1 /*
2 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
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 "prims/methodHandles.hpp"
31 #include "interpreter/bytecode.inline.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "oops/method.inline.hpp"
34 #include "runtime/handles.inline.hpp"
35 #include "runtime/mutexLocker.hpp"
36
37 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)
38 : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
39 _method(method), _mark_for_deoptimization_status(not_marked) {
40 init_defaults();
41 }
42
43 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)
44 : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
45 _method(method), _mark_for_deoptimization_status(not_marked) {
46 init_defaults();
47 }
48
49 void CompiledMethod::init_defaults() {
50 _has_unsafe_access = 0;
51 _has_method_handle_invokes = 0;
52 _lazy_critical_native = 0;
53 _has_wide_vectors = 0;
54 _unloading_clock = 0;
55 }
56
57 bool CompiledMethod::is_method_handle_return(address return_pc) {
58 if (!has_method_handle_invokes()) return false;
59 PcDesc* pd = pc_desc_at(return_pc);
60 if (pd == NULL)
61 return false;
62 return pd->is_method_handle_invoke();
63 }
64
65 // Returns a string version of the method state.
66 const char* CompiledMethod::state() const {
67 int state = get_state();
68 switch (state) {
69 case not_installed:
70 return "not installed";
71 case in_use:
72 return "in use";
73 case not_used:
74 return "not_used";
75 case not_entrant:
76 return "not_entrant";
77 case zombie:
78 return "zombie";
79 case unloaded:
80 return "unloaded";
81 default:
82 fatal("unexpected method state: %d", state);
83 return NULL;
84 }
85 }
86
87 //-----------------------------------------------------------------------------
88
89 void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) {
90 assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
91 assert(new_entry != NULL,"Must be non null");
92 assert(new_entry->next() == NULL, "Must be null");
93
94 ExceptionCache *ec = exception_cache();
95 if (ec != NULL) {
96 new_entry->set_next(ec);
97 }
98 release_set_exception_cache(new_entry);
99 }
100
101 void CompiledMethod::clean_exception_cache(BoolObjectClosure* is_alive) {
102 ExceptionCache* prev = NULL;
103 ExceptionCache* curr = exception_cache();
104
105 while (curr != NULL) {
106 ExceptionCache* next = curr->next();
107
108 Klass* ex_klass = curr->exception_type();
109 if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
110 if (prev == NULL) {
111 set_exception_cache(next);
112 } else {
113 prev->set_next(next);
114 }
115 delete curr;
116 // prev stays the same.
117 } else {
118 prev = curr;
119 }
120
121 curr = next;
122 }
123 }
124
125 // public method for accessing the exception cache
126 // These are the public access methods.
127 address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) {
128 // We never grab a lock to read the exception cache, so we may
129 // have false negatives. This is okay, as it can only happen during
130 // the first few exception lookups for a given nmethod.
131 ExceptionCache* ec = exception_cache();
132 while (ec != NULL) {
133 address ret_val;
134 if ((ret_val = ec->match(exception,pc)) != NULL) {
135 return ret_val;
136 }
137 ec = ec->next();
138 }
139 return NULL;
140 }
141
142 void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
143 // There are potential race conditions during exception cache updates, so we
144 // must own the ExceptionCache_lock before doing ANY modifications. Because
145 // we don't lock during reads, it is possible to have several threads attempt
146 // to update the cache with the same data. We need to check for already inserted
147 // copies of the current data before adding it.
148
149 MutexLocker ml(ExceptionCache_lock);
150 ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
151
152 if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
153 target_entry = new ExceptionCache(exception,pc,handler);
154 add_exception_cache_entry(target_entry);
155 }
156 }
157
158 //-------------end of code for ExceptionCache--------------
159
160 // private method for handling exception cache
161 // These methods are private, and used to manipulate the exception cache
162 // directly.
163 ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) {
164 ExceptionCache* ec = exception_cache();
165 while (ec != NULL) {
166 if (ec->match_exception_with_space(exception)) {
167 return ec;
168 }
169 ec = ec->next();
170 }
171 return NULL;
172 }
173
174 bool CompiledMethod::is_at_poll_return(address pc) {
175 RelocIterator iter(this, pc, pc+1);
176 while (iter.next()) {
177 if (iter.type() == relocInfo::poll_return_type)
178 return true;
179 }
180 return false;
181 }
182
183
184 bool CompiledMethod::is_at_poll_or_poll_return(address pc) {
185 RelocIterator iter(this, pc, pc+1);
186 while (iter.next()) {
187 relocInfo::relocType t = iter.type();
188 if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
189 return true;
190 }
191 return false;
192 }
193
194 void CompiledMethod::verify_oop_relocations() {
195 // Ensure sure that the code matches the current oop values
196 RelocIterator iter(this, NULL, NULL);
197 while (iter.next()) {
198 if (iter.type() == relocInfo::oop_type) {
199 oop_Relocation* reloc = iter.oop_reloc();
200 if (!reloc->oop_is_immediate()) {
201 reloc->verify_oop_relocation();
202 }
203 }
204 }
205 }
206
207
208 ScopeDesc* CompiledMethod::scope_desc_at(address pc) {
209 PcDesc* pd = pc_desc_at(pc);
210 guarantee(pd != NULL, "scope must be present");
211 return new ScopeDesc(this, pd->scope_decode_offset(),
212 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
213 pd->return_oop());
214 }
215
216 ScopeDesc* CompiledMethod::scope_desc_near(address pc) {
217 PcDesc* pd = pc_desc_near(pc);
218 guarantee(pd != NULL, "scope must be present");
219 return new ScopeDesc(this, pd->scope_decode_offset(),
220 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
221 pd->return_oop());
222 }
223
224 void CompiledMethod::cleanup_inline_caches(bool clean_all/*=false*/) {
225 assert_locked_or_safepoint(CompiledIC_lock);
226
227 // If the method is not entrant or zombie then a JMP is plastered over the
228 // first few bytes. If an oop in the old code was there, that oop
229 // should not get GC'd. Skip the first few bytes of oops on
230 // not-entrant methods.
231 address low_boundary = verified_entry_point();
232 if (!is_in_use() && is_nmethod()) {
233 low_boundary += NativeJump::instruction_size;
234 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
235 // This means that the low_boundary is going to be a little too high.
236 // This shouldn't matter, since oops of non-entrant methods are never used.
237 // In fact, why are we bothering to look at oops in a non-entrant method??
238 }
239
240 // Find all calls in an nmethod and clear the ones that point to non-entrant,
241 // zombie and unloaded nmethods.
242 ResourceMark rm;
243 RelocIterator iter(this, low_boundary);
244 while(iter.next()) {
245 switch(iter.type()) {
246 case relocInfo::virtual_call_type:
247 case relocInfo::opt_virtual_call_type: {
248 CompiledIC *ic = CompiledIC_at(&iter);
249 // Ok, to lookup references to zombies here
250 CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
251 if( cb != NULL && cb->is_compiled() ) {
252 CompiledMethod* nm = cb->as_compiled_method();
253 // Clean inline caches pointing to zombie, non-entrant and unloaded methods
254 if (clean_all || !nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive());
255 }
256 break;
257 }
258 case relocInfo::static_call_type: {
259 CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
260 CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
261 if( cb != NULL && cb->is_compiled() ) {
262 CompiledMethod* cm = cb->as_compiled_method();
263 // Clean inline caches pointing to zombie, non-entrant and unloaded methods
264 if (clean_all || !cm->is_in_use() || (cm->method()->code() != cm)) {
265 csc->set_to_clean();
266 }
267 }
268 break;
269 }
270 default:
271 break;
272 }
273 }
274 }
275
276 int CompiledMethod::verify_icholder_relocations() {
277 ResourceMark rm;
278 int count = 0;
279
280 RelocIterator iter(this);
281 while(iter.next()) {
282 if (iter.type() == relocInfo::virtual_call_type) {
283 if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) {
284 CompiledIC *ic = CompiledIC_at(&iter);
285 if (TraceCompiledIC) {
286 tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
287 ic->print();
288 }
289 assert(ic->cached_icholder() != NULL, "must be non-NULL");
290 count++;
291 }
292 }
293 }
294
295 return count;
296 }
297
298 // Method that knows how to preserve outgoing arguments at call. This method must be
299 // called with a frame corresponding to a Java invoke
300 void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
301 if (method() != NULL && !method()->is_native()) {
302 address pc = fr.pc();
303 SimpleScopeDesc ssd(this, pc);
304 Bytecode_invoke call(ssd.method(), ssd.bci());
305 bool has_receiver = call.has_receiver();
306 bool has_appendix = call.has_appendix();
307 Symbol* signature = call.signature();
308
309 // The method attached by JIT-compilers should be used, if present.
310 // Bytecode can be inaccurate in such case.
311 Method* callee = attached_method_before_pc(pc);
312 if (callee != NULL) {
313 has_receiver = !(callee->access_flags().is_static());
314 has_appendix = false;
315 signature = callee->signature();
316 }
317
318 fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
319 }
320 }
321
322 Method* CompiledMethod::attached_method(address call_instr) {
323 assert(code_contains(call_instr), "not part of the nmethod");
324 RelocIterator iter(this, call_instr, call_instr + 1);
325 while (iter.next()) {
326 if (iter.addr() == call_instr) {
327 switch(iter.type()) {
328 case relocInfo::static_call_type: return iter.static_call_reloc()->method_value();
329 case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
330 case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value();
331 default: break;
332 }
333 }
334 }
335 return NULL; // not found
336 }
337
338 Method* CompiledMethod::attached_method_before_pc(address pc) {
339 if (NativeCall::is_call_before(pc)) {
340 NativeCall* ncall = nativeCall_before(pc);
341 return attached_method(ncall->instruction_address());
342 }
343 return NULL; // not a call
344 }
345
346 void CompiledMethod::clear_inline_caches() {
347 assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
348 if (is_zombie()) {
349 return;
350 }
351
352 RelocIterator iter(this);
353 while (iter.next()) {
354 iter.reloc()->clear_inline_cache();
355 }
356 }
357
358 // Clear ICStubs of all compiled ICs
359 void CompiledMethod::clear_ic_stubs() {
360 assert_locked_or_safepoint(CompiledIC_lock);
361 RelocIterator iter(this);
362 while(iter.next()) {
363 if (iter.type() == relocInfo::virtual_call_type) {
364 CompiledIC* ic = CompiledIC_at(&iter);
365 ic->clear_ic_stub();
366 }
367 }
368 }
369
370 #ifdef ASSERT
371
372 class CheckClass : AllStatic {
373 static BoolObjectClosure* _is_alive;
374
375 // Check class_loader is alive for this bit of metadata.
376 static void check_class(Metadata* md) {
377 Klass* klass = NULL;
378 if (md->is_klass()) {
379 klass = ((Klass*)md);
380 } else if (md->is_method()) {
381 klass = ((Method*)md)->method_holder();
382 } else if (md->is_methodData()) {
383 klass = ((MethodData*)md)->method()->method_holder();
384 } else {
385 md->print();
386 ShouldNotReachHere();
387 }
388 assert(klass->is_loader_alive(_is_alive), "must be alive");
389 }
390 public:
391 static void do_check_class(BoolObjectClosure* is_alive, CompiledMethod* nm) {
392 assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
393 _is_alive = is_alive;
394 nm->metadata_do(check_class);
395 }
396 };
397
398 // This is called during a safepoint so can use static data
399 BoolObjectClosure* CheckClass::_is_alive = NULL;
400 #endif // ASSERT
401
402
403 void CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) {
404 if (ic->is_icholder_call()) {
405 // The only exception is compiledICHolder oops which may
406 // yet be marked below. (We check this further below).
407 CompiledICHolder* cichk_oop = ic->cached_icholder();
408
409 if (cichk_oop->is_loader_alive(is_alive)) {
410 return;
411 }
412 } else {
413 Metadata* ic_oop = ic->cached_metadata();
414 if (ic_oop != NULL) {
415 if (ic_oop->is_klass()) {
416 if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
417 return;
418 }
419 } else if (ic_oop->is_method()) {
420 if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
421 return;
422 }
423 } else {
424 ShouldNotReachHere();
425 }
426 }
427 }
428
429 ic->set_to_clean();
430 }
431
432 unsigned char CompiledMethod::_global_unloading_clock = 0;
433
434 void CompiledMethod::increase_unloading_clock() {
435 _global_unloading_clock++;
436 if (_global_unloading_clock == 0) {
437 // _nmethods are allocated with _unloading_clock == 0,
438 // so 0 is never used as a clock value.
439 _global_unloading_clock = 1;
440 }
441 }
442
443 void CompiledMethod::set_unloading_clock(unsigned char unloading_clock) {
444 OrderAccess::release_store(&_unloading_clock, unloading_clock);
445 }
446
447 unsigned char CompiledMethod::unloading_clock() {
448 return OrderAccess::load_acquire(&_unloading_clock);
449 }
450
451 // Processing of oop references should have been sufficient to keep
452 // all strong references alive. Any weak references should have been
453 // cleared as well. Visit all the metadata and ensure that it's
454 // really alive.
455 void CompiledMethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
456 #ifdef ASSERT
457 RelocIterator iter(this, low_boundary);
458 while (iter.next()) {
459 // static_stub_Relocations may have dangling references to
460 // Method*s so trim them out here. Otherwise it looks like
461 // compiled code is maintaining a link to dead metadata.
462 address static_call_addr = NULL;
463 if (iter.type() == relocInfo::opt_virtual_call_type) {
464 CompiledIC* cic = CompiledIC_at(&iter);
465 if (!cic->is_call_to_interpreted()) {
466 static_call_addr = iter.addr();
467 }
468 } else if (iter.type() == relocInfo::static_call_type) {
469 CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
470 if (!csc->is_call_to_interpreted()) {
471 static_call_addr = iter.addr();
472 }
473 }
474 if (static_call_addr != NULL) {
475 RelocIterator sciter(this, low_boundary);
476 while (sciter.next()) {
477 if (sciter.type() == relocInfo::static_stub_type &&
478 sciter.static_stub_reloc()->static_call() == static_call_addr) {
479 sciter.static_stub_reloc()->clear_inline_cache();
480 }
481 }
482 }
483 }
484 // Check that the metadata embedded in the nmethod is alive
485 CheckClass::do_check_class(is_alive, this);
486 #endif
487 }
488
489 // This is called at the end of the strong tracing/marking phase of a
490 // GC to unload an nmethod if it contains otherwise unreachable
491 // oops.
492
493 void CompiledMethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
494 // Make sure the oop's ready to receive visitors
495 assert(!is_zombie() && !is_unloaded(),
496 "should not call follow on zombie or unloaded nmethod");
497
498 // If the method is not entrant then a JMP is plastered over the
499 // first few bytes. If an oop in the old code was there, that oop
500 // should not get GC'd. Skip the first few bytes of oops on
501 // not-entrant methods.
502 address low_boundary = verified_entry_point();
503 if (is_not_entrant()) {
504 low_boundary += NativeJump::instruction_size;
505 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
506 // (See comment above.)
507 }
508
509 // The RedefineClasses() API can cause the class unloading invariant
510 // to no longer be true. See jvmtiExport.hpp for details.
511 // Also, leave a debugging breadcrumb in local flag.
512 if (JvmtiExport::has_redefined_a_class()) {
513 // This set of the unloading_occurred flag is done before the
514 // call to post_compiled_method_unload() so that the unloading
515 // of this nmethod is reported.
516 unloading_occurred = true;
517 }
518
519 // Exception cache
520 clean_exception_cache(is_alive);
521
522 // If class unloading occurred we first iterate over all inline caches and
523 // clear ICs where the cached oop is referring to an unloaded klass or method.
524 // The remaining live cached oops will be traversed in the relocInfo::oop_type
525 // iteration below.
526 if (unloading_occurred) {
527 RelocIterator iter(this, low_boundary);
528 while(iter.next()) {
529 if (iter.type() == relocInfo::virtual_call_type) {
530 CompiledIC *ic = CompiledIC_at(&iter);
531 clean_ic_if_metadata_is_dead(ic, is_alive);
532 }
533 }
534 }
535
536 if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) {
537 return;
538 }
539
540 #if INCLUDE_JVMCI
541 if (do_unloading_jvmci(is_alive, unloading_occurred)) {
542 return;
543 }
544 #endif
545
546 // Ensure that all metadata is still alive
547 verify_metadata_loaders(low_boundary, is_alive);
548 }
549
550 template <class CompiledICorStaticCall>
551 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, CompiledMethod* from) {
552 // Ok, to lookup references to zombies here
553 CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
554 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
555 if (nm != NULL) {
556 if (nm->unloading_clock() != CompiledMethod::global_unloading_clock()) {
557 // The nmethod has not been processed yet.
558 return true;
559 }
560
561 // Clean inline caches pointing to both zombie and not_entrant methods
562 if (!nm->is_in_use() || (nm->method()->code() != nm)) {
563 ic->set_to_clean();
564 assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string());
565 }
566 }
567
568 return false;
569 }
570
571 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, CompiledMethod* from) {
572 return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from);
573 }
574
575 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, CompiledMethod* from) {
576 return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from);
577 }
578
579 bool CompiledMethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
580 ResourceMark rm;
581
582 // Make sure the oop's ready to receive visitors
583 assert(!is_zombie() && !is_unloaded(),
584 "should not call follow on zombie or unloaded nmethod");
585
586 // If the method is not entrant then a JMP is plastered over the
587 // first few bytes. If an oop in the old code was there, that oop
588 // should not get GC'd. Skip the first few bytes of oops on
589 // not-entrant methods.
590 address low_boundary = verified_entry_point();
591 if (is_not_entrant()) {
592 low_boundary += NativeJump::instruction_size;
593 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
594 // (See comment above.)
595 }
596
597 // The RedefineClasses() API can cause the class unloading invariant
598 // to no longer be true. See jvmtiExport.hpp for details.
599 // Also, leave a debugging breadcrumb in local flag.
600 if (JvmtiExport::has_redefined_a_class()) {
601 // This set of the unloading_occurred flag is done before the
602 // call to post_compiled_method_unload() so that the unloading
603 // of this nmethod is reported.
604 unloading_occurred = true;
605 }
606
607 // Exception cache
608 clean_exception_cache(is_alive);
609
610 bool postponed = false;
611
612 RelocIterator iter(this, low_boundary);
613 while(iter.next()) {
614
615 switch (iter.type()) {
616
617 case relocInfo::virtual_call_type:
618 if (unloading_occurred) {
619 // If class unloading occurred we first iterate over all inline caches and
620 // clear ICs where the cached oop is referring to an unloaded klass or method.
621 clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive);
622 }
623
624 postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
625 break;
626
627 case relocInfo::opt_virtual_call_type:
628 postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
629 break;
630
631 case relocInfo::static_call_type:
632 postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
633 break;
634
635 case relocInfo::oop_type:
636 // handled by do_unloading_oops below
637 break;
638
639 case relocInfo::metadata_type:
640 break; // nothing to do.
641
642 default:
643 break;
644 }
645 }
646
647 if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) {
648 return postponed;
649 }
650
651 #if INCLUDE_JVMCI
652 if (do_unloading_jvmci(is_alive, unloading_occurred)) {
653 return postponed;
654 }
655 #endif
656
657 // Ensure that all metadata is still alive
658 verify_metadata_loaders(low_boundary, is_alive);
659
660 return postponed;
661 }
662
663 void CompiledMethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) {
664 ResourceMark rm;
665
666 // Make sure the oop's ready to receive visitors
667 assert(!is_zombie(),
668 "should not call follow on zombie nmethod");
669
670 // If the method is not entrant then a JMP is plastered over the
671 // first few bytes. If an oop in the old code was there, that oop
672 // should not get GC'd. Skip the first few bytes of oops on
673 // not-entrant methods.
674 address low_boundary = verified_entry_point();
675 if (is_not_entrant()) {
676 low_boundary += NativeJump::instruction_size;
677 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
678 // (See comment above.)
679 }
680
681 RelocIterator iter(this, low_boundary);
682 while(iter.next()) {
683
684 switch (iter.type()) {
685
686 case relocInfo::virtual_call_type:
687 clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
688 break;
689
690 case relocInfo::opt_virtual_call_type:
691 clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
692 break;
693
694 case relocInfo::static_call_type:
695 clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
696 break;
697
698 default:
699 break;
700 }
701 }
702 }