1 /*
2 * Copyright (c) 2015, 2019, 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 "code/compiledIC.hpp"
27 #include "code/compiledMethod.inline.hpp"
28 #include "code/scopeDesc.hpp"
29 #include "code/codeCache.hpp"
30 #include "code/icBuffer.hpp"
31 #include "gc/shared/barrierSet.hpp"
32 #include "gc/shared/gcBehaviours.hpp"
33 #include "interpreter/bytecode.inline.hpp"
34 #include "logging/log.hpp"
35 #include "logging/logTag.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/methodData.hpp"
38 #include "oops/method.inline.hpp"
39 #include "prims/methodHandles.hpp"
40 #include "runtime/handles.inline.hpp"
41 #include "runtime/mutexLocker.hpp"
42 #include "runtime/sharedRuntime.hpp"
43
44 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout,
45 int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps,
46 bool caller_must_gc_arguments)
47 : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
48 _mark_for_deoptimization_status(not_marked),
49 _method(method),
50 _gc_data(NULL)
51 {
52 init_defaults();
53 }
54
55 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, int size,
56 int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size,
57 OopMapSet* oop_maps, bool caller_must_gc_arguments)
58 : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb,
59 frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
60 _mark_for_deoptimization_status(not_marked),
61 _method(method),
62 _gc_data(NULL)
63 {
64 init_defaults();
65 }
66
67 void CompiledMethod::init_defaults() {
68 _has_unsafe_access = 0;
69 _has_method_handle_invokes = 0;
70 _lazy_critical_native = 0;
71 _has_wide_vectors = 0;
72 }
73
74 bool CompiledMethod::is_method_handle_return(address return_pc) {
75 if (!has_method_handle_invokes()) return false;
76 PcDesc* pd = pc_desc_at(return_pc);
77 if (pd == NULL)
78 return false;
79 return pd->is_method_handle_invoke();
80 }
81
82 // Returns a string version of the method state.
83 const char* CompiledMethod::state() const {
84 int state = get_state();
85 switch (state) {
86 case not_installed:
87 return "not installed";
88 case in_use:
89 return "in use";
90 case not_used:
91 return "not_used";
92 case not_entrant:
93 return "not_entrant";
94 case zombie:
95 return "zombie";
96 case unloaded:
97 return "unloaded";
98 default:
99 fatal("unexpected method state: %d", state);
100 return NULL;
101 }
102 }
103
104 //-----------------------------------------------------------------------------
105
106 ExceptionCache* CompiledMethod::exception_cache_acquire() const {
107 return OrderAccess::load_acquire(&_exception_cache);
108 }
109
110 void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) {
111 assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
112 assert(new_entry != NULL,"Must be non null");
113 assert(new_entry->next() == NULL, "Must be null");
114
115 for (;;) {
116 ExceptionCache *ec = exception_cache();
117 if (ec != NULL) {
118 Klass* ex_klass = ec->exception_type();
119 if (!ex_klass->is_loader_alive()) {
120 // We must guarantee that entries are not inserted with new next pointer
121 // edges to ExceptionCache entries with dead klasses, due to bad interactions
122 // with concurrent ExceptionCache cleanup. Therefore, the inserts roll
123 // the head pointer forward to the first live ExceptionCache, so that the new
124 // next pointers always point at live ExceptionCaches, that are not removed due
125 // to concurrent ExceptionCache cleanup.
126 ExceptionCache* next = ec->next();
127 if (Atomic::cmpxchg(next, &_exception_cache, ec) == ec) {
128 CodeCache::release_exception_cache(ec);
129 }
130 continue;
131 }
132 ec = exception_cache();
133 if (ec != NULL) {
134 new_entry->set_next(ec);
135 }
136 }
137 if (Atomic::cmpxchg(new_entry, &_exception_cache, ec) == ec) {
138 return;
139 }
140 }
141 }
142
143 void CompiledMethod::clean_exception_cache() {
144 // For each nmethod, only a single thread may call this cleanup function
145 // at the same time, whether called in STW cleanup or concurrent cleanup.
146 // Note that if the GC is processing exception cache cleaning in a concurrent phase,
147 // then a single writer may contend with cleaning up the head pointer to the
148 // first ExceptionCache node that has a Klass* that is alive. That is fine,
149 // as long as there is no concurrent cleanup of next pointers from concurrent writers.
150 // And the concurrent writers do not clean up next pointers, only the head.
151 // Also note that concurent readers will walk through Klass* pointers that are not
152 // alive. That does not cause ABA problems, because Klass* is deleted after
153 // a handshake with all threads, after all stale ExceptionCaches have been
154 // unlinked. That is also when the CodeCache::exception_cache_purge_list()
155 // is deleted, with all ExceptionCache entries that were cleaned concurrently.
156 // That similarly implies that CAS operations on ExceptionCache entries do not
157 // suffer from ABA problems as unlinking and deletion is separated by a global
158 // handshake operation.
159 ExceptionCache* prev = NULL;
160 ExceptionCache* curr = exception_cache_acquire();
161
162 while (curr != NULL) {
163 ExceptionCache* next = curr->next();
164
165 if (!curr->exception_type()->is_loader_alive()) {
166 if (prev == NULL) {
167 // Try to clean head; this is contended by concurrent inserts, that
168 // both lazily clean the head, and insert entries at the head. If
169 // the CAS fails, the operation is restarted.
170 if (Atomic::cmpxchg(next, &_exception_cache, curr) != curr) {
171 prev = NULL;
172 curr = exception_cache_acquire();
173 continue;
174 }
175 } else {
176 // It is impossible to during cleanup connect the next pointer to
177 // an ExceptionCache that has not been published before a safepoint
178 // prior to the cleanup. Therefore, release is not required.
179 prev->set_next(next);
180 }
181 // prev stays the same.
182
183 CodeCache::release_exception_cache(curr);
184 } else {
185 prev = curr;
186 }
187
188 curr = next;
189 }
190 }
191
192 // public method for accessing the exception cache
193 // These are the public access methods.
194 address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) {
195 // We never grab a lock to read the exception cache, so we may
196 // have false negatives. This is okay, as it can only happen during
197 // the first few exception lookups for a given nmethod.
198 ExceptionCache* ec = exception_cache_acquire();
199 while (ec != NULL) {
200 address ret_val;
201 if ((ret_val = ec->match(exception,pc)) != NULL) {
202 return ret_val;
203 }
204 ec = ec->next();
205 }
206 return NULL;
207 }
208
209 void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
210 // There are potential race conditions during exception cache updates, so we
211 // must own the ExceptionCache_lock before doing ANY modifications. Because
212 // we don't lock during reads, it is possible to have several threads attempt
213 // to update the cache with the same data. We need to check for already inserted
214 // copies of the current data before adding it.
215
216 MutexLocker ml(ExceptionCache_lock);
217 ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
218
219 if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
220 target_entry = new ExceptionCache(exception,pc,handler);
221 add_exception_cache_entry(target_entry);
222 }
223 }
224
225 // private method for handling exception cache
226 // These methods are private, and used to manipulate the exception cache
227 // directly.
228 ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) {
229 ExceptionCache* ec = exception_cache_acquire();
230 while (ec != NULL) {
231 if (ec->match_exception_with_space(exception)) {
232 return ec;
233 }
234 ec = ec->next();
235 }
236 return NULL;
237 }
238
239 //-------------end of code for ExceptionCache--------------
240
241 bool CompiledMethod::is_at_poll_return(address pc) {
242 RelocIterator iter(this, pc, pc+1);
243 while (iter.next()) {
244 if (iter.type() == relocInfo::poll_return_type)
245 return true;
246 }
247 return false;
248 }
249
250
251 bool CompiledMethod::is_at_poll_or_poll_return(address pc) {
252 RelocIterator iter(this, pc, pc+1);
253 while (iter.next()) {
254 relocInfo::relocType t = iter.type();
255 if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
256 return true;
257 }
258 return false;
259 }
260
261 void CompiledMethod::verify_oop_relocations() {
262 // Ensure sure that the code matches the current oop values
263 RelocIterator iter(this, NULL, NULL);
264 while (iter.next()) {
265 if (iter.type() == relocInfo::oop_type) {
266 oop_Relocation* reloc = iter.oop_reloc();
267 if (!reloc->oop_is_immediate()) {
268 reloc->verify_oop_relocation();
269 }
270 }
271 }
272 }
273
274
275 ScopeDesc* CompiledMethod::scope_desc_at(address pc) {
276 PcDesc* pd = pc_desc_at(pc);
277 guarantee(pd != NULL, "scope must be present");
278 return new ScopeDesc(this, pd->scope_decode_offset(),
279 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
280 pd->return_oop(), pd->return_vt());
281 }
282
283 ScopeDesc* CompiledMethod::scope_desc_near(address pc) {
284 PcDesc* pd = pc_desc_near(pc);
285 guarantee(pd != NULL, "scope must be present");
286 return new ScopeDesc(this, pd->scope_decode_offset(),
287 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
288 pd->return_oop(), pd->return_vt());
289 }
290
291 address CompiledMethod::oops_reloc_begin() const {
292 // If the method is not entrant or zombie then a JMP is plastered over the
293 // first few bytes. If an oop in the old code was there, that oop
294 // should not get GC'd. Skip the first few bytes of oops on
295 // not-entrant methods.
296 if (frame_complete_offset() != CodeOffsets::frame_never_safe &&
297 code_begin() + frame_complete_offset() >
298 verified_entry_point() + NativeJump::instruction_size)
299 {
300 // If we have a frame_complete_offset after the native jump, then there
301 // is no point trying to look for oops before that. This is a requirement
302 // for being allowed to scan oops concurrently.
303 return code_begin() + frame_complete_offset();
304 }
305
306 // It is not safe to read oops concurrently using entry barriers, if their
307 // location depend on whether the nmethod is entrant or not.
308 assert(BarrierSet::barrier_set()->barrier_set_nmethod() == NULL, "Not safe oop scan");
309
310 address low_boundary = verified_entry_point();
311 if (!is_in_use() && is_nmethod()) {
312 low_boundary += NativeJump::instruction_size;
313 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
314 // This means that the low_boundary is going to be a little too high.
315 // This shouldn't matter, since oops of non-entrant methods are never used.
316 // In fact, why are we bothering to look at oops in a non-entrant method??
317 }
318 return low_boundary;
319 }
320
321 int CompiledMethod::verify_icholder_relocations() {
322 ResourceMark rm;
323 int count = 0;
324
325 RelocIterator iter(this);
326 while(iter.next()) {
327 if (iter.type() == relocInfo::virtual_call_type) {
328 if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) {
329 CompiledIC *ic = CompiledIC_at(&iter);
330 if (TraceCompiledIC) {
331 tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
332 ic->print();
333 }
334 assert(ic->cached_icholder() != NULL, "must be non-NULL");
335 count++;
336 }
337 }
338 }
339
340 return count;
341 }
342
343 // Method that knows how to preserve outgoing arguments at call. This method must be
344 // called with a frame corresponding to a Java invoke
345 void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
346 if (method() != NULL && !method()->is_native()) {
347 address pc = fr.pc();
348 // The method attached by JIT-compilers should be used, if present.
349 // Bytecode can be inaccurate in such case.
350 Method* callee = attached_method_before_pc(pc);
351 bool has_receiver = false;
352 bool has_appendix = false;
353 Symbol* signature = NULL;
354 if (callee != NULL) {
355 has_receiver = !(callee->access_flags().is_static());
356 has_appendix = false;
357 signature = callee->signature();
358
359 // If value types are passed as fields, use the extended signature
360 // which contains the types of all (oop) fields of the value type.
361 if (this->is_compiled_by_c2() && callee->has_scalarized_args()) {
362 const GrowableArray<SigEntry>* sig = callee->adapter()->get_sig_cc();
363 assert(sig != NULL, "sig should never be null");
364 signature = SigEntry::create_symbol(sig);
365 has_receiver = false; // The extended signature contains the receiver type
366 }
367 } else {
368 SimpleScopeDesc ssd(this, pc);
369 Bytecode_invoke call(ssd.method(), ssd.bci());
370 has_receiver = call.has_receiver();
371 has_appendix = call.has_appendix();
372 signature = call.signature();
373 }
374
375 fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
376 }
377 }
378
379 Method* CompiledMethod::attached_method(address call_instr) {
380 assert(code_contains(call_instr), "not part of the nmethod");
381 RelocIterator iter(this, call_instr, call_instr + 1);
382 while (iter.next()) {
383 if (iter.addr() == call_instr) {
384 switch(iter.type()) {
385 case relocInfo::static_call_type: return iter.static_call_reloc()->method_value();
386 case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
387 case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value();
388 default: break;
389 }
390 }
391 }
392 return NULL; // not found
393 }
394
395 Method* CompiledMethod::attached_method_before_pc(address pc) {
396 if (NativeCall::is_call_before(pc)) {
397 NativeCall* ncall = nativeCall_before(pc);
398 return attached_method(ncall->instruction_address());
399 }
400 return NULL; // not a call
401 }
402
403 void CompiledMethod::clear_inline_caches() {
404 assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
405 if (is_zombie()) {
406 return;
407 }
408
409 RelocIterator iter(this);
410 while (iter.next()) {
411 iter.reloc()->clear_inline_cache();
412 }
413 }
414
415 // Clear IC callsites, releasing ICStubs of all compiled ICs
416 // as well as any associated CompiledICHolders.
417 void CompiledMethod::clear_ic_callsites() {
418 assert(CompiledICLocker::is_safe(this), "mt unsafe call");
419 ResourceMark rm;
420 RelocIterator iter(this);
421 while(iter.next()) {
422 if (iter.type() == relocInfo::virtual_call_type) {
423 CompiledIC* ic = CompiledIC_at(&iter);
424 ic->set_to_clean(false);
425 }
426 }
427 }
428
429 #ifdef ASSERT
430 // Check class_loader is alive for this bit of metadata.
431 class CheckClass : public MetadataClosure {
432 void do_metadata(Metadata* md) {
433 Klass* klass = NULL;
434 if (md->is_klass()) {
435 klass = ((Klass*)md);
436 } else if (md->is_method()) {
437 klass = ((Method*)md)->method_holder();
438 } else if (md->is_methodData()) {
439 klass = ((MethodData*)md)->method()->method_holder();
440 } else {
441 md->print();
442 ShouldNotReachHere();
443 }
444 assert(klass->is_loader_alive(), "must be alive");
445 }
446 };
447 #endif // ASSERT
448
449
450 bool CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic) {
451 if (ic->is_clean()) {
452 return true;
453 }
454 if (ic->is_icholder_call()) {
455 // The only exception is compiledICHolder metdata which may
456 // yet be marked below. (We check this further below).
457 CompiledICHolder* cichk_metdata = ic->cached_icholder();
458
459 if (cichk_metdata->is_loader_alive()) {
460 return true;
461 }
462 } else {
463 Metadata* ic_metdata = ic->cached_metadata();
464 if (ic_metdata != NULL) {
465 if (ic_metdata->is_klass()) {
466 if (((Klass*)ic_metdata)->is_loader_alive()) {
467 return true;
468 }
469 } else if (ic_metdata->is_method()) {
470 Method* method = (Method*)ic_metdata;
471 assert(!method->is_old(), "old method should have been cleaned");
472 if (method->method_holder()->is_loader_alive()) {
473 return true;
474 }
475 } else {
476 ShouldNotReachHere();
477 }
478 }
479 }
480
481 return ic->set_to_clean();
482 }
483
484 // static_stub_Relocations may have dangling references to
485 // nmethods so trim them out here. Otherwise it looks like
486 // compiled code is maintaining a link to dead metadata.
487 void CompiledMethod::clean_ic_stubs() {
488 #ifdef ASSERT
489 address low_boundary = oops_reloc_begin();
490 RelocIterator iter(this, low_boundary);
491 while (iter.next()) {
492 address static_call_addr = NULL;
493 if (iter.type() == relocInfo::opt_virtual_call_type) {
494 CompiledIC* cic = CompiledIC_at(&iter);
495 if (!cic->is_call_to_interpreted()) {
496 static_call_addr = iter.addr();
497 }
498 } else if (iter.type() == relocInfo::static_call_type) {
499 CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
500 if (!csc->is_call_to_interpreted()) {
501 static_call_addr = iter.addr();
502 }
503 }
504 if (static_call_addr != NULL) {
505 RelocIterator sciter(this, low_boundary);
506 while (sciter.next()) {
507 if (sciter.type() == relocInfo::static_stub_type &&
508 sciter.static_stub_reloc()->static_call() == static_call_addr) {
509 sciter.static_stub_reloc()->clear_inline_cache();
510 }
511 }
512 }
513 }
514 #endif
515 }
516
517 // Clean references to unloaded nmethods at addr from this one, which is not unloaded.
518 template <class CompiledICorStaticCall>
519 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, CompiledMethod* from,
520 bool clean_all) {
521 // Ok, to lookup references to zombies here
522 CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
523 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
524 if (nm != NULL) {
525 // Clean inline caches pointing to both zombie and not_entrant methods
526 if (clean_all || !nm->is_in_use() || nm->is_unloading() || (nm->method()->code() != nm)) {
527 if (!ic->set_to_clean(from->is_alive())) {
528 return false;
529 }
530 assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string());
531 }
532 }
533 return true;
534 }
535
536 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, CompiledMethod* from,
537 bool clean_all) {
538 return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), from, clean_all);
539 }
540
541 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, CompiledMethod* from,
542 bool clean_all) {
543 return clean_if_nmethod_is_unloaded(csc, csc->destination(), from, clean_all);
544 }
545
546 // Cleans caches in nmethods that point to either classes that are unloaded
547 // or nmethods that are unloaded.
548 //
549 // Can be called either in parallel by G1 currently or after all
550 // nmethods are unloaded. Return postponed=true in the parallel case for
551 // inline caches found that point to nmethods that are not yet visited during
552 // the do_unloading walk.
553 bool CompiledMethod::unload_nmethod_caches(bool unloading_occurred) {
554 ResourceMark rm;
555
556 // Exception cache only needs to be called if unloading occurred
557 if (unloading_occurred) {
558 clean_exception_cache();
559 }
560
561 if (!cleanup_inline_caches_impl(unloading_occurred, false)) {
562 return false;
563 }
564
565 // All static stubs need to be cleaned.
566 clean_ic_stubs();
567
568 #ifdef ASSERT
569 // Check that the metadata embedded in the nmethod is alive
570 CheckClass check_class;
571 metadata_do(&check_class);
572 #endif
573 return true;
574 }
575
576 void CompiledMethod::cleanup_inline_caches(bool clean_all) {
577 for (;;) {
578 ICRefillVerifier ic_refill_verifier;
579 { CompiledICLocker ic_locker(this);
580 if (cleanup_inline_caches_impl(false, clean_all)) {
581 return;
582 }
583 }
584 InlineCacheBuffer::refill_ic_stubs();
585 }
586 }
587
588 // Called to clean up after class unloading for live nmethods and from the sweeper
589 // for all methods.
590 bool CompiledMethod::cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all) {
591 assert(CompiledICLocker::is_safe(this), "mt unsafe call");
592 ResourceMark rm;
593
594 // Find all calls in an nmethod and clear the ones that point to non-entrant,
595 // zombie and unloaded nmethods.
596 RelocIterator iter(this, oops_reloc_begin());
597 while(iter.next()) {
598
599 switch (iter.type()) {
600
601 case relocInfo::virtual_call_type:
602 if (unloading_occurred) {
603 // If class unloading occurred we first clear ICs where the cached metadata
604 // is referring to an unloaded klass or method.
605 if (!clean_ic_if_metadata_is_dead(CompiledIC_at(&iter))) {
606 return false;
607 }
608 }
609
610 if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) {
611 return false;
612 }
613 break;
614
615 case relocInfo::opt_virtual_call_type:
616 if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) {
617 return false;
618 }
619 break;
620
621 case relocInfo::static_call_type:
622 if (!clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), this, clean_all)) {
623 return false;
624 }
625 break;
626
627 default:
628 break;
629 }
630 }
631
632 return true;
633 }
634
635 // Iterating over all nmethods, e.g. with the help of CodeCache::nmethods_do(fun) was found
636 // to not be inherently safe. There is a chance that fields are seen which are not properly
637 // initialized. This happens despite the fact that nmethods_do() asserts the CodeCache_lock
638 // to be held.
639 // To bundle knowledge about necessary checks in one place, this function was introduced.
640 // It is not claimed that these checks are sufficient, but they were found to be necessary.
641 bool CompiledMethod::nmethod_access_is_safe(nmethod* nm) {
642 Method* method = (nm == NULL) ? NULL : nm->method(); // nm->method() may be uninitialized, i.e. != NULL, but invalid
643 return (nm != NULL) && (method != NULL) && (method->signature() != NULL) &&
644 !nm->is_zombie() && !nm->is_not_installed() &&
645 os::is_readable_pointer(method) &&
646 os::is_readable_pointer(method->constants()) &&
647 os::is_readable_pointer(method->signature());
648 }
649
650 class HasEvolDependency : public MetadataClosure {
651 bool _has_evol_dependency;
652 public:
653 HasEvolDependency() : _has_evol_dependency(false) {}
654 void do_metadata(Metadata* md) {
655 if (md->is_method()) {
656 Method* method = (Method*)md;
657 if (method->is_old()) {
658 _has_evol_dependency = true;
659 }
660 }
661 }
662 bool has_evol_dependency() const { return _has_evol_dependency; }
663 };
664
665 bool CompiledMethod::has_evol_metadata() {
666 // Check the metadata in relocIter and CompiledIC and also deoptimize
667 // any nmethod that has reference to old methods.
668 HasEvolDependency check_evol;
669 metadata_do(&check_evol);
670 if (check_evol.has_evol_dependency() && log_is_enabled(Debug, redefine, class, nmethod)) {
671 ResourceMark rm;
672 log_debug(redefine, class, nmethod)
673 ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on in nmethod metadata",
674 _method->method_holder()->external_name(),
675 _method->name()->as_C_string(),
676 _method->signature()->as_C_string(),
677 compile_id());
678 }
679 return check_evol.has_evol_dependency();
680 }