1 /* 2 * Copyright (c) 2017, 2018, 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 #include "precompiled.hpp" 25 #include "code/relocInfo.hpp" 26 #include "code/nmethod.hpp" 27 #include "code/icBuffer.hpp" 28 #include "gc/shared/barrierSet.hpp" 29 #include "gc/shared/barrierSetNMethod.hpp" 30 #include "gc/z/zArray.inline.hpp" 31 #include "gc/z/zGlobals.hpp" 32 #include "gc/z/zHash.inline.hpp" 33 #include "gc/z/zLock.inline.hpp" 34 #include "gc/z/zNMethodTable.hpp" 35 #include "gc/z/zOopClosures.inline.hpp" 36 #include "gc/z/zTask.hpp" 37 #include "gc/z/zWorkers.hpp" 38 #include "logging/log.hpp" 39 #include "memory/allocation.inline.hpp" 40 #include "memory/resourceArea.hpp" 41 #include "runtime/atomic.hpp" 42 #include "runtime/orderAccess.hpp" 43 #include "utilities/debug.hpp" 44 45 class ZNMethodDataImmediateOops { 46 private: 47 const size_t _nimmediate_oops; 48 49 static size_t header_size(); 50 51 ZNMethodDataImmediateOops(const GrowableArray<oop*>& immediate_oops); 52 53 public: 54 static ZNMethodDataImmediateOops* create(const GrowableArray<oop*>& immediate_oops); 55 static void destroy(ZNMethodDataImmediateOops* data_immediate_oops); 56 57 size_t immediate_oops_count() const; 58 oop** immediate_oops_begin() const; 59 oop** immediate_oops_end() const; 60 }; 61 62 size_t ZNMethodDataImmediateOops::header_size() { 63 const size_t size = sizeof(ZNMethodDataImmediateOops); 64 assert(is_aligned(size, sizeof(oop*)), "Header misaligned"); 65 return size; 66 } 67 68 ZNMethodDataImmediateOops* ZNMethodDataImmediateOops::create(const GrowableArray<oop*>& immediate_oops) { 69 // Allocate memory for the ZNMethodDataImmediateOops object 70 // plus the immediate oop* array that follows right after. 71 const size_t size = ZNMethodDataImmediateOops::header_size() + (sizeof(oop*) * immediate_oops.length()); 72 void* const data_immediate_oops = NEW_C_HEAP_ARRAY(uint8_t, size, mtGC); 73 return ::new (data_immediate_oops) ZNMethodDataImmediateOops(immediate_oops); 74 } 75 76 void ZNMethodDataImmediateOops::destroy(ZNMethodDataImmediateOops* data_immediate_oops) { 77 ZNMethodTable::safe_delete(data_immediate_oops); 78 } 79 80 ZNMethodDataImmediateOops::ZNMethodDataImmediateOops(const GrowableArray<oop*>& immediate_oops) : 81 _nimmediate_oops(immediate_oops.length()) { 82 // Save all immediate oops 83 for (size_t i = 0; i < _nimmediate_oops; i++) { 84 immediate_oops_begin()[i] = immediate_oops.at(i); 85 } 86 } 87 88 size_t ZNMethodDataImmediateOops::immediate_oops_count() const { 89 return _nimmediate_oops; 90 } 91 92 oop** ZNMethodDataImmediateOops::immediate_oops_begin() const { 93 // The immediate oop* array starts immediately after this object 94 return (oop**)((uintptr_t)this + header_size()); 95 } 96 97 oop** ZNMethodDataImmediateOops::immediate_oops_end() const { 98 return immediate_oops_begin() + immediate_oops_count(); 99 } 100 101 class ZNMethodData { 102 private: 103 ZReentrantLock _lock; 104 ZNMethodDataImmediateOops* volatile _immediate_oops; 105 106 ZNMethodData(nmethod* nm); 107 108 public: 109 static ZNMethodData* create(nmethod* nm); 110 static void destroy(ZNMethodData* data); 111 112 ZReentrantLock* lock(); 113 114 ZNMethodDataImmediateOops* immediate_oops() const; 115 ZNMethodDataImmediateOops* swap_immediate_oops(const GrowableArray<oop*>& immediate_oops); 116 }; 117 118 ZNMethodData* ZNMethodData::create(nmethod* nm) { 119 void* const method = NEW_C_HEAP_ARRAY(uint8_t, sizeof(ZNMethodData), mtGC); 120 return ::new (method) ZNMethodData(nm); 121 } 122 123 void ZNMethodData::destroy(ZNMethodData* data) { 124 ZNMethodDataImmediateOops::destroy(data->immediate_oops()); 125 ZNMethodTable::safe_delete(data); 126 } 127 128 ZNMethodData::ZNMethodData(nmethod* nm) : 129 _lock(), 130 _immediate_oops(NULL) {} 131 132 ZReentrantLock* ZNMethodData::lock() { 133 return &_lock; 134 } 135 136 ZNMethodDataImmediateOops* ZNMethodData::immediate_oops() const { 137 return OrderAccess::load_acquire(&_immediate_oops); 138 } 139 140 ZNMethodDataImmediateOops* ZNMethodData::swap_immediate_oops(const GrowableArray<oop*>& immediate_oops) { 141 ZNMethodDataImmediateOops* const data_immediate_oops = 142 immediate_oops.is_empty() ? NULL : ZNMethodDataImmediateOops::create(immediate_oops); 143 return Atomic::xchg(data_immediate_oops, &_immediate_oops); 144 } 145 146 static ZNMethodData* gc_data(const nmethod* nm) { 147 return nm->gc_data<ZNMethodData>(); 148 } 149 150 static void set_gc_data(nmethod* nm, ZNMethodData* data) { 151 return nm->set_gc_data<ZNMethodData>(data); 152 } 153 154 ZNMethodTableEntry* ZNMethodTable::_table = NULL; 155 size_t ZNMethodTable::_size = 0; 156 ZLock ZNMethodTable::_iter_lock; 157 ZNMethodTableEntry* ZNMethodTable::_iter_table = NULL; 158 size_t ZNMethodTable::_iter_table_size = 0; 159 ZArray<void*> ZNMethodTable::_iter_deferred_deletes; 160 size_t ZNMethodTable::_nregistered = 0; 161 size_t ZNMethodTable::_nunregistered = 0; 162 volatile size_t ZNMethodTable::_claimed = 0; 163 164 void ZNMethodTable::safe_delete(void* data) { 165 if (data == NULL) { 166 return; 167 } 168 169 ZLocker<ZLock> locker(&_iter_lock); 170 if (_iter_table != NULL) { 171 // Iteration in progress, defer delete 172 _iter_deferred_deletes.add(data); 173 } else { 174 // Iteration not in progress, delete now 175 FREE_C_HEAP_ARRAY(uint8_t, data); 176 } 177 } 178 179 ZNMethodTableEntry ZNMethodTable::create_entry(nmethod* nm) { 180 GrowableArray<oop*> immediate_oops; 181 bool non_immediate_oops = false; 182 183 // Find all oops relocations 184 RelocIterator iter(nm); 185 while (iter.next()) { 186 if (iter.type() != relocInfo::oop_type) { 187 // Not an oop 188 continue; 189 } 190 191 oop_Relocation* r = iter.oop_reloc(); 192 193 if (!r->oop_is_immediate()) { 194 // Non-immediate oop found 195 non_immediate_oops = true; 196 continue; 197 } 198 199 if (r->oop_value() != NULL) { 200 // Non-NULL immediate oop found. NULL oops can safely be 201 // ignored since the method will be re-registered if they 202 // are later patched to be non-NULL. 203 immediate_oops.push(r->oop_addr()); 204 } 205 } 206 207 // Attach GC data to nmethod 208 ZNMethodData* data = gc_data(nm); 209 if (data == NULL) { 210 data = ZNMethodData::create(nm); 211 set_gc_data(nm, data); 212 } 213 214 // Attach immediate oops in GC data 215 ZNMethodDataImmediateOops* const old_data_immediate_oops = data->swap_immediate_oops(immediate_oops); 216 ZNMethodDataImmediateOops::destroy(old_data_immediate_oops); 217 218 // Create entry 219 return ZNMethodTableEntry(nm, non_immediate_oops, !immediate_oops.is_empty()); 220 } 221 222 ZReentrantLock* ZNMethodTable::lock_for_nmethod(nmethod* nm) { 223 ZNMethodData* const data = gc_data(nm); 224 if (data == NULL) { 225 return NULL; 226 } 227 return data->lock(); 228 } 229 230 size_t ZNMethodTable::first_index(const nmethod* nm, size_t size) { 231 assert(is_power_of_2(size), "Invalid size"); 232 const size_t mask = size - 1; 233 const size_t hash = ZHash::address_to_uint32((uintptr_t)nm); 234 return hash & mask; 235 } 236 237 size_t ZNMethodTable::next_index(size_t prev_index, size_t size) { 238 assert(is_power_of_2(size), "Invalid size"); 239 const size_t mask = size - 1; 240 return (prev_index + 1) & mask; 241 } 242 243 bool ZNMethodTable::register_entry(ZNMethodTableEntry* table, size_t size, ZNMethodTableEntry entry) { 244 const nmethod* const nm = entry.method(); 245 size_t index = first_index(nm, size); 246 247 for (;;) { 248 const ZNMethodTableEntry table_entry = table[index]; 249 250 if (!table_entry.registered() && !table_entry.unregistered()) { 251 // Insert new entry 252 table[index] = entry; 253 return true; 254 } 255 256 if (table_entry.registered() && table_entry.method() == nm) { 257 // Replace existing entry 258 table[index] = entry; 259 return false; 260 } 261 262 index = next_index(index, size); 263 } 264 } 265 266 void ZNMethodTable::unregister_entry(ZNMethodTableEntry* table, size_t size, nmethod* nm) { 267 if (size == 0) { 268 // Table is empty 269 return; 270 } 271 272 size_t index = first_index(nm, size); 273 274 for (;;) { 275 const ZNMethodTableEntry table_entry = table[index]; 276 assert(table_entry.registered() || table_entry.unregistered(), "Entry not found"); 277 278 if (table_entry.registered() && table_entry.method() == nm) { 279 // Remove entry 280 table[index] = ZNMethodTableEntry(true /* unregistered */); 281 282 // Destroy GC data 283 ZNMethodData::destroy(gc_data(nm)); 284 set_gc_data(nm, NULL); 285 return; 286 } 287 288 index = next_index(index, size); 289 } 290 } 291 292 void ZNMethodTable::rebuild(size_t new_size) { 293 ZLocker<ZLock> locker(&_iter_lock); 294 assert(is_power_of_2(new_size), "Invalid size"); 295 296 log_debug(gc, nmethod)("Rebuilding NMethod Table: " 297 SIZE_FORMAT "->" SIZE_FORMAT " entries, " 298 SIZE_FORMAT "(%.0lf%%->%.0lf%%) registered, " 299 SIZE_FORMAT "(%.0lf%%->%.0lf%%) unregistered", 300 _size, new_size, 301 _nregistered, percent_of(_nregistered, _size), percent_of(_nregistered, new_size), 302 _nunregistered, percent_of(_nunregistered, _size), 0.0); 303 304 // Allocate new table 305 ZNMethodTableEntry* const new_table = new ZNMethodTableEntry[new_size]; 306 307 // Transfer all registered entries 308 for (size_t i = 0; i < _size; i++) { 309 const ZNMethodTableEntry entry = _table[i]; 310 if (entry.registered()) { 311 register_entry(new_table, new_size, entry); 312 } 313 } 314 315 if (_iter_table != _table) { 316 // Delete old table 317 delete [] _table; 318 } 319 320 // Install new table 321 _table = new_table; 322 _size = new_size; 323 _nunregistered = 0; 324 } 325 326 void ZNMethodTable::rebuild_if_needed() { 327 // The hash table uses linear probing. To avoid wasting memory while 328 // at the same time maintaining good hash collision behavior we want 329 // to keep the table occupancy between 30% and 70%. The table always 330 // grows/shrinks by doubling/halving its size. Pruning of unregistered 331 // entries is done by rebuilding the table with or without resizing it. 332 const size_t min_size = 1024; 333 const size_t shrink_threshold = _size * 0.30; 334 const size_t prune_threshold = _size * 0.65; 335 const size_t grow_threshold = _size * 0.70; 336 337 if (_size == 0) { 338 // Initialize table 339 rebuild(min_size); 340 } else if (_nregistered < shrink_threshold && _size > min_size) { 341 // Shrink table 342 rebuild(_size / 2); 343 } else if (_nregistered + _nunregistered > grow_threshold) { 344 // Prune or grow table 345 if (_nregistered < prune_threshold) { 346 // Prune table 347 rebuild(_size); 348 } else { 349 // Grow table 350 rebuild(_size * 2); 351 } 352 } 353 } 354 355 void ZNMethodTable::log_register(const nmethod* nm, ZNMethodTableEntry entry) { 356 LogTarget(Trace, gc, nmethod) log; 357 if (!log.is_enabled()) { 358 return; 359 } 360 361 log.print("Register NMethod: %s.%s (" PTR_FORMAT "), " 362 "Compiler: %s, Oops: %d, ImmediateOops: " SIZE_FORMAT ", NonImmediateOops: %s", 363 nm->method()->method_holder()->external_name(), 364 nm->method()->name()->as_C_string(), 365 p2i(nm), 366 nm->compiler_name(), 367 nm->oops_count() - 1, 368 entry.immediate_oops() ? gc_data(nm)->immediate_oops()->immediate_oops_count() : 0, 369 entry.non_immediate_oops() ? "Yes" : "No"); 370 371 LogTarget(Trace, gc, nmethod, oops) log_oops; 372 if (!log_oops.is_enabled()) { 373 return; 374 } 375 376 // Print nmethod oops table 377 oop* const begin = nm->oops_begin(); 378 oop* const end = nm->oops_end(); 379 for (oop* p = begin; p < end; p++) { 380 log_oops.print(" Oop[" SIZE_FORMAT "] " PTR_FORMAT " (%s)", 381 (p - begin), p2i(*p), (*p)->klass()->external_name()); 382 } 383 384 if (entry.immediate_oops()) { 385 // Print nmethod immediate oops 386 const ZNMethodDataImmediateOops* const nmi = gc_data(nm)->immediate_oops(); 387 if (nmi != NULL) { 388 oop** const begin = nmi->immediate_oops_begin(); 389 oop** const end = nmi->immediate_oops_end(); 390 for (oop** p = begin; p < end; p++) { 391 log_oops.print(" ImmediateOop[" SIZE_FORMAT "] " PTR_FORMAT " @ " PTR_FORMAT " (%s)", 392 (p - begin), p2i(**p), p2i(*p), (**p)->klass()->external_name()); 393 } 394 } 395 } 396 } 397 398 void ZNMethodTable::log_unregister(const nmethod* nm) { 399 LogTarget(Debug, gc, nmethod) log; 400 if (!log.is_enabled()) { 401 return; 402 } 403 404 log.print("Unregister NMethod: %s.%s (" PTR_FORMAT ")", 405 nm->method()->method_holder()->external_name(), 406 nm->method()->name()->as_C_string(), 407 p2i(nm)); 408 } 409 410 size_t ZNMethodTable::registered_nmethods() { 411 return _nregistered; 412 } 413 414 size_t ZNMethodTable::unregistered_nmethods() { 415 return _nunregistered; 416 } 417 418 void ZNMethodTable::register_nmethod(nmethod* nm) { 419 assert(CodeCache_lock->owned_by_self(), "Lock must be held"); 420 ResourceMark rm; 421 422 // Grow/Shrink/Prune table if needed 423 rebuild_if_needed(); 424 425 // Create entry 426 const ZNMethodTableEntry entry = create_entry(nm); 427 428 log_register(nm, entry); 429 430 // Insert new entry 431 if (register_entry(_table, _size, entry)) { 432 // New entry registered. When register_entry() instead returns 433 // false the nmethod was already in the table so we do not want 434 // to increase number of registered entries in that case. 435 _nregistered++; 436 } 437 438 // Disarm nmethod entry barrier 439 disarm_nmethod(nm); 440 } 441 442 void ZNMethodTable::wait_until_iteration_done() { 443 assert(CodeCache_lock->owned_by_self(), "Lock must be held"); 444 445 while (_iter_table != NULL) { 446 CodeCache_lock->wait(Monitor::_no_safepoint_check_flag); 447 } 448 } 449 450 void ZNMethodTable::unregister_nmethod(nmethod* nm) { 451 assert(CodeCache_lock->owned_by_self(), "Lock must be held"); 452 453 if (Thread::current()->is_Code_cache_sweeper_thread()) { 454 // The sweeper must wait for any ongoing iteration to complete 455 // before it can unregister an nmethod. 456 ZNMethodTable::wait_until_iteration_done(); 457 } 458 459 ResourceMark rm; 460 461 log_unregister(nm); 462 463 // Remove entry 464 unregister_entry(_table, _size, nm); 465 _nunregistered++; 466 _nregistered--; 467 } 468 469 void ZNMethodTable::disarm_nmethod(nmethod* nm) { 470 BarrierSetNMethod* const bs = BarrierSet::barrier_set()->barrier_set_nmethod(); 471 if (bs != NULL) { 472 bs->disarm(nm); 473 } 474 } 475 476 void ZNMethodTable::nmethod_entries_do_begin() { 477 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 478 ZLocker<ZLock> locker(&_iter_lock); 479 480 // Prepare iteration 481 _iter_table = _table; 482 _iter_table_size = _size; 483 _claimed = 0; 484 assert(_iter_deferred_deletes.is_empty(), "Should be emtpy"); 485 } 486 487 void ZNMethodTable::nmethod_entries_do_end() { 488 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 489 ZLocker<ZLock> locker(&_iter_lock); 490 491 // Finish iteration 492 if (_iter_table != _table) { 493 delete [] _iter_table; 494 } 495 _iter_table = NULL; 496 497 assert(_claimed >= _iter_table_size, "Failed to claim all table entries"); 498 499 // Process deferred deletes 500 ZArrayIterator<void*> iter(&_iter_deferred_deletes); 501 for (void* data; iter.next(&data);) { 502 FREE_C_HEAP_ARRAY(uint8_t, data); 503 } 504 _iter_deferred_deletes.clear(); 505 506 // Notify iteration done 507 CodeCache_lock->notify_all(); 508 } 509 510 void ZNMethodTable::entry_oops_do(ZNMethodTableEntry entry, OopClosure* cl) { 511 nmethod* const nm = entry.method(); 512 513 // Process oops table 514 oop* const begin = nm->oops_begin(); 515 oop* const end = nm->oops_end(); 516 for (oop* p = begin; p < end; p++) { 517 if (*p != Universe::non_oop_word()) { 518 cl->do_oop(p); 519 } 520 } 521 522 // Process immediate oops 523 if (entry.immediate_oops()) { 524 const ZNMethodDataImmediateOops* const nmi = gc_data(nm)->immediate_oops(); 525 if (nmi != NULL) { 526 oop** const begin = nmi->immediate_oops_begin(); 527 oop** const end = nmi->immediate_oops_end(); 528 for (oop** p = begin; p < end; p++) { 529 if (**p != Universe::non_oop_word()) { 530 cl->do_oop(*p); 531 } 532 } 533 } 534 } 535 536 // Process non-immediate oops 537 if (entry.non_immediate_oops()) { 538 nmethod* const nm = entry.method(); 539 nm->fix_oop_relocations(); 540 } 541 } 542 543 class ZNMethodTableEntryToOopsDo : public ZNMethodTableEntryClosure { 544 private: 545 OopClosure* _cl; 546 547 public: 548 ZNMethodTableEntryToOopsDo(OopClosure* cl) : 549 _cl(cl) {} 550 551 void do_nmethod_entry(ZNMethodTableEntry entry) { 552 ZNMethodTable::entry_oops_do(entry, _cl); 553 } 554 }; 555 556 void ZNMethodTable::oops_do(OopClosure* cl) { 557 ZNMethodTableEntryToOopsDo entry_cl(cl); 558 nmethod_entries_do(&entry_cl); 559 } 560 561 void ZNMethodTable::nmethod_entries_do(ZNMethodTableEntryClosure* cl) { 562 for (;;) { 563 // Claim table partition. Each partition is currently sized to span 564 // two cache lines. This number is just a guess, but seems to work well. 565 const size_t partition_size = (ZCacheLineSize * 2) / sizeof(ZNMethodTableEntry); 566 const size_t partition_start = MIN2(Atomic::add(partition_size, &_claimed) - partition_size, _iter_table_size); 567 const size_t partition_end = MIN2(partition_start + partition_size, _iter_table_size); 568 if (partition_start == partition_end) { 569 // End of table 570 break; 571 } 572 573 // Process table partition 574 for (size_t i = partition_start; i < partition_end; i++) { 575 const ZNMethodTableEntry entry = _iter_table[i]; 576 if (entry.registered()) { 577 cl->do_nmethod_entry(entry); 578 } 579 } 580 } 581 } 582 583 class ZNMethodTableUnlinkClosure : public ZNMethodTableEntryClosure { 584 private: 585 bool _unloading_occurred; 586 volatile bool _failed; 587 588 void set_failed() { 589 Atomic::store(true, &_failed); 590 } 591 592 public: 593 ZNMethodTableUnlinkClosure(bool unloading_occurred) : 594 _unloading_occurred(unloading_occurred), 595 _failed(false) {} 596 597 virtual void do_nmethod_entry(ZNMethodTableEntry entry) { 598 if (failed()) { 599 return; 600 } 601 602 nmethod* const nm = entry.method(); 603 if (!nm->is_alive()) { 604 return; 605 } 606 607 ZLocker<ZReentrantLock> locker(ZNMethodTable::lock_for_nmethod(nm)); 608 609 if (nm->is_unloading()) { 610 // Unlinking of the dependencies must happen before the 611 // handshake separating unlink and purge. 612 nm->flush_dependencies(false /* delete_immediately */); 613 614 // We don't need to take the lock when unlinking nmethods from 615 // the Method, because it is only concurrently unlinked by 616 // the entry barrier, which acquires the per nmethod lock. 617 nm->unlink_from_method(false /* acquire_lock */); 618 return; 619 } 620 621 // Heal oops and disarm 622 ZNMethodOopClosure cl; 623 ZNMethodTable::entry_oops_do(entry, &cl); 624 ZNMethodTable::disarm_nmethod(nm); 625 626 // Clear compiled ICs and exception caches 627 if (!nm->unload_nmethod_caches(_unloading_occurred)) { 628 set_failed(); 629 } 630 } 631 632 bool failed() const { 633 return Atomic::load(&_failed); 634 } 635 }; 636 637 class ZNMethodTableUnlinkTask : public ZTask { 638 private: 639 ZNMethodTableUnlinkClosure _cl; 640 ICRefillVerifier* _verifier; 641 642 public: 643 ZNMethodTableUnlinkTask(bool unloading_occurred, ICRefillVerifier* verifier) : 644 ZTask("ZNMethodTableUnlinkTask"), 645 _cl(unloading_occurred), 646 _verifier(verifier) { 647 ZNMethodTable::nmethod_entries_do_begin(); 648 } 649 650 ~ZNMethodTableUnlinkTask() { 651 ZNMethodTable::nmethod_entries_do_end(); 652 } 653 654 virtual void work() { 655 ICRefillVerifierMark mark(_verifier); 656 ZNMethodTable::nmethod_entries_do(&_cl); 657 } 658 659 bool success() const { 660 return !_cl.failed(); 661 } 662 }; 663 664 void ZNMethodTable::unlink(ZWorkers* workers, bool unloading_occurred) { 665 for (;;) { 666 ICRefillVerifier verifier; 667 668 { 669 ZNMethodTableUnlinkTask task(unloading_occurred, &verifier); 670 workers->run_concurrent(&task); 671 if (task.success()) { 672 return; 673 } 674 } 675 676 // Cleaning failed because we ran out of transitional IC stubs, 677 // so we have to refill and try again. Refilling requires taking 678 // a safepoint, so we temporarily leave the suspendible thread set. 679 SuspendibleThreadSetLeaver sts; 680 InlineCacheBuffer::refill_ic_stubs(); 681 } 682 } 683 684 class ZNMethodTablePurgeClosure : public ZNMethodTableEntryClosure { 685 public: 686 virtual void do_nmethod_entry(ZNMethodTableEntry entry) { 687 nmethod* const nm = entry.method(); 688 if (nm->is_alive() && nm->is_unloading()) { 689 nm->make_unloaded(); 690 } 691 } 692 }; 693 694 class ZNMethodTablePurgeTask : public ZTask { 695 private: 696 ZNMethodTablePurgeClosure _cl; 697 698 public: 699 ZNMethodTablePurgeTask() : 700 ZTask("ZNMethodTablePurgeTask"), 701 _cl() { 702 ZNMethodTable::nmethod_entries_do_begin(); 703 } 704 705 ~ZNMethodTablePurgeTask() { 706 ZNMethodTable::nmethod_entries_do_end(); 707 } 708 709 virtual void work() { 710 ZNMethodTable::nmethod_entries_do(&_cl); 711 } 712 }; 713 714 void ZNMethodTable::purge(ZWorkers* workers) { 715 ZNMethodTablePurgeTask task; 716 workers->run_concurrent(&task); 717 }