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