1 /*
2 * Copyright (c) 1997, 2020, 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 "classfile/classLoaderDataGraph.hpp"
27 #include "classfile/metadataOnStackMark.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/debugInfoRec.hpp"
32 #include "compiler/compilationPolicy.hpp"
33 #include "gc/shared/collectedHeap.inline.hpp"
34 #include "interpreter/bytecodeStream.hpp"
35 #include "interpreter/bytecodeTracer.hpp"
36 #include "interpreter/bytecodes.hpp"
37 #include "interpreter/interpreter.hpp"
38 #include "interpreter/oopMapCache.hpp"
39 #include "logging/log.hpp"
40 #include "logging/logTag.hpp"
41 #include "logging/logStream.hpp"
42 #include "memory/allocation.inline.hpp"
43 #include "memory/cppVtables.hpp"
44 #include "memory/metadataFactory.hpp"
45 #include "memory/metaspaceClosure.hpp"
46 #include "memory/metaspaceShared.hpp"
47 #include "memory/oopFactory.hpp"
48 #include "memory/resourceArea.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/constMethod.hpp"
51 #include "oops/constantPool.hpp"
52 #include "oops/klass.inline.hpp"
53 #include "oops/method.inline.hpp"
54 #include "oops/methodData.hpp"
55 #include "oops/objArrayKlass.hpp"
56 #include "oops/objArrayOop.inline.hpp"
57 #include "oops/oop.inline.hpp"
58 #include "oops/symbol.hpp"
59 #include "prims/jvmtiExport.hpp"
60 #include "prims/methodHandles.hpp"
61 #include "prims/nativeLookup.hpp"
62 #include "runtime/arguments.hpp"
63 #include "runtime/atomic.hpp"
64 #include "runtime/frame.inline.hpp"
65 #include "runtime/handles.inline.hpp"
66 #include "runtime/init.hpp"
67 #include "runtime/orderAccess.hpp"
68 #include "runtime/relocator.hpp"
69 #include "runtime/safepointVerifiers.hpp"
70 #include "runtime/sharedRuntime.hpp"
71 #include "runtime/signature.hpp"
72 #include "services/memTracker.hpp"
73 #include "utilities/align.hpp"
74 #include "utilities/quickSort.hpp"
75 #include "utilities/vmError.hpp"
76 #include "utilities/xmlstream.hpp"
77
78 // Implementation of Method
79
allocate(ClassLoaderData * loader_data,int byte_code_size,AccessFlags access_flags,InlineTableSizes * sizes,ConstMethod::MethodType method_type,TRAPS)80 Method* Method::allocate(ClassLoaderData* loader_data,
81 int byte_code_size,
82 AccessFlags access_flags,
83 InlineTableSizes* sizes,
84 ConstMethod::MethodType method_type,
85 TRAPS) {
86 assert(!access_flags.is_native() || byte_code_size == 0,
87 "native methods should not contain byte codes");
88 ConstMethod* cm = ConstMethod::allocate(loader_data,
89 byte_code_size,
90 sizes,
91 method_type,
92 CHECK_NULL);
93 int size = Method::size(access_flags.is_native());
94 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
95 }
96
Method(ConstMethod * xconst,AccessFlags access_flags)97 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
98 NoSafepointVerifier no_safepoint;
99 set_constMethod(xconst);
100 set_access_flags(access_flags);
101 set_intrinsic_id(vmIntrinsics::_none);
102 set_force_inline(false);
103 set_hidden(false);
104 set_dont_inline(false);
105 set_has_injected_profile(false);
106 set_method_data(NULL);
107 clear_method_counters();
108 set_vtable_index(Method::garbage_vtable_index);
109
110 // Fix and bury in Method*
111 set_interpreter_entry(NULL); // sets i2i entry and from_int
112 set_adapter_entry(NULL);
113 Method::clear_code(); // from_c/from_i get set to c2i/i2i
114
115 if (access_flags.is_native()) {
116 clear_native_function();
117 set_signature_handler(NULL);
118 }
119
120 NOT_PRODUCT(set_compiled_invocation_count(0);)
121 }
122
123 // Release Method*. The nmethod will be gone when we get here because
124 // we've walked the code cache.
deallocate_contents(ClassLoaderData * loader_data)125 void Method::deallocate_contents(ClassLoaderData* loader_data) {
126 MetadataFactory::free_metadata(loader_data, constMethod());
127 set_constMethod(NULL);
128 MetadataFactory::free_metadata(loader_data, method_data());
129 set_method_data(NULL);
130 MetadataFactory::free_metadata(loader_data, method_counters());
131 clear_method_counters();
132 // The nmethod will be gone when we get here.
133 if (code() != NULL) _code = NULL;
134 }
135
release_C_heap_structures()136 void Method::release_C_heap_structures() {
137 if (method_data()) {
138 #if INCLUDE_JVMCI
139 FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
140 #endif
141 // Destroy MethodData
142 method_data()->~MethodData();
143 }
144 }
145
get_i2c_entry()146 address Method::get_i2c_entry() {
147 assert(adapter() != NULL, "must have");
148 return adapter()->get_i2c_entry();
149 }
150
get_c2i_entry()151 address Method::get_c2i_entry() {
152 assert(adapter() != NULL, "must have");
153 return adapter()->get_c2i_entry();
154 }
155
get_c2i_unverified_entry()156 address Method::get_c2i_unverified_entry() {
157 assert(adapter() != NULL, "must have");
158 return adapter()->get_c2i_unverified_entry();
159 }
160
get_c2i_no_clinit_check_entry()161 address Method::get_c2i_no_clinit_check_entry() {
162 assert(VM_Version::supports_fast_class_init_checks(), "");
163 assert(adapter() != NULL, "must have");
164 return adapter()->get_c2i_no_clinit_check_entry();
165 }
166
name_and_sig_as_C_string() const167 char* Method::name_and_sig_as_C_string() const {
168 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
169 }
170
name_and_sig_as_C_string(char * buf,int size) const171 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
172 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
173 }
174
name_and_sig_as_C_string(Klass * klass,Symbol * method_name,Symbol * signature)175 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
176 const char* klass_name = klass->external_name();
177 int klass_name_len = (int)strlen(klass_name);
178 int method_name_len = method_name->utf8_length();
179 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
180 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
181 strcpy(dest, klass_name);
182 dest[klass_name_len] = '.';
183 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
184 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
185 dest[len] = 0;
186 return dest;
187 }
188
name_and_sig_as_C_string(Klass * klass,Symbol * method_name,Symbol * signature,char * buf,int size)189 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
190 Symbol* klass_name = klass->name();
191 klass_name->as_klass_external_name(buf, size);
192 int len = (int)strlen(buf);
193
194 if (len < size - 1) {
195 buf[len++] = '.';
196
197 method_name->as_C_string(&(buf[len]), size - len);
198 len = (int)strlen(buf);
199
200 signature->as_C_string(&(buf[len]), size - len);
201 }
202
203 return buf;
204 }
205
external_name() const206 const char* Method::external_name() const {
207 return external_name(constants()->pool_holder(), name(), signature());
208 }
209
print_external_name(outputStream * os) const210 void Method::print_external_name(outputStream *os) const {
211 print_external_name(os, constants()->pool_holder(), name(), signature());
212 }
213
external_name(Klass * klass,Symbol * method_name,Symbol * signature)214 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
215 stringStream ss;
216 print_external_name(&ss, klass, method_name, signature);
217 return ss.as_string();
218 }
219
print_external_name(outputStream * os,Klass * klass,Symbol * method_name,Symbol * signature)220 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
221 signature->print_as_signature_external_return_type(os);
222 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
223 signature->print_as_signature_external_parameters(os);
224 os->print(")");
225 }
226
fast_exception_handler_bci_for(const methodHandle & mh,Klass * ex_klass,int throw_bci,TRAPS)227 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
228 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
229 // access exception table
230 ExceptionTable table(mh());
231 int length = table.length();
232 // iterate through all entries sequentially
233 constantPoolHandle pool(THREAD, mh->constants());
234 for (int i = 0; i < length; i ++) {
235 //reacquire the table in case a GC happened
236 ExceptionTable table(mh());
237 int beg_bci = table.start_pc(i);
238 int end_bci = table.end_pc(i);
239 assert(beg_bci <= end_bci, "inconsistent exception table");
240 if (beg_bci <= throw_bci && throw_bci < end_bci) {
241 // exception handler bci range covers throw_bci => investigate further
242 int handler_bci = table.handler_pc(i);
243 int klass_index = table.catch_type_index(i);
244 if (klass_index == 0) {
245 return handler_bci;
246 } else if (ex_klass == NULL) {
247 return handler_bci;
248 } else {
249 // we know the exception class => get the constraint class
250 // this may require loading of the constraint class; if verification
251 // fails or some other exception occurs, return handler_bci
252 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
253 assert(k != NULL, "klass not loaded");
254 if (ex_klass->is_subtype_of(k)) {
255 return handler_bci;
256 }
257 }
258 }
259 }
260
261 return -1;
262 }
263
mask_for(int bci,InterpreterOopMap * mask)264 void Method::mask_for(int bci, InterpreterOopMap* mask) {
265 methodHandle h_this(Thread::current(), this);
266 // Only GC uses the OopMapCache during thread stack root scanning
267 // any other uses generate an oopmap but do not save it in the cache.
268 if (Universe::heap()->is_gc_active()) {
269 method_holder()->mask_for(h_this, bci, mask);
270 } else {
271 OopMapCache::compute_one_oop_map(h_this, bci, mask);
272 }
273 return;
274 }
275
276
bci_from(address bcp) const277 int Method::bci_from(address bcp) const {
278 if (is_native() && bcp == 0) {
279 return 0;
280 }
281 #ifdef ASSERT
282 {
283 ResourceMark rm;
284 assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
285 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
286 p2i(bcp), name_and_sig_as_C_string());
287 }
288 #endif
289 return bcp - code_base();
290 }
291
292
validate_bci(int bci) const293 int Method::validate_bci(int bci) const {
294 return (bci == 0 || bci < code_size()) ? bci : -1;
295 }
296
297 // Return bci if it appears to be a valid bcp
298 // Return -1 otherwise.
299 // Used by profiling code, when invalid data is a possibility.
300 // The caller is responsible for validating the Method* itself.
validate_bci_from_bcp(address bcp) const301 int Method::validate_bci_from_bcp(address bcp) const {
302 // keep bci as -1 if not a valid bci
303 int bci = -1;
304 if (bcp == 0 || bcp == code_base()) {
305 // code_size() may return 0 and we allow 0 here
306 // the method may be native
307 bci = 0;
308 } else if (contains(bcp)) {
309 bci = bcp - code_base();
310 }
311 // Assert that if we have dodged any asserts, bci is negative.
312 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
313 return bci;
314 }
315
bcp_from(int bci) const316 address Method::bcp_from(int bci) const {
317 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
318 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
319 address bcp = code_base() + bci;
320 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
321 return bcp;
322 }
323
bcp_from(address bcp) const324 address Method::bcp_from(address bcp) const {
325 if (is_native() && bcp == NULL) {
326 return code_base();
327 } else {
328 return bcp;
329 }
330 }
331
size(bool is_native)332 int Method::size(bool is_native) {
333 // If native, then include pointers for native_function and signature_handler
334 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
335 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
336 return align_metadata_size(header_size() + extra_words);
337 }
338
klass_name() const339 Symbol* Method::klass_name() const {
340 return method_holder()->name();
341 }
342
metaspace_pointers_do(MetaspaceClosure * it)343 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
344 log_trace(cds)("Iter(Method): %p", this);
345
346 it->push(&_constMethod);
347 it->push(&_method_data);
348 it->push(&_method_counters);
349
350 Method* this_ptr = this;
351 it->push_method_entry(&this_ptr, (intptr_t*)&_i2i_entry);
352 it->push_method_entry(&this_ptr, (intptr_t*)&_from_compiled_entry);
353 it->push_method_entry(&this_ptr, (intptr_t*)&_from_interpreted_entry);
354 }
355
356 // Attempt to return method to original state. Clear any pointers
357 // (to objects outside the shared spaces). We won't be able to predict
358 // where they should point in a new JVM. Further initialize some
359 // entries now in order allow them to be write protected later.
360
remove_unshareable_info()361 void Method::remove_unshareable_info() {
362 unlink_method();
363 JFR_ONLY(REMOVE_METHOD_ID(this);)
364 }
365
set_vtable_index(int index)366 void Method::set_vtable_index(int index) {
367 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
368 // At runtime initialize_vtable is rerun as part of link_class_impl()
369 // for a shared class loaded by the non-boot loader to obtain the loader
370 // constraints based on the runtime classloaders' context.
371 return; // don't write into the shared class
372 } else {
373 _vtable_index = index;
374 }
375 }
376
set_itable_index(int index)377 void Method::set_itable_index(int index) {
378 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
379 // At runtime initialize_itable is rerun as part of link_class_impl()
380 // for a shared class loaded by the non-boot loader to obtain the loader
381 // constraints based on the runtime classloaders' context. The dumptime
382 // itable index should be the same as the runtime index.
383 assert(_vtable_index == itable_index_max - index,
384 "archived itable index is different from runtime index");
385 return; // don’t write into the shared class
386 } else {
387 _vtable_index = itable_index_max - index;
388 }
389 assert(valid_itable_index(), "");
390 }
391
392 // The RegisterNatives call being attempted tried to register with a method that
393 // is not native. Ask JVM TI what prefixes have been specified. Then check
394 // to see if the native method is now wrapped with the prefixes. See the
395 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
find_prefixed_native(Klass * k,Symbol * name,Symbol * signature,TRAPS)396 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
397 #if INCLUDE_JVMTI
398 ResourceMark rm(THREAD);
399 Method* method;
400 int name_len = name->utf8_length();
401 char* name_str = name->as_utf8();
402 int prefix_count;
403 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
404 for (int i = 0; i < prefix_count; i++) {
405 char* prefix = prefixes[i];
406 int prefix_len = (int)strlen(prefix);
407
408 // try adding this prefix to the method name and see if it matches another method name
409 int trial_len = name_len + prefix_len;
410 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
411 strcpy(trial_name_str, prefix);
412 strcat(trial_name_str, name_str);
413 TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
414 if (trial_name == NULL) {
415 continue; // no such symbol, so this prefix wasn't used, try the next prefix
416 }
417 method = k->lookup_method(trial_name, signature);
418 if (method == NULL) {
419 continue; // signature doesn't match, try the next prefix
420 }
421 if (method->is_native()) {
422 method->set_is_prefixed_native();
423 return method; // wahoo, we found a prefixed version of the method, return it
424 }
425 // found as non-native, so prefix is good, add it, probably just need more prefixes
426 name_len = trial_len;
427 name_str = trial_name_str;
428 }
429 #endif // INCLUDE_JVMTI
430 return NULL; // not found
431 }
432
register_native(Klass * k,Symbol * name,Symbol * signature,address entry,TRAPS)433 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
434 Method* method = k->lookup_method(name, signature);
435 if (method == NULL) {
436 ResourceMark rm(THREAD);
437 stringStream st;
438 st.print("Method '");
439 print_external_name(&st, k, name, signature);
440 st.print("' name or signature does not match");
441 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
442 }
443 if (!method->is_native()) {
444 // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
445 method = find_prefixed_native(k, name, signature, THREAD);
446 if (method == NULL) {
447 ResourceMark rm(THREAD);
448 stringStream st;
449 st.print("Method '");
450 print_external_name(&st, k, name, signature);
451 st.print("' is not declared as native");
452 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
453 }
454 }
455
456 if (entry != NULL) {
457 method->set_native_function(entry, native_bind_event_is_interesting);
458 } else {
459 method->clear_native_function();
460 }
461 if (log_is_enabled(Debug, jni, resolve)) {
462 ResourceMark rm(THREAD);
463 log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
464 method->method_holder()->external_name(),
465 method->name()->as_C_string());
466 }
467 return true;
468 }
469
was_executed_more_than(int n)470 bool Method::was_executed_more_than(int n) {
471 // Invocation counter is reset when the Method* is compiled.
472 // If the method has compiled code we therefore assume it has
473 // be excuted more than n times.
474 if (is_accessor() || is_empty_method() || (code() != NULL)) {
475 // interpreter doesn't bump invocation counter of trivial methods
476 // compiler does not bump invocation counter of compiled methods
477 return true;
478 }
479 else if ((method_counters() != NULL &&
480 method_counters()->invocation_counter()->carry()) ||
481 (method_data() != NULL &&
482 method_data()->invocation_counter()->carry())) {
483 // The carry bit is set when the counter overflows and causes
484 // a compilation to occur. We don't know how many times
485 // the counter has been reset, so we simply assume it has
486 // been executed more than n times.
487 return true;
488 } else {
489 return invocation_count() > n;
490 }
491 }
492
print_invocation_count()493 void Method::print_invocation_count() {
494 if (is_static()) tty->print("static ");
495 if (is_final()) tty->print("final ");
496 if (is_synchronized()) tty->print("synchronized ");
497 if (is_native()) tty->print("native ");
498 tty->print("%s::", method_holder()->external_name());
499 name()->print_symbol_on(tty);
500 signature()->print_symbol_on(tty);
501
502 if (WizardMode) {
503 // dump the size of the byte codes
504 tty->print(" {%d}", code_size());
505 }
506 tty->cr();
507
508 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
509 tty->print_cr (" invocation_counter: %8d ", invocation_count());
510 tty->print_cr (" backedge_counter: %8d ", backedge_count());
511 #ifndef PRODUCT
512 if (CountCompiledCalls) {
513 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
514 }
515 #endif
516 }
517
518 // Build a MethodData* object to hold information about this method
519 // collected in the interpreter.
build_interpreter_method_data(const methodHandle & method,TRAPS)520 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
521 // Do not profile the method if metaspace has hit an OOM previously
522 // allocating profiling data. Callers clear pending exception so don't
523 // add one here.
524 if (ClassLoaderDataGraph::has_metaspace_oom()) {
525 return;
526 }
527
528 // Grab a lock here to prevent multiple
529 // MethodData*s from being created.
530 MutexLocker ml(THREAD, MethodData_lock);
531 if (method->method_data() == NULL) {
532 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
533 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
534 if (HAS_PENDING_EXCEPTION) {
535 CompileBroker::log_metaspace_failure();
536 ClassLoaderDataGraph::set_metaspace_oom(true);
537 return; // return the exception (which is cleared)
538 }
539
540 method->set_method_data(method_data);
541 if (PrintMethodData && (Verbose || WizardMode)) {
542 ResourceMark rm(THREAD);
543 tty->print("build_interpreter_method_data for ");
544 method->print_name(tty);
545 tty->cr();
546 // At the end of the run, the MDO, full of data, will be dumped.
547 }
548 }
549 }
550
build_method_counters(Method * m,TRAPS)551 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
552 // Do not profile the method if metaspace has hit an OOM previously
553 if (ClassLoaderDataGraph::has_metaspace_oom()) {
554 return NULL;
555 }
556
557 methodHandle mh(THREAD, m);
558 MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
559 if (HAS_PENDING_EXCEPTION) {
560 CompileBroker::log_metaspace_failure();
561 ClassLoaderDataGraph::set_metaspace_oom(true);
562 return NULL; // return the exception (which is cleared)
563 }
564 if (!mh->init_method_counters(counters)) {
565 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
566 }
567
568 if (LogTouchedMethods) {
569 mh->log_touched(CHECK_NULL);
570 }
571
572 return mh->method_counters();
573 }
574
init_method_counters(MethodCounters * counters)575 bool Method::init_method_counters(MethodCounters* counters) {
576 // Try to install a pointer to MethodCounters, return true on success.
577 return Atomic::replace_if_null(&_method_counters, counters);
578 }
579
extra_stack_words()580 int Method::extra_stack_words() {
581 // not an inline function, to avoid a header dependency on Interpreter
582 return extra_stack_entries() * Interpreter::stackElementSize;
583 }
584
585 // Derive size of parameters, return type, and fingerprint,
586 // all in one pass, which is run at load time.
587 // We need the first two, and might as well grab the third.
compute_from_signature(Symbol * sig)588 void Method::compute_from_signature(Symbol* sig) {
589 // At this point, since we are scanning the signature,
590 // we might as well compute the whole fingerprint.
591 Fingerprinter fp(sig, is_static());
592 set_size_of_parameters(fp.size_of_parameters());
593 constMethod()->set_result_type(fp.return_type());
594 constMethod()->set_fingerprint(fp.fingerprint());
595 }
596
is_empty_method() const597 bool Method::is_empty_method() const {
598 return code_size() == 1
599 && *code_base() == Bytecodes::_return;
600 }
601
is_vanilla_constructor() const602 bool Method::is_vanilla_constructor() const {
603 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
604 // which only calls the superclass vanilla constructor and possibly does stores of
605 // zero constants to local fields:
606 //
607 // aload_0
608 // invokespecial
609 // indexbyte1
610 // indexbyte2
611 //
612 // followed by an (optional) sequence of:
613 //
614 // aload_0
615 // aconst_null / iconst_0 / fconst_0 / dconst_0
616 // putfield
617 // indexbyte1
618 // indexbyte2
619 //
620 // followed by:
621 //
622 // return
623
624 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
625 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
626 int size = code_size();
627 // Check if size match
628 if (size == 0 || size % 5 != 0) return false;
629 address cb = code_base();
630 int last = size - 1;
631 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
632 // Does not call superclass default constructor
633 return false;
634 }
635 // Check optional sequence
636 for (int i = 4; i < last; i += 5) {
637 if (cb[i] != Bytecodes::_aload_0) return false;
638 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
639 if (cb[i+2] != Bytecodes::_putfield) return false;
640 }
641 return true;
642 }
643
644
compute_has_loops_flag()645 bool Method::compute_has_loops_flag() {
646 BytecodeStream bcs(methodHandle(Thread::current(), this));
647 Bytecodes::Code bc;
648
649 while ((bc = bcs.next()) >= 0) {
650 switch (bc) {
651 case Bytecodes::_ifeq:
652 case Bytecodes::_ifnull:
653 case Bytecodes::_iflt:
654 case Bytecodes::_ifle:
655 case Bytecodes::_ifne:
656 case Bytecodes::_ifnonnull:
657 case Bytecodes::_ifgt:
658 case Bytecodes::_ifge:
659 case Bytecodes::_if_icmpeq:
660 case Bytecodes::_if_icmpne:
661 case Bytecodes::_if_icmplt:
662 case Bytecodes::_if_icmpgt:
663 case Bytecodes::_if_icmple:
664 case Bytecodes::_if_icmpge:
665 case Bytecodes::_if_acmpeq:
666 case Bytecodes::_if_acmpne:
667 case Bytecodes::_goto:
668 case Bytecodes::_jsr:
669 if (bcs.dest() < bcs.next_bci()) _access_flags.set_has_loops();
670 break;
671
672 case Bytecodes::_goto_w:
673 case Bytecodes::_jsr_w:
674 if (bcs.dest_w() < bcs.next_bci()) _access_flags.set_has_loops();
675 break;
676
677 case Bytecodes::_lookupswitch: {
678 Bytecode_lookupswitch lookupswitch(this, bcs.bcp());
679 if (lookupswitch.default_offset() < 0) {
680 _access_flags.set_has_loops();
681 } else {
682 for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) {
683 LookupswitchPair pair = lookupswitch.pair_at(i);
684 if (pair.offset() < 0) {
685 _access_flags.set_has_loops();
686 break;
687 }
688 }
689 }
690 break;
691 }
692 case Bytecodes::_tableswitch: {
693 Bytecode_tableswitch tableswitch(this, bcs.bcp());
694 if (tableswitch.default_offset() < 0) {
695 _access_flags.set_has_loops();
696 } else {
697 for (int i = 0; i < tableswitch.length(); ++i) {
698 if (tableswitch.dest_offset_at(i) < 0) {
699 _access_flags.set_has_loops();
700 }
701 }
702 }
703 break;
704 }
705 default:
706 break;
707 }
708 }
709 _access_flags.set_loops_flag_init();
710 return _access_flags.has_loops();
711 }
712
is_final_method(AccessFlags class_access_flags) const713 bool Method::is_final_method(AccessFlags class_access_flags) const {
714 // or "does_not_require_vtable_entry"
715 // default method or overpass can occur, is not final (reuses vtable entry)
716 // private methods in classes get vtable entries for backward class compatibility.
717 if (is_overpass() || is_default_method()) return false;
718 return is_final() || class_access_flags.is_final();
719 }
720
is_final_method() const721 bool Method::is_final_method() const {
722 return is_final_method(method_holder()->access_flags());
723 }
724
is_default_method() const725 bool Method::is_default_method() const {
726 if (method_holder() != NULL &&
727 method_holder()->is_interface() &&
728 !is_abstract() && !is_private()) {
729 return true;
730 } else {
731 return false;
732 }
733 }
734
can_be_statically_bound(AccessFlags class_access_flags) const735 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
736 if (is_final_method(class_access_flags)) return true;
737 #ifdef ASSERT
738 ResourceMark rm;
739 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
740 if (class_access_flags.is_interface()) {
741 assert(is_nonv == is_static() || is_nonv == is_private(),
742 "nonvirtual unexpected for non-static, non-private: %s",
743 name_and_sig_as_C_string());
744 }
745 #endif
746 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
747 return vtable_index() == nonvirtual_vtable_index;
748 }
749
can_be_statically_bound() const750 bool Method::can_be_statically_bound() const {
751 return can_be_statically_bound(method_holder()->access_flags());
752 }
753
can_be_statically_bound(InstanceKlass * context) const754 bool Method::can_be_statically_bound(InstanceKlass* context) const {
755 return (method_holder() == context) && can_be_statically_bound();
756 }
757
is_accessor() const758 bool Method::is_accessor() const {
759 return is_getter() || is_setter();
760 }
761
is_getter() const762 bool Method::is_getter() const {
763 if (code_size() != 5) return false;
764 if (size_of_parameters() != 1) return false;
765 if (java_code_at(0) != Bytecodes::_aload_0) return false;
766 if (java_code_at(1) != Bytecodes::_getfield) return false;
767 switch (java_code_at(4)) {
768 case Bytecodes::_ireturn:
769 case Bytecodes::_lreturn:
770 case Bytecodes::_freturn:
771 case Bytecodes::_dreturn:
772 case Bytecodes::_areturn:
773 break;
774 default:
775 return false;
776 }
777 return true;
778 }
779
is_setter() const780 bool Method::is_setter() const {
781 if (code_size() != 6) return false;
782 if (java_code_at(0) != Bytecodes::_aload_0) return false;
783 switch (java_code_at(1)) {
784 case Bytecodes::_iload_1:
785 case Bytecodes::_aload_1:
786 case Bytecodes::_fload_1:
787 if (size_of_parameters() != 2) return false;
788 break;
789 case Bytecodes::_dload_1:
790 case Bytecodes::_lload_1:
791 if (size_of_parameters() != 3) return false;
792 break;
793 default:
794 return false;
795 }
796 if (java_code_at(2) != Bytecodes::_putfield) return false;
797 if (java_code_at(5) != Bytecodes::_return) return false;
798 return true;
799 }
800
is_constant_getter() const801 bool Method::is_constant_getter() const {
802 int last_index = code_size() - 1;
803 // Check if the first 1-3 bytecodes are a constant push
804 // and the last bytecode is a return.
805 return (2 <= code_size() && code_size() <= 4 &&
806 Bytecodes::is_const(java_code_at(0)) &&
807 Bytecodes::length_for(java_code_at(0)) == last_index &&
808 Bytecodes::is_return(java_code_at(last_index)));
809 }
810
is_initializer() const811 bool Method::is_initializer() const {
812 return is_object_initializer() || is_static_initializer();
813 }
814
has_valid_initializer_flags() const815 bool Method::has_valid_initializer_flags() const {
816 return (is_static() ||
817 method_holder()->major_version() < 51);
818 }
819
is_static_initializer() const820 bool Method::is_static_initializer() const {
821 // For classfiles version 51 or greater, ensure that the clinit method is
822 // static. Non-static methods with the name "<clinit>" are not static
823 // initializers. (older classfiles exempted for backward compatibility)
824 return name() == vmSymbols::class_initializer_name() &&
825 has_valid_initializer_flags();
826 }
827
is_object_initializer() const828 bool Method::is_object_initializer() const {
829 return name() == vmSymbols::object_initializer_name();
830 }
831
needs_clinit_barrier() const832 bool Method::needs_clinit_barrier() const {
833 return is_static() && !method_holder()->is_initialized();
834 }
835
resolved_checked_exceptions_impl(Method * method,TRAPS)836 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
837 int length = method->checked_exceptions_length();
838 if (length == 0) { // common case
839 return objArrayHandle(THREAD, Universe::the_empty_class_array());
840 } else {
841 methodHandle h_this(THREAD, method);
842 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
843 objArrayHandle mirrors (THREAD, m_oop);
844 for (int i = 0; i < length; i++) {
845 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
846 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
847 if (log_is_enabled(Warning, exceptions) &&
848 !k->is_subclass_of(SystemDictionary::Throwable_klass())) {
849 ResourceMark rm(THREAD);
850 log_warning(exceptions)(
851 "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
852 k->external_name(), method->external_name());
853 }
854 mirrors->obj_at_put(i, k->java_mirror());
855 }
856 return mirrors;
857 }
858 };
859
860
line_number_from_bci(int bci) const861 int Method::line_number_from_bci(int bci) const {
862 int best_bci = 0;
863 int best_line = -1;
864 if (bci == SynchronizationEntryBCI) bci = 0;
865 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
866 // The line numbers are a short array of 2-tuples [start_pc, line_number].
867 // Not necessarily sorted and not necessarily one-to-one.
868 CompressedLineNumberReadStream stream(compressed_linenumber_table());
869 while (stream.read_pair()) {
870 if (stream.bci() == bci) {
871 // perfect match
872 return stream.line();
873 } else {
874 // update best_bci/line
875 if (stream.bci() < bci && stream.bci() >= best_bci) {
876 best_bci = stream.bci();
877 best_line = stream.line();
878 }
879 }
880 }
881 }
882 return best_line;
883 }
884
885
is_klass_loaded_by_klass_index(int klass_index) const886 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
887 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
888 Thread *thread = Thread::current();
889 Symbol* klass_name = constants()->klass_name_at(klass_index);
890 Handle loader(thread, method_holder()->class_loader());
891 Handle prot (thread, method_holder()->protection_domain());
892 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
893 } else {
894 return true;
895 }
896 }
897
898
is_klass_loaded(int refinfo_index,bool must_be_resolved) const899 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
900 int klass_index = constants()->klass_ref_index_at(refinfo_index);
901 if (must_be_resolved) {
902 // Make sure klass is resolved in constantpool.
903 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
904 }
905 return is_klass_loaded_by_klass_index(klass_index);
906 }
907
908
set_native_function(address function,bool post_event_flag)909 void Method::set_native_function(address function, bool post_event_flag) {
910 assert(function != NULL, "use clear_native_function to unregister natives");
911 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
912 address* native_function = native_function_addr();
913
914 // We can see racers trying to place the same native function into place. Once
915 // is plenty.
916 address current = *native_function;
917 if (current == function) return;
918 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
919 function != NULL) {
920 // native_method_throw_unsatisfied_link_error_entry() should only
921 // be passed when post_event_flag is false.
922 assert(function !=
923 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
924 "post_event_flag mis-match");
925
926 // post the bind event, and possible change the bind function
927 JvmtiExport::post_native_method_bind(this, &function);
928 }
929 *native_function = function;
930 // This function can be called more than once. We must make sure that we always
931 // use the latest registered method -> check if a stub already has been generated.
932 // If so, we have to make it not_entrant.
933 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
934 if (nm != NULL) {
935 nm->make_not_entrant();
936 }
937 }
938
939
has_native_function() const940 bool Method::has_native_function() const {
941 if (is_method_handle_intrinsic())
942 return false; // special-cased in SharedRuntime::generate_native_wrapper
943 address func = native_function();
944 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
945 }
946
947
clear_native_function()948 void Method::clear_native_function() {
949 // Note: is_method_handle_intrinsic() is allowed here.
950 set_native_function(
951 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
952 !native_bind_event_is_interesting);
953 this->unlink_code();
954 }
955
956
set_signature_handler(address handler)957 void Method::set_signature_handler(address handler) {
958 address* signature_handler = signature_handler_addr();
959 *signature_handler = handler;
960 }
961
962
print_made_not_compilable(int comp_level,bool is_osr,bool report,const char * reason)963 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
964 assert(reason != NULL, "must provide a reason");
965 if (PrintCompilation && report) {
966 ttyLocker ttyl;
967 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
968 if (comp_level == CompLevel_all) {
969 tty->print("all levels ");
970 } else {
971 tty->print("level %d ", comp_level);
972 }
973 this->print_short_name(tty);
974 int size = this->code_size();
975 if (size > 0) {
976 tty->print(" (%d bytes)", size);
977 }
978 if (reason != NULL) {
979 tty->print(" %s", reason);
980 }
981 tty->cr();
982 }
983 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
984 ttyLocker ttyl;
985 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
986 os::current_thread_id(), is_osr, comp_level);
987 if (reason != NULL) {
988 xtty->print(" reason=\'%s\'", reason);
989 }
990 xtty->method(this);
991 xtty->stamp();
992 xtty->end_elem();
993 }
994 }
995
is_always_compilable() const996 bool Method::is_always_compilable() const {
997 // Generated adapters must be compiled
998 if (is_method_handle_intrinsic() && is_synthetic()) {
999 assert(!is_not_c1_compilable(), "sanity check");
1000 assert(!is_not_c2_compilable(), "sanity check");
1001 return true;
1002 }
1003
1004 return false;
1005 }
1006
is_not_compilable(int comp_level) const1007 bool Method::is_not_compilable(int comp_level) const {
1008 if (number_of_breakpoints() > 0)
1009 return true;
1010 if (is_always_compilable())
1011 return false;
1012 if (comp_level == CompLevel_any)
1013 return is_not_c1_compilable() || is_not_c2_compilable();
1014 if (is_c1_compile(comp_level))
1015 return is_not_c1_compilable();
1016 if (is_c2_compile(comp_level))
1017 return is_not_c2_compilable();
1018 return false;
1019 }
1020
1021 // call this when compiler finds that this method is not compilable
set_not_compilable(const char * reason,int comp_level,bool report)1022 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
1023 if (is_always_compilable()) {
1024 // Don't mark a method which should be always compilable
1025 return;
1026 }
1027 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
1028 if (comp_level == CompLevel_all) {
1029 set_not_c1_compilable();
1030 set_not_c2_compilable();
1031 } else {
1032 if (is_c1_compile(comp_level))
1033 set_not_c1_compilable();
1034 if (is_c2_compile(comp_level))
1035 set_not_c2_compilable();
1036 }
1037 assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1038 }
1039
is_not_osr_compilable(int comp_level) const1040 bool Method::is_not_osr_compilable(int comp_level) const {
1041 if (is_not_compilable(comp_level))
1042 return true;
1043 if (comp_level == CompLevel_any)
1044 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
1045 if (is_c1_compile(comp_level))
1046 return is_not_c1_osr_compilable();
1047 if (is_c2_compile(comp_level))
1048 return is_not_c2_osr_compilable();
1049 return false;
1050 }
1051
set_not_osr_compilable(const char * reason,int comp_level,bool report)1052 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1053 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1054 if (comp_level == CompLevel_all) {
1055 set_not_c1_osr_compilable();
1056 set_not_c2_osr_compilable();
1057 } else {
1058 if (is_c1_compile(comp_level))
1059 set_not_c1_osr_compilable();
1060 if (is_c2_compile(comp_level))
1061 set_not_c2_osr_compilable();
1062 }
1063 assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1064 }
1065
1066 // Revert to using the interpreter and clear out the nmethod
clear_code()1067 void Method::clear_code() {
1068 // this may be NULL if c2i adapters have not been made yet
1069 // Only should happen at allocate time.
1070 if (adapter() == NULL) {
1071 _from_compiled_entry = NULL;
1072 } else {
1073 _from_compiled_entry = adapter()->get_c2i_entry();
1074 }
1075 OrderAccess::storestore();
1076 _from_interpreted_entry = _i2i_entry;
1077 OrderAccess::storestore();
1078 _code = NULL;
1079 }
1080
unlink_code(CompiledMethod * compare)1081 void Method::unlink_code(CompiledMethod *compare) {
1082 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1083 // We need to check if either the _code or _from_compiled_code_entry_point
1084 // refer to this nmethod because there is a race in setting these two fields
1085 // in Method* as seen in bugid 4947125.
1086 // If the vep() points to the zombie nmethod, the memory for the nmethod
1087 // could be flushed and the compiler and vtable stubs could still call
1088 // through it.
1089 if (code() == compare ||
1090 from_compiled_entry() == compare->verified_entry_point()) {
1091 clear_code();
1092 }
1093 }
1094
unlink_code()1095 void Method::unlink_code() {
1096 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1097 clear_code();
1098 }
1099
1100 #if INCLUDE_CDS
1101 // Called by class data sharing to remove any entry points (which are not shared)
unlink_method()1102 void Method::unlink_method() {
1103 _code = NULL;
1104
1105 Arguments::assert_is_dumping_archive();
1106 // Set the values to what they should be at run time. Note that
1107 // this Method can no longer be executed during dump time.
1108 _i2i_entry = Interpreter::entry_for_cds_method(methodHandle(Thread::current(), this));
1109 _from_interpreted_entry = _i2i_entry;
1110
1111 assert(_from_compiled_entry != NULL, "sanity");
1112 assert(*((int*)_from_compiled_entry) == 0,
1113 "must be NULL during dump time, to be initialized at run time");
1114
1115 if (is_native()) {
1116 *native_function_addr() = NULL;
1117 set_signature_handler(NULL);
1118 }
1119 NOT_PRODUCT(set_compiled_invocation_count(0);)
1120
1121 set_method_data(NULL);
1122 clear_method_counters();
1123 }
1124 #endif
1125
1126 /****************************************************************************
1127 // The following illustrates how the entries work for CDS shared Methods:
1128 //
1129 // Our goal is to delay writing into a shared Method until it's compiled.
1130 // Hence, we want to determine the initial values for _i2i_entry,
1131 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1132 //
1133 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1134 // They also have similar signatures so that they will share the same
1135 // AdapterHandlerEntry.
1136 //
1137 // _adapter_trampoline points to a fixed location in the RW section of
1138 // the CDS archive. This location initially contains a NULL pointer. When the
1139 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1140 // dynamically, and its c2i/i2c entries are generated.
1141 //
1142 // _i2i_entry and _from_interpreted_entry initially points to the same
1143 // (fixed) location in the CODE section of the CDS archive. This contains
1144 // an unconditional branch to the actual entry for "zero_locals", which is
1145 // generated at run time and may be on an arbitrary address. Thus, the
1146 // unconditional branch is also generated at run time to jump to the correct
1147 // address.
1148 //
1149 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1150 // section. This address has enough space for an unconditional branch
1151 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1152 // initialized, and the address for the actual c2i_entry is known, we emit a
1153 // branch instruction here to branch to the actual c2i_entry.
1154 //
1155 // The effect of the extra branch on the i2i and c2i entries is negligible.
1156 //
1157 // The reason for putting _adapter_trampoline in RO is many shared Methods
1158 // share the same AdapterHandlerEntry, so we can save space in the RW section
1159 // by having the extra indirection.
1160
1161
1162 [Method A: RW]
1163 _constMethod ----> [ConstMethod: RO]
1164 _adapter_trampoline -----------+
1165 |
1166 _i2i_entry (same value as method B) |
1167 _from_interpreted_entry (same value as method B) |
1168 _from_compiled_entry (same value as method B) |
1169 |
1170 |
1171 [Method B: RW] +--------+
1172 _constMethod ----> [ConstMethod: RO] |
1173 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1174 |
1175 +-------------------------------+
1176 |
1177 +----> [AdapterHandlerEntry] (allocated at run time)
1178 _fingerprint
1179 _c2i_entry ---------------------------------+->[c2i entry..]
1180 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1181 _from_interpreted_entry | _c2i_unverified_entry | |
1182 | | _c2i_no_clinit_check_entry| |
1183 | | (_cds_entry_table: CODE) | |
1184 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1185 | | (allocated at run time) | |
1186 | | ... [asm code ...] | |
1187 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1188 | | |
1189 | | |
1190 +-[compiled]-------------------------------------------------------------------+ |
1191 |
1192 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1193 [jmp c2i_entry] ------------------------------------------------------+
1194
1195 ***/
1196
1197 // Called when the method_holder is getting linked. Setup entrypoints so the method
1198 // is ready to be called from interpreter, compiler, and vtables.
link_method(const methodHandle & h_method,TRAPS)1199 void Method::link_method(const methodHandle& h_method, TRAPS) {
1200 // If the code cache is full, we may reenter this function for the
1201 // leftover methods that weren't linked.
1202 if (is_shared()) {
1203 // Can't assert that the adapters are sane, because methods get linked before
1204 // the interpreter is generated, and hence before its adapters are generated.
1205 // If you messed them up you will notice soon enough though, don't you worry.
1206 if (adapter() != NULL) {
1207 return;
1208 }
1209 } else if (_i2i_entry != NULL) {
1210 return;
1211 }
1212 assert( _code == NULL, "nothing compiled yet" );
1213
1214 // Setup interpreter entrypoint
1215 assert(this == h_method(), "wrong h_method()" );
1216
1217 if (!is_shared()) {
1218 assert(adapter() == NULL, "init'd to NULL");
1219 address entry = Interpreter::entry_for_method(h_method);
1220 assert(entry != NULL, "interpreter entry must be non-null");
1221 // Sets both _i2i_entry and _from_interpreted_entry
1222 set_interpreter_entry(entry);
1223 }
1224
1225 // Don't overwrite already registered native entries.
1226 if (is_native() && !has_native_function()) {
1227 set_native_function(
1228 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1229 !native_bind_event_is_interesting);
1230 }
1231
1232 // Setup compiler entrypoint. This is made eagerly, so we do not need
1233 // special handling of vtables. An alternative is to make adapters more
1234 // lazily by calling make_adapter() from from_compiled_entry() for the
1235 // normal calls. For vtable calls life gets more complicated. When a
1236 // call-site goes mega-morphic we need adapters in all methods which can be
1237 // called from the vtable. We need adapters on such methods that get loaded
1238 // later. Ditto for mega-morphic itable calls. If this proves to be a
1239 // problem we'll make these lazily later.
1240 (void) make_adapters(h_method, CHECK);
1241
1242 // ONLY USE the h_method now as make_adapter may have blocked
1243
1244 }
1245
make_adapters(const methodHandle & mh,TRAPS)1246 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1247 // Adapters for compiled code are made eagerly here. They are fairly
1248 // small (generally < 100 bytes) and quick to make (and cached and shared)
1249 // so making them eagerly shouldn't be too expensive.
1250 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1251 if (adapter == NULL ) {
1252 if (!is_init_completed()) {
1253 // Don't throw exceptions during VM initialization because java.lang.* classes
1254 // might not have been initialized, causing problems when constructing the
1255 // Java exception object.
1256 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1257 } else {
1258 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1259 }
1260 }
1261
1262 if (mh->is_shared()) {
1263 assert(mh->adapter() == adapter, "must be");
1264 assert(mh->_from_compiled_entry != NULL, "must be");
1265 } else {
1266 mh->set_adapter_entry(adapter);
1267 mh->_from_compiled_entry = adapter->get_c2i_entry();
1268 }
1269 return adapter->get_c2i_entry();
1270 }
1271
restore_unshareable_info(TRAPS)1272 void Method::restore_unshareable_info(TRAPS) {
1273 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1274
1275 // Since restore_unshareable_info can be called more than once for a method, don't
1276 // redo any work.
1277 if (adapter() == NULL) {
1278 methodHandle mh(THREAD, this);
1279 link_method(mh, CHECK);
1280 }
1281 }
1282
from_compiled_entry_no_trampoline() const1283 address Method::from_compiled_entry_no_trampoline() const {
1284 CompiledMethod *code = Atomic::load_acquire(&_code);
1285 if (code) {
1286 return code->verified_entry_point();
1287 } else {
1288 return adapter()->get_c2i_entry();
1289 }
1290 }
1291
1292 // The verified_code_entry() must be called when a invoke is resolved
1293 // on this method.
1294
1295 // It returns the compiled code entry point, after asserting not null.
1296 // This function is called after potential safepoints so that nmethod
1297 // or adapter that it points to is still live and valid.
1298 // This function must not hit a safepoint!
verified_code_entry()1299 address Method::verified_code_entry() {
1300 debug_only(NoSafepointVerifier nsv;)
1301 assert(_from_compiled_entry != NULL, "must be set");
1302 return _from_compiled_entry;
1303 }
1304
1305 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1306 // (could be racing a deopt).
1307 // Not inline to avoid circular ref.
check_code() const1308 bool Method::check_code() const {
1309 // cached in a register or local. There's a race on the value of the field.
1310 CompiledMethod *code = Atomic::load_acquire(&_code);
1311 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1312 }
1313
1314 // Install compiled code. Instantly it can execute.
set_code(const methodHandle & mh,CompiledMethod * code)1315 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1316 assert_lock_strong(CompiledMethod_lock);
1317 assert( code, "use clear_code to remove code" );
1318 assert( mh->check_code(), "" );
1319
1320 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1321
1322 // These writes must happen in this order, because the interpreter will
1323 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1324 // which jumps to _from_compiled_entry.
1325 mh->_code = code; // Assign before allowing compiled code to exec
1326
1327 int comp_level = code->comp_level();
1328 // In theory there could be a race here. In practice it is unlikely
1329 // and not worth worrying about.
1330 if (comp_level > mh->highest_comp_level()) {
1331 mh->set_highest_comp_level(comp_level);
1332 }
1333
1334 OrderAccess::storestore();
1335 mh->_from_compiled_entry = code->verified_entry_point();
1336 OrderAccess::storestore();
1337 // Instantly compiled code can execute.
1338 if (!mh->is_method_handle_intrinsic())
1339 mh->_from_interpreted_entry = mh->get_i2c_entry();
1340 }
1341
1342
is_overridden_in(Klass * k) const1343 bool Method::is_overridden_in(Klass* k) const {
1344 InstanceKlass* ik = InstanceKlass::cast(k);
1345
1346 if (ik->is_interface()) return false;
1347
1348 // If method is an interface, we skip it - except if it
1349 // is a miranda method
1350 if (method_holder()->is_interface()) {
1351 // Check that method is not a miranda method
1352 if (ik->lookup_method(name(), signature()) == NULL) {
1353 // No implementation exist - so miranda method
1354 return false;
1355 }
1356 return true;
1357 }
1358
1359 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1360 if (!has_vtable_index()) {
1361 return false;
1362 } else {
1363 Method* vt_m = ik->method_at_vtable(vtable_index());
1364 return vt_m != this;
1365 }
1366 }
1367
1368
1369 // give advice about whether this Method* should be cached or not
should_not_be_cached() const1370 bool Method::should_not_be_cached() const {
1371 if (is_old()) {
1372 // This method has been redefined. It is either EMCP or obsolete
1373 // and we don't want to cache it because that would pin the method
1374 // down and prevent it from being collectible if and when it
1375 // finishes executing.
1376 return true;
1377 }
1378
1379 // caching this method should be just fine
1380 return false;
1381 }
1382
1383
1384 /**
1385 * Returns true if this is one of the specially treated methods for
1386 * security related stack walks (like Reflection.getCallerClass).
1387 */
is_ignored_by_security_stack_walk() const1388 bool Method::is_ignored_by_security_stack_walk() const {
1389 if (intrinsic_id() == vmIntrinsics::_invoke) {
1390 // This is Method.invoke() -- ignore it
1391 return true;
1392 }
1393 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1394 // This is an auxilary frame -- ignore it
1395 return true;
1396 }
1397 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1398 // This is an internal adapter frame for method handles -- ignore it
1399 return true;
1400 }
1401 return false;
1402 }
1403
1404
1405 // Constant pool structure for invoke methods:
1406 enum {
1407 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1408 _imcp_invoke_signature, // utf8: (variable Symbol*)
1409 _imcp_limit
1410 };
1411
1412 // Test if this method is an MH adapter frame generated by Java code.
1413 // Cf. java/lang/invoke/InvokerBytecodeGenerator
is_compiled_lambda_form() const1414 bool Method::is_compiled_lambda_form() const {
1415 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1416 }
1417
1418 // Test if this method is an internal MH primitive method.
is_method_handle_intrinsic() const1419 bool Method::is_method_handle_intrinsic() const {
1420 vmIntrinsics::ID iid = intrinsic_id();
1421 return (MethodHandles::is_signature_polymorphic(iid) &&
1422 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1423 }
1424
has_member_arg() const1425 bool Method::has_member_arg() const {
1426 vmIntrinsics::ID iid = intrinsic_id();
1427 return (MethodHandles::is_signature_polymorphic(iid) &&
1428 MethodHandles::has_member_arg(iid));
1429 }
1430
1431 // Make an instance of a signature-polymorphic internal MH primitive.
make_method_handle_intrinsic(vmIntrinsics::ID iid,Symbol * signature,TRAPS)1432 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1433 Symbol* signature,
1434 TRAPS) {
1435 ResourceMark rm(THREAD);
1436 methodHandle empty;
1437
1438 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1439 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1440 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1441
1442 log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1443
1444 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1445 name->increment_refcount();
1446 signature->increment_refcount();
1447
1448 int cp_length = _imcp_limit;
1449 ClassLoaderData* loader_data = holder->class_loader_data();
1450 constantPoolHandle cp;
1451 {
1452 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1453 cp = constantPoolHandle(THREAD, cp_oop);
1454 }
1455 cp->copy_fields(holder->constants());
1456 cp->set_pool_holder(holder);
1457 cp->symbol_at_put(_imcp_invoke_name, name);
1458 cp->symbol_at_put(_imcp_invoke_signature, signature);
1459 cp->set_has_preresolution();
1460
1461 // decide on access bits: public or not?
1462 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1463 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1464 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1465 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1466
1467 methodHandle m;
1468 {
1469 InlineTableSizes sizes;
1470 Method* m_oop = Method::allocate(loader_data, 0,
1471 accessFlags_from(flags_bits), &sizes,
1472 ConstMethod::NORMAL, CHECK_(empty));
1473 m = methodHandle(THREAD, m_oop);
1474 }
1475 m->set_constants(cp());
1476 m->set_name_index(_imcp_invoke_name);
1477 m->set_signature_index(_imcp_invoke_signature);
1478 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1479 assert(m->signature() == signature, "");
1480 m->compute_from_signature(signature);
1481 m->init_intrinsic_id();
1482 assert(m->is_method_handle_intrinsic(), "");
1483 #ifdef ASSERT
1484 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1485 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1486 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1487 #endif //ASSERT
1488
1489 // Finally, set up its entry points.
1490 assert(m->can_be_statically_bound(), "");
1491 m->set_vtable_index(Method::nonvirtual_vtable_index);
1492 m->link_method(m, CHECK_(empty));
1493
1494 if (iid == vmIntrinsics::_linkToNative) {
1495 m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1496 }
1497 if (log_is_enabled(Info, methodhandles) && (Verbose || WizardMode)) {
1498 LogTarget(Info, methodhandles) lt;
1499 LogStream ls(lt);
1500 m->print_on(&ls);
1501 }
1502
1503 return m;
1504 }
1505
check_non_bcp_klass(Klass * klass)1506 Klass* Method::check_non_bcp_klass(Klass* klass) {
1507 if (klass != NULL && klass->class_loader() != NULL) {
1508 if (klass->is_objArray_klass())
1509 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1510 return klass;
1511 }
1512 return NULL;
1513 }
1514
1515
clone_with_new_data(const methodHandle & m,u_char * new_code,int new_code_length,u_char * new_compressed_linenumber_table,int new_compressed_linenumber_size,TRAPS)1516 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1517 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1518 // Code below does not work for native methods - they should never get rewritten anyway
1519 assert(!m->is_native(), "cannot rewrite native methods");
1520 // Allocate new Method*
1521 AccessFlags flags = m->access_flags();
1522
1523 ConstMethod* cm = m->constMethod();
1524 int checked_exceptions_len = cm->checked_exceptions_length();
1525 int localvariable_len = cm->localvariable_table_length();
1526 int exception_table_len = cm->exception_table_length();
1527 int method_parameters_len = cm->method_parameters_length();
1528 int method_annotations_len = cm->method_annotations_length();
1529 int parameter_annotations_len = cm->parameter_annotations_length();
1530 int type_annotations_len = cm->type_annotations_length();
1531 int default_annotations_len = cm->default_annotations_length();
1532
1533 InlineTableSizes sizes(
1534 localvariable_len,
1535 new_compressed_linenumber_size,
1536 exception_table_len,
1537 checked_exceptions_len,
1538 method_parameters_len,
1539 cm->generic_signature_index(),
1540 method_annotations_len,
1541 parameter_annotations_len,
1542 type_annotations_len,
1543 default_annotations_len,
1544 0);
1545
1546 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1547 Method* newm_oop = Method::allocate(loader_data,
1548 new_code_length,
1549 flags,
1550 &sizes,
1551 m->method_type(),
1552 CHECK_(methodHandle()));
1553 methodHandle newm (THREAD, newm_oop);
1554
1555 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1556 ConstMethod* newcm = newm->constMethod();
1557 int new_const_method_size = newm->constMethod()->size();
1558
1559 // This works because the source and target are both Methods. Some compilers
1560 // (e.g., clang) complain that the target vtable pointer will be stomped,
1561 // so cast away newm()'s and m()'s Methodness.
1562 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1563
1564 // Create shallow copy of ConstMethod.
1565 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1566
1567 // Reset correct method/const method, method size, and parameter info
1568 newm->set_constMethod(newcm);
1569 newm->constMethod()->set_code_size(new_code_length);
1570 newm->constMethod()->set_constMethod_size(new_const_method_size);
1571 assert(newm->code_size() == new_code_length, "check");
1572 assert(newm->method_parameters_length() == method_parameters_len, "check");
1573 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1574 assert(newm->exception_table_length() == exception_table_len, "check");
1575 assert(newm->localvariable_table_length() == localvariable_len, "check");
1576 // Copy new byte codes
1577 memcpy(newm->code_base(), new_code, new_code_length);
1578 // Copy line number table
1579 if (new_compressed_linenumber_size > 0) {
1580 memcpy(newm->compressed_linenumber_table(),
1581 new_compressed_linenumber_table,
1582 new_compressed_linenumber_size);
1583 }
1584 // Copy method_parameters
1585 if (method_parameters_len > 0) {
1586 memcpy(newm->method_parameters_start(),
1587 m->method_parameters_start(),
1588 method_parameters_len * sizeof(MethodParametersElement));
1589 }
1590 // Copy checked_exceptions
1591 if (checked_exceptions_len > 0) {
1592 memcpy(newm->checked_exceptions_start(),
1593 m->checked_exceptions_start(),
1594 checked_exceptions_len * sizeof(CheckedExceptionElement));
1595 }
1596 // Copy exception table
1597 if (exception_table_len > 0) {
1598 memcpy(newm->exception_table_start(),
1599 m->exception_table_start(),
1600 exception_table_len * sizeof(ExceptionTableElement));
1601 }
1602 // Copy local variable number table
1603 if (localvariable_len > 0) {
1604 memcpy(newm->localvariable_table_start(),
1605 m->localvariable_table_start(),
1606 localvariable_len * sizeof(LocalVariableTableElement));
1607 }
1608 // Copy stackmap table
1609 if (m->has_stackmap_table()) {
1610 int code_attribute_length = m->stackmap_data()->length();
1611 Array<u1>* stackmap_data =
1612 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
1613 memcpy((void*)stackmap_data->adr_at(0),
1614 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1615 newm->set_stackmap_data(stackmap_data);
1616 }
1617
1618 // copy annotations over to new method
1619 newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
1620 return newm;
1621 }
1622
klass_id_for_intrinsics(const Klass * holder)1623 vmSymbolID Method::klass_id_for_intrinsics(const Klass* holder) {
1624 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1625 // because we are not loading from core libraries
1626 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1627 // which does not use the class default class loader so we check for its loader here
1628 const InstanceKlass* ik = InstanceKlass::cast(holder);
1629 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1630 return vmSymbolID::NO_SID; // regardless of name, no intrinsics here
1631 }
1632
1633 // see if the klass name is well-known:
1634 Symbol* klass_name = ik->name();
1635 return vmSymbols::find_sid(klass_name);
1636 }
1637
init_intrinsic_id()1638 void Method::init_intrinsic_id() {
1639 assert(_intrinsic_id == static_cast<int>(vmIntrinsics::_none), "do this just once");
1640 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1641 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1642 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1643
1644 // the klass name is well-known:
1645 vmSymbolID klass_id = klass_id_for_intrinsics(method_holder());
1646 assert(klass_id != vmSymbolID::NO_SID, "caller responsibility");
1647
1648 // ditto for method and signature:
1649 vmSymbolID name_id = vmSymbols::find_sid(name());
1650 if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1651 && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1652 && name_id == vmSymbolID::NO_SID) {
1653 return;
1654 }
1655 vmSymbolID sig_id = vmSymbols::find_sid(signature());
1656 if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1657 && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1658 && sig_id == vmSymbolID::NO_SID) {
1659 return;
1660 }
1661 jshort flags = access_flags().as_short();
1662
1663 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1664 if (id != vmIntrinsics::_none) {
1665 set_intrinsic_id(id);
1666 if (id == vmIntrinsics::_Class_cast) {
1667 // Even if the intrinsic is rejected, we want to inline this simple method.
1668 set_force_inline(true);
1669 }
1670 return;
1671 }
1672
1673 // A few slightly irregular cases:
1674 switch (klass_id) {
1675 case VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1676 // Second chance: check in regular Math.
1677 switch (name_id) {
1678 case VM_SYMBOL_ENUM_NAME(min_name):
1679 case VM_SYMBOL_ENUM_NAME(max_name):
1680 case VM_SYMBOL_ENUM_NAME(sqrt_name):
1681 // pretend it is the corresponding method in the non-strict class:
1682 klass_id = VM_SYMBOL_ENUM_NAME(java_lang_Math);
1683 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1684 break;
1685 default:
1686 break;
1687 }
1688 break;
1689
1690 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1691 case VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1692 case VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1693 if (!is_native()) break;
1694 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1695 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1696 id = vmIntrinsics::_none;
1697 break;
1698
1699 default:
1700 break;
1701 }
1702
1703 if (id != vmIntrinsics::_none) {
1704 // Set up its iid. It is an alias method.
1705 set_intrinsic_id(id);
1706 return;
1707 }
1708 }
1709
load_signature_classes(const methodHandle & m,TRAPS)1710 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1711 if (!THREAD->can_call_java()) {
1712 // There is nothing useful this routine can do from within the Compile thread.
1713 // Hopefully, the signature contains only well-known classes.
1714 // We could scan for this and return true/false, but the caller won't care.
1715 return false;
1716 }
1717 bool sig_is_loaded = true;
1718 ResourceMark rm(THREAD);
1719 for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1720 if (ss.is_reference()) {
1721 // load everything, including arrays "[Lfoo;"
1722 Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD);
1723 // We are loading classes eagerly. If a ClassNotFoundException or
1724 // a LinkageError was generated, be sure to ignore it.
1725 if (HAS_PENDING_EXCEPTION) {
1726 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1727 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1728 CLEAR_PENDING_EXCEPTION;
1729 } else {
1730 return false;
1731 }
1732 }
1733 if( klass == NULL) { sig_is_loaded = false; }
1734 }
1735 }
1736 return sig_is_loaded;
1737 }
1738
has_unloaded_classes_in_signature(const methodHandle & m,TRAPS)1739 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1740 ResourceMark rm(THREAD);
1741 for(ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1742 if (ss.type() == T_OBJECT) {
1743 // Do not use ss.is_reference() here, since we don't care about
1744 // unloaded array component types.
1745 Klass* klass = ss.as_klass_if_loaded(THREAD);
1746 assert(!HAS_PENDING_EXCEPTION, "as_klass_if_loaded contract");
1747 if (klass == NULL) return true;
1748 }
1749 }
1750 return false;
1751 }
1752
1753 // Exposed so field engineers can debug VM
print_short_name(outputStream * st)1754 void Method::print_short_name(outputStream* st) {
1755 ResourceMark rm;
1756 #ifdef PRODUCT
1757 st->print(" %s::", method_holder()->external_name());
1758 #else
1759 st->print(" %s::", method_holder()->internal_name());
1760 #endif
1761 name()->print_symbol_on(st);
1762 if (WizardMode) signature()->print_symbol_on(st);
1763 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1764 MethodHandles::print_as_basic_type_signature_on(st, signature());
1765 }
1766
1767 // Comparer for sorting an object array containing
1768 // Method*s.
method_comparator(Method * a,Method * b)1769 static int method_comparator(Method* a, Method* b) {
1770 return a->name()->fast_compare(b->name());
1771 }
1772
1773 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1774 // default_methods also uses this without the ordering for fast find_method
sort_methods(Array<Method * > * methods,bool set_idnums,method_comparator_func func)1775 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1776 int length = methods->length();
1777 if (length > 1) {
1778 if (func == NULL) {
1779 func = method_comparator;
1780 }
1781 {
1782 NoSafepointVerifier nsv;
1783 QuickSort::sort(methods->data(), length, func, /*idempotent=*/false);
1784 }
1785 // Reset method ordering
1786 if (set_idnums) {
1787 for (int i = 0; i < length; i++) {
1788 Method* m = methods->at(i);
1789 m->set_method_idnum(i);
1790 m->set_orig_method_idnum(i);
1791 }
1792 }
1793 }
1794 }
1795
1796 //-----------------------------------------------------------------------------------
1797 // Non-product code unless JVM/TI needs it
1798
1799 #if !defined(PRODUCT) || INCLUDE_JVMTI
1800 class SignatureTypePrinter : public SignatureTypeNames {
1801 private:
1802 outputStream* _st;
1803 bool _use_separator;
1804
type_name(const char * name)1805 void type_name(const char* name) {
1806 if (_use_separator) _st->print(", ");
1807 _st->print("%s", name);
1808 _use_separator = true;
1809 }
1810
1811 public:
SignatureTypePrinter(Symbol * signature,outputStream * st)1812 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1813 _st = st;
1814 _use_separator = false;
1815 }
1816
print_parameters()1817 void print_parameters() { _use_separator = false; do_parameters_on(this); }
print_returntype()1818 void print_returntype() { _use_separator = false; do_type(return_type()); }
1819 };
1820
1821
print_name(outputStream * st)1822 void Method::print_name(outputStream* st) {
1823 Thread *thread = Thread::current();
1824 ResourceMark rm(thread);
1825 st->print("%s ", is_static() ? "static" : "virtual");
1826 if (WizardMode) {
1827 st->print("%s.", method_holder()->internal_name());
1828 name()->print_symbol_on(st);
1829 signature()->print_symbol_on(st);
1830 } else {
1831 SignatureTypePrinter sig(signature(), st);
1832 sig.print_returntype();
1833 st->print(" %s.", method_holder()->internal_name());
1834 name()->print_symbol_on(st);
1835 st->print("(");
1836 sig.print_parameters();
1837 st->print(")");
1838 }
1839 }
1840 #endif // !PRODUCT || INCLUDE_JVMTI
1841
1842
print_codes_on(outputStream * st) const1843 void Method::print_codes_on(outputStream* st) const {
1844 print_codes_on(0, code_size(), st);
1845 }
1846
print_codes_on(int from,int to,outputStream * st) const1847 void Method::print_codes_on(int from, int to, outputStream* st) const {
1848 Thread *thread = Thread::current();
1849 ResourceMark rm(thread);
1850 methodHandle mh (thread, (Method*)this);
1851 BytecodeStream s(mh);
1852 s.set_interval(from, to);
1853 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1854 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1855 }
1856
CompressedLineNumberReadStream(u_char * buffer)1857 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1858 _bci = 0;
1859 _line = 0;
1860 };
1861
read_pair()1862 bool CompressedLineNumberReadStream::read_pair() {
1863 jubyte next = read_byte();
1864 // Check for terminator
1865 if (next == 0) return false;
1866 if (next == 0xFF) {
1867 // Escape character, regular compression used
1868 _bci += read_signed_int();
1869 _line += read_signed_int();
1870 } else {
1871 // Single byte compression used
1872 _bci += next >> 3;
1873 _line += next & 0x7;
1874 }
1875 return true;
1876 }
1877
1878 #if INCLUDE_JVMTI
1879
orig_bytecode_at(int bci) const1880 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1881 BreakpointInfo* bp = method_holder()->breakpoints();
1882 for (; bp != NULL; bp = bp->next()) {
1883 if (bp->match(this, bci)) {
1884 return bp->orig_bytecode();
1885 }
1886 }
1887 {
1888 ResourceMark rm;
1889 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1890 }
1891 return Bytecodes::_shouldnotreachhere;
1892 }
1893
set_orig_bytecode_at(int bci,Bytecodes::Code code)1894 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1895 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1896 BreakpointInfo* bp = method_holder()->breakpoints();
1897 for (; bp != NULL; bp = bp->next()) {
1898 if (bp->match(this, bci)) {
1899 bp->set_orig_bytecode(code);
1900 // and continue, in case there is more than one
1901 }
1902 }
1903 }
1904
set_breakpoint(int bci)1905 void Method::set_breakpoint(int bci) {
1906 InstanceKlass* ik = method_holder();
1907 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1908 bp->set_next(ik->breakpoints());
1909 ik->set_breakpoints(bp);
1910 // do this last:
1911 bp->set(this);
1912 }
1913
clear_matches(Method * m,int bci)1914 static void clear_matches(Method* m, int bci) {
1915 InstanceKlass* ik = m->method_holder();
1916 BreakpointInfo* prev_bp = NULL;
1917 BreakpointInfo* next_bp;
1918 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1919 next_bp = bp->next();
1920 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1921 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1922 // do this first:
1923 bp->clear(m);
1924 // unhook it
1925 if (prev_bp != NULL)
1926 prev_bp->set_next(next_bp);
1927 else
1928 ik->set_breakpoints(next_bp);
1929 delete bp;
1930 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1931 // at same location. So we have multiple matching (method_index and bci)
1932 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1933 // breakpoint for clear_breakpoint request and keep all other method versions
1934 // BreakpointInfo for future clear_breakpoint request.
1935 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1936 // which is being called when class is unloaded. We delete all the Breakpoint
1937 // information for all versions of method. We may not correctly restore the original
1938 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1939 // so these methods won't be used anymore.
1940 if (bci >= 0) {
1941 break;
1942 }
1943 } else {
1944 // This one is a keeper.
1945 prev_bp = bp;
1946 }
1947 }
1948 }
1949
clear_breakpoint(int bci)1950 void Method::clear_breakpoint(int bci) {
1951 assert(bci >= 0, "");
1952 clear_matches(this, bci);
1953 }
1954
clear_all_breakpoints()1955 void Method::clear_all_breakpoints() {
1956 clear_matches(this, -1);
1957 }
1958
1959 #endif // INCLUDE_JVMTI
1960
invocation_count()1961 int Method::invocation_count() {
1962 MethodCounters *mcs = method_counters();
1963 if (TieredCompilation) {
1964 MethodData* const mdo = method_data();
1965 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1966 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1967 return InvocationCounter::count_limit;
1968 } else {
1969 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1970 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1971 }
1972 } else {
1973 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1974 }
1975 }
1976
backedge_count()1977 int Method::backedge_count() {
1978 MethodCounters *mcs = method_counters();
1979 if (TieredCompilation) {
1980 MethodData* const mdo = method_data();
1981 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1982 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1983 return InvocationCounter::count_limit;
1984 } else {
1985 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1986 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1987 }
1988 } else {
1989 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1990 }
1991 }
1992
highest_comp_level() const1993 int Method::highest_comp_level() const {
1994 const MethodCounters* mcs = method_counters();
1995 if (mcs != NULL) {
1996 return mcs->highest_comp_level();
1997 } else {
1998 return CompLevel_none;
1999 }
2000 }
2001
highest_osr_comp_level() const2002 int Method::highest_osr_comp_level() const {
2003 const MethodCounters* mcs = method_counters();
2004 if (mcs != NULL) {
2005 return mcs->highest_osr_comp_level();
2006 } else {
2007 return CompLevel_none;
2008 }
2009 }
2010
set_highest_comp_level(int level)2011 void Method::set_highest_comp_level(int level) {
2012 MethodCounters* mcs = method_counters();
2013 if (mcs != NULL) {
2014 mcs->set_highest_comp_level(level);
2015 }
2016 }
2017
set_highest_osr_comp_level(int level)2018 void Method::set_highest_osr_comp_level(int level) {
2019 MethodCounters* mcs = method_counters();
2020 if (mcs != NULL) {
2021 mcs->set_highest_osr_comp_level(level);
2022 }
2023 }
2024
2025 #if INCLUDE_JVMTI
2026
BreakpointInfo(Method * m,int bci)2027 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
2028 _bci = bci;
2029 _name_index = m->name_index();
2030 _signature_index = m->signature_index();
2031 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
2032 if (_orig_bytecode == Bytecodes::_breakpoint)
2033 _orig_bytecode = m->orig_bytecode_at(_bci);
2034 _next = NULL;
2035 }
2036
set(Method * method)2037 void BreakpointInfo::set(Method* method) {
2038 #ifdef ASSERT
2039 {
2040 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2041 if (code == Bytecodes::_breakpoint)
2042 code = method->orig_bytecode_at(_bci);
2043 assert(orig_bytecode() == code, "original bytecode must be the same");
2044 }
2045 #endif
2046 Thread *thread = Thread::current();
2047 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2048 method->incr_number_of_breakpoints(thread);
2049 {
2050 // Deoptimize all dependents on this method
2051 HandleMark hm(thread);
2052 methodHandle mh(thread, method);
2053 CodeCache::flush_dependents_on_method(mh);
2054 }
2055 }
2056
clear(Method * method)2057 void BreakpointInfo::clear(Method* method) {
2058 *method->bcp_from(_bci) = orig_bytecode();
2059 assert(method->number_of_breakpoints() > 0, "must not go negative");
2060 method->decr_number_of_breakpoints(Thread::current());
2061 }
2062
2063 #endif // INCLUDE_JVMTI
2064
2065 // jmethodID handling
2066
2067 // This is a block allocating object, sort of like JNIHandleBlock, only a
2068 // lot simpler.
2069 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2070 // never get rid of it.
2071
2072 static const int min_block_size = 8;
2073
2074 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2075 friend class JNIMethodBlock;
2076 Method** _methods;
2077 int _number_of_methods;
2078 int _top;
2079 JNIMethodBlockNode* _next;
2080
2081 public:
2082
2083 JNIMethodBlockNode(int num_methods = min_block_size);
2084
~JNIMethodBlockNode()2085 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2086
ensure_methods(int num_addl_methods)2087 void ensure_methods(int num_addl_methods) {
2088 if (_top < _number_of_methods) {
2089 num_addl_methods -= _number_of_methods - _top;
2090 if (num_addl_methods <= 0) {
2091 return;
2092 }
2093 }
2094 if (_next == NULL) {
2095 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2096 } else {
2097 _next->ensure_methods(num_addl_methods);
2098 }
2099 }
2100 };
2101
2102 class JNIMethodBlock : public CHeapObj<mtClass> {
2103 JNIMethodBlockNode _head;
2104 JNIMethodBlockNode *_last_free;
2105 public:
2106 static Method* const _free_method;
2107
JNIMethodBlock(int initial_capacity=min_block_size)2108 JNIMethodBlock(int initial_capacity = min_block_size)
2109 : _head(initial_capacity), _last_free(&_head) {}
2110
ensure_methods(int num_addl_methods)2111 void ensure_methods(int num_addl_methods) {
2112 _last_free->ensure_methods(num_addl_methods);
2113 }
2114
add_method(Method * m)2115 Method** add_method(Method* m) {
2116 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2117 if (b->_top < b->_number_of_methods) {
2118 // top points to the next free entry.
2119 int i = b->_top;
2120 b->_methods[i] = m;
2121 b->_top++;
2122 _last_free = b;
2123 return &(b->_methods[i]);
2124 } else if (b->_top == b->_number_of_methods) {
2125 // if the next free entry ran off the block see if there's a free entry
2126 for (int i = 0; i < b->_number_of_methods; i++) {
2127 if (b->_methods[i] == _free_method) {
2128 b->_methods[i] = m;
2129 _last_free = b;
2130 return &(b->_methods[i]);
2131 }
2132 }
2133 // Only check each block once for frees. They're very unlikely.
2134 // Increment top past the end of the block.
2135 b->_top++;
2136 }
2137 // need to allocate a next block.
2138 if (b->_next == NULL) {
2139 b->_next = _last_free = new JNIMethodBlockNode();
2140 }
2141 }
2142 guarantee(false, "Should always allocate a free block");
2143 return NULL;
2144 }
2145
contains(Method ** m)2146 bool contains(Method** m) {
2147 if (m == NULL) return false;
2148 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2149 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2150 // This is a bit of extra checking, for two reasons. One is
2151 // that contains() deals with pointers that are passed in by
2152 // JNI code, so making sure that the pointer is aligned
2153 // correctly is valuable. The other is that <= and > are
2154 // technically not defined on pointers, so the if guard can
2155 // pass spuriously; no modern compiler is likely to make that
2156 // a problem, though (and if one did, the guard could also
2157 // fail spuriously, which would be bad).
2158 ptrdiff_t idx = m - b->_methods;
2159 if (b->_methods + idx == m) {
2160 return true;
2161 }
2162 }
2163 }
2164 return false; // not found
2165 }
2166
2167 // Doesn't really destroy it, just marks it as free so it can be reused.
destroy_method(Method ** m)2168 void destroy_method(Method** m) {
2169 #ifdef ASSERT
2170 assert(contains(m), "should be a methodID");
2171 #endif // ASSERT
2172 *m = _free_method;
2173 }
2174
2175 // During class unloading the methods are cleared, which is different
2176 // than freed.
clear_all_methods()2177 void clear_all_methods() {
2178 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2179 for (int i = 0; i< b->_number_of_methods; i++) {
2180 b->_methods[i] = NULL;
2181 }
2182 }
2183 }
2184 #ifndef PRODUCT
count_methods()2185 int count_methods() {
2186 // count all allocated methods
2187 int count = 0;
2188 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2189 for (int i = 0; i< b->_number_of_methods; i++) {
2190 if (b->_methods[i] != _free_method) count++;
2191 }
2192 }
2193 return count;
2194 }
2195 #endif // PRODUCT
2196 };
2197
2198 // Something that can't be mistaken for an address or a markWord
2199 Method* const JNIMethodBlock::_free_method = (Method*)55;
2200
JNIMethodBlockNode(int num_methods)2201 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2202 _number_of_methods = MAX2(num_methods, min_block_size);
2203 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2204 for (int i = 0; i < _number_of_methods; i++) {
2205 _methods[i] = JNIMethodBlock::_free_method;
2206 }
2207 }
2208
ensure_jmethod_ids(ClassLoaderData * loader_data,int capacity)2209 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2210 ClassLoaderData* cld = loader_data;
2211 if (!SafepointSynchronize::is_at_safepoint()) {
2212 // Have to add jmethod_ids() to class loader data thread-safely.
2213 // Also have to add the method to the list safely, which the lock
2214 // protects as well.
2215 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2216 if (cld->jmethod_ids() == NULL) {
2217 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2218 } else {
2219 cld->jmethod_ids()->ensure_methods(capacity);
2220 }
2221 } else {
2222 // At safepoint, we are single threaded and can set this.
2223 if (cld->jmethod_ids() == NULL) {
2224 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2225 } else {
2226 cld->jmethod_ids()->ensure_methods(capacity);
2227 }
2228 }
2229 }
2230
2231 // Add a method id to the jmethod_ids
make_jmethod_id(ClassLoaderData * loader_data,Method * m)2232 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2233 ClassLoaderData* cld = loader_data;
2234
2235 if (!SafepointSynchronize::is_at_safepoint()) {
2236 // Have to add jmethod_ids() to class loader data thread-safely.
2237 // Also have to add the method to the list safely, which the lock
2238 // protects as well.
2239 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2240 if (cld->jmethod_ids() == NULL) {
2241 cld->set_jmethod_ids(new JNIMethodBlock());
2242 }
2243 // jmethodID is a pointer to Method*
2244 return (jmethodID)cld->jmethod_ids()->add_method(m);
2245 } else {
2246 // At safepoint, we are single threaded and can set this.
2247 if (cld->jmethod_ids() == NULL) {
2248 cld->set_jmethod_ids(new JNIMethodBlock());
2249 }
2250 // jmethodID is a pointer to Method*
2251 return (jmethodID)cld->jmethod_ids()->add_method(m);
2252 }
2253 }
2254
jmethod_id()2255 jmethodID Method::jmethod_id() {
2256 methodHandle mh(Thread::current(), this);
2257 return method_holder()->get_jmethod_id(mh);
2258 }
2259
2260 // Mark a jmethodID as free. This is called when there is a data race in
2261 // InstanceKlass while creating the jmethodID cache.
destroy_jmethod_id(ClassLoaderData * loader_data,jmethodID m)2262 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2263 ClassLoaderData* cld = loader_data;
2264 Method** ptr = (Method**)m;
2265 assert(cld->jmethod_ids() != NULL, "should have method handles");
2266 cld->jmethod_ids()->destroy_method(ptr);
2267 }
2268
change_method_associated_with_jmethod_id(jmethodID jmid,Method * new_method)2269 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2270 // Can't assert the method_holder is the same because the new method has the
2271 // scratch method holder.
2272 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2273 == new_method->method_holder()->class_loader() ||
2274 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2275 "changing to a different class loader");
2276 // Just change the method in place, jmethodID pointer doesn't change.
2277 *((Method**)jmid) = new_method;
2278 }
2279
is_method_id(jmethodID mid)2280 bool Method::is_method_id(jmethodID mid) {
2281 Method* m = resolve_jmethod_id(mid);
2282 assert(m != NULL, "should be called with non-null method");
2283 InstanceKlass* ik = m->method_holder();
2284 ClassLoaderData* cld = ik->class_loader_data();
2285 if (cld->jmethod_ids() == NULL) return false;
2286 return (cld->jmethod_ids()->contains((Method**)mid));
2287 }
2288
checked_resolve_jmethod_id(jmethodID mid)2289 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2290 if (mid == NULL) return NULL;
2291 Method* o = resolve_jmethod_id(mid);
2292 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2293 return NULL;
2294 }
2295 return o;
2296 };
2297
set_on_stack(const bool value)2298 void Method::set_on_stack(const bool value) {
2299 // Set both the method itself and its constant pool. The constant pool
2300 // on stack means some method referring to it is also on the stack.
2301 constants()->set_on_stack(value);
2302
2303 bool already_set = on_stack();
2304 _access_flags.set_on_stack(value);
2305 if (value && !already_set) {
2306 MetadataOnStackMark::record(this);
2307 }
2308 assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2309 "emcp methods cannot run after emcp bit is cleared");
2310 }
2311
2312 // Called when the class loader is unloaded to make all methods weak.
clear_jmethod_ids(ClassLoaderData * loader_data)2313 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2314 loader_data->jmethod_ids()->clear_all_methods();
2315 }
2316
has_method_vptr(const void * ptr)2317 bool Method::has_method_vptr(const void* ptr) {
2318 Method m;
2319 // This assumes that the vtbl pointer is the first word of a C++ object.
2320 return dereference_vptr(&m) == dereference_vptr(ptr);
2321 }
2322
2323 // Check that this pointer is valid by checking that the vtbl pointer matches
is_valid_method(const Method * m)2324 bool Method::is_valid_method(const Method* m) {
2325 if (m == NULL) {
2326 return false;
2327 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2328 // Quick sanity check on pointer.
2329 return false;
2330 } else if (m->is_shared()) {
2331 return CppVtables::is_valid_shared_method(m);
2332 } else if (Metaspace::contains_non_shared(m)) {
2333 return has_method_vptr((const void*)m);
2334 } else {
2335 return false;
2336 }
2337 }
2338
2339 #ifndef PRODUCT
print_jmethod_ids(const ClassLoaderData * loader_data,outputStream * out)2340 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2341 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2342 }
2343 #endif // PRODUCT
2344
2345
2346 // Printing
2347
2348 #ifndef PRODUCT
2349
print_on(outputStream * st) const2350 void Method::print_on(outputStream* st) const {
2351 ResourceMark rm;
2352 assert(is_method(), "must be method");
2353 st->print_cr("%s", internal_name());
2354 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2355 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2356 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2357 constants()->print_value_on(st); st->cr();
2358 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2359 st->print (" - name: "); name()->print_value_on(st); st->cr();
2360 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2361 st->print_cr(" - max stack: %d", max_stack());
2362 st->print_cr(" - max locals: %d", max_locals());
2363 st->print_cr(" - size of params: %d", size_of_parameters());
2364 st->print_cr(" - method size: %d", method_size());
2365 if (intrinsic_id() != vmIntrinsics::_none)
2366 st->print_cr(" - intrinsic id: %d %s", vmIntrinsics::as_int(intrinsic_id()), vmIntrinsics::name_at(intrinsic_id()));
2367 if (highest_comp_level() != CompLevel_none)
2368 st->print_cr(" - highest level: %d", highest_comp_level());
2369 st->print_cr(" - vtable index: %d", _vtable_index);
2370 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2371 st->print( " - adapters: ");
2372 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2373 if (a == NULL)
2374 st->print_cr(INTPTR_FORMAT, p2i(a));
2375 else
2376 a->print_adapter_on(st);
2377 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2378 st->print_cr(" - code size: %d", code_size());
2379 if (code_size() != 0) {
2380 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2381 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2382 }
2383 if (method_data() != NULL) {
2384 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2385 }
2386 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2387 if (checked_exceptions_length() > 0) {
2388 CheckedExceptionElement* table = checked_exceptions_start();
2389 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2390 if (Verbose) {
2391 for (int i = 0; i < checked_exceptions_length(); i++) {
2392 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2393 }
2394 }
2395 }
2396 if (has_linenumber_table()) {
2397 u_char* table = compressed_linenumber_table();
2398 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2399 if (Verbose) {
2400 CompressedLineNumberReadStream stream(table);
2401 while (stream.read_pair()) {
2402 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2403 }
2404 }
2405 }
2406 st->print_cr(" - localvar length: %d", localvariable_table_length());
2407 if (localvariable_table_length() > 0) {
2408 LocalVariableTableElement* table = localvariable_table_start();
2409 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2410 if (Verbose) {
2411 for (int i = 0; i < localvariable_table_length(); i++) {
2412 int bci = table[i].start_bci;
2413 int len = table[i].length;
2414 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2415 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2416 int slot = table[i].slot;
2417 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2418 }
2419 }
2420 }
2421 if (code() != NULL) {
2422 st->print (" - compiled code: ");
2423 code()->print_value_on(st);
2424 }
2425 if (is_native()) {
2426 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2427 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2428 }
2429 }
2430
print_linkage_flags(outputStream * st)2431 void Method::print_linkage_flags(outputStream* st) {
2432 access_flags().print_on(st);
2433 if (is_default_method()) {
2434 st->print("default ");
2435 }
2436 if (is_overpass()) {
2437 st->print("overpass ");
2438 }
2439 }
2440 #endif //PRODUCT
2441
print_value_on(outputStream * st) const2442 void Method::print_value_on(outputStream* st) const {
2443 assert(is_method(), "must be method");
2444 st->print("%s", internal_name());
2445 print_address_on(st);
2446 st->print(" ");
2447 name()->print_value_on(st);
2448 st->print(" ");
2449 signature()->print_value_on(st);
2450 st->print(" in ");
2451 method_holder()->print_value_on(st);
2452 if (WizardMode) st->print("#%d", _vtable_index);
2453 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2454 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2455 }
2456
2457 // LogTouchedMethods and PrintTouchedMethods
2458
2459 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2460 // the Method may be garbage collected. Let's roll our own hash table.
2461 class TouchedMethodRecord : CHeapObj<mtTracing> {
2462 public:
2463 // It's OK to store Symbols here because they will NOT be GC'ed if
2464 // LogTouchedMethods is enabled.
2465 TouchedMethodRecord* _next;
2466 Symbol* _class_name;
2467 Symbol* _method_name;
2468 Symbol* _method_signature;
2469 };
2470
2471 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2472 static TouchedMethodRecord** _touched_method_table = NULL;
2473
log_touched(TRAPS)2474 void Method::log_touched(TRAPS) {
2475
2476 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2477 Symbol* my_class = klass_name();
2478 Symbol* my_name = name();
2479 Symbol* my_sig = signature();
2480
2481 unsigned int hash = my_class->identity_hash() +
2482 my_name->identity_hash() +
2483 my_sig->identity_hash();
2484 juint index = juint(hash) % table_size;
2485
2486 MutexLocker ml(THREAD, TouchedMethodLog_lock);
2487 if (_touched_method_table == NULL) {
2488 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2489 mtTracing, CURRENT_PC);
2490 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2491 }
2492
2493 TouchedMethodRecord* ptr = _touched_method_table[index];
2494 while (ptr) {
2495 if (ptr->_class_name == my_class &&
2496 ptr->_method_name == my_name &&
2497 ptr->_method_signature == my_sig) {
2498 return;
2499 }
2500 if (ptr->_next == NULL) break;
2501 ptr = ptr->_next;
2502 }
2503 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2504 my_class->increment_refcount();
2505 my_name->increment_refcount();
2506 my_sig->increment_refcount();
2507 nptr->_class_name = my_class;
2508 nptr->_method_name = my_name;
2509 nptr->_method_signature = my_sig;
2510 nptr->_next = NULL;
2511
2512 if (ptr == NULL) {
2513 // first
2514 _touched_method_table[index] = nptr;
2515 } else {
2516 ptr->_next = nptr;
2517 }
2518 }
2519
print_touched_methods(outputStream * out)2520 void Method::print_touched_methods(outputStream* out) {
2521 MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2522 out->print_cr("# Method::print_touched_methods version 1");
2523 if (_touched_method_table) {
2524 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2525 TouchedMethodRecord* ptr = _touched_method_table[i];
2526 while(ptr) {
2527 ptr->_class_name->print_symbol_on(out); out->print(".");
2528 ptr->_method_name->print_symbol_on(out); out->print(":");
2529 ptr->_method_signature->print_symbol_on(out); out->cr();
2530 ptr = ptr->_next;
2531 }
2532 }
2533 }
2534 }
2535
2536 // Verification
2537
verify_on(outputStream * st)2538 void Method::verify_on(outputStream* st) {
2539 guarantee(is_method(), "object must be method");
2540 guarantee(constants()->is_constantPool(), "should be constant pool");
2541 MethodData* md = method_data();
2542 guarantee(md == NULL ||
2543 md->is_methodData(), "should be method data");
2544 }
2545