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 "runtime/os.hpp"
44 #include "utilities/debug.hpp"
45
46 class ZNMethodDataImmediateOops {
47 private:
48 const size_t _nimmediate_oops;
49
50 static size_t header_size();
51
52 ZNMethodDataImmediateOops(const GrowableArray<oop*>& immediate_oops);
53
54 public:
55 static ZNMethodDataImmediateOops* create(const GrowableArray<oop*>& immediate_oops);
56 static void destroy(ZNMethodDataImmediateOops* data_immediate_oops);
57
58 size_t immediate_oops_count() const;
59 oop** immediate_oops_begin() const;
60 oop** immediate_oops_end() const;
61 };
62
63 size_t ZNMethodDataImmediateOops::header_size() {
64 const size_t size = sizeof(ZNMethodDataImmediateOops);
65 assert(is_aligned(size, sizeof(oop*)), "Header misaligned");
66 return size;
67 }
68
69 ZNMethodDataImmediateOops* ZNMethodDataImmediateOops::create(const GrowableArray<oop*>& immediate_oops) {
70 // Allocate memory for the ZNMethodDataImmediateOops object
71 // plus the immediate oop* array that follows right after.
72 const size_t size = ZNMethodDataImmediateOops::header_size() + (sizeof(oop*) * immediate_oops.length());
73 void* const data_immediate_oops = NEW_C_HEAP_ARRAY(uint8_t, size, mtGC);
74 return ::new (data_immediate_oops) ZNMethodDataImmediateOops(immediate_oops);
75 }
76
77 void ZNMethodDataImmediateOops::destroy(ZNMethodDataImmediateOops* data_immediate_oops) {
78 ZNMethodTable::safe_delete(data_immediate_oops);
79 }
80
81 ZNMethodDataImmediateOops::ZNMethodDataImmediateOops(const GrowableArray<oop*>& immediate_oops) :
82 _nimmediate_oops(immediate_oops.length()) {
83 // Save all immediate oops
84 for (size_t i = 0; i < _nimmediate_oops; i++) {
85 immediate_oops_begin()[i] = immediate_oops.at(i);
86 }
87 }
88
89 size_t ZNMethodDataImmediateOops::immediate_oops_count() const {
90 return _nimmediate_oops;
91 }
92
93 oop** ZNMethodDataImmediateOops::immediate_oops_begin() const {
94 // The immediate oop* array starts immediately after this object
95 return (oop**)((uintptr_t)this + header_size());
96 }
97
98 oop** ZNMethodDataImmediateOops::immediate_oops_end() const {
99 return immediate_oops_begin() + immediate_oops_count();
100 }
101
102 class ZNMethodData {
103 private:
104 ZReentrantLock _lock;
105 ZNMethodDataImmediateOops* volatile _immediate_oops;
106
107 ZNMethodData(nmethod* nm);
108
109 public:
110 static ZNMethodData* create(nmethod* nm);
111 static void destroy(ZNMethodData* data);
112
113 ZReentrantLock* lock();
114
115 ZNMethodDataImmediateOops* immediate_oops() const;
116 ZNMethodDataImmediateOops* swap_immediate_oops(const GrowableArray<oop*>& immediate_oops);
117 };
118
119 ZNMethodData* ZNMethodData::create(nmethod* nm) {
120 void* const method = NEW_C_HEAP_ARRAY(uint8_t, sizeof(ZNMethodData), mtGC);
121 return ::new (method) ZNMethodData(nm);
122 }
123
124 void ZNMethodData::destroy(ZNMethodData* data) {
125 ZNMethodDataImmediateOops::destroy(data->immediate_oops());
126 ZNMethodTable::safe_delete(data);
127 }
128
129 ZNMethodData::ZNMethodData(nmethod* nm) :
130 _lock(),
131 _immediate_oops(NULL) {}
132
133 ZReentrantLock* ZNMethodData::lock() {
134 return &_lock;
135 }
136
137 ZNMethodDataImmediateOops* ZNMethodData::immediate_oops() const {
138 return OrderAccess::load_acquire(&_immediate_oops);
139 }
140
141 ZNMethodDataImmediateOops* ZNMethodData::swap_immediate_oops(const GrowableArray<oop*>& immediate_oops) {
142 ZNMethodDataImmediateOops* const data_immediate_oops =
143 immediate_oops.is_empty() ? NULL : ZNMethodDataImmediateOops::create(immediate_oops);
144 return Atomic::xchg(data_immediate_oops, &_immediate_oops);
145 }
146
147 static ZNMethodData* gc_data(const nmethod* nm) {
148 return nm->gc_data<ZNMethodData>();
149 }
150
151 static void set_gc_data(nmethod* nm, ZNMethodData* data) {
152 return nm->set_gc_data<ZNMethodData>(data);
153 }
154
155 ZNMethodTableEntry* ZNMethodTable::_table = NULL;
156 size_t ZNMethodTable::_size = 0;
157 ZLock ZNMethodTable::_iter_lock;
158 ZNMethodTableEntry* ZNMethodTable::_iter_table = NULL;
159 size_t ZNMethodTable::_iter_table_size = 0;
160 ZArray<void*> ZNMethodTable::_iter_deferred_deletes;
161 size_t ZNMethodTable::_nregistered = 0;
162 size_t ZNMethodTable::_nunregistered = 0;
163 volatile size_t ZNMethodTable::_claimed = 0;
164
165 void ZNMethodTable::safe_delete(void* data) {
166 if (data == NULL) {
167 return;
168 }
169
170 ZLocker<ZLock> locker(&_iter_lock);
171 if (_iter_table != NULL) {
172 // Iteration in progress, defer delete
173 _iter_deferred_deletes.add(data);
174 } else {
175 // Iteration not in progress, delete now
176 FREE_C_HEAP_ARRAY(uint8_t, data);
177 }
178 }
179
180 ZNMethodTableEntry ZNMethodTable::create_entry(nmethod* nm) {
181 GrowableArray<oop*> immediate_oops;
182 bool non_immediate_oops = false;
183
184 // Find all oops relocations
185 RelocIterator iter(nm);
186 while (iter.next()) {
187 if (iter.type() != relocInfo::oop_type) {
188 // Not an oop
189 continue;
190 }
191
192 oop_Relocation* r = iter.oop_reloc();
193
194 if (!r->oop_is_immediate()) {
195 // Non-immediate oop found
196 non_immediate_oops = true;
197 continue;
198 }
199
200 if (r->oop_value() != NULL) {
201 // Non-NULL immediate oop found. NULL oops can safely be
202 // ignored since the method will be re-registered if they
203 // are later patched to be non-NULL.
204 immediate_oops.push(r->oop_addr());
205 }
206 }
207
208 // Attach GC data to nmethod
209 ZNMethodData* data = gc_data(nm);
210 if (data == NULL) {
211 data = ZNMethodData::create(nm);
212 set_gc_data(nm, data);
213 }
214
215 // Attach immediate oops in GC data
216 ZNMethodDataImmediateOops* const old_data_immediate_oops = data->swap_immediate_oops(immediate_oops);
217 ZNMethodDataImmediateOops::destroy(old_data_immediate_oops);
218
219 // Create entry
220 return ZNMethodTableEntry(nm, non_immediate_oops, !immediate_oops.is_empty());
221 }
222
223 ZReentrantLock* ZNMethodTable::lock_for_nmethod(nmethod* nm) {
224 ZNMethodData* const data = gc_data(nm);
225 if (data == NULL) {
226 return NULL;
227 }
228 return data->lock();
229 }
230
231 size_t ZNMethodTable::first_index(const nmethod* nm, size_t size) {
232 assert(is_power_of_2(size), "Invalid size");
233 const size_t mask = size - 1;
234 const size_t hash = ZHash::address_to_uint32((uintptr_t)nm);
235 return hash & mask;
236 }
237
238 size_t ZNMethodTable::next_index(size_t prev_index, size_t size) {
239 assert(is_power_of_2(size), "Invalid size");
240 const size_t mask = size - 1;
241 return (prev_index + 1) & mask;
242 }
243
244 bool ZNMethodTable::register_entry(ZNMethodTableEntry* table, size_t size, ZNMethodTableEntry entry) {
245 const nmethod* const nm = entry.method();
246 size_t index = first_index(nm, size);
247
248 for (;;) {
249 const ZNMethodTableEntry table_entry = table[index];
250
251 if (!table_entry.registered() && !table_entry.unregistered()) {
252 // Insert new entry
253 table[index] = entry;
254 return true;
255 }
256
257 if (table_entry.registered() && table_entry.method() == nm) {
258 // Replace existing entry
259 table[index] = entry;
260 return false;
261 }
262
263 index = next_index(index, size);
264 }
265 }
266
267 bool ZNMethodTable::unregister_entry(ZNMethodTableEntry* table, size_t size, nmethod* nm) {
268 if (size == 0) {
269 // Table is empty
270 return false;
271 }
272
273 size_t index = first_index(nm, size);
274
275 for (;;) {
276 const ZNMethodTableEntry table_entry = table[index];
277
278 if (!table_entry.registered() && !table_entry.unregistered()) {
279 // Entry not found
280 return false;
281 }
282
283 if (table_entry.registered() && table_entry.method() == nm) {
284 // Remove entry
285 table[index] = ZNMethodTableEntry(true /* unregistered */);
286
287 // Destroy GC data
288 ZNMethodData::destroy(gc_data(nm));
289 set_gc_data(nm, NULL);
290 return true;
291 }
292
293 index = next_index(index, size);
294 }
295 }
296
297 void ZNMethodTable::rebuild(size_t new_size) {
298 ZLocker<ZLock> locker(&_iter_lock);
299 assert(is_power_of_2(new_size), "Invalid size");
300
301 log_debug(gc, nmethod)("Rebuilding NMethod Table: "
302 SIZE_FORMAT "->" SIZE_FORMAT " entries, "
303 SIZE_FORMAT "(%.0lf%%->%.0lf%%) registered, "
304 SIZE_FORMAT "(%.0lf%%->%.0lf%%) unregistered",
305 _size, new_size,
306 _nregistered, percent_of(_nregistered, _size), percent_of(_nregistered, new_size),
307 _nunregistered, percent_of(_nunregistered, _size), 0.0);
308
309 // Allocate new table
310 ZNMethodTableEntry* const new_table = new ZNMethodTableEntry[new_size];
311
312 // Transfer all registered entries
313 for (size_t i = 0; i < _size; i++) {
314 const ZNMethodTableEntry entry = _table[i];
315 if (entry.registered()) {
316 register_entry(new_table, new_size, entry);
317 }
318 }
319
320 if (_iter_table != _table) {
321 // Delete old table
322 delete [] _table;
323 }
324
325 // Install new table
326 _table = new_table;
327 _size = new_size;
328 _nunregistered = 0;
329 }
330
331 void ZNMethodTable::rebuild_if_needed() {
332 // The hash table uses linear probing. To avoid wasting memory while
333 // at the same time maintaining good hash collision behavior we want
334 // to keep the table occupancy between 30% and 70%. The table always
335 // grows/shrinks by doubling/halving its size. Pruning of unregistered
336 // entries is done by rebuilding the table with or without resizing it.
337 const size_t min_size = 1024;
338 const size_t shrink_threshold = _size * 0.30;
339 const size_t prune_threshold = _size * 0.65;
340 const size_t grow_threshold = _size * 0.70;
341
342 if (_size == 0) {
343 // Initialize table
344 rebuild(min_size);
345 } else if (_nregistered < shrink_threshold && _size > min_size) {
346 // Shrink table
347 rebuild(_size / 2);
348 } else if (_nregistered + _nunregistered > grow_threshold) {
349 // Prune or grow table
350 if (_nregistered < prune_threshold) {
351 // Prune table
352 rebuild(_size);
353 } else {
354 // Grow table
355 rebuild(_size * 2);
356 }
357 }
358 }
359
360 void ZNMethodTable::log_register(const nmethod* nm, ZNMethodTableEntry entry) {
361 LogTarget(Trace, gc, nmethod) log;
362 if (!log.is_enabled()) {
363 return;
364 }
365
366 log.print("Register NMethod: %s.%s (" PTR_FORMAT "), "
367 "Compiler: %s, Oops: %d, ImmediateOops: " SIZE_FORMAT ", NonImmediateOops: %s",
368 nm->method()->method_holder()->external_name(),
369 nm->method()->name()->as_C_string(),
370 p2i(nm),
371 nm->compiler_name(),
372 nm->oops_count() - 1,
373 entry.immediate_oops() ? gc_data(nm)->immediate_oops()->immediate_oops_count() : 0,
374 entry.non_immediate_oops() ? "Yes" : "No");
375
376 LogTarget(Trace, gc, nmethod, oops) log_oops;
377 if (!log_oops.is_enabled()) {
378 return;
379 }
380
381 // Print nmethod oops table
382 oop* const begin = nm->oops_begin();
383 oop* const end = nm->oops_end();
384 for (oop* p = begin; p < end; p++) {
385 log_oops.print(" Oop[" SIZE_FORMAT "] " PTR_FORMAT " (%s)",
386 (p - begin), p2i(*p), (*p)->klass()->external_name());
387 }
388
389 if (entry.immediate_oops()) {
390 // Print nmethod immediate oops
391 const ZNMethodDataImmediateOops* const nmi = gc_data(nm)->immediate_oops();
392 if (nmi != NULL) {
393 oop** const begin = nmi->immediate_oops_begin();
394 oop** const end = nmi->immediate_oops_end();
395 for (oop** p = begin; p < end; p++) {
396 log_oops.print(" ImmediateOop[" SIZE_FORMAT "] " PTR_FORMAT " @ " PTR_FORMAT " (%s)",
397 (p - begin), p2i(**p), p2i(*p), (**p)->klass()->external_name());
398 }
399 }
400 }
401 }
402
403 void ZNMethodTable::log_unregister(const nmethod* nm) {
404 LogTarget(Debug, gc, nmethod) log;
405 if (!log.is_enabled()) {
406 return;
407 }
408
409 log.print("Unregister NMethod: %s.%s (" PTR_FORMAT ")",
410 nm->method()->method_holder()->external_name(),
411 nm->method()->name()->as_C_string(),
412 p2i(nm));
413 }
414
415 size_t ZNMethodTable::registered_nmethods() {
416 return _nregistered;
417 }
418
419 size_t ZNMethodTable::unregistered_nmethods() {
420 return _nunregistered;
421 }
422
423 void ZNMethodTable::register_nmethod(nmethod* nm) {
424 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
425 ResourceMark rm;
426
427 // Grow/Shrink/Prune table if needed
428 rebuild_if_needed();
429
430 // Create entry
431 const ZNMethodTableEntry entry = create_entry(nm);
432
433 log_register(nm, entry);
434
435 // Insert new entry
436 if (register_entry(_table, _size, entry)) {
437 // New entry registered. When register_entry() instead returns
438 // false the nmethod was already in the table so we do not want
439 // to increase number of registered entries in that case.
440 _nregistered++;
441 }
442
443 // Disarm nmethod entry barrier
444 disarm_nmethod(nm);
445 }
446
447 void ZNMethodTable::sweeper_wait_for_iteration() {
448 // The sweeper must wait for any ongoing iteration to complete
449 // before it can unregister an nmethod.
450 if (!Thread::current()->is_Code_cache_sweeper_thread()) {
451 return;
452 }
453
454 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
455
456 while (_iter_table != NULL) {
457 MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
458 os::naked_short_sleep(1);
459 }
460 }
461
462 void ZNMethodTable::unregister_nmethod(nmethod* nm) {
463 ResourceMark rm;
464
465 sweeper_wait_for_iteration();
466
467 log_unregister(nm);
468
469 // Remove entry
470 if (unregister_entry(_table, _size, nm)) {
471 // Entry was unregistered. When unregister_entry() instead returns
472 // false the nmethod was not in the table (because it didn't have
473 // any oops) so we do not want to decrease the number of registered
474 // entries in that case.
475 _nregistered--;
476 _nunregistered++;
477 }
478 }
479
480 void ZNMethodTable::disarm_nmethod(nmethod* nm) {
481 BarrierSetNMethod* const bs = BarrierSet::barrier_set()->barrier_set_nmethod();
482 if (bs != NULL) {
483 bs->disarm(nm);
484 }
485 }
486
487 void ZNMethodTable::nmethod_entries_do_begin() {
488 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
489 ZLocker<ZLock> locker(&_iter_lock);
490
491 // Prepare iteration
492 _iter_table = _table;
493 _iter_table_size = _size;
494 _claimed = 0;
495 assert(_iter_deferred_deletes.is_empty(), "Should be emtpy");
496 }
497
498 void ZNMethodTable::nmethod_entries_do_end() {
499 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
500 ZLocker<ZLock> locker(&_iter_lock);
501
502 // Finish iteration
503 if (_iter_table != _table) {
504 delete [] _iter_table;
505 }
506 _iter_table = NULL;
507 assert(_claimed >= _iter_table_size, "Failed to claim all table entries");
508
509 // Process deferred deletes
510 ZArrayIterator<void*> iter(&_iter_deferred_deletes);
511 for (void* data; iter.next(&data);) {
512 FREE_C_HEAP_ARRAY(uint8_t, data);
513 }
514 _iter_deferred_deletes.clear();
515 }
516
517 void ZNMethodTable::entry_oops_do(ZNMethodTableEntry entry, OopClosure* cl) {
518 nmethod* const nm = entry.method();
519
520 // Process oops table
521 oop* const begin = nm->oops_begin();
522 oop* const end = nm->oops_end();
523 for (oop* p = begin; p < end; p++) {
524 if (*p != Universe::non_oop_word()) {
525 cl->do_oop(p);
526 }
527 }
528
529 // Process immediate oops
530 if (entry.immediate_oops()) {
531 const ZNMethodDataImmediateOops* const nmi = gc_data(nm)->immediate_oops();
532 if (nmi != NULL) {
533 oop** const begin = nmi->immediate_oops_begin();
534 oop** const end = nmi->immediate_oops_end();
535 for (oop** p = begin; p < end; p++) {
536 if (**p != Universe::non_oop_word()) {
537 cl->do_oop(*p);
538 }
539 }
540 }
541 }
542
543 // Process non-immediate oops
544 if (entry.non_immediate_oops()) {
545 nmethod* const nm = entry.method();
546 nm->fix_oop_relocations();
547 }
548 }
549
550 class ZNMethodTableEntryToOopsDo : public ZNMethodTableEntryClosure {
551 private:
552 OopClosure* _cl;
553
554 public:
555 ZNMethodTableEntryToOopsDo(OopClosure* cl) :
556 _cl(cl) {}
557
558 void do_nmethod_entry(ZNMethodTableEntry entry) {
559 ZNMethodTable::entry_oops_do(entry, _cl);
560 }
561 };
562
563 void ZNMethodTable::oops_do(OopClosure* cl) {
564 ZNMethodTableEntryToOopsDo entry_cl(cl);
565 nmethod_entries_do(&entry_cl);
566 }
567
568 void ZNMethodTable::nmethod_entries_do(ZNMethodTableEntryClosure* cl) {
569 for (;;) {
570 // Claim table partition. Each partition is currently sized to span
571 // two cache lines. This number is just a guess, but seems to work well.
572 const size_t partition_size = (ZCacheLineSize * 2) / sizeof(ZNMethodTableEntry);
573 const size_t partition_start = MIN2(Atomic::add(partition_size, &_claimed) - partition_size, _iter_table_size);
574 const size_t partition_end = MIN2(partition_start + partition_size, _iter_table_size);
575 if (partition_start == partition_end) {
576 // End of table
577 break;
578 }
579
580 // Process table partition
581 for (size_t i = partition_start; i < partition_end; i++) {
582 const ZNMethodTableEntry entry = _iter_table[i];
583 if (entry.registered()) {
584 cl->do_nmethod_entry(entry);
585 }
586 }
587 }
588 }
589
590 class ZNMethodTableUnlinkClosure : public ZNMethodTableEntryClosure {
591 private:
592 bool _unloading_occurred;
593 volatile bool _failed;
594
595 void set_failed() {
596 Atomic::store(true, &_failed);
597 }
598
599 public:
600 ZNMethodTableUnlinkClosure(bool unloading_occurred) :
601 _unloading_occurred(unloading_occurred),
602 _failed(false) {}
603
604 virtual void do_nmethod_entry(ZNMethodTableEntry entry) {
605 if (failed()) {
606 return;
607 }
608
609 nmethod* const nm = entry.method();
610 if (!nm->is_alive()) {
611 return;
612 }
613
614 ZLocker<ZReentrantLock> locker(ZNMethodTable::lock_for_nmethod(nm));
615
616 if (nm->is_unloading()) {
617 // Unlinking of the dependencies must happen before the
618 // handshake separating unlink and purge.
619 nm->flush_dependencies(false /* delete_immediately */);
620
621 // We don't need to take the lock when unlinking nmethods from
622 // the Method, because it is only concurrently unlinked by
623 // the entry barrier, which acquires the per nmethod lock.
624 nm->unlink_from_method(false /* acquire_lock */);
625 return;
626 }
627
628 // Heal oops and disarm
629 ZNMethodOopClosure cl;
630 ZNMethodTable::entry_oops_do(entry, &cl);
631 ZNMethodTable::disarm_nmethod(nm);
632
633 // Clear compiled ICs and exception caches
634 if (!nm->unload_nmethod_caches(_unloading_occurred)) {
635 set_failed();
636 }
637 }
638
639 bool failed() const {
640 return Atomic::load(&_failed);
641 }
642 };
643
644 class ZNMethodTableUnlinkTask : public ZTask {
645 private:
646 ZNMethodTableUnlinkClosure _cl;
647 ICRefillVerifier* _verifier;
648
649 public:
650 ZNMethodTableUnlinkTask(bool unloading_occurred, ICRefillVerifier* verifier) :
651 ZTask("ZNMethodTableUnlinkTask"),
652 _cl(unloading_occurred),
653 _verifier(verifier) {
654 ZNMethodTable::nmethod_entries_do_begin();
655 }
656
657 ~ZNMethodTableUnlinkTask() {
658 ZNMethodTable::nmethod_entries_do_end();
659 }
660
661 virtual void work() {
662 ICRefillVerifierMark mark(_verifier);
663 ZNMethodTable::nmethod_entries_do(&_cl);
664 }
665
666 bool success() const {
667 return !_cl.failed();
668 }
669 };
670
671 void ZNMethodTable::unlink(ZWorkers* workers, bool unloading_occurred) {
672 for (;;) {
673 ICRefillVerifier verifier;
674
675 {
676 ZNMethodTableUnlinkTask task(unloading_occurred, &verifier);
677 workers->run_concurrent(&task);
678 if (task.success()) {
679 return;
680 }
681 }
682
683 // Cleaning failed because we ran out of transitional IC stubs,
684 // so we have to refill and try again. Refilling requires taking
685 // a safepoint, so we temporarily leave the suspendible thread set.
686 SuspendibleThreadSetLeaver sts;
687 InlineCacheBuffer::refill_ic_stubs();
688 }
689 }
690
691 class ZNMethodTablePurgeClosure : public ZNMethodTableEntryClosure {
692 public:
693 virtual void do_nmethod_entry(ZNMethodTableEntry entry) {
694 nmethod* const nm = entry.method();
695 if (nm->is_alive() && nm->is_unloading()) {
696 nm->make_unloaded();
697 }
698 }
699 };
700
701 class ZNMethodTablePurgeTask : public ZTask {
702 private:
703 ZNMethodTablePurgeClosure _cl;
704
705 public:
706 ZNMethodTablePurgeTask() :
707 ZTask("ZNMethodTablePurgeTask"),
708 _cl() {
709 ZNMethodTable::nmethod_entries_do_begin();
710 }
711
712 ~ZNMethodTablePurgeTask() {
713 ZNMethodTable::nmethod_entries_do_end();
714 }
715
716 virtual void work() {
717 ZNMethodTable::nmethod_entries_do(&_cl);
718 }
719 };
720
721 void ZNMethodTable::purge(ZWorkers* workers) {
722 ZNMethodTablePurgeTask task;
723 workers->run_concurrent(&task);
724 }