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