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/exceptionHandlerTable.hpp"
29 #include "code/scopeDesc.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "gc/shared/barrierSet.hpp"
33 #include "gc/shared/gcBehaviours.hpp"
34 #include "interpreter/bytecode.inline.hpp"
35 #include "logging/log.hpp"
36 #include "logging/logTag.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "oops/methodData.hpp"
39 #include "oops/method.inline.hpp"
40 #include "prims/methodHandles.hpp"
41 #include "runtime/deoptimization.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/mutexLocker.hpp"
44 #include "runtime/sharedRuntime.hpp"
45
46 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout,
47 int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps,
48 bool caller_must_gc_arguments)
49 : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
50 _mark_for_deoptimization_status(not_marked),
51 _method(method),
52 _gc_data(NULL)
53 {
54 init_defaults();
55 }
56
57 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, int size,
58 int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size,
59 OopMapSet* oop_maps, bool caller_must_gc_arguments)
60 : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb,
61 frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
62 _mark_for_deoptimization_status(not_marked),
63 _method(method),
64 _gc_data(NULL)
65 {
66 init_defaults();
67 }
68
69 void CompiledMethod::init_defaults() {
70 _has_unsafe_access = 0;
71 _has_method_handle_invokes = 0;
72 _lazy_critical_native = 0;
73 _has_wide_vectors = 0;
74 }
75
76 bool CompiledMethod::is_method_handle_return(address return_pc) {
77 if (!has_method_handle_invokes()) return false;
78 PcDesc* pd = pc_desc_at(return_pc);
79 if (pd == NULL)
80 return false;
81 return pd->is_method_handle_invoke();
82 }
83
84 // Returns a string version of the method state.
85 const char* CompiledMethod::state() const {
86 int state = get_state();
87 switch (state) {
88 case not_installed:
89 return "not installed";
90 case in_use:
91 return "in use";
92 case not_used:
93 return "not_used";
94 case not_entrant:
95 return "not_entrant";
96 case zombie:
97 return "zombie";
98 case unloaded:
99 return "unloaded";
100 default:
101 fatal("unexpected method state: %d", state);
102 return NULL;
103 }
104 }
105
106 //-----------------------------------------------------------------------------
107 void CompiledMethod::mark_for_deoptimization(bool inc_recompile_counts) {
108 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
109 Mutex::_no_safepoint_check_flag);
110 _mark_for_deoptimization_status = (inc_recompile_counts ? deoptimize : deoptimize_noupdate);
111 }
112
113 //-----------------------------------------------------------------------------
114
115 ExceptionCache* CompiledMethod::exception_cache_acquire() const {
116 return OrderAccess::load_acquire(&_exception_cache);
117 }
118
119 void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) {
120 assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
121 assert(new_entry != NULL,"Must be non null");
122 assert(new_entry->next() == NULL, "Must be null");
123
124 for (;;) {
125 ExceptionCache *ec = exception_cache();
126 if (ec != NULL) {
127 Klass* ex_klass = ec->exception_type();
128 if (!ex_klass->is_loader_alive()) {
129 // We must guarantee that entries are not inserted with new next pointer
130 // edges to ExceptionCache entries with dead klasses, due to bad interactions
131 // with concurrent ExceptionCache cleanup. Therefore, the inserts roll
132 // the head pointer forward to the first live ExceptionCache, so that the new
133 // next pointers always point at live ExceptionCaches, that are not removed due
134 // to concurrent ExceptionCache cleanup.
135 ExceptionCache* next = ec->next();
136 if (Atomic::cmpxchg(next, &_exception_cache, ec) == ec) {
137 CodeCache::release_exception_cache(ec);
138 }
139 continue;
140 }
141 ec = exception_cache();
142 if (ec != NULL) {
143 new_entry->set_next(ec);
144 }
145 }
146 if (Atomic::cmpxchg(new_entry, &_exception_cache, ec) == ec) {
147 return;
148 }
149 }
150 }
151
152 void CompiledMethod::clean_exception_cache() {
153 // For each nmethod, only a single thread may call this cleanup function
154 // at the same time, whether called in STW cleanup or concurrent cleanup.
155 // Note that if the GC is processing exception cache cleaning in a concurrent phase,
156 // then a single writer may contend with cleaning up the head pointer to the
157 // first ExceptionCache node that has a Klass* that is alive. That is fine,
158 // as long as there is no concurrent cleanup of next pointers from concurrent writers.
159 // And the concurrent writers do not clean up next pointers, only the head.
160 // Also note that concurent readers will walk through Klass* pointers that are not
161 // alive. That does not cause ABA problems, because Klass* is deleted after
162 // a handshake with all threads, after all stale ExceptionCaches have been
163 // unlinked. That is also when the CodeCache::exception_cache_purge_list()
164 // is deleted, with all ExceptionCache entries that were cleaned concurrently.
165 // That similarly implies that CAS operations on ExceptionCache entries do not
166 // suffer from ABA problems as unlinking and deletion is separated by a global
167 // handshake operation.
168 ExceptionCache* prev = NULL;
169 ExceptionCache* curr = exception_cache_acquire();
170
171 while (curr != NULL) {
172 ExceptionCache* next = curr->next();
173
174 if (!curr->exception_type()->is_loader_alive()) {
175 if (prev == NULL) {
176 // Try to clean head; this is contended by concurrent inserts, that
177 // both lazily clean the head, and insert entries at the head. If
178 // the CAS fails, the operation is restarted.
179 if (Atomic::cmpxchg(next, &_exception_cache, curr) != curr) {
180 prev = NULL;
181 curr = exception_cache_acquire();
182 continue;
183 }
184 } else {
185 // It is impossible to during cleanup connect the next pointer to
186 // an ExceptionCache that has not been published before a safepoint
187 // prior to the cleanup. Therefore, release is not required.
188 prev->set_next(next);
189 }
190 // prev stays the same.
191
192 CodeCache::release_exception_cache(curr);
193 } else {
194 prev = curr;
195 }
196
197 curr = next;
198 }
199 }
200
201 // public method for accessing the exception cache
202 // These are the public access methods.
203 address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) {
204 // We never grab a lock to read the exception cache, so we may
205 // have false negatives. This is okay, as it can only happen during
206 // the first few exception lookups for a given nmethod.
207 ExceptionCache* ec = exception_cache_acquire();
208 while (ec != NULL) {
209 address ret_val;
210 if ((ret_val = ec->match(exception,pc)) != NULL) {
211 return ret_val;
212 }
213 ec = ec->next();
214 }
215 return NULL;
216 }
217
218 void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
219 // There are potential race conditions during exception cache updates, so we
220 // must own the ExceptionCache_lock before doing ANY modifications. Because
221 // we don't lock during reads, it is possible to have several threads attempt
222 // to update the cache with the same data. We need to check for already inserted
223 // copies of the current data before adding it.
224
225 MutexLocker ml(ExceptionCache_lock);
226 ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
227
228 if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
229 target_entry = new ExceptionCache(exception,pc,handler);
230 add_exception_cache_entry(target_entry);
231 }
232 }
233
234 // private method for handling exception cache
235 // These methods are private, and used to manipulate the exception cache
236 // directly.
237 ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) {
238 ExceptionCache* ec = exception_cache_acquire();
239 while (ec != NULL) {
240 if (ec->match_exception_with_space(exception)) {
241 return ec;
242 }
243 ec = ec->next();
244 }
245 return NULL;
246 }
247
248 //-------------end of code for ExceptionCache--------------
249
250 bool CompiledMethod::is_at_poll_return(address pc) {
251 RelocIterator iter(this, pc, pc+1);
252 while (iter.next()) {
253 if (iter.type() == relocInfo::poll_return_type)
254 return true;
255 }
256 return false;
257 }
258
259
260 bool CompiledMethod::is_at_poll_or_poll_return(address pc) {
261 RelocIterator iter(this, pc, pc+1);
262 while (iter.next()) {
263 relocInfo::relocType t = iter.type();
264 if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
265 return true;
266 }
267 return false;
268 }
269
270 void CompiledMethod::verify_oop_relocations() {
271 // Ensure sure that the code matches the current oop values
272 RelocIterator iter(this, NULL, NULL);
273 while (iter.next()) {
274 if (iter.type() == relocInfo::oop_type) {
275 oop_Relocation* reloc = iter.oop_reloc();
276 if (!reloc->oop_is_immediate()) {
277 reloc->verify_oop_relocation();
278 }
279 }
280 }
281 }
282
283
284 ScopeDesc* CompiledMethod::scope_desc_at(address pc) {
285 PcDesc* pd = pc_desc_at(pc);
286 guarantee(pd != NULL, "scope must be present");
287 return new ScopeDesc(this, pd->scope_decode_offset(),
288 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
289 pd->return_oop());
290 }
291
292 ScopeDesc* CompiledMethod::scope_desc_near(address pc) {
293 PcDesc* pd = pc_desc_near(pc);
294 guarantee(pd != NULL, "scope must be present");
295 return new ScopeDesc(this, pd->scope_decode_offset(),
296 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
297 pd->return_oop());
298 }
299
300 address CompiledMethod::oops_reloc_begin() const {
301 // If the method is not entrant or zombie then a JMP is plastered over the
302 // first few bytes. If an oop in the old code was there, that oop
303 // should not get GC'd. Skip the first few bytes of oops on
304 // not-entrant methods.
305 if (frame_complete_offset() != CodeOffsets::frame_never_safe &&
306 code_begin() + frame_complete_offset() >
307 verified_entry_point() + NativeJump::instruction_size)
308 {
309 // If we have a frame_complete_offset after the native jump, then there
310 // is no point trying to look for oops before that. This is a requirement
311 // for being allowed to scan oops concurrently.
312 return code_begin() + frame_complete_offset();
313 }
314
315 // It is not safe to read oops concurrently using entry barriers, if their
316 // location depend on whether the nmethod is entrant or not.
317 assert(BarrierSet::barrier_set()->barrier_set_nmethod() == NULL, "Not safe oop scan");
318
319 address low_boundary = verified_entry_point();
320 if (!is_in_use() && is_nmethod()) {
321 low_boundary += NativeJump::instruction_size;
322 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
323 // This means that the low_boundary is going to be a little too high.
324 // This shouldn't matter, since oops of non-entrant methods are never used.
325 // In fact, why are we bothering to look at oops in a non-entrant method??
326 }
327 return low_boundary;
328 }
329
330 int CompiledMethod::verify_icholder_relocations() {
331 ResourceMark rm;
332 int count = 0;
333
334 RelocIterator iter(this);
335 while(iter.next()) {
336 if (iter.type() == relocInfo::virtual_call_type) {
337 if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) {
338 CompiledIC *ic = CompiledIC_at(&iter);
339 if (TraceCompiledIC) {
340 tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
341 ic->print();
342 }
343 assert(ic->cached_icholder() != NULL, "must be non-NULL");
344 count++;
345 }
346 }
347 }
348
349 return count;
350 }
351
352 // Method that knows how to preserve outgoing arguments at call. This method must be
353 // called with a frame corresponding to a Java invoke
354 void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
355 if (method() != NULL && !method()->is_native()) {
356 address pc = fr.pc();
357 SimpleScopeDesc ssd(this, pc);
358 Bytecode_invoke call(ssd.method(), ssd.bci());
359 bool has_receiver = call.has_receiver();
360 bool has_appendix = call.has_appendix();
361 Symbol* signature = call.signature();
362
363 // The method attached by JIT-compilers should be used, if present.
364 // Bytecode can be inaccurate in such case.
365 Method* callee = attached_method_before_pc(pc);
366 if (callee != NULL) {
367 has_receiver = !(callee->access_flags().is_static());
368 has_appendix = false;
369 signature = callee->signature();
370 }
371
372 fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
373 }
374 }
375
376 Method* CompiledMethod::attached_method(address call_instr) {
377 assert(code_contains(call_instr), "not part of the nmethod");
378 RelocIterator iter(this, call_instr, call_instr + 1);
379 while (iter.next()) {
380 if (iter.addr() == call_instr) {
381 switch(iter.type()) {
382 case relocInfo::static_call_type: return iter.static_call_reloc()->method_value();
383 case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
384 case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value();
385 default: break;
386 }
387 }
388 }
389 return NULL; // not found
390 }
391
392 Method* CompiledMethod::attached_method_before_pc(address pc) {
393 if (NativeCall::is_call_before(pc)) {
394 NativeCall* ncall = nativeCall_before(pc);
395 return attached_method(ncall->instruction_address());
396 }
397 return NULL; // not a call
398 }
399
400 void CompiledMethod::clear_inline_caches() {
401 assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
402 if (is_zombie()) {
403 return;
404 }
405
406 RelocIterator iter(this);
407 while (iter.next()) {
408 iter.reloc()->clear_inline_cache();
409 }
410 }
411
412 // Clear IC callsites, releasing ICStubs of all compiled ICs
413 // as well as any associated CompiledICHolders.
414 void CompiledMethod::clear_ic_callsites() {
415 assert(CompiledICLocker::is_safe(this), "mt unsafe call");
416 ResourceMark rm;
417 RelocIterator iter(this);
418 while(iter.next()) {
419 if (iter.type() == relocInfo::virtual_call_type) {
420 CompiledIC* ic = CompiledIC_at(&iter);
421 ic->set_to_clean(false);
422 }
423 }
424 }
425
426 #ifdef ASSERT
427 // Check class_loader is alive for this bit of metadata.
428 class CheckClass : public MetadataClosure {
429 void do_metadata(Metadata* md) {
430 Klass* klass = NULL;
431 if (md->is_klass()) {
432 klass = ((Klass*)md);
433 } else if (md->is_method()) {
434 klass = ((Method*)md)->method_holder();
435 } else if (md->is_methodData()) {
436 klass = ((MethodData*)md)->method()->method_holder();
437 } else {
438 md->print();
439 ShouldNotReachHere();
440 }
441 assert(klass->is_loader_alive(), "must be alive");
442 }
443 };
444 #endif // ASSERT
445
446
447 bool CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic) {
448 if (ic->is_clean()) {
449 return true;
450 }
451 if (ic->is_icholder_call()) {
452 // The only exception is compiledICHolder metdata which may
453 // yet be marked below. (We check this further below).
454 CompiledICHolder* cichk_metdata = ic->cached_icholder();
455
456 if (cichk_metdata->is_loader_alive()) {
457 return true;
458 }
459 } else {
460 Metadata* ic_metdata = ic->cached_metadata();
461 if (ic_metdata != NULL) {
462 if (ic_metdata->is_klass()) {
463 if (((Klass*)ic_metdata)->is_loader_alive()) {
464 return true;
465 }
466 } else if (ic_metdata->is_method()) {
467 Method* method = (Method*)ic_metdata;
468 assert(!method->is_old(), "old method should have been cleaned");
469 if (method->method_holder()->is_loader_alive()) {
470 return true;
471 }
472 } else {
473 ShouldNotReachHere();
474 }
475 }
476 }
477
478 return ic->set_to_clean();
479 }
480
481 // Clean references to unloaded nmethods at addr from this one, which is not unloaded.
482 template <class CompiledICorStaticCall>
483 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, CompiledMethod* from,
484 bool clean_all) {
485 // Ok, to lookup references to zombies here
486 CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
487 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
488 if (nm != NULL) {
489 // Clean inline caches pointing to both zombie and not_entrant methods
490 if (clean_all || !nm->is_in_use() || nm->is_unloading() || (nm->method()->code() != nm)) {
491 if (!ic->set_to_clean(from->is_alive())) {
492 return false;
493 }
494 assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string());
495 }
496 }
497 return true;
498 }
499
500 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, CompiledMethod* from,
501 bool clean_all) {
502 return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), from, clean_all);
503 }
504
505 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, CompiledMethod* from,
506 bool clean_all) {
507 return clean_if_nmethod_is_unloaded(csc, csc->destination(), from, clean_all);
508 }
509
510 // Cleans caches in nmethods that point to either classes that are unloaded
511 // or nmethods that are unloaded.
512 //
513 // Can be called either in parallel by G1 currently or after all
514 // nmethods are unloaded. Return postponed=true in the parallel case for
515 // inline caches found that point to nmethods that are not yet visited during
516 // the do_unloading walk.
517 bool CompiledMethod::unload_nmethod_caches(bool unloading_occurred) {
518 ResourceMark rm;
519
520 // Exception cache only needs to be called if unloading occurred
521 if (unloading_occurred) {
522 clean_exception_cache();
523 }
524
525 if (!cleanup_inline_caches_impl(unloading_occurred, false)) {
526 return false;
527 }
528
529 #ifdef ASSERT
530 // Check that the metadata embedded in the nmethod is alive
531 CheckClass check_class;
532 metadata_do(&check_class);
533 #endif
534 return true;
535 }
536
537 void CompiledMethod::cleanup_inline_caches(bool clean_all) {
538 for (;;) {
539 ICRefillVerifier ic_refill_verifier;
540 { CompiledICLocker ic_locker(this);
541 if (cleanup_inline_caches_impl(false, clean_all)) {
542 return;
543 }
544 }
545 InlineCacheBuffer::refill_ic_stubs();
546 }
547 }
548
549 // Called to clean up after class unloading for live nmethods and from the sweeper
550 // for all methods.
551 bool CompiledMethod::cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all) {
552 assert(CompiledICLocker::is_safe(this), "mt unsafe call");
553 ResourceMark rm;
554
555 // Find all calls in an nmethod and clear the ones that point to non-entrant,
556 // zombie and unloaded nmethods.
557 RelocIterator iter(this, oops_reloc_begin());
558 bool is_in_static_stub = false;
559 while(iter.next()) {
560
561 switch (iter.type()) {
562
563 case relocInfo::virtual_call_type:
564 if (unloading_occurred) {
565 // If class unloading occurred we first clear ICs where the cached metadata
566 // is referring to an unloaded klass or method.
567 if (!clean_ic_if_metadata_is_dead(CompiledIC_at(&iter))) {
568 return false;
569 }
570 }
571
572 if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) {
573 return false;
574 }
575 break;
576
577 case relocInfo::opt_virtual_call_type:
578 if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) {
579 return false;
580 }
581 break;
582
583 case relocInfo::static_call_type:
584 if (!clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), this, clean_all)) {
585 return false;
586 }
587 break;
588
589 case relocInfo::static_stub_type: {
590 is_in_static_stub = true;
591 break;
592 }
593
594 case relocInfo::metadata_type: {
595 // Only the metadata relocations contained in static/opt virtual call stubs
596 // contains the Method* passed to c2i adapters. It is the only metadata
597 // relocation that needs to be walked, as it is the one metadata relocation
598 // that violates the invariant that all metadata relocations have an oop
599 // in the compiled method (due to deferred resolution and code patching).
600
601 // This causes dead metadata to remain in compiled methods that are not
602 // unloading. Unless these slippery metadata relocations of the static
603 // stubs are at least cleared, subsequent class redefinition operations
604 // will access potentially free memory, and JavaThread execution
605 // concurrent to class unloading may call c2i adapters with dead methods.
606 if (!is_in_static_stub) {
607 // The first metadata relocation after a static stub relocation is the
608 // metadata relocation of the static stub used to pass the Method* to
609 // c2i adapters.
610 continue;
611 }
612 is_in_static_stub = false;
613 metadata_Relocation* r = iter.metadata_reloc();
614 Metadata* md = r->metadata_value();
615 if (md != NULL && md->is_method()) {
616 Method* method = static_cast<Method*>(md);
617 if (!method->method_holder()->is_loader_alive()) {
618 Atomic::store((Method*)NULL, r->metadata_addr());
619
620 if (!r->metadata_is_immediate()) {
621 r->fix_metadata_relocation();
622 }
623 }
624 }
625 break;
626 }
627
628 default:
629 break;
630 }
631 }
632
633 return true;
634 }
635
636 // Iterating over all nmethods, e.g. with the help of CodeCache::nmethods_do(fun) was found
637 // to not be inherently safe. There is a chance that fields are seen which are not properly
638 // initialized. This happens despite the fact that nmethods_do() asserts the CodeCache_lock
639 // to be held.
640 // To bundle knowledge about necessary checks in one place, this function was introduced.
641 // It is not claimed that these checks are sufficient, but they were found to be necessary.
642 bool CompiledMethod::nmethod_access_is_safe(nmethod* nm) {
643 Method* method = (nm == NULL) ? NULL : nm->method(); // nm->method() may be uninitialized, i.e. != NULL, but invalid
644 return (nm != NULL) && (method != NULL) && (method->signature() != NULL) &&
645 !nm->is_zombie() && !nm->is_not_installed() &&
646 os::is_readable_pointer(method) &&
647 os::is_readable_pointer(method->constants()) &&
648 os::is_readable_pointer(method->signature());
649 }
650
651 address CompiledMethod::continuation_for_implicit_exception(address pc, bool for_div0_check) {
652 // Exception happened outside inline-cache check code => we are inside
653 // an active nmethod => use cpc to determine a return address
654 int exception_offset = pc - code_begin();
655 int cont_offset = ImplicitExceptionTable(this).continuation_offset( exception_offset );
656 #ifdef ASSERT
657 if (cont_offset == 0) {
658 Thread* thread = Thread::current();
659 ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
660 HandleMark hm(thread);
661 ResourceMark rm(thread);
662 CodeBlob* cb = CodeCache::find_blob(pc);
663 assert(cb != NULL && cb == this, "");
664 ttyLocker ttyl;
665 tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
666 print();
667 method()->print_codes();
668 print_code();
669 print_pcs();
670 }
671 #endif
672 if (cont_offset == 0) {
673 // Let the normal error handling report the exception
674 return NULL;
675 }
676 if (cont_offset == exception_offset) {
677 #if INCLUDE_JVMCI
678 Deoptimization::DeoptReason deopt_reason = for_div0_check ? Deoptimization::Reason_div0_check : Deoptimization::Reason_null_check;
679 JavaThread *thread = JavaThread::current();
680 thread->set_jvmci_implicit_exception_pc(pc);
681 thread->set_pending_deoptimization(Deoptimization::make_trap_request(deopt_reason,
682 Deoptimization::Action_reinterpret));
683 return (SharedRuntime::deopt_blob()->implicit_exception_uncommon_trap());
684 #else
685 ShouldNotReachHere();
686 #endif
687 }
688 return code_begin() + cont_offset;
689 }
690
691 class HasEvolDependency : public MetadataClosure {
692 bool _has_evol_dependency;
693 public:
694 HasEvolDependency() : _has_evol_dependency(false) {}
695 void do_metadata(Metadata* md) {
696 if (md->is_method()) {
697 Method* method = (Method*)md;
698 if (method->is_old()) {
699 _has_evol_dependency = true;
700 }
701 }
702 }
703 bool has_evol_dependency() const { return _has_evol_dependency; }
704 };
705
706 bool CompiledMethod::has_evol_metadata() {
707 // Check the metadata in relocIter and CompiledIC and also deoptimize
708 // any nmethod that has reference to old methods.
709 HasEvolDependency check_evol;
710 metadata_do(&check_evol);
711 if (check_evol.has_evol_dependency() && log_is_enabled(Debug, redefine, class, nmethod)) {
712 ResourceMark rm;
713 log_debug(redefine, class, nmethod)
714 ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on in nmethod metadata",
715 _method->method_holder()->external_name(),
716 _method->name()->as_C_string(),
717 _method->signature()->as_C_string(),
718 compile_id());
719 }
720 return check_evol.has_evol_dependency();
721 }