1 /*
2 * Copyright (c) 1997, 2025, 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 "cds/cdsConfig.hpp"
26 #include "cds/cppVtables.hpp"
27 #include "cds/metaspaceShared.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/classLoaderDataGraph.hpp"
30 #include "classfile/metadataOnStackMark.hpp"
31 #include "classfile/symbolTable.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/vmClasses.hpp"
34 #include "code/codeCache.hpp"
35 #include "code/debugInfoRec.hpp"
36 #include "compiler/compilationPolicy.hpp"
37 #include "gc/shared/collectedHeap.inline.hpp"
38 #include "interpreter/bytecodeStream.hpp"
39 #include "interpreter/bytecodeTracer.hpp"
40 #include "interpreter/bytecodes.hpp"
41 #include "interpreter/interpreter.hpp"
42 #include "interpreter/oopMapCache.hpp"
43 #include "logging/log.hpp"
44 #include "logging/logStream.hpp"
45 #include "logging/logTag.hpp"
46 #include "memory/allocation.inline.hpp"
47 #include "memory/metadataFactory.hpp"
48 #include "memory/metaspaceClosure.hpp"
49 #include "memory/oopFactory.hpp"
50 #include "memory/resourceArea.hpp"
51 #include "memory/universe.hpp"
52 #include "nmt/memTracker.hpp"
53 #include "oops/constMethod.hpp"
54 #include "oops/constantPool.hpp"
55 #include "oops/klass.inline.hpp"
56 #include "oops/method.inline.hpp"
57 #include "oops/methodData.hpp"
58 #include "oops/objArrayKlass.hpp"
59 #include "oops/objArrayOop.inline.hpp"
60 #include "oops/oop.inline.hpp"
61 #include "oops/symbol.hpp"
62 #include "prims/jvmtiExport.hpp"
63 #include "prims/methodHandles.hpp"
64 #include "runtime/atomic.hpp"
65 #include "runtime/arguments.hpp"
66 #include "runtime/continuationEntry.hpp"
67 #include "runtime/frame.inline.hpp"
68 #include "runtime/handles.inline.hpp"
69 #include "runtime/init.hpp"
70 #include "runtime/java.hpp"
71 #include "runtime/orderAccess.hpp"
72 #include "runtime/perfData.hpp"
73 #include "runtime/relocator.hpp"
74 #include "runtime/safepointVerifiers.hpp"
75 #include "runtime/sharedRuntime.hpp"
76 #include "runtime/signature.hpp"
77 #include "runtime/threads.hpp"
78 #include "runtime/vm_version.hpp"
79 #include "utilities/align.hpp"
80 #include "utilities/quickSort.hpp"
81 #include "utilities/vmError.hpp"
82 #include "utilities/xmlstream.hpp"
83
84 // Implementation of Method
85
86 Method* Method::allocate(ClassLoaderData* loader_data,
87 int byte_code_size,
88 AccessFlags access_flags,
89 InlineTableSizes* sizes,
90 ConstMethod::MethodType method_type,
91 Symbol* name,
92 TRAPS) {
93 assert(!access_flags.is_native() || byte_code_size == 0,
94 "native methods should not contain byte codes");
95 ConstMethod* cm = ConstMethod::allocate(loader_data,
96 byte_code_size,
97 sizes,
98 method_type,
99 CHECK_NULL);
100 int size = Method::size(access_flags.is_native());
101 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, name);
102 }
103
104 Method::Method(ConstMethod* xconst, AccessFlags access_flags, Symbol* name) {
105 NoSafepointVerifier no_safepoint;
106 set_constMethod(xconst);
107 set_access_flags(access_flags);
108 set_intrinsic_id(vmIntrinsics::_none);
109 clear_method_data();
110 clear_method_counters();
111 set_vtable_index(Method::garbage_vtable_index);
112
113 // Fix and bury in Method*
114 set_interpreter_entry(nullptr); // sets i2i entry and from_int
115 set_adapter_entry(nullptr);
116 Method::clear_code(); // from_c/from_i get set to c2i/i2i
117
118 if (access_flags.is_native()) {
119 clear_native_function();
120 set_signature_handler(nullptr);
121 }
122
123 NOT_PRODUCT(set_compiled_invocation_count(0);)
124 // Name is very useful for debugging.
125 NOT_PRODUCT(_name = name;)
126 }
127
128 // Release Method*. The nmethod will be gone when we get here because
129 // we've walked the code cache.
130 void Method::deallocate_contents(ClassLoaderData* loader_data) {
131 MetadataFactory::free_metadata(loader_data, constMethod());
132 set_constMethod(nullptr);
133 MetadataFactory::free_metadata(loader_data, method_data());
134 clear_method_data();
135 MetadataFactory::free_metadata(loader_data, method_counters());
136 clear_method_counters();
137 // The nmethod will be gone when we get here.
138 if (code() != nullptr) _code = nullptr;
139 }
140
141 void Method::release_C_heap_structures() {
142 if (method_data()) {
143 method_data()->release_C_heap_structures();
144
145 // Destroy MethodData embedded lock
146 method_data()->~MethodData();
147 }
148 }
149
150 address Method::get_i2c_entry() {
151 assert(adapter() != nullptr, "must have");
152 return adapter()->get_i2c_entry();
153 }
154
155 address Method::get_c2i_entry() {
156 assert(adapter() != nullptr, "must have");
157 return adapter()->get_c2i_entry();
158 }
159
160 address Method::get_c2i_unverified_entry() {
161 assert(adapter() != nullptr, "must have");
162 return adapter()->get_c2i_unverified_entry();
163 }
164
165 address Method::get_c2i_no_clinit_check_entry() {
166 assert(VM_Version::supports_fast_class_init_checks(), "");
167 assert(adapter() != nullptr, "must have");
168 return adapter()->get_c2i_no_clinit_check_entry();
169 }
170
171 char* Method::name_and_sig_as_C_string() const {
172 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
173 }
174
175 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
176 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
177 }
178
179 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
180 const char* klass_name = klass->external_name();
181 int klass_name_len = (int)strlen(klass_name);
182 int method_name_len = method_name->utf8_length();
183 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
184 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
185 strcpy(dest, klass_name);
186 dest[klass_name_len] = '.';
187 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
188 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
189 dest[len] = 0;
190 return dest;
191 }
192
193 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
194 Symbol* klass_name = klass->name();
195 klass_name->as_klass_external_name(buf, size);
196 int len = (int)strlen(buf);
197
198 if (len < size - 1) {
199 buf[len++] = '.';
200
201 method_name->as_C_string(&(buf[len]), size - len);
202 len = (int)strlen(buf);
203
204 signature->as_C_string(&(buf[len]), size - len);
205 }
206
207 return buf;
208 }
209
210 const char* Method::external_name() const {
211 return external_name(constants()->pool_holder(), name(), signature());
212 }
213
214 void Method::print_external_name(outputStream *os) const {
215 print_external_name(os, constants()->pool_holder(), name(), signature());
216 }
217
218 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
219 stringStream ss;
220 print_external_name(&ss, klass, method_name, signature);
221 return ss.as_string();
222 }
223
224 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
225 signature->print_as_signature_external_return_type(os);
226 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
227 signature->print_as_signature_external_parameters(os);
228 os->print(")");
229 }
230
231 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
232 if (log_is_enabled(Debug, exceptions)) {
233 ResourceMark rm(THREAD);
234 log_debug(exceptions)("Looking for catch handler for exception of type \"%s\" in method \"%s\"",
235 ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string());
236 }
237 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
238 // access exception table
239 ExceptionTable table(mh());
240 int length = table.length();
241 // iterate through all entries sequentially
242 constantPoolHandle pool(THREAD, mh->constants());
243 for (int i = 0; i < length; i ++) {
244 //reacquire the table in case a GC happened
245 ExceptionTable table(mh());
246 int beg_bci = table.start_pc(i);
247 int end_bci = table.end_pc(i);
248 assert(beg_bci <= end_bci, "inconsistent exception table");
249 log_debug(exceptions)(" - checking exception table entry for BCI %d to %d",
250 beg_bci, end_bci);
251
252 if (beg_bci <= throw_bci && throw_bci < end_bci) {
253 // exception handler bci range covers throw_bci => investigate further
254 log_debug(exceptions)(" - entry covers throw point BCI %d", throw_bci);
255
256 int handler_bci = table.handler_pc(i);
257 int klass_index = table.catch_type_index(i);
258 if (klass_index == 0) {
259 if (log_is_enabled(Info, exceptions)) {
260 ResourceMark rm(THREAD);
261 log_info(exceptions)("Found catch-all handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
262 ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
263 }
264 return handler_bci;
265 } else if (ex_klass == nullptr) {
266 // Is this even possible?
267 if (log_is_enabled(Info, exceptions)) {
268 ResourceMark rm(THREAD);
269 log_info(exceptions)("null exception class is implicitly caught by handler in method \"%s\" at BCI: %d",
270 mh()->name()->as_C_string(), handler_bci);
271 }
272 return handler_bci;
273 } else {
274 if (log_is_enabled(Debug, exceptions)) {
275 ResourceMark rm(THREAD);
276 log_debug(exceptions)(" - resolving catch type \"%s\"",
277 pool->klass_name_at(klass_index)->as_C_string());
278 }
279 // we know the exception class => get the constraint class
280 // this may require loading of the constraint class; if verification
281 // fails or some other exception occurs, return handler_bci
282 Klass* k = pool->klass_at(klass_index, THREAD);
283 if (HAS_PENDING_EXCEPTION) {
284 if (log_is_enabled(Debug, exceptions)) {
285 ResourceMark rm(THREAD);
286 log_debug(exceptions)(" - exception \"%s\" occurred resolving catch type",
287 PENDING_EXCEPTION->klass()->external_name());
288 }
289 return handler_bci;
290 }
291 assert(k != nullptr, "klass not loaded");
292 if (ex_klass->is_subtype_of(k)) {
293 if (log_is_enabled(Info, exceptions)) {
294 ResourceMark rm(THREAD);
295 log_info(exceptions)("Found matching handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
296 ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
297 }
298 return handler_bci;
299 }
300 }
301 }
302 }
303
304 if (log_is_enabled(Debug, exceptions)) {
305 ResourceMark rm(THREAD);
306 log_debug(exceptions)("No catch handler found for exception of type \"%s\" in method \"%s\"",
307 ex_klass->external_name(), mh->name()->as_C_string());
308 }
309
310 return -1;
311 }
312
313 void Method::mask_for(int bci, InterpreterOopMap* mask) {
314 methodHandle h_this(Thread::current(), this);
315 mask_for(h_this, bci, mask);
316 }
317
318 void Method::mask_for(const methodHandle& this_mh, int bci, InterpreterOopMap* mask) {
319 assert(this_mh() == this, "Sanity");
320 method_holder()->mask_for(this_mh, bci, mask);
321 }
322
323 int Method::bci_from(address bcp) const {
324 if (is_native() && bcp == nullptr) {
325 return 0;
326 }
327 // Do not have a ResourceMark here because AsyncGetCallTrace stack walking code
328 // may call this after interrupting a nested ResourceMark.
329 assert((is_native() && bcp == code_base()) || contains(bcp) || VMError::is_error_reported(),
330 "bcp doesn't belong to this method. bcp: " PTR_FORMAT, p2i(bcp));
331
332 return int(bcp - code_base());
333 }
334
335
336 int Method::validate_bci(int bci) const {
337 // Called from the verifier, and should return -1 if not valid.
338 return ((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size())) ? bci : -1;
339 }
340
341 // Return bci if it appears to be a valid bcp
342 // Return -1 otherwise.
343 // Used by profiling code, when invalid data is a possibility.
344 // The caller is responsible for validating the Method* itself.
345 int Method::validate_bci_from_bcp(address bcp) const {
346 // keep bci as -1 if not a valid bci
347 int bci = -1;
348 if (bcp == nullptr || bcp == code_base()) {
349 // code_size() may return 0 and we allow 0 here
350 // the method may be native
351 bci = 0;
352 } else if (contains(bcp)) {
353 bci = int(bcp - code_base());
354 }
355 // Assert that if we have dodged any asserts, bci is negative.
356 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
357 return bci;
358 }
359
360 address Method::bcp_from(int bci) const {
361 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
362 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
363 address bcp = code_base() + bci;
364 assert((is_native() && bcp == code_base()) || contains(bcp), "bcp doesn't belong to this method");
365 return bcp;
366 }
367
368 address Method::bcp_from(address bcp) const {
369 if (is_native() && bcp == nullptr) {
370 return code_base();
371 } else {
372 return bcp;
373 }
374 }
375
376 int Method::size(bool is_native) {
377 // If native, then include pointers for native_function and signature_handler
378 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
379 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
380 return align_metadata_size(header_size() + extra_words);
381 }
382
383 Symbol* Method::klass_name() const {
384 return method_holder()->name();
385 }
386
387 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
388 log_trace(cds)("Iter(Method): %p", this);
389
390 if (!method_holder()->is_rewritten()) {
391 it->push(&_constMethod, MetaspaceClosure::_writable);
392 } else {
393 it->push(&_constMethod);
394 }
395 it->push(&_method_data);
396 it->push(&_method_counters);
397 NOT_PRODUCT(it->push(&_name);)
398 }
399
400 #if INCLUDE_CDS
401 // Attempt to return method to original state. Clear any pointers
402 // (to objects outside the shared spaces). We won't be able to predict
403 // where they should point in a new JVM. Further initialize some
404 // entries now in order allow them to be write protected later.
405
406 void Method::remove_unshareable_info() {
407 unlink_method();
408 JFR_ONLY(REMOVE_METHOD_ID(this);)
409 }
410
411 void Method::restore_unshareable_info(TRAPS) {
412 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
413 assert(!queued_for_compilation(), "method's queued_for_compilation flag should not be set");
414 }
415 #endif
416
417 void Method::set_vtable_index(int index) {
418 if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
419 // At runtime initialize_vtable is rerun as part of link_class_impl()
420 // for a shared class loaded by the non-boot loader to obtain the loader
421 // constraints based on the runtime classloaders' context.
422 return; // don't write into the shared class
423 } else {
424 _vtable_index = index;
425 }
426 }
427
428 void Method::set_itable_index(int index) {
429 if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
430 // At runtime initialize_itable is rerun as part of link_class_impl()
431 // for a shared class loaded by the non-boot loader to obtain the loader
432 // constraints based on the runtime classloaders' context. The dumptime
433 // itable index should be the same as the runtime index.
434 assert(_vtable_index == itable_index_max - index,
435 "archived itable index is different from runtime index");
436 return; // don’t write into the shared class
437 } else {
438 _vtable_index = itable_index_max - index;
439 }
440 assert(valid_itable_index(), "");
441 }
442
443 // The RegisterNatives call being attempted tried to register with a method that
444 // is not native. Ask JVM TI what prefixes have been specified. Then check
445 // to see if the native method is now wrapped with the prefixes. See the
446 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
447 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
448 #if INCLUDE_JVMTI
449 ResourceMark rm(THREAD);
450 Method* method;
451 int name_len = name->utf8_length();
452 char* name_str = name->as_utf8();
453 int prefix_count;
454 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
455 for (int i = 0; i < prefix_count; i++) {
456 char* prefix = prefixes[i];
457 int prefix_len = (int)strlen(prefix);
458
459 // try adding this prefix to the method name and see if it matches another method name
460 int trial_len = name_len + prefix_len;
461 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
462 strcpy(trial_name_str, prefix);
463 strcat(trial_name_str, name_str);
464 TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
465 if (trial_name == nullptr) {
466 continue; // no such symbol, so this prefix wasn't used, try the next prefix
467 }
468 method = k->lookup_method(trial_name, signature);
469 if (method == nullptr) {
470 continue; // signature doesn't match, try the next prefix
471 }
472 if (method->is_native()) {
473 method->set_is_prefixed_native();
474 return method; // wahoo, we found a prefixed version of the method, return it
475 }
476 // found as non-native, so prefix is good, add it, probably just need more prefixes
477 name_len = trial_len;
478 name_str = trial_name_str;
479 }
480 #endif // INCLUDE_JVMTI
481 return nullptr; // not found
482 }
483
484 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
485 Method* method = k->lookup_method(name, signature);
486 if (method == nullptr) {
487 ResourceMark rm(THREAD);
488 stringStream st;
489 st.print("Method '");
490 print_external_name(&st, k, name, signature);
491 st.print("' name or signature does not match");
492 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
493 }
494 if (!method->is_native()) {
495 // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
496 method = find_prefixed_native(k, name, signature, THREAD);
497 if (method == nullptr) {
498 ResourceMark rm(THREAD);
499 stringStream st;
500 st.print("Method '");
501 print_external_name(&st, k, name, signature);
502 st.print("' is not declared as native");
503 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
504 }
505 }
506
507 if (entry != nullptr) {
508 method->set_native_function(entry, native_bind_event_is_interesting);
509 } else {
510 method->clear_native_function();
511 }
512 if (log_is_enabled(Debug, jni, resolve)) {
513 ResourceMark rm(THREAD);
514 log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
515 method->method_holder()->external_name(),
516 method->name()->as_C_string());
517 }
518 return true;
519 }
520
521 bool Method::was_executed_more_than(int n) {
522 // Invocation counter is reset when the Method* is compiled.
523 // If the method has compiled code we therefore assume it has
524 // be executed more than n times.
525 if (is_accessor() || is_empty_method() || (code() != nullptr)) {
526 // interpreter doesn't bump invocation counter of trivial methods
527 // compiler does not bump invocation counter of compiled methods
528 return true;
529 }
530 else if ((method_counters() != nullptr &&
531 method_counters()->invocation_counter()->carry()) ||
532 (method_data() != nullptr &&
533 method_data()->invocation_counter()->carry())) {
534 // The carry bit is set when the counter overflows and causes
535 // a compilation to occur. We don't know how many times
536 // the counter has been reset, so we simply assume it has
537 // been executed more than n times.
538 return true;
539 } else {
540 return invocation_count() > n;
541 }
542 }
543
544 void Method::print_invocation_count(outputStream* st) {
545 //---< compose+print method return type, klass, name, and signature >---
546 if (is_static()) { st->print("static "); }
547 if (is_final()) { st->print("final "); }
548 if (is_synchronized()) { st->print("synchronized "); }
549 if (is_native()) { st->print("native "); }
550 st->print("%s::", method_holder()->external_name());
551 name()->print_symbol_on(st);
552 signature()->print_symbol_on(st);
553
554 if (WizardMode) {
555 // dump the size of the byte codes
556 st->print(" {%d}", code_size());
557 }
558 st->cr();
559
560 // Counting based on signed int counters tends to overflow with
561 // longer-running workloads on fast machines. The counters under
562 // consideration here, however, are limited in range by counting
563 // logic. See InvocationCounter:count_limit for example.
564 // No "overflow precautions" need to be implemented here.
565 st->print_cr (" interpreter_invocation_count: " INT32_FORMAT_W(11), interpreter_invocation_count());
566 st->print_cr (" invocation_counter: " INT32_FORMAT_W(11), invocation_count());
567 st->print_cr (" backedge_counter: " INT32_FORMAT_W(11), backedge_count());
568
569 if (method_data() != nullptr) {
570 st->print_cr (" decompile_count: " UINT32_FORMAT_W(11), method_data()->decompile_count());
571 }
572
573 #ifndef PRODUCT
574 if (CountCompiledCalls) {
575 st->print_cr (" compiled_invocation_count: " INT64_FORMAT_W(11), compiled_invocation_count());
576 }
577 #endif
578 }
579
580 // Build a MethodData* object to hold profiling information collected on this
581 // method when requested.
582 void Method::build_profiling_method_data(const methodHandle& method, TRAPS) {
583 // Do not profile the method if metaspace has hit an OOM previously
584 // allocating profiling data. Callers clear pending exception so don't
585 // add one here.
586 if (ClassLoaderDataGraph::has_metaspace_oom()) {
587 return;
588 }
589
590 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
591 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
592 if (HAS_PENDING_EXCEPTION) {
593 CompileBroker::log_metaspace_failure();
594 ClassLoaderDataGraph::set_metaspace_oom(true);
595 return; // return the exception (which is cleared)
596 }
597
598 if (!Atomic::replace_if_null(&method->_method_data, method_data)) {
599 MetadataFactory::free_metadata(loader_data, method_data);
600 return;
601 }
602
603 if (PrintMethodData && (Verbose || WizardMode)) {
604 ResourceMark rm(THREAD);
605 tty->print("build_profiling_method_data for ");
606 method->print_name(tty);
607 tty->cr();
608 // At the end of the run, the MDO, full of data, will be dumped.
609 }
610 }
611
612 MethodCounters* Method::build_method_counters(Thread* current, Method* m) {
613 // Do not profile the method if metaspace has hit an OOM previously
614 if (ClassLoaderDataGraph::has_metaspace_oom()) {
615 return nullptr;
616 }
617
618 methodHandle mh(current, m);
619 MethodCounters* counters;
620 if (current->is_Java_thread()) {
621 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
622 // Use the TRAPS version for a JavaThread so it will adjust the GC threshold
623 // if needed.
624 counters = MethodCounters::allocate_with_exception(mh, THREAD);
625 if (HAS_PENDING_EXCEPTION) {
626 CLEAR_PENDING_EXCEPTION;
627 }
628 } else {
629 // Call metaspace allocation that doesn't throw exception if the
630 // current thread isn't a JavaThread, ie. the VMThread.
631 counters = MethodCounters::allocate_no_exception(mh);
632 }
633
634 if (counters == nullptr) {
635 CompileBroker::log_metaspace_failure();
636 ClassLoaderDataGraph::set_metaspace_oom(true);
637 return nullptr;
638 }
639
640 if (!mh->init_method_counters(counters)) {
641 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
642 }
643
644 return mh->method_counters();
645 }
646
647 bool Method::init_method_counters(MethodCounters* counters) {
648 // Try to install a pointer to MethodCounters, return true on success.
649 return Atomic::replace_if_null(&_method_counters, counters);
650 }
651
652 void Method::set_exception_handler_entered(int handler_bci) {
653 if (ProfileExceptionHandlers) {
654 MethodData* mdo = method_data();
655 if (mdo != nullptr) {
656 BitData handler_data = mdo->exception_handler_bci_to_data(handler_bci);
657 handler_data.set_exception_handler_entered();
658 }
659 }
660 }
661
662 int Method::extra_stack_words() {
663 // not an inline function, to avoid a header dependency on Interpreter
664 return extra_stack_entries() * Interpreter::stackElementSize;
665 }
666
667 bool Method::compute_has_loops_flag() {
668 BytecodeStream bcs(methodHandle(Thread::current(), this));
669 Bytecodes::Code bc;
670
671 while ((bc = bcs.next()) >= 0) {
672 switch (bc) {
673 case Bytecodes::_ifeq:
674 case Bytecodes::_ifnull:
675 case Bytecodes::_iflt:
676 case Bytecodes::_ifle:
677 case Bytecodes::_ifne:
678 case Bytecodes::_ifnonnull:
679 case Bytecodes::_ifgt:
680 case Bytecodes::_ifge:
681 case Bytecodes::_if_icmpeq:
682 case Bytecodes::_if_icmpne:
683 case Bytecodes::_if_icmplt:
684 case Bytecodes::_if_icmpgt:
685 case Bytecodes::_if_icmple:
686 case Bytecodes::_if_icmpge:
687 case Bytecodes::_if_acmpeq:
688 case Bytecodes::_if_acmpne:
689 case Bytecodes::_goto:
690 case Bytecodes::_jsr:
691 if (bcs.dest() < bcs.next_bci()) {
692 return set_has_loops();
693 }
694 break;
695
696 case Bytecodes::_goto_w:
697 case Bytecodes::_jsr_w:
698 if (bcs.dest_w() < bcs.next_bci()) {
699 return set_has_loops();
700 }
701 break;
702
703 case Bytecodes::_lookupswitch: {
704 Bytecode_lookupswitch lookupswitch(this, bcs.bcp());
705 if (lookupswitch.default_offset() < 0) {
706 return set_has_loops();
707 } else {
708 for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) {
709 LookupswitchPair pair = lookupswitch.pair_at(i);
710 if (pair.offset() < 0) {
711 return set_has_loops();
712 }
713 }
714 }
715 break;
716 }
717 case Bytecodes::_tableswitch: {
718 Bytecode_tableswitch tableswitch(this, bcs.bcp());
719 if (tableswitch.default_offset() < 0) {
720 return set_has_loops();
721 } else {
722 for (int i = 0; i < tableswitch.length(); ++i) {
723 if (tableswitch.dest_offset_at(i) < 0) {
724 return set_has_loops();
725 }
726 }
727 }
728 break;
729 }
730 default:
731 break;
732 }
733 }
734
735 _flags.set_has_loops_flag_init(true);
736 return false;
737 }
738
739 bool Method::is_final_method(AccessFlags class_access_flags) const {
740 // or "does_not_require_vtable_entry"
741 // default method or overpass can occur, is not final (reuses vtable entry)
742 // private methods in classes get vtable entries for backward class compatibility.
743 if (is_overpass() || is_default_method()) return false;
744 return is_final() || class_access_flags.is_final();
745 }
746
747 bool Method::is_final_method() const {
748 return is_final_method(method_holder()->access_flags());
749 }
750
751 bool Method::is_default_method() const {
752 if (method_holder() != nullptr &&
753 method_holder()->is_interface() &&
754 !is_abstract() && !is_private()) {
755 return true;
756 } else {
757 return false;
758 }
759 }
760
761 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
762 if (is_final_method(class_access_flags)) return true;
763 #ifdef ASSERT
764 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
765 if (class_access_flags.is_interface()) {
766 ResourceMark rm;
767 assert(is_nonv == is_static() || is_nonv == is_private(),
768 "nonvirtual unexpected for non-static, non-private: %s",
769 name_and_sig_as_C_string());
770 }
771 #endif
772 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
773 return vtable_index() == nonvirtual_vtable_index;
774 }
775
776 bool Method::can_be_statically_bound() const {
777 return can_be_statically_bound(method_holder()->access_flags());
778 }
779
780 bool Method::can_be_statically_bound(InstanceKlass* context) const {
781 return (method_holder() == context) && can_be_statically_bound();
782 }
783
784 /**
785 * Returns false if this is one of specially treated methods for
786 * which we have to provide stack trace in throw in compiled code.
787 * Returns true otherwise.
788 */
789 bool Method::can_omit_stack_trace() {
790 if (klass_name() == vmSymbols::sun_invoke_util_ValueConversions()) {
791 return false; // All methods in sun.invoke.util.ValueConversions
792 }
793 return true;
794 }
795
796 bool Method::is_accessor() const {
797 return is_getter() || is_setter();
798 }
799
800 bool Method::is_getter() const {
801 if (code_size() != 5) return false;
802 if (size_of_parameters() != 1) return false;
803 if (java_code_at(0) != Bytecodes::_aload_0) return false;
804 if (java_code_at(1) != Bytecodes::_getfield) return false;
805 switch (java_code_at(4)) {
806 case Bytecodes::_ireturn:
807 case Bytecodes::_lreturn:
808 case Bytecodes::_freturn:
809 case Bytecodes::_dreturn:
810 case Bytecodes::_areturn:
811 break;
812 default:
813 return false;
814 }
815 return true;
816 }
817
818 bool Method::is_setter() const {
819 if (code_size() != 6) return false;
820 if (java_code_at(0) != Bytecodes::_aload_0) return false;
821 switch (java_code_at(1)) {
822 case Bytecodes::_iload_1:
823 case Bytecodes::_aload_1:
824 case Bytecodes::_fload_1:
825 if (size_of_parameters() != 2) return false;
826 break;
827 case Bytecodes::_dload_1:
828 case Bytecodes::_lload_1:
829 if (size_of_parameters() != 3) return false;
830 break;
831 default:
832 return false;
833 }
834 if (java_code_at(2) != Bytecodes::_putfield) return false;
835 if (java_code_at(5) != Bytecodes::_return) return false;
836 return true;
837 }
838
839 bool Method::is_constant_getter() const {
840 int last_index = code_size() - 1;
841 // Check if the first 1-3 bytecodes are a constant push
842 // and the last bytecode is a return.
843 return (2 <= code_size() && code_size() <= 4 &&
844 Bytecodes::is_const(java_code_at(0)) &&
845 Bytecodes::length_for(java_code_at(0)) == last_index &&
846 Bytecodes::is_return(java_code_at(last_index)));
847 }
848
849 bool Method::has_valid_initializer_flags() const {
850 return (is_static() ||
851 method_holder()->major_version() < 51);
852 }
853
854 bool Method::is_static_initializer() const {
855 // For classfiles version 51 or greater, ensure that the clinit method is
856 // static. Non-static methods with the name "<clinit>" are not static
857 // initializers. (older classfiles exempted for backward compatibility)
858 return name() == vmSymbols::class_initializer_name() &&
859 has_valid_initializer_flags();
860 }
861
862 bool Method::is_object_initializer() const {
863 return name() == vmSymbols::object_initializer_name();
864 }
865
866 bool Method::needs_clinit_barrier() const {
867 return is_static() && !method_holder()->is_initialized();
868 }
869
870 bool Method::is_object_wait0() const {
871 return klass_name() == vmSymbols::java_lang_Object()
872 && name() == vmSymbols::wait_name();
873 }
874
875 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
876 int length = method->checked_exceptions_length();
877 if (length == 0) { // common case
878 return objArrayHandle(THREAD, Universe::the_empty_class_array());
879 } else {
880 methodHandle h_this(THREAD, method);
881 objArrayOop m_oop = oopFactory::new_objArray(vmClasses::Class_klass(), length, CHECK_(objArrayHandle()));
882 objArrayHandle mirrors (THREAD, m_oop);
883 for (int i = 0; i < length; i++) {
884 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
885 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
886 if (log_is_enabled(Warning, exceptions) &&
887 !k->is_subclass_of(vmClasses::Throwable_klass())) {
888 ResourceMark rm(THREAD);
889 log_warning(exceptions)(
890 "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
891 k->external_name(), method->external_name());
892 }
893 mirrors->obj_at_put(i, k->java_mirror());
894 }
895 return mirrors;
896 }
897 };
898
899
900 int Method::line_number_from_bci(int bci) const {
901 int best_bci = 0;
902 int best_line = -1;
903 if (bci == SynchronizationEntryBCI) bci = 0;
904 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
905 // The line numbers are a short array of 2-tuples [start_pc, line_number].
906 // Not necessarily sorted and not necessarily one-to-one.
907 CompressedLineNumberReadStream stream(compressed_linenumber_table());
908 while (stream.read_pair()) {
909 if (stream.bci() == bci) {
910 // perfect match
911 return stream.line();
912 } else {
913 // update best_bci/line
914 if (stream.bci() < bci && stream.bci() >= best_bci) {
915 best_bci = stream.bci();
916 best_line = stream.line();
917 }
918 }
919 }
920 }
921 return best_line;
922 }
923
924
925 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
926 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
927 Thread *thread = Thread::current();
928 Symbol* klass_name = constants()->klass_name_at(klass_index);
929 Handle loader(thread, method_holder()->class_loader());
930 return SystemDictionary::find_instance_klass(thread, klass_name, loader) != nullptr;
931 } else {
932 return true;
933 }
934 }
935
936
937 bool Method::is_klass_loaded(int refinfo_index, Bytecodes::Code bc, bool must_be_resolved) const {
938 int klass_index = constants()->klass_ref_index_at(refinfo_index, bc);
939 if (must_be_resolved) {
940 // Make sure klass is resolved in constantpool.
941 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
942 }
943 return is_klass_loaded_by_klass_index(klass_index);
944 }
945
946
947 void Method::set_native_function(address function, bool post_event_flag) {
948 assert(function != nullptr, "use clear_native_function to unregister natives");
949 assert(!is_special_native_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
950 address* native_function = native_function_addr();
951
952 // We can see racers trying to place the same native function into place. Once
953 // is plenty.
954 address current = *native_function;
955 if (current == function) return;
956 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
957 function != nullptr) {
958 // native_method_throw_unsatisfied_link_error_entry() should only
959 // be passed when post_event_flag is false.
960 assert(function !=
961 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
962 "post_event_flag mismatch");
963
964 // post the bind event, and possible change the bind function
965 JvmtiExport::post_native_method_bind(this, &function);
966 }
967 *native_function = function;
968 // This function can be called more than once. We must make sure that we always
969 // use the latest registered method -> check if a stub already has been generated.
970 // If so, we have to make it not_entrant.
971 nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
972 if (nm != nullptr) {
973 nm->make_not_entrant();
974 }
975 }
976
977
978 bool Method::has_native_function() const {
979 if (is_special_native_intrinsic())
980 return false; // special-cased in SharedRuntime::generate_native_wrapper
981 address func = native_function();
982 return (func != nullptr && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
983 }
984
985
986 void Method::clear_native_function() {
987 // Note: is_method_handle_intrinsic() is allowed here.
988 set_native_function(
989 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
990 !native_bind_event_is_interesting);
991 this->unlink_code();
992 }
993
994
995 void Method::set_signature_handler(address handler) {
996 address* signature_handler = signature_handler_addr();
997 *signature_handler = handler;
998 }
999
1000
1001 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
1002 assert(reason != nullptr, "must provide a reason");
1003 if (PrintCompilation && report) {
1004 ttyLocker ttyl;
1005 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
1006 if (comp_level == CompLevel_all) {
1007 tty->print("all levels ");
1008 } else {
1009 tty->print("level %d ", comp_level);
1010 }
1011 this->print_short_name(tty);
1012 int size = this->code_size();
1013 if (size > 0) {
1014 tty->print(" (%d bytes)", size);
1015 }
1016 if (reason != nullptr) {
1017 tty->print(" %s", reason);
1018 }
1019 tty->cr();
1020 }
1021 if ((TraceDeoptimization || LogCompilation) && (xtty != nullptr)) {
1022 ttyLocker ttyl;
1023 xtty->begin_elem("make_not_compilable thread='%zu' osr='%d' level='%d'",
1024 os::current_thread_id(), is_osr, comp_level);
1025 if (reason != nullptr) {
1026 xtty->print(" reason=\'%s\'", reason);
1027 }
1028 xtty->method(this);
1029 xtty->stamp();
1030 xtty->end_elem();
1031 }
1032 }
1033
1034 bool Method::is_always_compilable() const {
1035 // Generated adapters must be compiled
1036 if (is_special_native_intrinsic() && is_synthetic()) {
1037 assert(!is_not_c1_compilable(), "sanity check");
1038 assert(!is_not_c2_compilable(), "sanity check");
1039 return true;
1040 }
1041
1042 return false;
1043 }
1044
1045 bool Method::is_not_compilable(int comp_level) const {
1046 if (number_of_breakpoints() > 0)
1047 return true;
1048 if (is_always_compilable())
1049 return false;
1050 if (comp_level == CompLevel_any)
1051 return is_not_c1_compilable() && is_not_c2_compilable();
1052 if (is_c1_compile(comp_level))
1053 return is_not_c1_compilable();
1054 if (is_c2_compile(comp_level))
1055 return is_not_c2_compilable();
1056 return false;
1057 }
1058
1059 // call this when compiler finds that this method is not compilable
1060 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
1061 if (is_always_compilable()) {
1062 // Don't mark a method which should be always compilable
1063 return;
1064 }
1065 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
1066 if (comp_level == CompLevel_all) {
1067 set_is_not_c1_compilable();
1068 set_is_not_c2_compilable();
1069 } else {
1070 if (is_c1_compile(comp_level))
1071 set_is_not_c1_compilable();
1072 if (is_c2_compile(comp_level))
1073 set_is_not_c2_compilable();
1074 }
1075 assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1076 }
1077
1078 bool Method::is_not_osr_compilable(int comp_level) const {
1079 if (is_not_compilable(comp_level))
1080 return true;
1081 if (comp_level == CompLevel_any)
1082 return is_not_c1_osr_compilable() && is_not_c2_osr_compilable();
1083 if (is_c1_compile(comp_level))
1084 return is_not_c1_osr_compilable();
1085 if (is_c2_compile(comp_level))
1086 return is_not_c2_osr_compilable();
1087 return false;
1088 }
1089
1090 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1091 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1092 if (comp_level == CompLevel_all) {
1093 set_is_not_c1_osr_compilable();
1094 set_is_not_c2_osr_compilable();
1095 } else {
1096 if (is_c1_compile(comp_level))
1097 set_is_not_c1_osr_compilable();
1098 if (is_c2_compile(comp_level))
1099 set_is_not_c2_osr_compilable();
1100 }
1101 assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1102 }
1103
1104 // Revert to using the interpreter and clear out the nmethod
1105 void Method::clear_code() {
1106 // this may be null if c2i adapters have not been made yet
1107 // Only should happen at allocate time.
1108 if (adapter() == nullptr) {
1109 _from_compiled_entry = nullptr;
1110 } else {
1111 _from_compiled_entry = adapter()->get_c2i_entry();
1112 }
1113 OrderAccess::storestore();
1114 _from_interpreted_entry = _i2i_entry;
1115 OrderAccess::storestore();
1116 _code = nullptr;
1117 }
1118
1119 void Method::unlink_code(nmethod *compare) {
1120 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
1121 // We need to check if either the _code or _from_compiled_code_entry_point
1122 // refer to this nmethod because there is a race in setting these two fields
1123 // in Method* as seen in bugid 4947125.
1124 if (code() == compare ||
1125 from_compiled_entry() == compare->verified_entry_point()) {
1126 clear_code();
1127 }
1128 }
1129
1130 void Method::unlink_code() {
1131 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
1132 clear_code();
1133 }
1134
1135 #if INCLUDE_CDS
1136 // Called by class data sharing to remove any entry points (which are not shared)
1137 void Method::unlink_method() {
1138 assert(CDSConfig::is_dumping_archive(), "sanity");
1139 _code = nullptr;
1140 _adapter = nullptr;
1141 _i2i_entry = nullptr;
1142 _from_compiled_entry = nullptr;
1143 _from_interpreted_entry = nullptr;
1144
1145 if (is_native()) {
1146 *native_function_addr() = nullptr;
1147 set_signature_handler(nullptr);
1148 }
1149 NOT_PRODUCT(set_compiled_invocation_count(0);)
1150
1151 clear_method_data();
1152 clear_method_counters();
1153 remove_unshareable_flags();
1154 }
1155
1156 void Method::remove_unshareable_flags() {
1157 // clear all the flags that shouldn't be in the archived version
1158 assert(!is_old(), "must be");
1159 assert(!is_obsolete(), "must be");
1160 assert(!is_deleted(), "must be");
1161
1162 set_is_prefixed_native(false);
1163 set_queued_for_compilation(false);
1164 set_is_not_c2_compilable(false);
1165 set_is_not_c1_compilable(false);
1166 set_is_not_c2_osr_compilable(false);
1167 set_on_stack_flag(false);
1168 }
1169 #endif
1170
1171 // Called when the method_holder is getting linked. Setup entrypoints so the method
1172 // is ready to be called from interpreter, compiler, and vtables.
1173 void Method::link_method(const methodHandle& h_method, TRAPS) {
1174 if (log_is_enabled(Info, perf, class, link)) {
1175 ClassLoader::perf_ik_link_methods_count()->inc();
1176 }
1177
1178 // If the code cache is full, we may reenter this function for the
1179 // leftover methods that weren't linked.
1180 if (adapter() != nullptr) {
1181 return;
1182 }
1183 assert( _code == nullptr, "nothing compiled yet" );
1184
1185 // Setup interpreter entrypoint
1186 assert(this == h_method(), "wrong h_method()" );
1187
1188 assert(adapter() == nullptr, "init'd to null");
1189 address entry = Interpreter::entry_for_method(h_method);
1190 assert(entry != nullptr, "interpreter entry must be non-null");
1191 // Sets both _i2i_entry and _from_interpreted_entry
1192 set_interpreter_entry(entry);
1193
1194 // Don't overwrite already registered native entries.
1195 if (is_native() && !has_native_function()) {
1196 set_native_function(
1197 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1198 !native_bind_event_is_interesting);
1199 }
1200
1201 // Setup compiler entrypoint. This is made eagerly, so we do not need
1202 // special handling of vtables. An alternative is to make adapters more
1203 // lazily by calling make_adapter() from from_compiled_entry() for the
1204 // normal calls. For vtable calls life gets more complicated. When a
1205 // call-site goes mega-morphic we need adapters in all methods which can be
1206 // called from the vtable. We need adapters on such methods that get loaded
1207 // later. Ditto for mega-morphic itable calls. If this proves to be a
1208 // problem we'll make these lazily later.
1209 (void) make_adapters(h_method, CHECK);
1210
1211 // ONLY USE the h_method now as make_adapter may have blocked
1212
1213 if (h_method->is_continuation_native_intrinsic()) {
1214 _from_interpreted_entry = nullptr;
1215 _from_compiled_entry = nullptr;
1216 _i2i_entry = nullptr;
1217 if (Continuations::enabled()) {
1218 assert(!Threads::is_vm_complete(), "should only be called during vm init");
1219 AdapterHandlerLibrary::create_native_wrapper(h_method);
1220 if (!h_method->has_compiled_code()) {
1221 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Initial size of CodeCache is too small");
1222 }
1223 assert(_from_interpreted_entry == get_i2c_entry(), "invariant");
1224 }
1225 }
1226 }
1227
1228 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1229 PerfTraceTime timer(ClassLoader::perf_method_adapters_time());
1230
1231 // Adapters for compiled code are made eagerly here. They are fairly
1232 // small (generally < 100 bytes) and quick to make (and cached and shared)
1233 // so making them eagerly shouldn't be too expensive.
1234 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1235 if (adapter == nullptr ) {
1236 if (!is_init_completed()) {
1237 // Don't throw exceptions during VM initialization because java.lang.* classes
1238 // might not have been initialized, causing problems when constructing the
1239 // Java exception object.
1240 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1241 } else {
1242 THROW_MSG_NULL(vmSymbols::java_lang_OutOfMemoryError(), "Out of space in CodeCache for adapters");
1243 }
1244 }
1245
1246 mh->set_adapter_entry(adapter);
1247 mh->_from_compiled_entry = adapter->get_c2i_entry();
1248 return adapter->get_c2i_entry();
1249 }
1250
1251 // The verified_code_entry() must be called when a invoke is resolved
1252 // on this method.
1253
1254 // It returns the compiled code entry point, after asserting not null.
1255 // This function is called after potential safepoints so that nmethod
1256 // or adapter that it points to is still live and valid.
1257 // This function must not hit a safepoint!
1258 address Method::verified_code_entry() {
1259 debug_only(NoSafepointVerifier nsv;)
1260 assert(_from_compiled_entry != nullptr, "must be set");
1261 return _from_compiled_entry;
1262 }
1263
1264 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1265 // (could be racing a deopt).
1266 // Not inline to avoid circular ref.
1267 bool Method::check_code() const {
1268 // cached in a register or local. There's a race on the value of the field.
1269 nmethod *code = Atomic::load_acquire(&_code);
1270 return code == nullptr || (code->method() == nullptr) || (code->method() == (Method*)this && !code->is_osr_method());
1271 }
1272
1273 // Install compiled code. Instantly it can execute.
1274 void Method::set_code(const methodHandle& mh, nmethod *code) {
1275 assert_lock_strong(NMethodState_lock);
1276 assert( code, "use clear_code to remove code" );
1277 assert( mh->check_code(), "" );
1278
1279 guarantee(mh->adapter() != nullptr, "Adapter blob must already exist!");
1280
1281 // These writes must happen in this order, because the interpreter will
1282 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1283 // which jumps to _from_compiled_entry.
1284 mh->_code = code; // Assign before allowing compiled code to exec
1285
1286 int comp_level = code->comp_level();
1287 // In theory there could be a race here. In practice it is unlikely
1288 // and not worth worrying about.
1289 if (comp_level > mh->highest_comp_level()) {
1290 mh->set_highest_comp_level(comp_level);
1291 }
1292
1293 OrderAccess::storestore();
1294 mh->_from_compiled_entry = code->verified_entry_point();
1295 OrderAccess::storestore();
1296
1297 if (mh->is_continuation_native_intrinsic()) {
1298 assert(mh->_from_interpreted_entry == nullptr, "initialized incorrectly"); // see link_method
1299
1300 if (mh->is_continuation_enter_intrinsic()) {
1301 // This is the entry used when we're in interpreter-only mode; see InterpreterMacroAssembler::jump_from_interpreted
1302 mh->_i2i_entry = ContinuationEntry::interpreted_entry();
1303 } else if (mh->is_continuation_yield_intrinsic()) {
1304 mh->_i2i_entry = mh->get_i2c_entry();
1305 } else {
1306 guarantee(false, "Unknown Continuation native intrinsic");
1307 }
1308 // This must come last, as it is what's tested in LinkResolver::resolve_static_call
1309 Atomic::release_store(&mh->_from_interpreted_entry , mh->get_i2c_entry());
1310 } else if (!mh->is_method_handle_intrinsic()) {
1311 // Instantly compiled code can execute.
1312 mh->_from_interpreted_entry = mh->get_i2c_entry();
1313 }
1314 }
1315
1316
1317 bool Method::is_overridden_in(Klass* k) const {
1318 InstanceKlass* ik = InstanceKlass::cast(k);
1319
1320 if (ik->is_interface()) return false;
1321
1322 // If method is an interface, we skip it - except if it
1323 // is a miranda method
1324 if (method_holder()->is_interface()) {
1325 // Check that method is not a miranda method
1326 if (ik->lookup_method(name(), signature()) == nullptr) {
1327 // No implementation exist - so miranda method
1328 return false;
1329 }
1330 return true;
1331 }
1332
1333 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1334 if (!has_vtable_index()) {
1335 return false;
1336 } else {
1337 Method* vt_m = ik->method_at_vtable(vtable_index());
1338 return vt_m != this;
1339 }
1340 }
1341
1342
1343 // give advice about whether this Method* should be cached or not
1344 bool Method::should_not_be_cached() const {
1345 if (is_old()) {
1346 // This method has been redefined. It is either EMCP or obsolete
1347 // and we don't want to cache it because that would pin the method
1348 // down and prevent it from being collectible if and when it
1349 // finishes executing.
1350 return true;
1351 }
1352
1353 // caching this method should be just fine
1354 return false;
1355 }
1356
1357
1358 /**
1359 * Returns true if this is one of the specially treated methods for
1360 * security related stack walks (like Reflection.getCallerClass).
1361 */
1362 bool Method::is_ignored_by_security_stack_walk() const {
1363 if (intrinsic_id() == vmIntrinsics::_invoke) {
1364 // This is Method.invoke() -- ignore it
1365 return true;
1366 }
1367 if (method_holder()->is_subclass_of(vmClasses::reflect_MethodAccessorImpl_klass())) {
1368 // This is an auxiliary frame -- ignore it
1369 return true;
1370 }
1371 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1372 // This is an internal adapter frame for method handles -- ignore it
1373 return true;
1374 }
1375 return false;
1376 }
1377
1378
1379 // Constant pool structure for invoke methods:
1380 enum {
1381 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1382 _imcp_invoke_signature, // utf8: (variable Symbol*)
1383 _imcp_limit
1384 };
1385
1386 // Test if this method is an MH adapter frame generated by Java code.
1387 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1388 bool Method::is_compiled_lambda_form() const {
1389 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1390 }
1391
1392 // Test if this method is an internal MH primitive method.
1393 bool Method::is_method_handle_intrinsic() const {
1394 vmIntrinsics::ID iid = intrinsic_id();
1395 return (MethodHandles::is_signature_polymorphic(iid) &&
1396 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1397 }
1398
1399 bool Method::has_member_arg() const {
1400 vmIntrinsics::ID iid = intrinsic_id();
1401 return (MethodHandles::is_signature_polymorphic(iid) &&
1402 MethodHandles::has_member_arg(iid));
1403 }
1404
1405 // Make an instance of a signature-polymorphic internal MH primitive.
1406 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1407 Symbol* signature,
1408 TRAPS) {
1409 ResourceMark rm(THREAD);
1410 methodHandle empty;
1411
1412 InstanceKlass* holder = vmClasses::MethodHandle_klass();
1413 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1414 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1415
1416 log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1417
1418 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1419 name->increment_refcount();
1420 signature->increment_refcount();
1421
1422 int cp_length = _imcp_limit;
1423 ClassLoaderData* loader_data = holder->class_loader_data();
1424 constantPoolHandle cp;
1425 {
1426 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1427 cp = constantPoolHandle(THREAD, cp_oop);
1428 }
1429 cp->copy_fields(holder->constants());
1430 cp->set_pool_holder(holder);
1431 cp->symbol_at_put(_imcp_invoke_name, name);
1432 cp->symbol_at_put(_imcp_invoke_signature, signature);
1433 cp->set_has_preresolution();
1434 cp->set_is_for_method_handle_intrinsic();
1435
1436 // decide on access bits: public or not?
1437 u2 flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1438 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1439 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1440 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1441
1442 methodHandle m;
1443 {
1444 InlineTableSizes sizes;
1445 Method* m_oop = Method::allocate(loader_data, 0,
1446 accessFlags_from(flags_bits), &sizes,
1447 ConstMethod::NORMAL,
1448 name,
1449 CHECK_(empty));
1450 m = methodHandle(THREAD, m_oop);
1451 }
1452 m->set_constants(cp());
1453 m->set_name_index(_imcp_invoke_name);
1454 m->set_signature_index(_imcp_invoke_signature);
1455 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1456 assert(m->signature() == signature, "");
1457 m->constMethod()->compute_from_signature(signature, must_be_static);
1458 m->init_intrinsic_id(klass_id_for_intrinsics(m->method_holder()));
1459 assert(m->is_method_handle_intrinsic(), "");
1460 #ifdef ASSERT
1461 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1462 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1463 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1464 #endif //ASSERT
1465
1466 // Finally, set up its entry points.
1467 assert(m->can_be_statically_bound(), "");
1468 m->set_vtable_index(Method::nonvirtual_vtable_index);
1469 m->link_method(m, CHECK_(empty));
1470
1471 if (iid == vmIntrinsics::_linkToNative) {
1472 m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1473 }
1474 if (log_is_enabled(Debug, methodhandles)) {
1475 LogTarget(Debug, methodhandles) lt;
1476 LogStream ls(lt);
1477 m->print_on(&ls);
1478 }
1479
1480 return m;
1481 }
1482
1483 #if INCLUDE_CDS
1484 void Method::restore_archived_method_handle_intrinsic(methodHandle m, TRAPS) {
1485 m->link_method(m, CHECK);
1486
1487 if (m->intrinsic_id() == vmIntrinsics::_linkToNative) {
1488 m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1489 }
1490 }
1491 #endif
1492
1493 Klass* Method::check_non_bcp_klass(Klass* klass) {
1494 if (klass != nullptr && klass->class_loader() != nullptr) {
1495 if (klass->is_objArray_klass())
1496 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1497 return klass;
1498 }
1499 return nullptr;
1500 }
1501
1502
1503 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1504 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1505 // Code below does not work for native methods - they should never get rewritten anyway
1506 assert(!m->is_native(), "cannot rewrite native methods");
1507 // Allocate new Method*
1508 AccessFlags flags = m->access_flags();
1509
1510 ConstMethod* cm = m->constMethod();
1511 int checked_exceptions_len = cm->checked_exceptions_length();
1512 int localvariable_len = cm->localvariable_table_length();
1513 int exception_table_len = cm->exception_table_length();
1514 int method_parameters_len = cm->method_parameters_length();
1515 int method_annotations_len = cm->method_annotations_length();
1516 int parameter_annotations_len = cm->parameter_annotations_length();
1517 int type_annotations_len = cm->type_annotations_length();
1518 int default_annotations_len = cm->default_annotations_length();
1519
1520 InlineTableSizes sizes(
1521 localvariable_len,
1522 new_compressed_linenumber_size,
1523 exception_table_len,
1524 checked_exceptions_len,
1525 method_parameters_len,
1526 cm->generic_signature_index(),
1527 method_annotations_len,
1528 parameter_annotations_len,
1529 type_annotations_len,
1530 default_annotations_len,
1531 0);
1532
1533 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1534 Method* newm_oop = Method::allocate(loader_data,
1535 new_code_length,
1536 flags,
1537 &sizes,
1538 m->method_type(),
1539 m->name(),
1540 CHECK_(methodHandle()));
1541 methodHandle newm (THREAD, newm_oop);
1542
1543 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1544 ConstMethod* newcm = newm->constMethod();
1545 int new_const_method_size = newm->constMethod()->size();
1546
1547 // This works because the source and target are both Methods. Some compilers
1548 // (e.g., clang) complain that the target vtable pointer will be stomped,
1549 // so cast away newm()'s and m()'s Methodness.
1550 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1551
1552 // Create shallow copy of ConstMethod.
1553 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1554
1555 // Reset correct method/const method, method size, and parameter info
1556 newm->set_constMethod(newcm);
1557 newm->constMethod()->set_code_size(new_code_length);
1558 newm->constMethod()->set_constMethod_size(new_const_method_size);
1559 assert(newm->code_size() == new_code_length, "check");
1560 assert(newm->method_parameters_length() == method_parameters_len, "check");
1561 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1562 assert(newm->exception_table_length() == exception_table_len, "check");
1563 assert(newm->localvariable_table_length() == localvariable_len, "check");
1564 // Copy new byte codes
1565 memcpy(newm->code_base(), new_code, new_code_length);
1566 // Copy line number table
1567 if (new_compressed_linenumber_size > 0) {
1568 memcpy(newm->compressed_linenumber_table(),
1569 new_compressed_linenumber_table,
1570 new_compressed_linenumber_size);
1571 }
1572 // Copy method_parameters
1573 if (method_parameters_len > 0) {
1574 memcpy(newm->method_parameters_start(),
1575 m->method_parameters_start(),
1576 method_parameters_len * sizeof(MethodParametersElement));
1577 }
1578 // Copy checked_exceptions
1579 if (checked_exceptions_len > 0) {
1580 memcpy(newm->checked_exceptions_start(),
1581 m->checked_exceptions_start(),
1582 checked_exceptions_len * sizeof(CheckedExceptionElement));
1583 }
1584 // Copy exception table
1585 if (exception_table_len > 0) {
1586 memcpy(newm->exception_table_start(),
1587 m->exception_table_start(),
1588 exception_table_len * sizeof(ExceptionTableElement));
1589 }
1590 // Copy local variable number table
1591 if (localvariable_len > 0) {
1592 memcpy(newm->localvariable_table_start(),
1593 m->localvariable_table_start(),
1594 localvariable_len * sizeof(LocalVariableTableElement));
1595 }
1596 // Copy stackmap table
1597 if (m->has_stackmap_table()) {
1598 int code_attribute_length = m->stackmap_data()->length();
1599 Array<u1>* stackmap_data =
1600 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
1601 memcpy((void*)stackmap_data->adr_at(0),
1602 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1603 newm->set_stackmap_data(stackmap_data);
1604 }
1605
1606 // copy annotations over to new method
1607 newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
1608 return newm;
1609 }
1610
1611 vmSymbolID Method::klass_id_for_intrinsics(const Klass* holder) {
1612 // if loader is not the default loader (i.e., non-null), we can't know the intrinsics
1613 // because we are not loading from core libraries
1614 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1615 // which does not use the class default class loader so we check for its loader here
1616 const InstanceKlass* ik = InstanceKlass::cast(holder);
1617 if ((ik->class_loader() != nullptr) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1618 return vmSymbolID::NO_SID; // regardless of name, no intrinsics here
1619 }
1620
1621 // see if the klass name is well-known:
1622 Symbol* klass_name = ik->name();
1623 vmSymbolID id = vmSymbols::find_sid(klass_name);
1624 if (id != vmSymbolID::NO_SID && vmIntrinsics::class_has_intrinsics(id)) {
1625 return id;
1626 } else {
1627 return vmSymbolID::NO_SID;
1628 }
1629 }
1630
1631 void Method::init_intrinsic_id(vmSymbolID klass_id) {
1632 assert(_intrinsic_id == static_cast<int>(vmIntrinsics::_none), "do this just once");
1633 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1634 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1635 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1636
1637 // the klass name is well-known:
1638 assert(klass_id == klass_id_for_intrinsics(method_holder()), "must be");
1639 assert(klass_id != vmSymbolID::NO_SID, "caller responsibility");
1640
1641 // ditto for method and signature:
1642 vmSymbolID name_id = vmSymbols::find_sid(name());
1643 if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1644 && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1645 && name_id == vmSymbolID::NO_SID) {
1646 return;
1647 }
1648 vmSymbolID sig_id = vmSymbols::find_sid(signature());
1649 if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1650 && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1651 && sig_id == vmSymbolID::NO_SID) {
1652 return;
1653 }
1654
1655 u2 flags = access_flags().as_method_flags();
1656 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1657 if (id != vmIntrinsics::_none) {
1658 set_intrinsic_id(id);
1659 if (id == vmIntrinsics::_Class_cast) {
1660 // Even if the intrinsic is rejected, we want to inline this simple method.
1661 set_force_inline();
1662 }
1663 return;
1664 }
1665
1666 // A few slightly irregular cases:
1667 switch (klass_id) {
1668 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1669 case VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1670 case VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1671 if (!is_native()) break;
1672 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1673 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1674 id = vmIntrinsics::_none;
1675 break;
1676
1677 default:
1678 break;
1679 }
1680
1681 if (id != vmIntrinsics::_none) {
1682 // Set up its iid. It is an alias method.
1683 set_intrinsic_id(id);
1684 return;
1685 }
1686 }
1687
1688 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1689 if (!THREAD->can_call_java()) {
1690 // There is nothing useful this routine can do from within the Compile thread.
1691 // Hopefully, the signature contains only well-known classes.
1692 // We could scan for this and return true/false, but the caller won't care.
1693 return false;
1694 }
1695 bool sig_is_loaded = true;
1696 ResourceMark rm(THREAD);
1697 for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1698 if (ss.is_reference()) {
1699 // load everything, including arrays "[Lfoo;"
1700 Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD);
1701 // We are loading classes eagerly. If a ClassNotFoundException or
1702 // a LinkageError was generated, be sure to ignore it.
1703 if (HAS_PENDING_EXCEPTION) {
1704 if (PENDING_EXCEPTION->is_a(vmClasses::ClassNotFoundException_klass()) ||
1705 PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass())) {
1706 CLEAR_PENDING_EXCEPTION;
1707 } else {
1708 return false;
1709 }
1710 }
1711 if( klass == nullptr) { sig_is_loaded = false; }
1712 }
1713 }
1714 return sig_is_loaded;
1715 }
1716
1717 // Exposed so field engineers can debug VM
1718 void Method::print_short_name(outputStream* st) const {
1719 ResourceMark rm;
1720 #ifdef PRODUCT
1721 st->print(" %s::", method_holder()->external_name());
1722 #else
1723 st->print(" %s::", method_holder()->internal_name());
1724 #endif
1725 name()->print_symbol_on(st);
1726 if (WizardMode) signature()->print_symbol_on(st);
1727 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1728 MethodHandles::print_as_basic_type_signature_on(st, signature());
1729 }
1730
1731 // Comparer for sorting an object array containing
1732 // Method*s.
1733 static int method_comparator(Method* a, Method* b) {
1734 return a->name()->fast_compare(b->name());
1735 }
1736
1737 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1738 // default_methods also uses this without the ordering for fast find_method
1739 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1740 int length = methods->length();
1741 if (length > 1) {
1742 if (func == nullptr) {
1743 func = method_comparator;
1744 }
1745 {
1746 NoSafepointVerifier nsv;
1747 QuickSort::sort(methods->data(), length, func);
1748 }
1749 // Reset method ordering
1750 if (set_idnums) {
1751 for (u2 i = 0; i < length; i++) {
1752 Method* m = methods->at(i);
1753 m->set_method_idnum(i);
1754 m->set_orig_method_idnum(i);
1755 }
1756 }
1757 }
1758 }
1759
1760 //-----------------------------------------------------------------------------------
1761 // Non-product code unless JVM/TI needs it
1762
1763 #if !defined(PRODUCT) || INCLUDE_JVMTI
1764 class SignatureTypePrinter : public SignatureTypeNames {
1765 private:
1766 outputStream* _st;
1767 bool _use_separator;
1768
1769 void type_name(const char* name) {
1770 if (_use_separator) _st->print(", ");
1771 _st->print("%s", name);
1772 _use_separator = true;
1773 }
1774
1775 public:
1776 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1777 _st = st;
1778 _use_separator = false;
1779 }
1780
1781 void print_parameters() { _use_separator = false; do_parameters_on(this); }
1782 void print_returntype() { _use_separator = false; do_type(return_type()); }
1783 };
1784
1785
1786 void Method::print_name(outputStream* st) const {
1787 Thread *thread = Thread::current();
1788 ResourceMark rm(thread);
1789 st->print("%s ", is_static() ? "static" : "virtual");
1790 if (WizardMode) {
1791 st->print("%s.", method_holder()->internal_name());
1792 name()->print_symbol_on(st);
1793 signature()->print_symbol_on(st);
1794 } else {
1795 SignatureTypePrinter sig(signature(), st);
1796 sig.print_returntype();
1797 st->print(" %s.", method_holder()->internal_name());
1798 name()->print_symbol_on(st);
1799 st->print("(");
1800 sig.print_parameters();
1801 st->print(")");
1802 }
1803 }
1804 #endif // !PRODUCT || INCLUDE_JVMTI
1805
1806
1807 void Method::print_codes_on(outputStream* st, int flags) const {
1808 print_codes_on(0, code_size(), st, flags);
1809 }
1810
1811 void Method::print_codes_on(int from, int to, outputStream* st, int flags) const {
1812 Thread *thread = Thread::current();
1813 ResourceMark rm(thread);
1814 methodHandle mh (thread, (Method*)this);
1815 BytecodeTracer::print_method_codes(mh, from, to, st, flags);
1816 }
1817
1818 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1819 _bci = 0;
1820 _line = 0;
1821 };
1822
1823 bool CompressedLineNumberReadStream::read_pair() {
1824 jubyte next = read_byte();
1825 // Check for terminator
1826 if (next == 0) return false;
1827 if (next == 0xFF) {
1828 // Escape character, regular compression used
1829 _bci += read_signed_int();
1830 _line += read_signed_int();
1831 } else {
1832 // Single byte compression used
1833 _bci += next >> 3;
1834 _line += next & 0x7;
1835 }
1836 return true;
1837 }
1838
1839 #if INCLUDE_JVMTI
1840
1841 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1842 BreakpointInfo* bp = method_holder()->breakpoints();
1843 for (; bp != nullptr; bp = bp->next()) {
1844 if (bp->match(this, bci)) {
1845 return bp->orig_bytecode();
1846 }
1847 }
1848 {
1849 ResourceMark rm;
1850 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1851 }
1852 return Bytecodes::_shouldnotreachhere;
1853 }
1854
1855 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1856 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1857 BreakpointInfo* bp = method_holder()->breakpoints();
1858 for (; bp != nullptr; bp = bp->next()) {
1859 if (bp->match(this, bci)) {
1860 bp->set_orig_bytecode(code);
1861 // and continue, in case there is more than one
1862 }
1863 }
1864 }
1865
1866 void Method::set_breakpoint(int bci) {
1867 InstanceKlass* ik = method_holder();
1868 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1869 bp->set_next(ik->breakpoints());
1870 ik->set_breakpoints(bp);
1871 // do this last:
1872 bp->set(this);
1873 }
1874
1875 static void clear_matches(Method* m, int bci) {
1876 InstanceKlass* ik = m->method_holder();
1877 BreakpointInfo* prev_bp = nullptr;
1878 BreakpointInfo* next_bp;
1879 for (BreakpointInfo* bp = ik->breakpoints(); bp != nullptr; bp = next_bp) {
1880 next_bp = bp->next();
1881 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1882 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1883 // do this first:
1884 bp->clear(m);
1885 // unhook it
1886 if (prev_bp != nullptr)
1887 prev_bp->set_next(next_bp);
1888 else
1889 ik->set_breakpoints(next_bp);
1890 delete bp;
1891 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1892 // at same location. So we have multiple matching (method_index and bci)
1893 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1894 // breakpoint for clear_breakpoint request and keep all other method versions
1895 // BreakpointInfo for future clear_breakpoint request.
1896 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1897 // which is being called when class is unloaded. We delete all the Breakpoint
1898 // information for all versions of method. We may not correctly restore the original
1899 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1900 // so these methods won't be used anymore.
1901 if (bci >= 0) {
1902 break;
1903 }
1904 } else {
1905 // This one is a keeper.
1906 prev_bp = bp;
1907 }
1908 }
1909 }
1910
1911 void Method::clear_breakpoint(int bci) {
1912 assert(bci >= 0, "");
1913 clear_matches(this, bci);
1914 }
1915
1916 void Method::clear_all_breakpoints() {
1917 clear_matches(this, -1);
1918 }
1919
1920 #endif // INCLUDE_JVMTI
1921
1922 int Method::highest_osr_comp_level() const {
1923 const MethodCounters* mcs = method_counters();
1924 if (mcs != nullptr) {
1925 return mcs->highest_osr_comp_level();
1926 } else {
1927 return CompLevel_none;
1928 }
1929 }
1930
1931 void Method::set_highest_comp_level(int level) {
1932 MethodCounters* mcs = method_counters();
1933 if (mcs != nullptr) {
1934 mcs->set_highest_comp_level(level);
1935 }
1936 }
1937
1938 void Method::set_highest_osr_comp_level(int level) {
1939 MethodCounters* mcs = method_counters();
1940 if (mcs != nullptr) {
1941 mcs->set_highest_osr_comp_level(level);
1942 }
1943 }
1944
1945 #if INCLUDE_JVMTI
1946
1947 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1948 _bci = bci;
1949 _name_index = m->name_index();
1950 _signature_index = m->signature_index();
1951 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1952 if (_orig_bytecode == Bytecodes::_breakpoint)
1953 _orig_bytecode = m->orig_bytecode_at(_bci);
1954 _next = nullptr;
1955 }
1956
1957 void BreakpointInfo::set(Method* method) {
1958 #ifdef ASSERT
1959 {
1960 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1961 if (code == Bytecodes::_breakpoint)
1962 code = method->orig_bytecode_at(_bci);
1963 assert(orig_bytecode() == code, "original bytecode must be the same");
1964 }
1965 #endif
1966 Thread *thread = Thread::current();
1967 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1968 method->incr_number_of_breakpoints(thread);
1969 {
1970 // Deoptimize all dependents on this method
1971 HandleMark hm(thread);
1972 methodHandle mh(thread, method);
1973 CodeCache::mark_dependents_on_method_for_breakpoint(mh);
1974 }
1975 }
1976
1977 void BreakpointInfo::clear(Method* method) {
1978 *method->bcp_from(_bci) = orig_bytecode();
1979 assert(method->number_of_breakpoints() > 0, "must not go negative");
1980 method->decr_number_of_breakpoints(Thread::current());
1981 }
1982
1983 #endif // INCLUDE_JVMTI
1984
1985 // jmethodID handling
1986
1987 // This is a block allocating object, sort of like JNIHandleBlock, only a
1988 // lot simpler.
1989 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1990 // never get rid of it.
1991
1992 static const int min_block_size = 8;
1993
1994 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1995 friend class JNIMethodBlock;
1996 Method** _methods;
1997 int _number_of_methods;
1998 int _top;
1999 JNIMethodBlockNode* _next;
2000
2001 public:
2002
2003 JNIMethodBlockNode(int num_methods = min_block_size);
2004
2005 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2006
2007 void ensure_methods(int num_addl_methods) {
2008 if (_top < _number_of_methods) {
2009 num_addl_methods -= _number_of_methods - _top;
2010 if (num_addl_methods <= 0) {
2011 return;
2012 }
2013 }
2014 if (_next == nullptr) {
2015 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2016 } else {
2017 _next->ensure_methods(num_addl_methods);
2018 }
2019 }
2020 };
2021
2022 class JNIMethodBlock : public CHeapObj<mtClass> {
2023 JNIMethodBlockNode _head;
2024 JNIMethodBlockNode *_last_free;
2025 public:
2026 static Method* const _free_method;
2027
2028 JNIMethodBlock(int initial_capacity = min_block_size)
2029 : _head(initial_capacity), _last_free(&_head) {}
2030
2031 void ensure_methods(int num_addl_methods) {
2032 _last_free->ensure_methods(num_addl_methods);
2033 }
2034
2035 Method** add_method(Method* m) {
2036 for (JNIMethodBlockNode* b = _last_free; b != nullptr; b = b->_next) {
2037 if (b->_top < b->_number_of_methods) {
2038 // top points to the next free entry.
2039 int i = b->_top;
2040 b->_methods[i] = m;
2041 b->_top++;
2042 _last_free = b;
2043 return &(b->_methods[i]);
2044 } else if (b->_top == b->_number_of_methods) {
2045 // if the next free entry ran off the block see if there's a free entry
2046 for (int i = 0; i < b->_number_of_methods; i++) {
2047 if (b->_methods[i] == _free_method) {
2048 b->_methods[i] = m;
2049 _last_free = b;
2050 return &(b->_methods[i]);
2051 }
2052 }
2053 // Only check each block once for frees. They're very unlikely.
2054 // Increment top past the end of the block.
2055 b->_top++;
2056 }
2057 // need to allocate a next block.
2058 if (b->_next == nullptr) {
2059 b->_next = _last_free = new JNIMethodBlockNode();
2060 }
2061 }
2062 guarantee(false, "Should always allocate a free block");
2063 return nullptr;
2064 }
2065
2066 bool contains(Method** m) {
2067 if (m == nullptr) return false;
2068 for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) {
2069 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2070 // This is a bit of extra checking, for two reasons. One is
2071 // that contains() deals with pointers that are passed in by
2072 // JNI code, so making sure that the pointer is aligned
2073 // correctly is valuable. The other is that <= and > are
2074 // technically not defined on pointers, so the if guard can
2075 // pass spuriously; no modern compiler is likely to make that
2076 // a problem, though (and if one did, the guard could also
2077 // fail spuriously, which would be bad).
2078 ptrdiff_t idx = m - b->_methods;
2079 if (b->_methods + idx == m) {
2080 return true;
2081 }
2082 }
2083 }
2084 return false; // not found
2085 }
2086
2087 // During class unloading the methods are cleared, which is different
2088 // than freed.
2089 void clear_all_methods() {
2090 for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) {
2091 for (int i = 0; i< b->_number_of_methods; i++) {
2092 b->_methods[i] = nullptr;
2093 }
2094 }
2095 }
2096 #ifndef PRODUCT
2097 int count_methods() {
2098 // count all allocated methods
2099 int count = 0;
2100 for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) {
2101 for (int i = 0; i< b->_number_of_methods; i++) {
2102 if (b->_methods[i] != _free_method) count++;
2103 }
2104 }
2105 return count;
2106 }
2107 #endif // PRODUCT
2108 };
2109
2110 // Something that can't be mistaken for an address or a markWord
2111 Method* const JNIMethodBlock::_free_method = (Method*)55;
2112
2113 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(nullptr) {
2114 _number_of_methods = MAX2(num_methods, min_block_size);
2115 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2116 for (int i = 0; i < _number_of_methods; i++) {
2117 _methods[i] = JNIMethodBlock::_free_method;
2118 }
2119 }
2120
2121 void Method::ensure_jmethod_ids(ClassLoaderData* cld, int capacity) {
2122 // Have to add jmethod_ids() to class loader data thread-safely.
2123 // Also have to add the method to the list safely, which the lock
2124 // protects as well.
2125 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2126 if (cld->jmethod_ids() == nullptr) {
2127 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2128 } else {
2129 cld->jmethod_ids()->ensure_methods(capacity);
2130 }
2131 }
2132
2133 // Add a method id to the jmethod_ids
2134 jmethodID Method::make_jmethod_id(ClassLoaderData* cld, Method* m) {
2135 // Have to add jmethod_ids() to class loader data thread-safely.
2136 // Also have to add the method to the list safely, which the lock
2137 // protects as well.
2138 assert(JmethodIdCreation_lock->owned_by_self(), "sanity check");
2139
2140 ResourceMark rm;
2141 log_debug(jmethod)("Creating jmethodID for Method %s", m->external_name());
2142 if (cld->jmethod_ids() == nullptr) {
2143 cld->set_jmethod_ids(new JNIMethodBlock());
2144 }
2145 // jmethodID is a pointer to Method*
2146 return (jmethodID)cld->jmethod_ids()->add_method(m);
2147 }
2148
2149 jmethodID Method::jmethod_id() {
2150 methodHandle mh(Thread::current(), this);
2151 return method_holder()->get_jmethod_id(mh);
2152 }
2153
2154 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2155 // Can't assert the method_holder is the same because the new method has the
2156 // scratch method holder.
2157 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2158 == new_method->method_holder()->class_loader() ||
2159 new_method->method_holder()->class_loader() == nullptr, // allow Unsafe substitution
2160 "changing to a different class loader");
2161 // Just change the method in place, jmethodID pointer doesn't change.
2162 *((Method**)jmid) = new_method;
2163 }
2164
2165 bool Method::is_method_id(jmethodID mid) {
2166 Method* m = resolve_jmethod_id(mid);
2167 assert(m != nullptr, "should be called with non-null method");
2168 InstanceKlass* ik = m->method_holder();
2169 ClassLoaderData* cld = ik->class_loader_data();
2170 if (cld->jmethod_ids() == nullptr) return false;
2171 return (cld->jmethod_ids()->contains((Method**)mid));
2172 }
2173
2174 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2175 if (mid == nullptr) return nullptr;
2176 Method* o = resolve_jmethod_id(mid);
2177 if (o == nullptr || o == JNIMethodBlock::_free_method) {
2178 return nullptr;
2179 }
2180 // Method should otherwise be valid. Assert for testing.
2181 assert(is_valid_method(o), "should be valid jmethodid");
2182 // If the method's class holder object is unreferenced, but not yet marked as
2183 // unloaded, we need to return null here too because after a safepoint, its memory
2184 // will be reclaimed.
2185 return o->method_holder()->is_loader_alive() ? o : nullptr;
2186 };
2187
2188 void Method::set_on_stack(const bool value) {
2189 // Set both the method itself and its constant pool. The constant pool
2190 // on stack means some method referring to it is also on the stack.
2191 constants()->set_on_stack(value);
2192
2193 bool already_set = on_stack_flag();
2194 set_on_stack_flag(value);
2195 if (value && !already_set) {
2196 MetadataOnStackMark::record(this);
2197 }
2198 }
2199
2200 void Method::record_gc_epoch() {
2201 // If any method is on the stack in continuations, none of them can be reclaimed,
2202 // so save the marking cycle to check for the whole class in the cpCache.
2203 // The cpCache is writeable.
2204 constants()->cache()->record_gc_epoch();
2205 }
2206
2207 // Called when the class loader is unloaded to make all methods weak.
2208 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2209 loader_data->jmethod_ids()->clear_all_methods();
2210 }
2211
2212 void Method::clear_jmethod_id() {
2213 // Being at a safepoint prevents racing against other class redefinitions
2214 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
2215 // The jmethodID is not stored in the Method instance, we need to look it up first
2216 jmethodID methodid = find_jmethod_id_or_null();
2217 // We need to make sure that jmethodID actually resolves to this method
2218 // - multiple redefined versions may share jmethodID slots and if a method
2219 // has already been rewired to a newer version we could be removing reference
2220 // to a still existing method instance
2221 if (methodid != nullptr && *((Method**)methodid) == this) {
2222 *((Method**)methodid) = nullptr;
2223 }
2224 }
2225
2226 bool Method::has_method_vptr(const void* ptr) {
2227 Method m;
2228 // This assumes that the vtbl pointer is the first word of a C++ object.
2229 return dereference_vptr(&m) == dereference_vptr(ptr);
2230 }
2231
2232 // Check that this pointer is valid by checking that the vtbl pointer matches
2233 bool Method::is_valid_method(const Method* m) {
2234 if (m == nullptr) {
2235 return false;
2236 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2237 // Quick sanity check on pointer.
2238 return false;
2239 } else if (!os::is_readable_range(m, m + 1)) {
2240 return false;
2241 } else if (m->is_shared()) {
2242 return CppVtables::is_valid_shared_method(m);
2243 } else if (Metaspace::contains_non_shared(m)) {
2244 return has_method_vptr((const void*)m);
2245 } else {
2246 return false;
2247 }
2248 }
2249
2250 #ifndef PRODUCT
2251 void Method::print_jmethod_ids_count(const ClassLoaderData* loader_data, outputStream* out) {
2252 out->print("%d", loader_data->jmethod_ids()->count_methods());
2253 }
2254 #endif // PRODUCT
2255
2256
2257 // Printing
2258
2259 #ifndef PRODUCT
2260
2261 void Method::print_on(outputStream* st) const {
2262 ResourceMark rm;
2263 assert(is_method(), "must be method");
2264 st->print_cr("%s", internal_name());
2265 st->print_cr(" - this oop: " PTR_FORMAT, p2i(this));
2266 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2267 st->print (" - constants: " PTR_FORMAT " ", p2i(constants()));
2268 constants()->print_value_on(st); st->cr();
2269 st->print (" - access: 0x%x ", access_flags().as_method_flags()); access_flags().print_on(st); st->cr();
2270 st->print (" - flags: 0x%x ", _flags.as_int()); _flags.print_on(st); st->cr();
2271 st->print (" - name: "); name()->print_value_on(st); st->cr();
2272 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2273 st->print_cr(" - max stack: %d", max_stack());
2274 st->print_cr(" - max locals: %d", max_locals());
2275 st->print_cr(" - size of params: %d", size_of_parameters());
2276 st->print_cr(" - method size: %d", method_size());
2277 if (intrinsic_id() != vmIntrinsics::_none)
2278 st->print_cr(" - intrinsic id: %d %s", vmIntrinsics::as_int(intrinsic_id()), vmIntrinsics::name_at(intrinsic_id()));
2279 if (highest_comp_level() != CompLevel_none)
2280 st->print_cr(" - highest level: %d", highest_comp_level());
2281 st->print_cr(" - vtable index: %d", _vtable_index);
2282 st->print_cr(" - i2i entry: " PTR_FORMAT, p2i(interpreter_entry()));
2283 st->print( " - adapters: ");
2284 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2285 if (a == nullptr)
2286 st->print_cr(PTR_FORMAT, p2i(a));
2287 else
2288 a->print_adapter_on(st);
2289 st->print_cr(" - compiled entry " PTR_FORMAT, p2i(from_compiled_entry()));
2290 st->print_cr(" - code size: %d", code_size());
2291 if (code_size() != 0) {
2292 st->print_cr(" - code start: " PTR_FORMAT, p2i(code_base()));
2293 st->print_cr(" - code end (excl): " PTR_FORMAT, p2i(code_base() + code_size()));
2294 }
2295 if (method_data() != nullptr) {
2296 st->print_cr(" - method data: " PTR_FORMAT, p2i(method_data()));
2297 }
2298 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2299 if (checked_exceptions_length() > 0) {
2300 CheckedExceptionElement* table = checked_exceptions_start();
2301 st->print_cr(" - checked ex start: " PTR_FORMAT, p2i(table));
2302 if (Verbose) {
2303 for (int i = 0; i < checked_exceptions_length(); i++) {
2304 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2305 }
2306 }
2307 }
2308 if (has_linenumber_table()) {
2309 u_char* table = compressed_linenumber_table();
2310 st->print_cr(" - linenumber start: " PTR_FORMAT, p2i(table));
2311 if (Verbose) {
2312 CompressedLineNumberReadStream stream(table);
2313 while (stream.read_pair()) {
2314 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2315 }
2316 }
2317 }
2318 st->print_cr(" - localvar length: %d", localvariable_table_length());
2319 if (localvariable_table_length() > 0) {
2320 LocalVariableTableElement* table = localvariable_table_start();
2321 st->print_cr(" - localvar start: " PTR_FORMAT, p2i(table));
2322 if (Verbose) {
2323 for (int i = 0; i < localvariable_table_length(); i++) {
2324 int bci = table[i].start_bci;
2325 int len = table[i].length;
2326 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2327 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2328 int slot = table[i].slot;
2329 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2330 }
2331 }
2332 }
2333 if (code() != nullptr) {
2334 st->print (" - compiled code: ");
2335 code()->print_value_on(st);
2336 }
2337 if (is_native()) {
2338 st->print_cr(" - native function: " PTR_FORMAT, p2i(native_function()));
2339 st->print_cr(" - signature handler: " PTR_FORMAT, p2i(signature_handler()));
2340 }
2341 }
2342
2343 void Method::print_linkage_flags(outputStream* st) {
2344 access_flags().print_on(st);
2345 if (is_default_method()) {
2346 st->print("default ");
2347 }
2348 if (is_overpass()) {
2349 st->print("overpass ");
2350 }
2351 }
2352 #endif //PRODUCT
2353
2354 void Method::print_value_on(outputStream* st) const {
2355 assert(is_method(), "must be method");
2356 st->print("%s", internal_name());
2357 print_address_on(st);
2358 st->print(" ");
2359 name()->print_value_on(st);
2360 st->print(" ");
2361 signature()->print_value_on(st);
2362 st->print(" in ");
2363 method_holder()->print_value_on(st);
2364 if (WizardMode) st->print("#%d", _vtable_index);
2365 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2366 if (WizardMode && code() != nullptr) st->print(" ((nmethod*)%p)", code());
2367 }
2368
2369 // Verification
2370
2371 void Method::verify_on(outputStream* st) {
2372 guarantee(is_method(), "object must be method");
2373 guarantee(constants()->is_constantPool(), "should be constant pool");
2374 MethodData* md = method_data();
2375 guarantee(md == nullptr ||
2376 md->is_methodData(), "should be method data");
2377 }