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 ZNMethodTableEntry* ZNMethodTable::_iter_table = NULL;
157 size_t ZNMethodTable::_iter_table_size = 0;
158 ZArray<void*> ZNMethodTable::_iter_deferred_deletes;
159 size_t ZNMethodTable::_nregistered = 0;
160 size_t ZNMethodTable::_nunregistered = 0;
161 volatile size_t ZNMethodTable::_claimed = 0;
162
163 void ZNMethodTable::safe_delete(void* data) {
164 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
165
166 if (data == NULL) {
167 return;
168 }
169
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 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
294
295 assert(is_power_of_2(new_size), "Invalid size");
296
297 log_debug(gc, nmethod)("Rebuilding NMethod Table: "
298 SIZE_FORMAT "->" SIZE_FORMAT " entries, "
299 SIZE_FORMAT "(%.0lf%%->%.0lf%%) registered, "
300 SIZE_FORMAT "(%.0lf%%->%.0lf%%) unregistered",
301 _size, new_size,
302 _nregistered, percent_of(_nregistered, _size), percent_of(_nregistered, new_size),
303 _nunregistered, percent_of(_nunregistered, _size), 0.0);
304
305 // Allocate new table
306 ZNMethodTableEntry* const new_table = new ZNMethodTableEntry[new_size];
307
308 // Transfer all registered entries
309 for (size_t i = 0; i < _size; i++) {
310 const ZNMethodTableEntry entry = _table[i];
311 if (entry.registered()) {
312 register_entry(new_table, new_size, entry);
313 }
314 }
315
316 if (_iter_table != _table) {
317 // Delete old table
318 delete [] _table;
319 }
320
321 // Install new table
322 _table = new_table;
323 _size = new_size;
324 _nunregistered = 0;
325 }
326
327 void ZNMethodTable::rebuild_if_needed() {
328 // The hash table uses linear probing. To avoid wasting memory while
329 // at the same time maintaining good hash collision behavior we want
330 // to keep the table occupancy between 30% and 70%. The table always
331 // grows/shrinks by doubling/halving its size. Pruning of unregistered
332 // entries is done by rebuilding the table with or without resizing it.
333 const size_t min_size = 1024;
334 const size_t shrink_threshold = _size * 0.30;
335 const size_t prune_threshold = _size * 0.65;
336 const size_t grow_threshold = _size * 0.70;
337
338 if (_size == 0) {
339 // Initialize table
340 rebuild(min_size);
341 } else if (_nregistered < shrink_threshold && _size > min_size) {
342 // Shrink table
343 rebuild(_size / 2);
344 } else if (_nregistered + _nunregistered > grow_threshold) {
345 // Prune or grow table
346 if (_nregistered < prune_threshold) {
347 // Prune table
348 rebuild(_size);
349 } else {
350 // Grow table
351 rebuild(_size * 2);
352 }
353 }
354 }
355
356 void ZNMethodTable::log_register(const nmethod* nm, ZNMethodTableEntry entry) {
357 LogTarget(Trace, gc, nmethod) log;
358 if (!log.is_enabled()) {
359 return;
360 }
361
362 log.print("Register NMethod: %s.%s (" PTR_FORMAT "), "
363 "Compiler: %s, Oops: %d, ImmediateOops: " SIZE_FORMAT ", NonImmediateOops: %s",
364 nm->method()->method_holder()->external_name(),
365 nm->method()->name()->as_C_string(),
366 p2i(nm),
367 nm->compiler_name(),
368 nm->oops_count() - 1,
369 entry.immediate_oops() ? gc_data(nm)->immediate_oops()->immediate_oops_count() : 0,
370 entry.non_immediate_oops() ? "Yes" : "No");
371
372 LogTarget(Trace, gc, nmethod, oops) log_oops;
373 if (!log_oops.is_enabled()) {
374 return;
375 }
376
377 // Print nmethod oops table
378 oop* const begin = nm->oops_begin();
379 oop* const end = nm->oops_end();
380 for (oop* p = begin; p < end; p++) {
381 log_oops.print(" Oop[" SIZE_FORMAT "] " PTR_FORMAT " (%s)",
382 (p - begin), p2i(*p), (*p)->klass()->external_name());
383 }
384
385 if (entry.immediate_oops()) {
386 // Print nmethod immediate oops
387 const ZNMethodDataImmediateOops* const nmi = gc_data(nm)->immediate_oops();
388 if (nmi != NULL) {
389 oop** const begin = nmi->immediate_oops_begin();
390 oop** const end = nmi->immediate_oops_end();
391 for (oop** p = begin; p < end; p++) {
392 log_oops.print(" ImmediateOop[" SIZE_FORMAT "] " PTR_FORMAT " @ " PTR_FORMAT " (%s)",
393 (p - begin), p2i(**p), p2i(*p), (**p)->klass()->external_name());
394 }
395 }
396 }
397 }
398
399 void ZNMethodTable::log_unregister(const nmethod* nm) {
400 LogTarget(Debug, gc, nmethod) log;
401 if (!log.is_enabled()) {
402 return;
403 }
404
405 log.print("Unregister NMethod: %s.%s (" PTR_FORMAT ")",
406 nm->method()->method_holder()->external_name(),
407 nm->method()->name()->as_C_string(),
408 p2i(nm));
409 }
410
411 size_t ZNMethodTable::registered_nmethods() {
412 return _nregistered;
413 }
414
415 size_t ZNMethodTable::unregistered_nmethods() {
416 return _nunregistered;
417 }
418
419 void ZNMethodTable::register_nmethod(nmethod* nm) {
420 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
421 ResourceMark rm;
422
423 // Grow/Shrink/Prune table if needed
424 rebuild_if_needed();
425
426 // Create entry
427 const ZNMethodTableEntry entry = create_entry(nm);
428
429 log_register(nm, entry);
430
431 // Insert new entry
432 if (register_entry(_table, _size, entry)) {
433 // New entry registered. When register_entry() instead returns
434 // false the nmethod was already in the table so we do not want
435 // to increase number of registered entries in that case.
436 _nregistered++;
437 }
438
439 // Disarm nmethod entry barrier
440 disarm_nmethod(nm);
441 }
442
443 void ZNMethodTable::wait_until_iteration_done() {
444 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
445
446 while (_iter_table != NULL) {
447 CodeCache_lock->wait(Monitor::_no_safepoint_check_flag);
448 }
449 }
450
451 void ZNMethodTable::unregister_nmethod(nmethod* nm) {
452 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
453
454 if (Thread::current()->is_Code_cache_sweeper_thread()) {
455 // The sweeper must wait for any ongoing iteration to complete
456 // before it can unregister an nmethod.
457 ZNMethodTable::wait_until_iteration_done();
458 }
459
460 ResourceMark rm;
461
462 log_unregister(nm);
463
464 // Remove entry
465 unregister_entry(_table, _size, nm);
466 _nunregistered++;
467 _nregistered--;
468 }
469
470 void ZNMethodTable::disarm_nmethod(nmethod* nm) {
471 BarrierSetNMethod* const bs = BarrierSet::barrier_set()->barrier_set_nmethod();
472 if (bs != NULL) {
473 bs->disarm(nm);
474 }
475 }
476
477 void ZNMethodTable::nmethod_entries_do_begin() {
478 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
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
490 // Finish iteration
491 if (_iter_table != _table) {
492 delete [] _iter_table;
493 }
494 _iter_table = NULL;
495
496 assert(_claimed >= _iter_table_size, "Failed to claim all table entries");
497
498 // Process deferred deletes
499 ZArrayIterator<void*> iter(&_iter_deferred_deletes);
500 for (void* data; iter.next(&data);) {
501 FREE_C_HEAP_ARRAY(uint8_t, data);
502 }
503 _iter_deferred_deletes.clear();
504
505 // Notify iteration done
506 CodeCache_lock->notify_all();
507 }
508
509 void ZNMethodTable::entry_oops_do(ZNMethodTableEntry entry, OopClosure* cl) {
510 nmethod* const nm = entry.method();
511
512 // Process oops table
513 oop* const begin = nm->oops_begin();
514 oop* const end = nm->oops_end();
515 for (oop* p = begin; p < end; p++) {
516 if (*p != Universe::non_oop_word()) {
517 cl->do_oop(p);
518 }
519 }
520
521 // Process immediate oops
522 if (entry.immediate_oops()) {
523 const ZNMethodDataImmediateOops* const nmi = gc_data(nm)->immediate_oops();
524 if (nmi != NULL) {
525 oop** const begin = nmi->immediate_oops_begin();
526 oop** const end = nmi->immediate_oops_end();
527 for (oop** p = begin; p < end; p++) {
528 if (**p != Universe::non_oop_word()) {
529 cl->do_oop(*p);
530 }
531 }
532 }
533 }
534
535 // Process non-immediate oops
536 if (entry.non_immediate_oops()) {
537 nmethod* const nm = entry.method();
538 nm->fix_oop_relocations();
539 }
540 }
541
542 class ZNMethodTableEntryToOopsDo : public ZNMethodTableEntryClosure {
543 private:
544 OopClosure* _cl;
545
546 public:
547 ZNMethodTableEntryToOopsDo(OopClosure* cl) :
548 _cl(cl) {}
549
550 void do_nmethod_entry(ZNMethodTableEntry entry) {
551 ZNMethodTable::entry_oops_do(entry, _cl);
552 }
553 };
554
555 void ZNMethodTable::oops_do(OopClosure* cl) {
556 ZNMethodTableEntryToOopsDo entry_cl(cl);
557 nmethod_entries_do(&entry_cl);
558 }
559
560 void ZNMethodTable::nmethod_entries_do(ZNMethodTableEntryClosure* cl) {
561 for (;;) {
562 // Claim table partition. Each partition is currently sized to span
563 // two cache lines. This number is just a guess, but seems to work well.
564 const size_t partition_size = (ZCacheLineSize * 2) / sizeof(ZNMethodTableEntry);
565 const size_t partition_start = MIN2(Atomic::add(partition_size, &_claimed) - partition_size, _iter_table_size);
566 const size_t partition_end = MIN2(partition_start + partition_size, _iter_table_size);
567 if (partition_start == partition_end) {
568 // End of table
569 break;
570 }
571
572 // Process table partition
573 for (size_t i = partition_start; i < partition_end; i++) {
574 const ZNMethodTableEntry entry = _iter_table[i];
575 if (entry.registered()) {
576 cl->do_nmethod_entry(entry);
577 }
578 }
579 }
580 }
581
582 class ZNMethodTableUnlinkClosure : public ZNMethodTableEntryClosure {
583 private:
584 bool _unloading_occurred;
585 volatile bool _failed;
586
587 void set_failed() {
588 Atomic::store(true, &_failed);
589 }
590
591 public:
592 ZNMethodTableUnlinkClosure(bool unloading_occurred) :
593 _unloading_occurred(unloading_occurred),
594 _failed(false) {}
595
596 virtual void do_nmethod_entry(ZNMethodTableEntry entry) {
597 if (failed()) {
598 return;
599 }
600
601 nmethod* const nm = entry.method();
602 if (!nm->is_alive()) {
603 return;
604 }
605
606 ZLocker<ZReentrantLock> locker(ZNMethodTable::lock_for_nmethod(nm));
607
608 if (nm->is_unloading()) {
609 // Unlinking of the dependencies must happen before the
610 // handshake separating unlink and purge.
611 nm->flush_dependencies(false /* delete_immediately */);
612
613 // We don't need to take the lock when unlinking nmethods from
614 // the Method, because it is only concurrently unlinked by
615 // the entry barrier, which acquires the per nmethod lock.
616 nm->unlink_from_method(false /* acquire_lock */);
617 return;
618 }
619
620 // Heal oops and disarm
621 ZNMethodOopClosure cl;
622 ZNMethodTable::entry_oops_do(entry, &cl);
623 ZNMethodTable::disarm_nmethod(nm);
624
625 // Clear compiled ICs and exception caches
626 if (!nm->unload_nmethod_caches(_unloading_occurred)) {
627 set_failed();
628 }
629 }
630
631 bool failed() const {
632 return Atomic::load(&_failed);
633 }
634 };
635
636 class ZNMethodTableUnlinkTask : public ZTask {
637 private:
638 ZNMethodTableUnlinkClosure _cl;
639 ICRefillVerifier* _verifier;
640
641 public:
642 ZNMethodTableUnlinkTask(bool unloading_occurred, ICRefillVerifier* verifier) :
643 ZTask("ZNMethodTableUnlinkTask"),
644 _cl(unloading_occurred),
645 _verifier(verifier) {
646 ZNMethodTable::nmethod_entries_do_begin();
647 }
648
649 ~ZNMethodTableUnlinkTask() {
650 ZNMethodTable::nmethod_entries_do_end();
651 }
652
653 virtual void work() {
654 ICRefillVerifierMark mark(_verifier);
655 ZNMethodTable::nmethod_entries_do(&_cl);
656 }
657
658 bool success() const {
659 return !_cl.failed();
660 }
661 };
662
663 void ZNMethodTable::unlink(ZWorkers* workers, bool unloading_occurred) {
664 for (;;) {
665 ICRefillVerifier verifier;
666
667 {
668 ZNMethodTableUnlinkTask task(unloading_occurred, &verifier);
669 workers->run_concurrent(&task);
670 if (task.success()) {
671 return;
672 }
673 }
674
675 // Cleaning failed because we ran out of transitional IC stubs,
676 // so we have to refill and try again. Refilling requires taking
677 // a safepoint, so we temporarily leave the suspendible thread set.
678 SuspendibleThreadSetLeaver sts;
679 InlineCacheBuffer::refill_ic_stubs();
680 }
681 }
682
683 class ZNMethodTablePurgeClosure : public ZNMethodTableEntryClosure {
684 public:
685 virtual void do_nmethod_entry(ZNMethodTableEntry entry) {
686 nmethod* const nm = entry.method();
687 if (nm->is_alive() && nm->is_unloading()) {
688 nm->make_unloaded();
689 }
690 }
691 };
692
693 class ZNMethodTablePurgeTask : public ZTask {
694 private:
695 ZNMethodTablePurgeClosure _cl;
696
697 public:
698 ZNMethodTablePurgeTask() :
699 ZTask("ZNMethodTablePurgeTask"),
700 _cl() {
701 ZNMethodTable::nmethod_entries_do_begin();
702 }
703
704 ~ZNMethodTablePurgeTask() {
705 ZNMethodTable::nmethod_entries_do_end();
706 }
707
708 virtual void work() {
709 ZNMethodTable::nmethod_entries_do(&_cl);
710 }
711 };
712
713 void ZNMethodTable::purge(ZWorkers* workers) {
714 ZNMethodTablePurgeTask task;
715 workers->run_concurrent(&task);
716 }