1 /*
2 * Copyright (c) 2015, 2016, 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/scopeDesc.hpp"
28 #include "code/codeCache.hpp"
29 #include "prims/methodHandles.hpp"
30 #include "interpreter/bytecode.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "runtime/mutexLocker.hpp"
33 #include "runtime/sharedRuntime.hpp"
34
35 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments)
36 : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
37 _method(method), _mark_for_deoptimization_status(not_marked) {
38 init_defaults();
39 }
40
41 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, int size, int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments)
42 : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
43 _method(method), _mark_for_deoptimization_status(not_marked) {
44 init_defaults();
45 }
46
47 void CompiledMethod::init_defaults() {
48 _has_unsafe_access = 0;
49 _has_method_handle_invokes = 0;
50 _lazy_critical_native = 0;
51 _has_wide_vectors = 0;
52 _unloading_clock = 0;
53 }
54
55 bool CompiledMethod::is_method_handle_return(address return_pc) {
56 if (!has_method_handle_invokes()) return false;
57 PcDesc* pd = pc_desc_at(return_pc);
58 if (pd == NULL)
59 return false;
60 return pd->is_method_handle_invoke();
61 }
62
63 // When using JVMCI the address might be off by the size of a call instruction.
64 bool CompiledMethod::is_deopt_entry(address pc) {
65 return pc == deopt_handler_begin()
66 #if INCLUDE_JVMCI
67 || (is_compiled_by_jvmci() && pc == (deopt_handler_begin() + NativeCall::instruction_size))
68 #endif
69 ;
70 }
71
72 // Returns a string version of the method state.
73 const char* CompiledMethod::state() const {
74 int state = get_state();
75 switch (state) {
76 case in_use:
77 return "in use";
78 case not_used:
79 return "not_used";
80 case not_entrant:
81 return "not_entrant";
82 case zombie:
83 return "zombie";
84 case unloaded:
85 return "unloaded";
86 default:
87 fatal("unexpected method state: %d", state);
88 return NULL;
89 }
90 }
91
92 //-----------------------------------------------------------------------------
93
94 void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) {
95 assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
96 assert(new_entry != NULL,"Must be non null");
97 assert(new_entry->next() == NULL, "Must be null");
98
99 ExceptionCache *ec = exception_cache();
100 if (ec != NULL) {
101 new_entry->set_next(ec);
102 }
103 release_set_exception_cache(new_entry);
104 }
105
106 void CompiledMethod::clean_exception_cache(BoolObjectClosure* is_alive) {
107 ExceptionCache* prev = NULL;
108 ExceptionCache* curr = exception_cache();
109
110 while (curr != NULL) {
111 ExceptionCache* next = curr->next();
112
113 Klass* ex_klass = curr->exception_type();
114 if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
115 if (prev == NULL) {
116 set_exception_cache(next);
117 } else {
118 prev->set_next(next);
119 }
120 delete curr;
121 // prev stays the same.
122 } else {
123 prev = curr;
124 }
125
126 curr = next;
127 }
128 }
129
130 // public method for accessing the exception cache
131 // These are the public access methods.
132 address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) {
133 // We never grab a lock to read the exception cache, so we may
134 // have false negatives. This is okay, as it can only happen during
135 // the first few exception lookups for a given nmethod.
136 ExceptionCache* ec = exception_cache();
137 while (ec != NULL) {
138 address ret_val;
139 if ((ret_val = ec->match(exception,pc)) != NULL) {
140 return ret_val;
141 }
142 ec = ec->next();
143 }
144 return NULL;
145 }
146
147 void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
148 // There are potential race conditions during exception cache updates, so we
149 // must own the ExceptionCache_lock before doing ANY modifications. Because
150 // we don't lock during reads, it is possible to have several threads attempt
151 // to update the cache with the same data. We need to check for already inserted
152 // copies of the current data before adding it.
153
154 MutexLocker ml(ExceptionCache_lock);
155 ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
156
157 if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
158 target_entry = new ExceptionCache(exception,pc,handler);
159 add_exception_cache_entry(target_entry);
160 }
161 }
162
163 //-------------end of code for ExceptionCache--------------
164
165 // private method for handling exception cache
166 // These methods are private, and used to manipulate the exception cache
167 // directly.
168 ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) {
169 ExceptionCache* ec = exception_cache();
170 while (ec != NULL) {
171 if (ec->match_exception_with_space(exception)) {
172 return ec;
173 }
174 ec = ec->next();
175 }
176 return NULL;
177 }
178
179 bool CompiledMethod::is_at_poll_return(address pc) {
180 RelocIterator iter(this, pc, pc+1);
181 while (iter.next()) {
182 if (iter.type() == relocInfo::poll_return_type)
183 return true;
184 }
185 return false;
186 }
187
188
189 bool CompiledMethod::is_at_poll_or_poll_return(address pc) {
190 RelocIterator iter(this, pc, pc+1);
191 while (iter.next()) {
192 relocInfo::relocType t = iter.type();
193 if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
194 return true;
195 }
196 return false;
197 }
198
199 void CompiledMethod::verify_oop_relocations() {
200 // Ensure sure that the code matches the current oop values
201 RelocIterator iter(this, NULL, NULL);
202 while (iter.next()) {
203 if (iter.type() == relocInfo::oop_type) {
204 oop_Relocation* reloc = iter.oop_reloc();
205 if (!reloc->oop_is_immediate()) {
206 reloc->verify_oop_relocation();
207 }
208 }
209 }
210 }
211
212
213 ScopeDesc* CompiledMethod::scope_desc_at(address pc) {
214 PcDesc* pd = pc_desc_at(pc);
215 guarantee(pd != NULL, "scope must be present");
216 return new ScopeDesc(this, pd->scope_decode_offset(),
217 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
218 pd->return_oop(), pd->return_vt());
219 }
220
221 void CompiledMethod::cleanup_inline_caches(bool clean_all/*=false*/) {
222 assert_locked_or_safepoint(CompiledIC_lock);
223
224 // If the method is not entrant or zombie then a JMP is plastered over the
225 // first few bytes. If an oop in the old code was there, that oop
226 // should not get GC'd. Skip the first few bytes of oops on
227 // not-entrant methods.
228 address low_boundary = verified_entry_point();
229 if (!is_in_use() && is_nmethod()) {
230 low_boundary += NativeJump::instruction_size;
231 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
232 // This means that the low_boundary is going to be a little too high.
233 // This shouldn't matter, since oops of non-entrant methods are never used.
234 // In fact, why are we bothering to look at oops in a non-entrant method??
235 }
236
237 // Find all calls in an nmethod and clear the ones that point to non-entrant,
238 // zombie and unloaded nmethods.
239 ResourceMark rm;
240 RelocIterator iter(this, low_boundary);
241 while(iter.next()) {
242 switch(iter.type()) {
243 case relocInfo::virtual_call_type:
244 case relocInfo::opt_virtual_call_type: {
245 CompiledIC *ic = CompiledIC_at(&iter);
246 // Ok, to lookup references to zombies here
247 CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
248 if( cb != NULL && cb->is_compiled() ) {
249 CompiledMethod* nm = cb->as_compiled_method();
250 // Clean inline caches pointing to zombie, non-entrant and unloaded methods
251 if (clean_all || !nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive());
252 }
253 break;
254 }
255 case relocInfo::static_call_type: {
256 CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
257 CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
258 if( cb != NULL && cb->is_compiled() ) {
259 CompiledMethod* cm = cb->as_compiled_method();
260 // Clean inline caches pointing to zombie, non-entrant and unloaded methods
261 if (clean_all || !cm->is_in_use() || (cm->method()->code() != cm)) {
262 csc->set_to_clean();
263 }
264 }
265 break;
266 }
267 }
268 }
269 }
270
271 int CompiledMethod::verify_icholder_relocations() {
272 ResourceMark rm;
273 int count = 0;
274
275 RelocIterator iter(this);
276 while(iter.next()) {
277 if (iter.type() == relocInfo::virtual_call_type) {
278 if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) {
279 CompiledIC *ic = CompiledIC_at(&iter);
280 if (TraceCompiledIC) {
281 tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
282 ic->print();
283 }
284 assert(ic->cached_icholder() != NULL, "must be non-NULL");
285 count++;
286 }
287 }
288 }
289
290 return count;
291 }
292
293 // Method that knows how to preserve outgoing arguments at call. This method must be
294 // called with a frame corresponding to a Java invoke
295 void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
296 #ifndef SHARK
297 if (method() != NULL && !method()->is_native()) {
298 address pc = fr.pc();
299 SimpleScopeDesc ssd(this, pc);
300 Bytecode_invoke call(ssd.method(), ssd.bci());
301 bool has_receiver = call.has_receiver();
302 bool has_appendix = call.has_appendix();
303 Symbol* signature = call.signature();
304
305 // The method attached by JIT-compilers should be used, if present.
306 // Bytecode can be inaccurate in such case.
307 Method* callee = attached_method_before_pc(pc);
308 if (callee != NULL) {
309 has_receiver = !(callee->access_flags().is_static());
310 has_appendix = false;
311 signature = callee->signature();
312 }
313
314 // If value types are passed as fields, use the extended signature
315 // which contains the types of all (oop) fields of the value type.
316 if (ValueTypePassFieldsAsArgs && callee != NULL) {
317 // Check if receiver or one of the arguments is a value type
318 bool has_value_receiver = has_receiver && callee->method_holder()->is_value();
319 bool has_value_argument = has_value_receiver;
320 for (SignatureStream ss(signature); !has_value_argument && !ss.at_return_type(); ss.next()) {
321 if (ss.type() == T_VALUETYPE) {
322 has_value_argument = true;
323 }
324 }
325 if (has_value_argument) {
326 // Get the extended signature from the callee's adapter through the attached method
327 signature = callee->adapter()->get_sig_extended();
328 assert(signature != NULL, "signature is null");
329 has_receiver = false; // The extended signature contains the receiver type
330 }
331 }
332
333 fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
334 }
335 #endif // !SHARK
336 }
337
338 // -----------------------------------------------------------------------------
339 // CompiledMethod::get_deopt_original_pc
340 //
341 // Return the original PC for the given PC if:
342 // (a) the given PC belongs to a nmethod and
343 // (b) it is a deopt PC
344 address CompiledMethod::get_deopt_original_pc(const frame* fr) {
345 if (fr->cb() == NULL) return NULL;
346
347 CompiledMethod* cm = fr->cb()->as_compiled_method_or_null();
348 if (cm != NULL && cm->is_deopt_pc(fr->pc()))
349 return cm->get_original_pc(fr);
350
351 return NULL;
352 }
353
354 Method* CompiledMethod::attached_method(address call_instr) {
355 assert(code_contains(call_instr), "not part of the nmethod");
356 RelocIterator iter(this, call_instr, call_instr + 1);
357 while (iter.next()) {
358 if (iter.addr() == call_instr) {
359 switch(iter.type()) {
360 case relocInfo::static_call_type: return iter.static_call_reloc()->method_value();
361 case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
362 case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value();
363 }
364 }
365 }
366 return NULL; // not found
367 }
368
369 Method* CompiledMethod::attached_method_before_pc(address pc) {
370 if (NativeCall::is_call_before(pc)) {
371 NativeCall* ncall = nativeCall_before(pc);
372 return attached_method(ncall->instruction_address());
373 }
374 return NULL; // not a call
375 }
376
377 void CompiledMethod::clear_inline_caches() {
378 assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
379 if (is_zombie()) {
380 return;
381 }
382
383 RelocIterator iter(this);
384 while (iter.next()) {
385 iter.reloc()->clear_inline_cache();
386 }
387 }
388
389 // Clear ICStubs of all compiled ICs
390 void CompiledMethod::clear_ic_stubs() {
391 assert_locked_or_safepoint(CompiledIC_lock);
392 RelocIterator iter(this);
393 while(iter.next()) {
394 if (iter.type() == relocInfo::virtual_call_type) {
395 CompiledIC* ic = CompiledIC_at(&iter);
396 ic->clear_ic_stub();
397 }
398 }
399 }
400
401 #ifdef ASSERT
402
403 class CheckClass : AllStatic {
404 static BoolObjectClosure* _is_alive;
405
406 // Check class_loader is alive for this bit of metadata.
407 static void check_class(Metadata* md) {
408 Klass* klass = NULL;
409 if (md->is_klass()) {
410 klass = ((Klass*)md);
411 } else if (md->is_method()) {
412 klass = ((Method*)md)->method_holder();
413 } else if (md->is_methodData()) {
414 klass = ((MethodData*)md)->method()->method_holder();
415 } else {
416 md->print();
417 ShouldNotReachHere();
418 }
419 assert(klass->is_loader_alive(_is_alive), "must be alive");
420 }
421 public:
422 static void do_check_class(BoolObjectClosure* is_alive, CompiledMethod* nm) {
423 assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
424 _is_alive = is_alive;
425 nm->metadata_do(check_class);
426 }
427 };
428
429 // This is called during a safepoint so can use static data
430 BoolObjectClosure* CheckClass::_is_alive = NULL;
431 #endif // ASSERT
432
433
434 void CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) {
435 if (ic->is_icholder_call()) {
436 // The only exception is compiledICHolder oops which may
437 // yet be marked below. (We check this further below).
438 CompiledICHolder* cichk_oop = ic->cached_icholder();
439
440 if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
441 cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
442 return;
443 }
444 } else {
445 Metadata* ic_oop = ic->cached_metadata();
446 if (ic_oop != NULL) {
447 if (ic_oop->is_klass()) {
448 if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
449 return;
450 }
451 } else if (ic_oop->is_method()) {
452 if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
453 return;
454 }
455 } else {
456 ShouldNotReachHere();
457 }
458 }
459 }
460
461 ic->set_to_clean();
462 }
463
464 unsigned char CompiledMethod::_global_unloading_clock = 0;
465
466 void CompiledMethod::increase_unloading_clock() {
467 _global_unloading_clock++;
468 if (_global_unloading_clock == 0) {
469 // _nmethods are allocated with _unloading_clock == 0,
470 // so 0 is never used as a clock value.
471 _global_unloading_clock = 1;
472 }
473 }
474
475 void CompiledMethod::set_unloading_clock(unsigned char unloading_clock) {
476 OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock);
477 }
478
479 unsigned char CompiledMethod::unloading_clock() {
480 return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock);
481 }
482
483 // Processing of oop references should have been sufficient to keep
484 // all strong references alive. Any weak references should have been
485 // cleared as well. Visit all the metadata and ensure that it's
486 // really alive.
487 void CompiledMethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
488 #ifdef ASSERT
489 RelocIterator iter(this, low_boundary);
490 while (iter.next()) {
491 // static_stub_Relocations may have dangling references to
492 // Method*s so trim them out here. Otherwise it looks like
493 // compiled code is maintaining a link to dead metadata.
494 address static_call_addr = NULL;
495 if (iter.type() == relocInfo::opt_virtual_call_type) {
496 CompiledIC* cic = CompiledIC_at(&iter);
497 if (!cic->is_call_to_interpreted()) {
498 static_call_addr = iter.addr();
499 }
500 } else if (iter.type() == relocInfo::static_call_type) {
501 CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
502 if (!csc->is_call_to_interpreted()) {
503 static_call_addr = iter.addr();
504 }
505 }
506 if (static_call_addr != NULL) {
507 RelocIterator sciter(this, low_boundary);
508 while (sciter.next()) {
509 if (sciter.type() == relocInfo::static_stub_type &&
510 sciter.static_stub_reloc()->static_call() == static_call_addr) {
511 sciter.static_stub_reloc()->clear_inline_cache();
512 }
513 }
514 }
515 }
516 // Check that the metadata embedded in the nmethod is alive
517 CheckClass::do_check_class(is_alive, this);
518 #endif
519 }
520
521 // This is called at the end of the strong tracing/marking phase of a
522 // GC to unload an nmethod if it contains otherwise unreachable
523 // oops.
524
525 void CompiledMethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
526 // Make sure the oop's ready to receive visitors
527 assert(!is_zombie() && !is_unloaded(),
528 "should not call follow on zombie or unloaded nmethod");
529
530 // If the method is not entrant then a JMP is plastered over the
531 // first few bytes. If an oop in the old code was there, that oop
532 // should not get GC'd. Skip the first few bytes of oops on
533 // not-entrant methods.
534 address low_boundary = verified_entry_point();
535 if (is_not_entrant()) {
536 low_boundary += NativeJump::instruction_size;
537 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
538 // (See comment above.)
539 }
540
541 // The RedefineClasses() API can cause the class unloading invariant
542 // to no longer be true. See jvmtiExport.hpp for details.
543 // Also, leave a debugging breadcrumb in local flag.
544 if (JvmtiExport::has_redefined_a_class()) {
545 // This set of the unloading_occurred flag is done before the
546 // call to post_compiled_method_unload() so that the unloading
547 // of this nmethod is reported.
548 unloading_occurred = true;
549 }
550
551 // Exception cache
552 clean_exception_cache(is_alive);
553
554 // If class unloading occurred we first iterate over all inline caches and
555 // clear ICs where the cached oop is referring to an unloaded klass or method.
556 // The remaining live cached oops will be traversed in the relocInfo::oop_type
557 // iteration below.
558 if (unloading_occurred) {
559 RelocIterator iter(this, low_boundary);
560 while(iter.next()) {
561 if (iter.type() == relocInfo::virtual_call_type) {
562 CompiledIC *ic = CompiledIC_at(&iter);
563 clean_ic_if_metadata_is_dead(ic, is_alive);
564 }
565 }
566 }
567
568 if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) {
569 return;
570 }
571
572 #if INCLUDE_JVMCI
573 if (do_unloading_jvmci(is_alive, unloading_occurred)) {
574 return;
575 }
576 #endif
577
578 // Ensure that all metadata is still alive
579 verify_metadata_loaders(low_boundary, is_alive);
580 }
581
582 template <class CompiledICorStaticCall>
583 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, CompiledMethod* from) {
584 // Ok, to lookup references to zombies here
585 CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
586 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
587 if (nm != NULL) {
588 if (nm->unloading_clock() != CompiledMethod::global_unloading_clock()) {
589 // The nmethod has not been processed yet.
590 return true;
591 }
592
593 // Clean inline caches pointing to both zombie and not_entrant methods
594 if (!nm->is_in_use() || (nm->method()->code() != nm)) {
595 ic->set_to_clean();
596 assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string());
597 }
598 }
599
600 return false;
601 }
602
603 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, CompiledMethod* from) {
604 return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from);
605 }
606
607 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, CompiledMethod* from) {
608 return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from);
609 }
610
611 bool CompiledMethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
612 ResourceMark rm;
613
614 // Make sure the oop's ready to receive visitors
615 assert(!is_zombie() && !is_unloaded(),
616 "should not call follow on zombie or unloaded nmethod");
617
618 // If the method is not entrant then a JMP is plastered over the
619 // first few bytes. If an oop in the old code was there, that oop
620 // should not get GC'd. Skip the first few bytes of oops on
621 // not-entrant methods.
622 address low_boundary = verified_entry_point();
623 if (is_not_entrant()) {
624 low_boundary += NativeJump::instruction_size;
625 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
626 // (See comment above.)
627 }
628
629 // The RedefineClasses() API can cause the class unloading invariant
630 // to no longer be true. See jvmtiExport.hpp for details.
631 // Also, leave a debugging breadcrumb in local flag.
632 if (JvmtiExport::has_redefined_a_class()) {
633 // This set of the unloading_occurred flag is done before the
634 // call to post_compiled_method_unload() so that the unloading
635 // of this nmethod is reported.
636 unloading_occurred = true;
637 }
638
639 // Exception cache
640 clean_exception_cache(is_alive);
641
642 bool postponed = false;
643
644 RelocIterator iter(this, low_boundary);
645 while(iter.next()) {
646
647 switch (iter.type()) {
648
649 case relocInfo::virtual_call_type:
650 if (unloading_occurred) {
651 // If class unloading occurred we first iterate over all inline caches and
652 // clear ICs where the cached oop is referring to an unloaded klass or method.
653 clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive);
654 }
655
656 postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
657 break;
658
659 case relocInfo::opt_virtual_call_type:
660 postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
661 break;
662
663 case relocInfo::static_call_type:
664 postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
665 break;
666
667 case relocInfo::oop_type:
668 // handled by do_unloading_oops below
669 break;
670
671 case relocInfo::metadata_type:
672 break; // nothing to do.
673 }
674 }
675
676 if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) {
677 return postponed;
678 }
679
680 #if INCLUDE_JVMCI
681 if (do_unloading_jvmci(is_alive, unloading_occurred)) {
682 return postponed;
683 }
684 #endif
685
686 // Ensure that all metadata is still alive
687 verify_metadata_loaders(low_boundary, is_alive);
688
689 return postponed;
690 }
691
692 void CompiledMethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) {
693 ResourceMark rm;
694
695 // Make sure the oop's ready to receive visitors
696 assert(!is_zombie(),
697 "should not call follow on zombie nmethod");
698
699 // If the method is not entrant then a JMP is plastered over the
700 // first few bytes. If an oop in the old code was there, that oop
701 // should not get GC'd. Skip the first few bytes of oops on
702 // not-entrant methods.
703 address low_boundary = verified_entry_point();
704 if (is_not_entrant()) {
705 low_boundary += NativeJump::instruction_size;
706 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
707 // (See comment above.)
708 }
709
710 RelocIterator iter(this, low_boundary);
711 while(iter.next()) {
712
713 switch (iter.type()) {
714
715 case relocInfo::virtual_call_type:
716 clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
717 break;
718
719 case relocInfo::opt_virtual_call_type:
720 clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
721 break;
722
723 case relocInfo::static_call_type:
724 clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
725 break;
726 }
727 }
728 }