty->print_cr(" Non NULL normal " INTPTR_FORMAT, obj); 73 } 74 ) 75 MarkSweep::mark_and_push(referent_addr); 76 } 77 } 78 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 79 if (ReferenceProcessor::pending_list_uses_discovered_field()) { 80 // Treat discovered as normal oop, if ref is not "active", 81 // i.e. if next is non-NULL. 82 T next_oop = oopDesc::load_heap_oop(next_addr); 83 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 84 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 85 debug_only( 86 if(TraceReferenceGC && PrintGCDetails) { 87 gclog_or_tty->print_cr(" Process discovered as normal " 88 INTPTR_FORMAT, discovered_addr); 89 } 90 ) 91 MarkSweep::mark_and_push(discovered_addr); 92 } 93 } else { 94#ifdef ASSERT 95 // In the case of older JDKs which do not use the discovered 96 // field for the pending list, an inactive ref (next != NULL) 97 // must always have a NULL discovered field. 98 oop next = oopDesc::load_decode_heap_oop(next_addr); 99 oop discovered = java_lang_ref_Reference::discovered(obj); 100 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered), 101 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", 102 (oopDesc*)obj)); 103#endif 104 } 105 // treat next as normal oop. next is a link in the reference queue. 106 debug_only( 107 if(TraceReferenceGC && PrintGCDetails) { 108 gclog_or_tty->print_cr(" Process next as normal " INTPTR_FORMAT, next_addr); 109 } 110 ) 111 MarkSweep::mark_and_push(next_addr); 112 ref->InstanceKlass::oop_follow_contents(obj); 113} 114 115void instanceRefKlass::oop_follow_contents(oop obj) { 116 if (UseCompressedOops) { 117 specialized_oop_follow_contents<narrowOop>(this, obj); 118 } else { 119 specialized_oop_follow_contents<oop>(this, obj); 120 } 121} 122 123#ifndef SERIALGC 124template <class T> 125void specialized_oop_follow_contents(instanceRefKlass* ref, 126 ParCompactionManager* cm, 127 oop obj) { 128 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 129 T heap_oop = oopDesc::load_heap_oop(referent_addr); 130 debug_only( 131 if(TraceReferenceGC && PrintGCDetails) { 132 gclog_or_tty->print_cr("instanceRefKlass::oop_follow_contents " INTPTR_FORMAT, obj); 133 } 134 ) 135 if (!oopDesc::is_null(heap_oop)) { 136 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); 137 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) && 138 PSParallelCompact::ref_processor()-> 139 discover_reference(obj, ref->reference_type())) { 140 // reference already enqueued, referent will be traversed later 141 ref->InstanceKlass::oop_follow_contents(cm, obj); 142 debug_only( 143 if(TraceReferenceGC && PrintGCDetails) { 144 gclog_or_tty->print_cr(" Non NULL enqueued " INTPTR_FORMAT, obj); 145 } 146 ) 147 return; 148 } else { 149 // treat referent as normal oop 150 debug_only( 151 if(TraceReferenceGC && PrintGCDetails) { 152 gclog_or_tty->print_cr(" Non NULL normal " INTPTR_FORMAT, obj); 153 } 154 ) 155 PSParallelCompact::mark_and_push(cm, referent_addr); 156 } 157 } 158 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 159 if (ReferenceProcessor::pending_list_uses_discovered_field()) { 160 // Treat discovered as normal oop, if ref is not "active", 161 // i.e. if next is non-NULL. 162 T next_oop = oopDesc::load_heap_oop(next_addr); 163 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 164 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 165 debug_only( 166 if(TraceReferenceGC && PrintGCDetails) { 167 gclog_or_tty->print_cr(" Process discovered as normal " 168 INTPTR_FORMAT, discovered_addr); 169 } 170 ) 171 PSParallelCompact::mark_and_push(cm, discovered_addr); 172 } 173 } else { 174#ifdef ASSERT 175 // In the case of older JDKs which do not use the discovered 176 // field for the pending list, an inactive ref (next != NULL) 177 // must always have a NULL discovered field. 178 T next = oopDesc::load_heap_oop(next_addr); 179 oop discovered = java_lang_ref_Reference::discovered(obj); 180 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered), 181 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", 182 (oopDesc*)obj)); 183#endif 184 } 185 PSParallelCompact::mark_and_push(cm, next_addr); 186 ref->InstanceKlass::oop_follow_contents(cm, obj); 187} 188 189void instanceRefKlass::oop_follow_contents(ParCompactionManager* cm, 190 oop obj) { 191 if (UseCompressedOops) { 192 specialized_oop_follow_contents<narrowOop>(this, cm, obj); 193 } else { 194 specialized_oop_follow_contents<oop>(this, cm, obj); 195 } 196} 197#endif // SERIALGC 198 199#ifdef ASSERT 200template <class T> void trace_reference_gc(const char *s, oop obj, 201 T* referent_addr, 202 T* next_addr, 203 T* discovered_addr) { 204 if(TraceReferenceGC && PrintGCDetails) { 205 gclog_or_tty->print_cr("%s obj " INTPTR_FORMAT, s, (address)obj); 206 gclog_or_tty->print_cr(" referent_addr/* " INTPTR_FORMAT " / " 207 INTPTR_FORMAT, referent_addr, 208 referent_addr ? 209 (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL); 210 gclog_or_tty->print_cr(" next_addr/* " INTPTR_FORMAT " / " 211 INTPTR_FORMAT, next_addr, 212 next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL); 213 gclog_or_tty->print_cr(" discovered_addr/* " INTPTR_FORMAT " / " 214 INTPTR_FORMAT, discovered_addr, 215 discovered_addr ? 216 (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL); 217 } 218} 219#endif 220 221template <class T> void specialized_oop_adjust_pointers(instanceRefKlass *ref, oop obj) { 222 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 223 MarkSweep::adjust_pointer(referent_addr); 224 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 225 MarkSweep::adjust_pointer(next_addr); 226 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 227 MarkSweep::adjust_pointer(discovered_addr); 228 debug_only(trace_reference_gc("instanceRefKlass::oop_adjust_pointers", obj, 229 referent_addr, next_addr, discovered_addr);) 230} 231 232int instanceRefKlass::oop_adjust_pointers(oop obj) { 233 int size = size_helper(); 234 InstanceKlass::oop_adjust_pointers(obj); 235 236 if (UseCompressedOops) { 237 specialized_oop_adjust_pointers<narrowOop>(this, obj); 238 } else { 239 specialized_oop_adjust_pointers<oop>(this, obj); 240 } 241 return size; 242} 243 244#define InstanceRefKlass_SPECIALIZED_OOP_ITERATE(T, nv_suffix, contains) \ 245 T* disc_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); \ 246 if (closure->apply_to_weak_ref_discovered_field()) { \ 247 closure->do_oop##nv_suffix(disc_addr); \ 248 } \ 249 \ 250 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); \ 251 T heap_oop = oopDesc::load_heap_oop(referent_addr); \ 252 ReferenceProcessor* rp = closure->_ref_processor; \ 253 if (!oopDesc::is_null(heap_oop)) { \ 254 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); \ 255 if (!referent->is_gc_marked() && (rp != NULL) && \ 256 rp->discover_reference(obj, reference_type())) { \ 257 return size; \ 258 } else if (contains(referent_addr)) { \ 259 /* treat referent as normal oop */ \ 260 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\ 261 closure->do_oop##nv_suffix(referent_addr); \ 262 } \ 263 } \ 264 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); \ 265 if (ReferenceProcessor::pending_list_uses_discovered_field()) { \ 266 T next_oop = oopDesc::load_heap_oop(next_addr); \ 267 /* Treat discovered as normal oop, if ref is not "active" (next non-NULL) */\ 268 if (!oopDesc::is_null(next_oop) && contains(disc_addr)) { \ 269 /* i.e. ref is not "active" */ \ 270 debug_only( \ 271 if(TraceReferenceGC && PrintGCDetails) { \ 272 gclog_or_tty->print_cr(" Process discovered as normal " \ 273 INTPTR_FORMAT, disc_addr); \ 274 } \ 275 ) \ 276 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\ 277 closure->do_oop##nv_suffix(disc_addr); \ 278 } \ 279 } else { \ 280 /* In the case of older JDKs which do not use the discovered field for */ \ 281 /* the pending list, an inactive ref (next != NULL) must always have a */ \ 282 /* NULL discovered field. */ \ 283 debug_only( \ 284 T next_oop = oopDesc::load_heap_oop(next_addr); \ 285 T disc_oop = oopDesc::load_heap_oop(disc_addr); \ 286 assert(oopDesc::is_null(next_oop) || oopDesc::is_null(disc_oop), \ 287 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL" \ 288 "discovered field", (oopDesc*)obj)); \ 289 ) \ 290 } \ 291 /* treat next as normal oop */ \ 292 if (contains(next_addr)) { \ 293 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk); \ 294 closure->do_oop##nv_suffix(next_addr); \ 295 } \ 296 return size; \ 297 298 299template <class T> bool contains(T *t) { return true; } 300 301// Macro to define instanceRefKlass::oop_oop_iterate for virtual/nonvirtual for 302// all closures. Macros calling macros above for each oop size. 303 304#define InstanceRefKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 305 \ 306int instanceRefKlass:: \ 307oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \ 308 /* Get size before changing pointers */ \ 309 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\ 310 \ 311 int size = InstanceKlass::oop_oop_iterate##nv_suffix(obj, closure); \ 312 \ 313 if (UseCompressedOops) { \ 314 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains); \ 315 } else { \ 316 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains); \ 317 } \ 318} 319 320#ifndef SERIALGC 321#define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 322 \ 323int instanceRefKlass:: \ 324oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \ 325 /* Get size before changing pointers */ \ 326 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\ 327 \ 328 int size = InstanceKlass::oop_oop_iterate_backwards##nv_suffix(obj, closure); \ 329 \ 330 if (UseCompressedOops) { \ 331 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains); \ 332 } else { \ 333 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains); \ 334 } \ 335} 336#endif // !SERIALGC 337 338 339#define InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \ 340 \ 341int instanceRefKlass:: \ 342oop_oop_iterate##nv_suffix##_m(oop obj, \ 343 OopClosureType* closure, \ 344 MemRegion mr) { \ 345 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\ 346 \ 347 int size = InstanceKlass::oop_oop_iterate##nv_suffix##_m(obj, closure, mr); \ 348 if (UseCompressedOops) { \ 349 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, mr.contains); \ 350 } else { \ 351 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, mr.contains); \ 352 } \ 353} 354 355ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN) 356ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN) 357#ifndef SERIALGC 358ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN) 359ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN) 360#endif // SERIALGC 361ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m) 362ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m) 363 364#ifndef SERIALGC 365template <class T> 366void specialized_oop_push_contents(instanceRefKlass *ref, 367 PSPromotionManager* pm, oop obj) { 368 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 369 if (PSScavenge::should_scavenge(referent_addr)) { 370 ReferenceProcessor* rp = PSScavenge::reference_processor(); 371 if (rp->discover_reference(obj, ref->reference_type())) { 372 // reference already enqueued, referent and next will be traversed later 373 ref->InstanceKlass::oop_push_contents(pm, obj); 374 return; 375 } else { 376 // treat referent as normal oop 377 pm->claim_or_forward_depth(referent_addr); 378 } 379 } 380 // Treat discovered as normal oop, if ref is not "active", 381 // i.e. if next is non-NULL. 382 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 383 if (ReferenceProcessor::pending_list_uses_discovered_field()) { 384 T next_oop = oopDesc::load_heap_oop(next_addr); 385 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 386 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 387 debug_only( 388 if(TraceReferenceGC && PrintGCDetails) { 389 gclog_or_tty->print_cr(" Process discovered as normal " 390 INTPTR_FORMAT, discovered_addr); 391 } 392 ) 393 if (PSScavenge::should_scavenge(discovered_addr)) { 394 pm->claim_or_forward_depth(discovered_addr); 395 } 396 } 397 } else { 398#ifdef ASSERT 399 // In the case of older JDKs which do not use the discovered 400 // field for the pending list, an inactive ref (next != NULL) 401 // must always have a NULL discovered field. 402 oop next = oopDesc::load_decode_heap_oop(next_addr); 403 oop discovered = java_lang_ref_Reference::discovered(obj); 404 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered), 405 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", 406 (oopDesc*)obj)); 407#endif 408 } 409 410 // Treat next as normal oop; next is a link in the reference queue. 411 if (PSScavenge::should_scavenge(next_addr)) { 412 pm->claim_or_forward_depth(next_addr); 413 } 414 ref->InstanceKlass::oop_push_contents(pm, obj); 415} 416 417void instanceRefKlass::oop_push_contents(PSPromotionManager* pm, oop obj) { 418 if (UseCompressedOops) { 419 specialized_oop_push_contents<narrowOop>(this, pm, obj); 420 } else { 421 specialized_oop_push_contents<oop>(this, pm, obj); 422 } 423} 424 425template <class T> 426void specialized_oop_update_pointers(instanceRefKlass *ref, 427 ParCompactionManager* cm, oop obj) { 428 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 429 PSParallelCompact::adjust_pointer(referent_addr); 430 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 431 PSParallelCompact::adjust_pointer(next_addr); 432 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 433 PSParallelCompact::adjust_pointer(discovered_addr); 434 debug_only(trace_reference_gc("instanceRefKlass::oop_update_ptrs", obj, 435 referent_addr, next_addr, discovered_addr);) 436} 437 438int instanceRefKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) { 439 InstanceKlass::oop_update_pointers(cm, obj); 440 if (UseCompressedOops) { 441 specialized_oop_update_pointers<narrowOop>(this, cm, obj); 442 } else { 443 specialized_oop_update_pointers<oop>(this, cm, obj); 444 } 445 return size_helper(); 446} 447#endif // SERIALGC 448 449void instanceRefKlass::update_nonstatic_oop_maps(Klass* k) { 450 // Clear the nonstatic oop-map entries corresponding to referent 451 // and nextPending field. They are treated specially by the 452 // garbage collector. 453 // The discovered field is used only by the garbage collector 454 // and is also treated specially. 455 InstanceKlass* ik = InstanceKlass::cast(k); 456 457 // Check that we have the right class 458 debug_only(static bool first_time = true); 459 assert(k == SystemDictionary::Reference_klass() && first_time, 460 "Invalid update of maps"); 461 debug_only(first_time = false); 462 assert(ik->nonstatic_oop_map_count() == 1, "just checking"); 463 464 OopMapBlock* map = ik->start_of_nonstatic_oop_maps(); 465 466 // Check that the current map is (2,4) - currently points at field with 467 // offset 2 (words) and has 4 map entries. 468 debug_only(int offset = java_lang_ref_Reference::referent_offset); 469 debug_only(unsigned int count = ((java_lang_ref_Reference::discovered_offset - 470 java_lang_ref_Reference::referent_offset)/heapOopSize) + 1); 471 472 if (UseSharedSpaces) { 473 assert(map->offset() == java_lang_ref_Reference::queue_offset && 474 map->count() == 1, "just checking"); 475 } else { 476 assert(map->offset() == offset && map->count() == count, 477 "just checking"); 478 479 // Update map to (3,1) - point to offset of 3 (words) with 1 map entry. 480 map->set_offset(java_lang_ref_Reference::queue_offset); 481 map->set_count(1); 482 } 483} 484 485 486// Verification 487 488void instanceRefKlass::oop_verify_on(oop obj, outputStream* st) { 489 InstanceKlass::oop_verify_on(obj, st); 490 // Verify referent field 491 oop referent = java_lang_ref_Reference::referent(obj); 492 493 // We should make this general to all heaps 494 GenCollectedHeap* gch = NULL; 495 if (Universe::heap()->kind() == CollectedHeap::GenCollectedHeap) 496 gch = GenCollectedHeap::heap(); 497 498 if (referent != NULL) { 499 guarantee(referent->is_oop(), "referent field heap failed"); 500 } 501 // Verify next field 502 oop next = java_lang_ref_Reference::next(obj); 503 if (next != NULL) { 504 guarantee(next->is_oop(), "next field verify failed"); 505 guarantee(next->is_instanceRef(), "next field verify failed"); 506 } 507} 508 509bool instanceRefKlass::owns_pending_list_lock(JavaThread* thread) { 510 if (java_lang_ref_Reference::pending_list_lock() == NULL) return false; 511 Handle h_lock(thread, java_lang_ref_Reference::pending_list_lock()); 512 return ObjectSynchronizer::current_thread_holds_lock(thread, h_lock); 513} 514 515void instanceRefKlass::acquire_pending_list_lock(BasicLock *pending_list_basic_lock) { 516 // we may enter this with pending exception set 517 PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument 518 519 // Create a HandleMark in case we retry a GC multiple times. 520 // Each time we attempt the GC, we allocate the handle below 521 // to hold the pending list lock. We want to free this handle. 522 HandleMark hm; 523 524 Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock()); 525 ObjectSynchronizer::fast_enter(h_lock, pending_list_basic_lock, false, THREAD); 526 assert(ObjectSynchronizer::current_thread_holds_lock( 527 JavaThread::current(), h_lock), 528 "Locking should have succeeded"); 529 if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION; 530} 531 532void instanceRefKlass::release_and_notify_pending_list_lock( 533 BasicLock *pending_list_basic_lock) { 534 // we may enter this with pending exception set 535 PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument 536 537 // Create a HandleMark in case we retry a GC multiple times. 538 // Each time we attempt the GC, we allocate the handle below 539 // to hold the pending list lock. We want to free this handle. 540 HandleMark hm; 541 542 Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock()); 543 assert(ObjectSynchronizer::current_thread_holds_lock( 544 JavaThread::current(), h_lock), 545 "Lock should be held"); 546 // Notify waiters on pending lists lock if there is any reference. 547 if (java_lang_ref_Reference::pending_list() != NULL) { 548 ObjectSynchronizer::notifyall(h_lock, THREAD); 549 } 550 ObjectSynchronizer::fast_exit(h_lock(), pending_list_basic_lock, THREAD); 551 if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION; 552} 553