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/metadataFactory.hpp"
44 #include "memory/metaspaceClosure.hpp"
45 #include "memory/metaspaceShared.hpp"
46 #include "memory/oopFactory.hpp"
47 #include "memory/resourceArea.hpp"
48 #include "memory/universe.hpp"
49 #include "oops/constMethod.hpp"
50 #include "oops/constantPool.hpp"
51 #include "oops/method.inline.hpp"
52 #include "oops/methodData.hpp"
53 #include "oops/objArrayKlass.hpp"
54 #include "oops/objArrayOop.inline.hpp"
55 #include "oops/oop.inline.hpp"
56 #include "oops/symbol.hpp"
57 #include "prims/jvmtiExport.hpp"
58 #include "prims/methodHandles.hpp"
59 #include "prims/nativeLookup.hpp"
60 #include "runtime/arguments.hpp"
61 #include "runtime/atomic.hpp"
62 #include "runtime/frame.inline.hpp"
63 #include "runtime/handles.inline.hpp"
64 #include "runtime/init.hpp"
65 #include "runtime/orderAccess.hpp"
66 #include "runtime/relocator.hpp"
67 #include "runtime/safepointVerifiers.hpp"
68 #include "runtime/sharedRuntime.hpp"
69 #include "runtime/signature.hpp"
70 #include "utilities/align.hpp"
71 #include "utilities/quickSort.hpp"
72 #include "utilities/vmError.hpp"
73 #include "utilities/xmlstream.hpp"
74
75 // Implementation of Method
76
77 Method* Method::allocate(ClassLoaderData* loader_data,
78 int byte_code_size,
79 AccessFlags access_flags,
80 InlineTableSizes* sizes,
81 ConstMethod::MethodType method_type,
82 TRAPS) {
83 assert(!access_flags.is_native() || byte_code_size == 0,
84 "native methods should not contain byte codes");
85 ConstMethod* cm = ConstMethod::allocate(loader_data,
86 byte_code_size,
87 sizes,
88 method_type,
89 CHECK_NULL);
90 int size = Method::size(access_flags.is_native());
91 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
92 }
93
94 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
95 NoSafepointVerifier no_safepoint;
96 set_constMethod(xconst);
97 set_access_flags(access_flags);
98 set_intrinsic_id(vmIntrinsics::_none);
99 set_force_inline(false);
100 set_hidden(false);
101 set_dont_inline(false);
102 set_has_injected_profile(false);
103 set_method_data(NULL);
104 clear_method_counters();
105 set_vtable_index(Method::garbage_vtable_index);
106
107 // Fix and bury in Method*
108 set_interpreter_entry(NULL); // sets i2i entry and from_int
109 set_adapter_entry(NULL);
110 Method::clear_code(); // from_c/from_i get set to c2i/i2i
111
112 if (access_flags.is_native()) {
113 clear_native_function();
114 set_signature_handler(NULL);
115 }
116
117 NOT_PRODUCT(set_compiled_invocation_count(0);)
118 }
119
120 // Release Method*. The nmethod will be gone when we get here because
121 // we've walked the code cache.
122 void Method::deallocate_contents(ClassLoaderData* loader_data) {
123 MetadataFactory::free_metadata(loader_data, constMethod());
124 set_constMethod(NULL);
125 MetadataFactory::free_metadata(loader_data, method_data());
126 set_method_data(NULL);
127 MetadataFactory::free_metadata(loader_data, method_counters());
128 clear_method_counters();
129 // The nmethod will be gone when we get here.
130 if (code() != NULL) _code = NULL;
131 }
132
133 void Method::release_C_heap_structures() {
134 if (method_data()) {
135 #if INCLUDE_JVMCI
136 FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
137 #endif
138 // Destroy MethodData
139 method_data()->~MethodData();
140 }
141 }
142
143 address Method::get_i2c_entry() {
144 assert(adapter() != NULL, "must have");
145 return adapter()->get_i2c_entry();
146 }
147
148 address Method::get_c2i_entry() {
149 assert(adapter() != NULL, "must have");
150 return adapter()->get_c2i_entry();
151 }
152
153 address Method::get_c2i_unverified_entry() {
154 assert(adapter() != NULL, "must have");
155 return adapter()->get_c2i_unverified_entry();
156 }
157
158 address Method::get_c2i_no_clinit_check_entry() {
159 assert(VM_Version::supports_fast_class_init_checks(), "");
160 assert(adapter() != NULL, "must have");
161 return adapter()->get_c2i_no_clinit_check_entry();
162 }
163
164 char* Method::name_and_sig_as_C_string() const {
165 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
166 }
167
168 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
169 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
170 }
171
172 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
173 const char* klass_name = klass->external_name();
174 int klass_name_len = (int)strlen(klass_name);
175 int method_name_len = method_name->utf8_length();
176 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
177 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
178 strcpy(dest, klass_name);
179 dest[klass_name_len] = '.';
180 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
181 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
182 dest[len] = 0;
183 return dest;
184 }
185
186 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
187 Symbol* klass_name = klass->name();
188 klass_name->as_klass_external_name(buf, size);
189 int len = (int)strlen(buf);
190
191 if (len < size - 1) {
192 buf[len++] = '.';
193
194 method_name->as_C_string(&(buf[len]), size - len);
195 len = (int)strlen(buf);
196
197 signature->as_C_string(&(buf[len]), size - len);
198 }
199
200 return buf;
201 }
202
203 const char* Method::external_name() const {
204 return external_name(constants()->pool_holder(), name(), signature());
205 }
206
207 void Method::print_external_name(outputStream *os) const {
208 print_external_name(os, constants()->pool_holder(), name(), signature());
209 }
210
211 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
212 stringStream ss;
213 print_external_name(&ss, klass, method_name, signature);
214 return ss.as_string();
215 }
216
217 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
218 signature->print_as_signature_external_return_type(os);
219 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
220 signature->print_as_signature_external_parameters(os);
221 os->print(")");
222 }
223
224 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
225 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
226 // access exception table
227 ExceptionTable table(mh());
228 int length = table.length();
229 // iterate through all entries sequentially
230 constantPoolHandle pool(THREAD, mh->constants());
231 for (int i = 0; i < length; i ++) {
232 //reacquire the table in case a GC happened
233 ExceptionTable table(mh());
234 int beg_bci = table.start_pc(i);
235 int end_bci = table.end_pc(i);
236 assert(beg_bci <= end_bci, "inconsistent exception table");
237 if (beg_bci <= throw_bci && throw_bci < end_bci) {
238 // exception handler bci range covers throw_bci => investigate further
239 int handler_bci = table.handler_pc(i);
240 int klass_index = table.catch_type_index(i);
241 if (klass_index == 0) {
242 return handler_bci;
243 } else if (ex_klass == NULL) {
244 return handler_bci;
245 } else {
246 // we know the exception class => get the constraint class
247 // this may require loading of the constraint class; if verification
248 // fails or some other exception occurs, return handler_bci
249 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
250 assert(k != NULL, "klass not loaded");
251 if (ex_klass->is_subtype_of(k)) {
252 return handler_bci;
253 }
254 }
255 }
256 }
257
258 return -1;
259 }
260
261 void Method::mask_for(int bci, InterpreterOopMap* mask) {
262 methodHandle h_this(Thread::current(), this);
263 // Only GC uses the OopMapCache during thread stack root scanning
264 // any other uses generate an oopmap but do not save it in the cache.
265 if (Universe::heap()->is_gc_active()) {
266 method_holder()->mask_for(h_this, bci, mask);
267 } else {
268 OopMapCache::compute_one_oop_map(h_this, bci, mask);
269 }
270 return;
271 }
272
273
274 int Method::bci_from(address bcp) const {
275 if (is_native() && bcp == 0) {
276 return 0;
277 }
278 #ifdef ASSERT
279 {
280 ResourceMark rm;
281 assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
282 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
283 p2i(bcp), name_and_sig_as_C_string());
284 }
285 #endif
286 return bcp - code_base();
287 }
288
289
290 int Method::validate_bci(int bci) const {
291 return (bci == 0 || bci < code_size()) ? bci : -1;
292 }
293
294 // Return bci if it appears to be a valid bcp
295 // Return -1 otherwise.
296 // Used by profiling code, when invalid data is a possibility.
297 // The caller is responsible for validating the Method* itself.
298 int Method::validate_bci_from_bcp(address bcp) const {
299 // keep bci as -1 if not a valid bci
300 int bci = -1;
301 if (bcp == 0 || bcp == code_base()) {
302 // code_size() may return 0 and we allow 0 here
303 // the method may be native
304 bci = 0;
305 } else if (contains(bcp)) {
306 bci = bcp - code_base();
307 }
308 // Assert that if we have dodged any asserts, bci is negative.
309 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
310 return bci;
311 }
312
313 address Method::bcp_from(int bci) const {
314 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
315 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
316 address bcp = code_base() + bci;
317 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
318 return bcp;
319 }
320
321 address Method::bcp_from(address bcp) const {
322 if (is_native() && bcp == NULL) {
323 return code_base();
324 } else {
325 return bcp;
326 }
327 }
328
329 int Method::size(bool is_native) {
330 // If native, then include pointers for native_function and signature_handler
331 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
332 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
333 return align_metadata_size(header_size() + extra_words);
334 }
335
336 Symbol* Method::klass_name() const {
337 return method_holder()->name();
338 }
339
340 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
341 log_trace(cds)("Iter(Method): %p", this);
342
343 it->push(&_constMethod);
344 it->push(&_method_data);
345 it->push(&_method_counters);
346
347 Method* this_ptr = this;
348 it->push_method_entry(&this_ptr, (intptr_t*)&_i2i_entry);
349 it->push_method_entry(&this_ptr, (intptr_t*)&_from_compiled_entry);
350 it->push_method_entry(&this_ptr, (intptr_t*)&_from_interpreted_entry);
351 }
352
353 // Attempt to return method oop to original state. Clear any pointers
354 // (to objects outside the shared spaces). We won't be able to predict
355 // where they should point in a new JVM. Further initialize some
356 // entries now in order allow them to be write protected later.
357
358 void Method::remove_unshareable_info() {
359 unlink_method();
360 }
361
362 void Method::set_vtable_index(int index) {
363 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
364 // At runtime initialize_vtable is rerun as part of link_class_impl()
365 // for a shared class loaded by the non-boot loader to obtain the loader
366 // constraints based on the runtime classloaders' context.
367 return; // don't write into the shared class
368 } else {
369 _vtable_index = index;
370 }
371 }
372
373 void Method::set_itable_index(int index) {
374 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
375 // At runtime initialize_itable is rerun as part of link_class_impl()
376 // for a shared class loaded by the non-boot loader to obtain the loader
377 // constraints based on the runtime classloaders' context. The dumptime
378 // itable index should be the same as the runtime index.
379 assert(_vtable_index == itable_index_max - index,
380 "archived itable index is different from runtime index");
381 return; // don’t write into the shared class
382 } else {
383 _vtable_index = itable_index_max - index;
384 }
385 assert(valid_itable_index(), "");
386 }
387
388 // The RegisterNatives call being attempted tried to register with a method that
389 // is not native. Ask JVM TI what prefixes have been specified. Then check
390 // to see if the native method is now wrapped with the prefixes. See the
391 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
392 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
393 #if INCLUDE_JVMTI
394 ResourceMark rm(THREAD);
395 Method* method;
396 int name_len = name->utf8_length();
397 char* name_str = name->as_utf8();
398 int prefix_count;
399 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
400 for (int i = 0; i < prefix_count; i++) {
401 char* prefix = prefixes[i];
402 int prefix_len = (int)strlen(prefix);
403
404 // try adding this prefix to the method name and see if it matches another method name
405 int trial_len = name_len + prefix_len;
406 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
407 strcpy(trial_name_str, prefix);
408 strcat(trial_name_str, name_str);
409 TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
410 if (trial_name == NULL) {
411 continue; // no such symbol, so this prefix wasn't used, try the next prefix
412 }
413 method = k->lookup_method(trial_name, signature);
414 if (method == NULL) {
415 continue; // signature doesn't match, try the next prefix
416 }
417 if (method->is_native()) {
418 method->set_is_prefixed_native();
419 return method; // wahoo, we found a prefixed version of the method, return it
420 }
421 // found as non-native, so prefix is good, add it, probably just need more prefixes
422 name_len = trial_len;
423 name_str = trial_name_str;
424 }
425 #endif // INCLUDE_JVMTI
426 return NULL; // not found
427 }
428
429 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
430 Method* method = k->lookup_method(name, signature);
431 if (method == NULL) {
432 ResourceMark rm(THREAD);
433 stringStream st;
434 st.print("Method '");
435 print_external_name(&st, k, name, signature);
436 st.print("' name or signature does not match");
437 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
438 }
439 if (!method->is_native()) {
440 // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
441 method = find_prefixed_native(k, name, signature, THREAD);
442 if (method == NULL) {
443 ResourceMark rm(THREAD);
444 stringStream st;
445 st.print("Method '");
446 print_external_name(&st, k, name, signature);
447 st.print("' is not declared as native");
448 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
449 }
450 }
451
452 if (entry != NULL) {
453 method->set_native_function(entry, native_bind_event_is_interesting);
454 } else {
455 method->clear_native_function();
456 }
457 if (log_is_enabled(Debug, jni, resolve)) {
458 ResourceMark rm(THREAD);
459 log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
460 method->method_holder()->external_name(),
461 method->name()->as_C_string());
462 }
463 return true;
464 }
465
466 bool Method::was_executed_more_than(int n) {
467 // Invocation counter is reset when the Method* is compiled.
468 // If the method has compiled code we therefore assume it has
469 // be excuted more than n times.
470 if (is_accessor() || is_empty_method() || (code() != NULL)) {
471 // interpreter doesn't bump invocation counter of trivial methods
472 // compiler does not bump invocation counter of compiled methods
473 return true;
474 }
475 else if ((method_counters() != NULL &&
476 method_counters()->invocation_counter()->carry()) ||
477 (method_data() != NULL &&
478 method_data()->invocation_counter()->carry())) {
479 // The carry bit is set when the counter overflows and causes
480 // a compilation to occur. We don't know how many times
481 // the counter has been reset, so we simply assume it has
482 // been executed more than n times.
483 return true;
484 } else {
485 return invocation_count() > n;
486 }
487 }
488
489 void Method::print_invocation_count() {
490 if (is_static()) tty->print("static ");
491 if (is_final()) tty->print("final ");
492 if (is_synchronized()) tty->print("synchronized ");
493 if (is_native()) tty->print("native ");
494 tty->print("%s::", method_holder()->external_name());
495 name()->print_symbol_on(tty);
496 signature()->print_symbol_on(tty);
497
498 if (WizardMode) {
499 // dump the size of the byte codes
500 tty->print(" {%d}", code_size());
501 }
502 tty->cr();
503
504 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
505 tty->print_cr (" invocation_counter: %8d ", invocation_count());
506 tty->print_cr (" backedge_counter: %8d ", backedge_count());
507 #ifndef PRODUCT
508 if (CountCompiledCalls) {
509 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
510 }
511 #endif
512 }
513
514 // Build a MethodData* object to hold information about this method
515 // collected in the interpreter.
516 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
517 // Do not profile the method if metaspace has hit an OOM previously
518 // allocating profiling data. Callers clear pending exception so don't
519 // add one here.
520 if (ClassLoaderDataGraph::has_metaspace_oom()) {
521 return;
522 }
523
524 // Grab a lock here to prevent multiple
525 // MethodData*s from being created.
526 MutexLocker ml(THREAD, MethodData_lock);
527 if (method->method_data() == NULL) {
528 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
529 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
530 if (HAS_PENDING_EXCEPTION) {
531 CompileBroker::log_metaspace_failure();
532 ClassLoaderDataGraph::set_metaspace_oom(true);
533 return; // return the exception (which is cleared)
534 }
535
536 method->set_method_data(method_data);
537 if (PrintMethodData && (Verbose || WizardMode)) {
538 ResourceMark rm(THREAD);
539 tty->print("build_interpreter_method_data for ");
540 method->print_name(tty);
541 tty->cr();
542 // At the end of the run, the MDO, full of data, will be dumped.
543 }
544 }
545 }
546
547 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
548 // Do not profile the method if metaspace has hit an OOM previously
549 if (ClassLoaderDataGraph::has_metaspace_oom()) {
550 return NULL;
551 }
552
553 methodHandle mh(THREAD, m);
554 MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
555 if (HAS_PENDING_EXCEPTION) {
556 CompileBroker::log_metaspace_failure();
557 ClassLoaderDataGraph::set_metaspace_oom(true);
558 return NULL; // return the exception (which is cleared)
559 }
560 if (!mh->init_method_counters(counters)) {
561 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
562 }
563
564 if (LogTouchedMethods) {
565 mh->log_touched(CHECK_NULL);
566 }
567
568 return mh->method_counters();
569 }
570
571 bool Method::init_method_counters(MethodCounters* counters) {
572 // Try to install a pointer to MethodCounters, return true on success.
573 return Atomic::replace_if_null(&_method_counters, counters);
574 }
575
576 int Method::extra_stack_words() {
577 // not an inline function, to avoid a header dependency on Interpreter
578 return extra_stack_entries() * Interpreter::stackElementSize;
579 }
580
581 // Derive size of parameters, return type, and fingerprint,
582 // all in one pass, which is run at load time.
583 // We need the first two, and might as well grab the third.
584 void Method::compute_from_signature(Symbol* sig) {
585 // At this point, since we are scanning the signature,
586 // we might as well compute the whole fingerprint.
587 Fingerprinter fp(sig, is_static());
588 set_size_of_parameters(fp.size_of_parameters());
589 constMethod()->set_result_type(fp.return_type());
590 constMethod()->set_fingerprint(fp.fingerprint());
591 }
592
593 bool Method::is_empty_method() const {
594 return code_size() == 1
595 && *code_base() == Bytecodes::_return;
596 }
597
598 bool Method::is_vanilla_constructor() const {
599 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
600 // which only calls the superclass vanilla constructor and possibly does stores of
601 // zero constants to local fields:
602 //
603 // aload_0
604 // invokespecial
605 // indexbyte1
606 // indexbyte2
607 //
608 // followed by an (optional) sequence of:
609 //
610 // aload_0
611 // aconst_null / iconst_0 / fconst_0 / dconst_0
612 // putfield
613 // indexbyte1
614 // indexbyte2
615 //
616 // followed by:
617 //
618 // return
619
620 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
621 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
622 int size = code_size();
623 // Check if size match
624 if (size == 0 || size % 5 != 0) return false;
625 address cb = code_base();
626 int last = size - 1;
627 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
628 // Does not call superclass default constructor
629 return false;
630 }
631 // Check optional sequence
632 for (int i = 4; i < last; i += 5) {
633 if (cb[i] != Bytecodes::_aload_0) return false;
634 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
635 if (cb[i+2] != Bytecodes::_putfield) return false;
636 }
637 return true;
638 }
639
640
641 bool Method::compute_has_loops_flag() {
642 BytecodeStream bcs(methodHandle(Thread::current(), this));
643 Bytecodes::Code bc;
644
645 while ((bc = bcs.next()) >= 0) {
646 switch( bc ) {
647 case Bytecodes::_ifeq:
648 case Bytecodes::_ifnull:
649 case Bytecodes::_iflt:
650 case Bytecodes::_ifle:
651 case Bytecodes::_ifne:
652 case Bytecodes::_ifnonnull:
653 case Bytecodes::_ifgt:
654 case Bytecodes::_ifge:
655 case Bytecodes::_if_icmpeq:
656 case Bytecodes::_if_icmpne:
657 case Bytecodes::_if_icmplt:
658 case Bytecodes::_if_icmpgt:
659 case Bytecodes::_if_icmple:
660 case Bytecodes::_if_icmpge:
661 case Bytecodes::_if_acmpeq:
662 case Bytecodes::_if_acmpne:
663 case Bytecodes::_goto:
664 case Bytecodes::_jsr:
665 if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
666 break;
667
668 case Bytecodes::_goto_w:
669 case Bytecodes::_jsr_w:
670 if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
671 break;
672
673 default:
674 break;
675 }
676 }
677 _access_flags.set_loops_flag_init();
678 return _access_flags.has_loops();
679 }
680
681 bool Method::is_final_method(AccessFlags class_access_flags) const {
682 // or "does_not_require_vtable_entry"
683 // default method or overpass can occur, is not final (reuses vtable entry)
684 // private methods in classes get vtable entries for backward class compatibility.
685 if (is_overpass() || is_default_method()) return false;
686 return is_final() || class_access_flags.is_final();
687 }
688
689 bool Method::is_final_method() const {
690 return is_final_method(method_holder()->access_flags());
691 }
692
693 bool Method::is_default_method() const {
694 if (method_holder() != NULL &&
695 method_holder()->is_interface() &&
696 !is_abstract() && !is_private()) {
697 return true;
698 } else {
699 return false;
700 }
701 }
702
703 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
704 if (is_final_method(class_access_flags)) return true;
705 #ifdef ASSERT
706 ResourceMark rm;
707 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
708 if (class_access_flags.is_interface()) {
709 assert(is_nonv == is_static() || is_nonv == is_private(),
710 "nonvirtual unexpected for non-static, non-private: %s",
711 name_and_sig_as_C_string());
712 }
713 #endif
714 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
715 return vtable_index() == nonvirtual_vtable_index;
716 }
717
718 bool Method::can_be_statically_bound() const {
719 return can_be_statically_bound(method_holder()->access_flags());
720 }
721
722 bool Method::can_be_statically_bound(InstanceKlass* context) const {
723 return (method_holder() == context) && can_be_statically_bound();
724 }
725
726 bool Method::is_accessor() const {
727 return is_getter() || is_setter();
728 }
729
730 bool Method::is_getter() const {
731 if (code_size() != 5) return false;
732 if (size_of_parameters() != 1) return false;
733 if (java_code_at(0) != Bytecodes::_aload_0) return false;
734 if (java_code_at(1) != Bytecodes::_getfield) return false;
735 switch (java_code_at(4)) {
736 case Bytecodes::_ireturn:
737 case Bytecodes::_lreturn:
738 case Bytecodes::_freturn:
739 case Bytecodes::_dreturn:
740 case Bytecodes::_areturn:
741 break;
742 default:
743 return false;
744 }
745 return true;
746 }
747
748 bool Method::is_setter() const {
749 if (code_size() != 6) return false;
750 if (java_code_at(0) != Bytecodes::_aload_0) return false;
751 switch (java_code_at(1)) {
752 case Bytecodes::_iload_1:
753 case Bytecodes::_aload_1:
754 case Bytecodes::_fload_1:
755 if (size_of_parameters() != 2) return false;
756 break;
757 case Bytecodes::_dload_1:
758 case Bytecodes::_lload_1:
759 if (size_of_parameters() != 3) return false;
760 break;
761 default:
762 return false;
763 }
764 if (java_code_at(2) != Bytecodes::_putfield) return false;
765 if (java_code_at(5) != Bytecodes::_return) return false;
766 return true;
767 }
768
769 bool Method::is_constant_getter() const {
770 int last_index = code_size() - 1;
771 // Check if the first 1-3 bytecodes are a constant push
772 // and the last bytecode is a return.
773 return (2 <= code_size() && code_size() <= 4 &&
774 Bytecodes::is_const(java_code_at(0)) &&
775 Bytecodes::length_for(java_code_at(0)) == last_index &&
776 Bytecodes::is_return(java_code_at(last_index)));
777 }
778
779 bool Method::is_initializer() const {
780 return is_object_initializer() || is_static_initializer();
781 }
782
783 bool Method::has_valid_initializer_flags() const {
784 return (is_static() ||
785 method_holder()->major_version() < 51);
786 }
787
788 bool Method::is_static_initializer() const {
789 // For classfiles version 51 or greater, ensure that the clinit method is
790 // static. Non-static methods with the name "<clinit>" are not static
791 // initializers. (older classfiles exempted for backward compatibility)
792 return name() == vmSymbols::class_initializer_name() &&
793 has_valid_initializer_flags();
794 }
795
796 bool Method::is_object_initializer() const {
797 return name() == vmSymbols::object_initializer_name();
798 }
799
800 bool Method::needs_clinit_barrier() const {
801 return is_static() && !method_holder()->is_initialized();
802 }
803
804 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
805 int length = method->checked_exceptions_length();
806 if (length == 0) { // common case
807 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
808 } else {
809 methodHandle h_this(THREAD, method);
810 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
811 objArrayHandle mirrors (THREAD, m_oop);
812 for (int i = 0; i < length; i++) {
813 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
814 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
815 if (log_is_enabled(Warning, exceptions) &&
816 !k->is_subclass_of(SystemDictionary::Throwable_klass())) {
817 ResourceMark rm(THREAD);
818 log_warning(exceptions)(
819 "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
820 k->external_name(), method->external_name());
821 }
822 mirrors->obj_at_put(i, k->java_mirror());
823 }
824 return mirrors;
825 }
826 };
827
828
829 int Method::line_number_from_bci(int bci) const {
830 int best_bci = 0;
831 int best_line = -1;
832 if (bci == SynchronizationEntryBCI) bci = 0;
833 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
834 // The line numbers are a short array of 2-tuples [start_pc, line_number].
835 // Not necessarily sorted and not necessarily one-to-one.
836 CompressedLineNumberReadStream stream(compressed_linenumber_table());
837 while (stream.read_pair()) {
838 if (stream.bci() == bci) {
839 // perfect match
840 return stream.line();
841 } else {
842 // update best_bci/line
843 if (stream.bci() < bci && stream.bci() >= best_bci) {
844 best_bci = stream.bci();
845 best_line = stream.line();
846 }
847 }
848 }
849 }
850 return best_line;
851 }
852
853
854 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
855 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
856 Thread *thread = Thread::current();
857 Symbol* klass_name = constants()->klass_name_at(klass_index);
858 Handle loader(thread, method_holder()->class_loader());
859 Handle prot (thread, method_holder()->protection_domain());
860 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
861 } else {
862 return true;
863 }
864 }
865
866
867 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
868 int klass_index = constants()->klass_ref_index_at(refinfo_index);
869 if (must_be_resolved) {
870 // Make sure klass is resolved in constantpool.
871 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
872 }
873 return is_klass_loaded_by_klass_index(klass_index);
874 }
875
876
877 void Method::set_native_function(address function, bool post_event_flag) {
878 assert(function != NULL, "use clear_native_function to unregister natives");
879 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
880 address* native_function = native_function_addr();
881
882 // We can see racers trying to place the same native function into place. Once
883 // is plenty.
884 address current = *native_function;
885 if (current == function) return;
886 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
887 function != NULL) {
888 // native_method_throw_unsatisfied_link_error_entry() should only
889 // be passed when post_event_flag is false.
890 assert(function !=
891 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
892 "post_event_flag mis-match");
893
894 // post the bind event, and possible change the bind function
895 JvmtiExport::post_native_method_bind(this, &function);
896 }
897 *native_function = function;
898 // This function can be called more than once. We must make sure that we always
899 // use the latest registered method -> check if a stub already has been generated.
900 // If so, we have to make it not_entrant.
901 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
902 if (nm != NULL) {
903 nm->make_not_entrant();
904 }
905 }
906
907
908 bool Method::has_native_function() const {
909 if (is_method_handle_intrinsic())
910 return false; // special-cased in SharedRuntime::generate_native_wrapper
911 address func = native_function();
912 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
913 }
914
915
916 void Method::clear_native_function() {
917 // Note: is_method_handle_intrinsic() is allowed here.
918 set_native_function(
919 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
920 !native_bind_event_is_interesting);
921 this->unlink_code();
922 }
923
924
925 void Method::set_signature_handler(address handler) {
926 address* signature_handler = signature_handler_addr();
927 *signature_handler = handler;
928 }
929
930
931 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
932 assert(reason != NULL, "must provide a reason");
933 if (PrintCompilation && report) {
934 ttyLocker ttyl;
935 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
936 if (comp_level == CompLevel_all) {
937 tty->print("all levels ");
938 } else {
939 tty->print("level %d ", comp_level);
940 }
941 this->print_short_name(tty);
942 int size = this->code_size();
943 if (size > 0) {
944 tty->print(" (%d bytes)", size);
945 }
946 if (reason != NULL) {
947 tty->print(" %s", reason);
948 }
949 tty->cr();
950 }
951 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
952 ttyLocker ttyl;
953 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
954 os::current_thread_id(), is_osr, comp_level);
955 if (reason != NULL) {
956 xtty->print(" reason=\'%s\'", reason);
957 }
958 xtty->method(this);
959 xtty->stamp();
960 xtty->end_elem();
961 }
962 }
963
964 bool Method::is_always_compilable() const {
965 // Generated adapters must be compiled
966 if (is_method_handle_intrinsic() && is_synthetic()) {
967 assert(!is_not_c1_compilable(), "sanity check");
968 assert(!is_not_c2_compilable(), "sanity check");
969 return true;
970 }
971
972 return false;
973 }
974
975 bool Method::is_not_compilable(int comp_level) const {
976 if (number_of_breakpoints() > 0)
977 return true;
978 if (is_always_compilable())
979 return false;
980 if (comp_level == CompLevel_any)
981 return is_not_c1_compilable() || is_not_c2_compilable();
982 if (is_c1_compile(comp_level))
983 return is_not_c1_compilable();
984 if (is_c2_compile(comp_level))
985 return is_not_c2_compilable();
986 return false;
987 }
988
989 // call this when compiler finds that this method is not compilable
990 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
991 if (is_always_compilable()) {
992 // Don't mark a method which should be always compilable
993 return;
994 }
995 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
996 if (comp_level == CompLevel_all) {
997 set_not_c1_compilable();
998 set_not_c2_compilable();
999 } else {
1000 if (is_c1_compile(comp_level))
1001 set_not_c1_compilable();
1002 if (is_c2_compile(comp_level))
1003 set_not_c2_compilable();
1004 }
1005 assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1006 }
1007
1008 bool Method::is_not_osr_compilable(int comp_level) const {
1009 if (is_not_compilable(comp_level))
1010 return true;
1011 if (comp_level == CompLevel_any)
1012 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
1013 if (is_c1_compile(comp_level))
1014 return is_not_c1_osr_compilable();
1015 if (is_c2_compile(comp_level))
1016 return is_not_c2_osr_compilable();
1017 return false;
1018 }
1019
1020 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1021 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1022 if (comp_level == CompLevel_all) {
1023 set_not_c1_osr_compilable();
1024 set_not_c2_osr_compilable();
1025 } else {
1026 if (is_c1_compile(comp_level))
1027 set_not_c1_osr_compilable();
1028 if (is_c2_compile(comp_level))
1029 set_not_c2_osr_compilable();
1030 }
1031 assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1032 }
1033
1034 // Revert to using the interpreter and clear out the nmethod
1035 void Method::clear_code() {
1036 // this may be NULL if c2i adapters have not been made yet
1037 // Only should happen at allocate time.
1038 if (adapter() == NULL) {
1039 _from_compiled_entry = NULL;
1040 } else {
1041 _from_compiled_entry = adapter()->get_c2i_entry();
1042 }
1043 OrderAccess::storestore();
1044 _from_interpreted_entry = _i2i_entry;
1045 OrderAccess::storestore();
1046 _code = NULL;
1047 }
1048
1049 void Method::unlink_code(CompiledMethod *compare) {
1050 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1051 // We need to check if either the _code or _from_compiled_code_entry_point
1052 // refer to this nmethod because there is a race in setting these two fields
1053 // in Method* as seen in bugid 4947125.
1054 // If the vep() points to the zombie nmethod, the memory for the nmethod
1055 // could be flushed and the compiler and vtable stubs could still call
1056 // through it.
1057 if (code() == compare ||
1058 from_compiled_entry() == compare->verified_entry_point()) {
1059 clear_code();
1060 }
1061 }
1062
1063 void Method::unlink_code() {
1064 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1065 clear_code();
1066 }
1067
1068 #if INCLUDE_CDS
1069 // Called by class data sharing to remove any entry points (which are not shared)
1070 void Method::unlink_method() {
1071 _code = NULL;
1072
1073 Arguments::assert_is_dumping_archive();
1074 // Set the values to what they should be at run time. Note that
1075 // this Method can no longer be executed during dump time.
1076 _i2i_entry = Interpreter::entry_for_cds_method(methodHandle(Thread::current(), this));
1077 _from_interpreted_entry = _i2i_entry;
1078
1079 if (DynamicDumpSharedSpaces) {
1080 assert(_from_compiled_entry != NULL, "sanity");
1081 } else {
1082 // TODO: Simplify the adapter trampoline allocation for static archiving.
1083 // Remove the use of CDSAdapterHandlerEntry.
1084 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
1085 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
1086 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
1087 assert(*((int*)_from_compiled_entry) == 0,
1088 "must be NULL during dump time, to be initialized at run time");
1089 }
1090
1091 if (is_native()) {
1092 *native_function_addr() = NULL;
1093 set_signature_handler(NULL);
1094 }
1095 NOT_PRODUCT(set_compiled_invocation_count(0);)
1096
1097 set_method_data(NULL);
1098 clear_method_counters();
1099 }
1100 #endif
1101
1102 /****************************************************************************
1103 // The following illustrates how the entries work for CDS shared Methods:
1104 //
1105 // Our goal is to delay writing into a shared Method until it's compiled.
1106 // Hence, we want to determine the initial values for _i2i_entry,
1107 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1108 //
1109 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1110 // They also have similar signatures so that they will share the same
1111 // AdapterHandlerEntry.
1112 //
1113 // _adapter_trampoline points to a fixed location in the RW section of
1114 // the CDS archive. This location initially contains a NULL pointer. When the
1115 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1116 // dynamically, and its c2i/i2c entries are generated.
1117 //
1118 // _i2i_entry and _from_interpreted_entry initially points to the same
1119 // (fixed) location in the CODE section of the CDS archive. This contains
1120 // an unconditional branch to the actual entry for "zero_locals", which is
1121 // generated at run time and may be on an arbitrary address. Thus, the
1122 // unconditional branch is also generated at run time to jump to the correct
1123 // address.
1124 //
1125 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1126 // section. This address has enough space for an unconditional branch
1127 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1128 // initialized, and the address for the actual c2i_entry is known, we emit a
1129 // branch instruction here to branch to the actual c2i_entry.
1130 //
1131 // The effect of the extra branch on the i2i and c2i entries is negligible.
1132 //
1133 // The reason for putting _adapter_trampoline in RO is many shared Methods
1134 // share the same AdapterHandlerEntry, so we can save space in the RW section
1135 // by having the extra indirection.
1136
1137
1138 [Method A: RW]
1139 _constMethod ----> [ConstMethod: RO]
1140 _adapter_trampoline -----------+
1141 |
1142 _i2i_entry (same value as method B) |
1143 _from_interpreted_entry (same value as method B) |
1144 _from_compiled_entry (same value as method B) |
1145 |
1146 |
1147 [Method B: RW] +--------+
1148 _constMethod ----> [ConstMethod: RO] |
1149 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1150 |
1151 +-------------------------------+
1152 |
1153 +----> [AdapterHandlerEntry] (allocated at run time)
1154 _fingerprint
1155 _c2i_entry ---------------------------------+->[c2i entry..]
1156 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1157 _from_interpreted_entry | _c2i_unverified_entry | |
1158 | | _c2i_no_clinit_check_entry| |
1159 | | (_cds_entry_table: CODE) | |
1160 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1161 | | (allocated at run time) | |
1162 | | ... [asm code ...] | |
1163 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1164 | | |
1165 | | |
1166 +-[compiled]-------------------------------------------------------------------+ |
1167 |
1168 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1169 [jmp c2i_entry] ------------------------------------------------------+
1170
1171 ***/
1172
1173 // Called when the method_holder is getting linked. Setup entrypoints so the method
1174 // is ready to be called from interpreter, compiler, and vtables.
1175 void Method::link_method(const methodHandle& h_method, TRAPS) {
1176 // If the code cache is full, we may reenter this function for the
1177 // leftover methods that weren't linked.
1178 if (is_shared()) {
1179 // Can't assert that the adapters are sane, because methods get linked before
1180 // the interpreter is generated, and hence before its adapters are generated.
1181 // If you messed them up you will notice soon enough though, don't you worry.
1182 if (adapter() != NULL) {
1183 return;
1184 }
1185 } else if (_i2i_entry != NULL) {
1186 return;
1187 }
1188 assert( _code == NULL, "nothing compiled yet" );
1189
1190 // Setup interpreter entrypoint
1191 assert(this == h_method(), "wrong h_method()" );
1192
1193 if (!is_shared()) {
1194 assert(adapter() == NULL, "init'd to NULL");
1195 address entry = Interpreter::entry_for_method(h_method);
1196 assert(entry != NULL, "interpreter entry must be non-null");
1197 // Sets both _i2i_entry and _from_interpreted_entry
1198 set_interpreter_entry(entry);
1199 }
1200
1201 // Don't overwrite already registered native entries.
1202 if (is_native() && !has_native_function()) {
1203 set_native_function(
1204 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1205 !native_bind_event_is_interesting);
1206 }
1207
1208 // Setup compiler entrypoint. This is made eagerly, so we do not need
1209 // special handling of vtables. An alternative is to make adapters more
1210 // lazily by calling make_adapter() from from_compiled_entry() for the
1211 // normal calls. For vtable calls life gets more complicated. When a
1212 // call-site goes mega-morphic we need adapters in all methods which can be
1213 // called from the vtable. We need adapters on such methods that get loaded
1214 // later. Ditto for mega-morphic itable calls. If this proves to be a
1215 // problem we'll make these lazily later.
1216 (void) make_adapters(h_method, CHECK);
1217
1218 // ONLY USE the h_method now as make_adapter may have blocked
1219
1220 }
1221
1222 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1223 // Adapters for compiled code are made eagerly here. They are fairly
1224 // small (generally < 100 bytes) and quick to make (and cached and shared)
1225 // so making them eagerly shouldn't be too expensive.
1226 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1227 if (adapter == NULL ) {
1228 if (!is_init_completed()) {
1229 // Don't throw exceptions during VM initialization because java.lang.* classes
1230 // might not have been initialized, causing problems when constructing the
1231 // Java exception object.
1232 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1233 } else {
1234 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1235 }
1236 }
1237
1238 if (mh->is_shared()) {
1239 assert(mh->adapter() == adapter, "must be");
1240 assert(mh->_from_compiled_entry != NULL, "must be");
1241 } else {
1242 mh->set_adapter_entry(adapter);
1243 mh->_from_compiled_entry = adapter->get_c2i_entry();
1244 }
1245 return adapter->get_c2i_entry();
1246 }
1247
1248 void Method::restore_unshareable_info(TRAPS) {
1249 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1250
1251 // Since restore_unshareable_info can be called more than once for a method, don't
1252 // redo any work.
1253 if (adapter() == NULL) {
1254 methodHandle mh(THREAD, this);
1255 link_method(mh, CHECK);
1256 }
1257 }
1258
1259 address Method::from_compiled_entry_no_trampoline() const {
1260 CompiledMethod *code = Atomic::load_acquire(&_code);
1261 if (code) {
1262 return code->verified_entry_point();
1263 } else {
1264 return adapter()->get_c2i_entry();
1265 }
1266 }
1267
1268 // The verified_code_entry() must be called when a invoke is resolved
1269 // on this method.
1270
1271 // It returns the compiled code entry point, after asserting not null.
1272 // This function is called after potential safepoints so that nmethod
1273 // or adapter that it points to is still live and valid.
1274 // This function must not hit a safepoint!
1275 address Method::verified_code_entry() {
1276 debug_only(NoSafepointVerifier nsv;)
1277 assert(_from_compiled_entry != NULL, "must be set");
1278 return _from_compiled_entry;
1279 }
1280
1281 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1282 // (could be racing a deopt).
1283 // Not inline to avoid circular ref.
1284 bool Method::check_code() const {
1285 // cached in a register or local. There's a race on the value of the field.
1286 CompiledMethod *code = Atomic::load_acquire(&_code);
1287 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1288 }
1289
1290 // Install compiled code. Instantly it can execute.
1291 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1292 assert_lock_strong(CompiledMethod_lock);
1293 assert( code, "use clear_code to remove code" );
1294 assert( mh->check_code(), "" );
1295
1296 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1297
1298 // These writes must happen in this order, because the interpreter will
1299 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1300 // which jumps to _from_compiled_entry.
1301 mh->_code = code; // Assign before allowing compiled code to exec
1302
1303 int comp_level = code->comp_level();
1304 // In theory there could be a race here. In practice it is unlikely
1305 // and not worth worrying about.
1306 if (comp_level > mh->highest_comp_level()) {
1307 mh->set_highest_comp_level(comp_level);
1308 }
1309
1310 OrderAccess::storestore();
1311 mh->_from_compiled_entry = code->verified_entry_point();
1312 OrderAccess::storestore();
1313 // Instantly compiled code can execute.
1314 if (!mh->is_method_handle_intrinsic())
1315 mh->_from_interpreted_entry = mh->get_i2c_entry();
1316 }
1317
1318
1319 bool Method::is_overridden_in(Klass* k) const {
1320 InstanceKlass* ik = InstanceKlass::cast(k);
1321
1322 if (ik->is_interface()) return false;
1323
1324 // If method is an interface, we skip it - except if it
1325 // is a miranda method
1326 if (method_holder()->is_interface()) {
1327 // Check that method is not a miranda method
1328 if (ik->lookup_method(name(), signature()) == NULL) {
1329 // No implementation exist - so miranda method
1330 return false;
1331 }
1332 return true;
1333 }
1334
1335 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1336 if (!has_vtable_index()) {
1337 return false;
1338 } else {
1339 Method* vt_m = ik->method_at_vtable(vtable_index());
1340 return vt_m != this;
1341 }
1342 }
1343
1344
1345 // give advice about whether this Method* should be cached or not
1346 bool Method::should_not_be_cached() const {
1347 if (is_old()) {
1348 // This method has been redefined. It is either EMCP or obsolete
1349 // and we don't want to cache it because that would pin the method
1350 // down and prevent it from being collectible if and when it
1351 // finishes executing.
1352 return true;
1353 }
1354
1355 // caching this method should be just fine
1356 return false;
1357 }
1358
1359
1360 /**
1361 * Returns true if this is one of the specially treated methods for
1362 * security related stack walks (like Reflection.getCallerClass).
1363 */
1364 bool Method::is_ignored_by_security_stack_walk() const {
1365 if (intrinsic_id() == vmIntrinsics::_invoke) {
1366 // This is Method.invoke() -- ignore it
1367 return true;
1368 }
1369 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1370 // This is an auxilary frame -- ignore it
1371 return true;
1372 }
1373 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1374 // This is an internal adapter frame for method handles -- ignore it
1375 return true;
1376 }
1377 return false;
1378 }
1379
1380
1381 // Constant pool structure for invoke methods:
1382 enum {
1383 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1384 _imcp_invoke_signature, // utf8: (variable Symbol*)
1385 _imcp_limit
1386 };
1387
1388 // Test if this method is an MH adapter frame generated by Java code.
1389 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1390 bool Method::is_compiled_lambda_form() const {
1391 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1392 }
1393
1394 // Test if this method is an internal MH primitive method.
1395 bool Method::is_method_handle_intrinsic() const {
1396 vmIntrinsics::ID iid = intrinsic_id();
1397 return (MethodHandles::is_signature_polymorphic(iid) &&
1398 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1399 }
1400
1401 bool Method::has_member_arg() const {
1402 vmIntrinsics::ID iid = intrinsic_id();
1403 return (MethodHandles::is_signature_polymorphic(iid) &&
1404 MethodHandles::has_member_arg(iid));
1405 }
1406
1407 // Make an instance of a signature-polymorphic internal MH primitive.
1408 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1409 Symbol* signature,
1410 TRAPS) {
1411 ResourceMark rm(THREAD);
1412 methodHandle empty;
1413
1414 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1415 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1416 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1417
1418 log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1419
1420 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1421 name->increment_refcount();
1422 signature->increment_refcount();
1423
1424 int cp_length = _imcp_limit;
1425 ClassLoaderData* loader_data = holder->class_loader_data();
1426 constantPoolHandle cp;
1427 {
1428 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1429 cp = constantPoolHandle(THREAD, cp_oop);
1430 }
1431 cp->copy_fields(holder->constants());
1432 cp->set_pool_holder(holder);
1433 cp->symbol_at_put(_imcp_invoke_name, name);
1434 cp->symbol_at_put(_imcp_invoke_signature, signature);
1435 cp->set_has_preresolution();
1436
1437 // decide on access bits: public or not?
1438 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1439 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1440 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1441 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1442
1443 methodHandle m;
1444 {
1445 InlineTableSizes sizes;
1446 Method* m_oop = Method::allocate(loader_data, 0,
1447 accessFlags_from(flags_bits), &sizes,
1448 ConstMethod::NORMAL, CHECK_(empty));
1449 m = methodHandle(THREAD, m_oop);
1450 }
1451 m->set_constants(cp());
1452 m->set_name_index(_imcp_invoke_name);
1453 m->set_signature_index(_imcp_invoke_signature);
1454 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1455 assert(m->signature() == signature, "");
1456 m->compute_from_signature(signature);
1457 m->init_intrinsic_id();
1458 assert(m->is_method_handle_intrinsic(), "");
1459 #ifdef ASSERT
1460 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1461 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1462 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1463 #endif //ASSERT
1464
1465 // Finally, set up its entry points.
1466 assert(m->can_be_statically_bound(), "");
1467 m->set_vtable_index(Method::nonvirtual_vtable_index);
1468 m->link_method(m, CHECK_(empty));
1469
1470 if (log_is_enabled(Info, methodhandles) && (Verbose || WizardMode)) {
1471 LogTarget(Info, methodhandles) lt;
1472 LogStream ls(lt);
1473 m->print_on(&ls);
1474 }
1475
1476 return m;
1477 }
1478
1479 Klass* Method::check_non_bcp_klass(Klass* klass) {
1480 if (klass != NULL && klass->class_loader() != NULL) {
1481 if (klass->is_objArray_klass())
1482 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1483 return klass;
1484 }
1485 return NULL;
1486 }
1487
1488
1489 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1490 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1491 // Code below does not work for native methods - they should never get rewritten anyway
1492 assert(!m->is_native(), "cannot rewrite native methods");
1493 // Allocate new Method*
1494 AccessFlags flags = m->access_flags();
1495
1496 ConstMethod* cm = m->constMethod();
1497 int checked_exceptions_len = cm->checked_exceptions_length();
1498 int localvariable_len = cm->localvariable_table_length();
1499 int exception_table_len = cm->exception_table_length();
1500 int method_parameters_len = cm->method_parameters_length();
1501 int method_annotations_len = cm->method_annotations_length();
1502 int parameter_annotations_len = cm->parameter_annotations_length();
1503 int type_annotations_len = cm->type_annotations_length();
1504 int default_annotations_len = cm->default_annotations_length();
1505
1506 InlineTableSizes sizes(
1507 localvariable_len,
1508 new_compressed_linenumber_size,
1509 exception_table_len,
1510 checked_exceptions_len,
1511 method_parameters_len,
1512 cm->generic_signature_index(),
1513 method_annotations_len,
1514 parameter_annotations_len,
1515 type_annotations_len,
1516 default_annotations_len,
1517 0);
1518
1519 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1520 Method* newm_oop = Method::allocate(loader_data,
1521 new_code_length,
1522 flags,
1523 &sizes,
1524 m->method_type(),
1525 CHECK_(methodHandle()));
1526 methodHandle newm (THREAD, newm_oop);
1527
1528 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1529 ConstMethod* newcm = newm->constMethod();
1530 int new_const_method_size = newm->constMethod()->size();
1531
1532 // This works because the source and target are both Methods. Some compilers
1533 // (e.g., clang) complain that the target vtable pointer will be stomped,
1534 // so cast away newm()'s and m()'s Methodness.
1535 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1536
1537 // Create shallow copy of ConstMethod.
1538 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1539
1540 // Reset correct method/const method, method size, and parameter info
1541 newm->set_constMethod(newcm);
1542 newm->constMethod()->set_code_size(new_code_length);
1543 newm->constMethod()->set_constMethod_size(new_const_method_size);
1544 assert(newm->code_size() == new_code_length, "check");
1545 assert(newm->method_parameters_length() == method_parameters_len, "check");
1546 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1547 assert(newm->exception_table_length() == exception_table_len, "check");
1548 assert(newm->localvariable_table_length() == localvariable_len, "check");
1549 // Copy new byte codes
1550 memcpy(newm->code_base(), new_code, new_code_length);
1551 // Copy line number table
1552 if (new_compressed_linenumber_size > 0) {
1553 memcpy(newm->compressed_linenumber_table(),
1554 new_compressed_linenumber_table,
1555 new_compressed_linenumber_size);
1556 }
1557 // Copy method_parameters
1558 if (method_parameters_len > 0) {
1559 memcpy(newm->method_parameters_start(),
1560 m->method_parameters_start(),
1561 method_parameters_len * sizeof(MethodParametersElement));
1562 }
1563 // Copy checked_exceptions
1564 if (checked_exceptions_len > 0) {
1565 memcpy(newm->checked_exceptions_start(),
1566 m->checked_exceptions_start(),
1567 checked_exceptions_len * sizeof(CheckedExceptionElement));
1568 }
1569 // Copy exception table
1570 if (exception_table_len > 0) {
1571 memcpy(newm->exception_table_start(),
1572 m->exception_table_start(),
1573 exception_table_len * sizeof(ExceptionTableElement));
1574 }
1575 // Copy local variable number table
1576 if (localvariable_len > 0) {
1577 memcpy(newm->localvariable_table_start(),
1578 m->localvariable_table_start(),
1579 localvariable_len * sizeof(LocalVariableTableElement));
1580 }
1581 // Copy stackmap table
1582 if (m->has_stackmap_table()) {
1583 int code_attribute_length = m->stackmap_data()->length();
1584 Array<u1>* stackmap_data =
1585 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
1586 memcpy((void*)stackmap_data->adr_at(0),
1587 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1588 newm->set_stackmap_data(stackmap_data);
1589 }
1590
1591 // copy annotations over to new method
1592 newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
1593 return newm;
1594 }
1595
1596 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1597 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1598 // because we are not loading from core libraries
1599 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1600 // which does not use the class default class loader so we check for its loader here
1601 const InstanceKlass* ik = InstanceKlass::cast(holder);
1602 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1603 return vmSymbols::NO_SID; // regardless of name, no intrinsics here
1604 }
1605
1606 // see if the klass name is well-known:
1607 Symbol* klass_name = ik->name();
1608 return vmSymbols::find_sid(klass_name);
1609 }
1610
1611 void Method::init_intrinsic_id() {
1612 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1613 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1614 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1615 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1616
1617 // the klass name is well-known:
1618 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1619 assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1620
1621 // ditto for method and signature:
1622 vmSymbols::SID name_id = vmSymbols::find_sid(name());
1623 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1624 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1625 && name_id == vmSymbols::NO_SID) {
1626 return;
1627 }
1628 vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
1629 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1630 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1631 && sig_id == vmSymbols::NO_SID) {
1632 return;
1633 }
1634 jshort flags = access_flags().as_short();
1635
1636 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1637 if (id != vmIntrinsics::_none) {
1638 set_intrinsic_id(id);
1639 if (id == vmIntrinsics::_Class_cast) {
1640 // Even if the intrinsic is rejected, we want to inline this simple method.
1641 set_force_inline(true);
1642 }
1643 return;
1644 }
1645
1646 // A few slightly irregular cases:
1647 switch (klass_id) {
1648 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1649 // Second chance: check in regular Math.
1650 switch (name_id) {
1651 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1652 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1653 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1654 // pretend it is the corresponding method in the non-strict class:
1655 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1656 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1657 break;
1658 default:
1659 break;
1660 }
1661 break;
1662
1663 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1664 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1665 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1666 if (!is_native()) break;
1667 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1668 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1669 id = vmIntrinsics::_none;
1670 break;
1671
1672 default:
1673 break;
1674 }
1675
1676 if (id != vmIntrinsics::_none) {
1677 // Set up its iid. It is an alias method.
1678 set_intrinsic_id(id);
1679 return;
1680 }
1681 }
1682
1683 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1684 if (!THREAD->can_call_java()) {
1685 // There is nothing useful this routine can do from within the Compile thread.
1686 // Hopefully, the signature contains only well-known classes.
1687 // We could scan for this and return true/false, but the caller won't care.
1688 return false;
1689 }
1690 bool sig_is_loaded = true;
1691 ResourceMark rm(THREAD);
1692 for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1693 if (ss.is_reference()) {
1694 // load everything, including arrays "[Lfoo;"
1695 Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD);
1696 // We are loading classes eagerly. If a ClassNotFoundException or
1697 // a LinkageError was generated, be sure to ignore it.
1698 if (HAS_PENDING_EXCEPTION) {
1699 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1700 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1701 CLEAR_PENDING_EXCEPTION;
1702 } else {
1703 return false;
1704 }
1705 }
1706 if( klass == NULL) { sig_is_loaded = false; }
1707 }
1708 }
1709 return sig_is_loaded;
1710 }
1711
1712 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1713 ResourceMark rm(THREAD);
1714 for(ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1715 if (ss.type() == T_OBJECT) {
1716 // Do not use ss.is_reference() here, since we don't care about
1717 // unloaded array component types.
1718 Klass* klass = ss.as_klass_if_loaded(THREAD);
1719 assert(!HAS_PENDING_EXCEPTION, "as_klass_if_loaded contract");
1720 if (klass == NULL) return true;
1721 }
1722 }
1723 return false;
1724 }
1725
1726 // Exposed so field engineers can debug VM
1727 void Method::print_short_name(outputStream* st) {
1728 ResourceMark rm;
1729 #ifdef PRODUCT
1730 st->print(" %s::", method_holder()->external_name());
1731 #else
1732 st->print(" %s::", method_holder()->internal_name());
1733 #endif
1734 name()->print_symbol_on(st);
1735 if (WizardMode) signature()->print_symbol_on(st);
1736 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1737 MethodHandles::print_as_basic_type_signature_on(st, signature());
1738 }
1739
1740 // Comparer for sorting an object array containing
1741 // Method*s.
1742 static int method_comparator(Method* a, Method* b) {
1743 return a->name()->fast_compare(b->name());
1744 }
1745
1746 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1747 // default_methods also uses this without the ordering for fast find_method
1748 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1749 int length = methods->length();
1750 if (length > 1) {
1751 if (func == NULL) {
1752 func = method_comparator;
1753 }
1754 {
1755 NoSafepointVerifier nsv;
1756 QuickSort::sort(methods->data(), length, func, /*idempotent=*/false);
1757 }
1758 // Reset method ordering
1759 if (set_idnums) {
1760 for (int i = 0; i < length; i++) {
1761 Method* m = methods->at(i);
1762 m->set_method_idnum(i);
1763 m->set_orig_method_idnum(i);
1764 }
1765 }
1766 }
1767 }
1768
1769 //-----------------------------------------------------------------------------------
1770 // Non-product code unless JVM/TI needs it
1771
1772 #if !defined(PRODUCT) || INCLUDE_JVMTI
1773 class SignatureTypePrinter : public SignatureTypeNames {
1774 private:
1775 outputStream* _st;
1776 bool _use_separator;
1777
1778 void type_name(const char* name) {
1779 if (_use_separator) _st->print(", ");
1780 _st->print("%s", name);
1781 _use_separator = true;
1782 }
1783
1784 public:
1785 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1786 _st = st;
1787 _use_separator = false;
1788 }
1789
1790 void print_parameters() { _use_separator = false; do_parameters_on(this); }
1791 void print_returntype() { _use_separator = false; do_type(return_type()); }
1792 };
1793
1794
1795 void Method::print_name(outputStream* st) {
1796 Thread *thread = Thread::current();
1797 ResourceMark rm(thread);
1798 st->print("%s ", is_static() ? "static" : "virtual");
1799 if (WizardMode) {
1800 st->print("%s.", method_holder()->internal_name());
1801 name()->print_symbol_on(st);
1802 signature()->print_symbol_on(st);
1803 } else {
1804 SignatureTypePrinter sig(signature(), st);
1805 sig.print_returntype();
1806 st->print(" %s.", method_holder()->internal_name());
1807 name()->print_symbol_on(st);
1808 st->print("(");
1809 sig.print_parameters();
1810 st->print(")");
1811 }
1812 }
1813 #endif // !PRODUCT || INCLUDE_JVMTI
1814
1815
1816 void Method::print_codes_on(outputStream* st) const {
1817 print_codes_on(0, code_size(), st);
1818 }
1819
1820 void Method::print_codes_on(int from, int to, outputStream* st) const {
1821 Thread *thread = Thread::current();
1822 ResourceMark rm(thread);
1823 methodHandle mh (thread, (Method*)this);
1824 BytecodeStream s(mh);
1825 s.set_interval(from, to);
1826 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1827 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1828 }
1829
1830 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1831 _bci = 0;
1832 _line = 0;
1833 };
1834
1835 bool CompressedLineNumberReadStream::read_pair() {
1836 jubyte next = read_byte();
1837 // Check for terminator
1838 if (next == 0) return false;
1839 if (next == 0xFF) {
1840 // Escape character, regular compression used
1841 _bci += read_signed_int();
1842 _line += read_signed_int();
1843 } else {
1844 // Single byte compression used
1845 _bci += next >> 3;
1846 _line += next & 0x7;
1847 }
1848 return true;
1849 }
1850
1851 #if INCLUDE_JVMTI
1852
1853 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1854 BreakpointInfo* bp = method_holder()->breakpoints();
1855 for (; bp != NULL; bp = bp->next()) {
1856 if (bp->match(this, bci)) {
1857 return bp->orig_bytecode();
1858 }
1859 }
1860 {
1861 ResourceMark rm;
1862 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1863 }
1864 return Bytecodes::_shouldnotreachhere;
1865 }
1866
1867 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1868 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1869 BreakpointInfo* bp = method_holder()->breakpoints();
1870 for (; bp != NULL; bp = bp->next()) {
1871 if (bp->match(this, bci)) {
1872 bp->set_orig_bytecode(code);
1873 // and continue, in case there is more than one
1874 }
1875 }
1876 }
1877
1878 void Method::set_breakpoint(int bci) {
1879 InstanceKlass* ik = method_holder();
1880 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1881 bp->set_next(ik->breakpoints());
1882 ik->set_breakpoints(bp);
1883 // do this last:
1884 bp->set(this);
1885 }
1886
1887 static void clear_matches(Method* m, int bci) {
1888 InstanceKlass* ik = m->method_holder();
1889 BreakpointInfo* prev_bp = NULL;
1890 BreakpointInfo* next_bp;
1891 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1892 next_bp = bp->next();
1893 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1894 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1895 // do this first:
1896 bp->clear(m);
1897 // unhook it
1898 if (prev_bp != NULL)
1899 prev_bp->set_next(next_bp);
1900 else
1901 ik->set_breakpoints(next_bp);
1902 delete bp;
1903 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1904 // at same location. So we have multiple matching (method_index and bci)
1905 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1906 // breakpoint for clear_breakpoint request and keep all other method versions
1907 // BreakpointInfo for future clear_breakpoint request.
1908 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1909 // which is being called when class is unloaded. We delete all the Breakpoint
1910 // information for all versions of method. We may not correctly restore the original
1911 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1912 // so these methods won't be used anymore.
1913 if (bci >= 0) {
1914 break;
1915 }
1916 } else {
1917 // This one is a keeper.
1918 prev_bp = bp;
1919 }
1920 }
1921 }
1922
1923 void Method::clear_breakpoint(int bci) {
1924 assert(bci >= 0, "");
1925 clear_matches(this, bci);
1926 }
1927
1928 void Method::clear_all_breakpoints() {
1929 clear_matches(this, -1);
1930 }
1931
1932 #endif // INCLUDE_JVMTI
1933
1934 int Method::invocation_count() {
1935 MethodCounters *mcs = method_counters();
1936 if (TieredCompilation) {
1937 MethodData* const mdo = method_data();
1938 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1939 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1940 return InvocationCounter::count_limit;
1941 } else {
1942 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1943 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1944 }
1945 } else {
1946 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1947 }
1948 }
1949
1950 int Method::backedge_count() {
1951 MethodCounters *mcs = method_counters();
1952 if (TieredCompilation) {
1953 MethodData* const mdo = method_data();
1954 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1955 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1956 return InvocationCounter::count_limit;
1957 } else {
1958 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1959 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1960 }
1961 } else {
1962 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1963 }
1964 }
1965
1966 int Method::highest_comp_level() const {
1967 const MethodCounters* mcs = method_counters();
1968 if (mcs != NULL) {
1969 return mcs->highest_comp_level();
1970 } else {
1971 return CompLevel_none;
1972 }
1973 }
1974
1975 int Method::highest_osr_comp_level() const {
1976 const MethodCounters* mcs = method_counters();
1977 if (mcs != NULL) {
1978 return mcs->highest_osr_comp_level();
1979 } else {
1980 return CompLevel_none;
1981 }
1982 }
1983
1984 void Method::set_highest_comp_level(int level) {
1985 MethodCounters* mcs = method_counters();
1986 if (mcs != NULL) {
1987 mcs->set_highest_comp_level(level);
1988 }
1989 }
1990
1991 void Method::set_highest_osr_comp_level(int level) {
1992 MethodCounters* mcs = method_counters();
1993 if (mcs != NULL) {
1994 mcs->set_highest_osr_comp_level(level);
1995 }
1996 }
1997
1998 #if INCLUDE_JVMTI
1999
2000 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
2001 _bci = bci;
2002 _name_index = m->name_index();
2003 _signature_index = m->signature_index();
2004 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
2005 if (_orig_bytecode == Bytecodes::_breakpoint)
2006 _orig_bytecode = m->orig_bytecode_at(_bci);
2007 _next = NULL;
2008 }
2009
2010 void BreakpointInfo::set(Method* method) {
2011 #ifdef ASSERT
2012 {
2013 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2014 if (code == Bytecodes::_breakpoint)
2015 code = method->orig_bytecode_at(_bci);
2016 assert(orig_bytecode() == code, "original bytecode must be the same");
2017 }
2018 #endif
2019 Thread *thread = Thread::current();
2020 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2021 method->incr_number_of_breakpoints(thread);
2022 {
2023 // Deoptimize all dependents on this method
2024 HandleMark hm(thread);
2025 methodHandle mh(thread, method);
2026 CodeCache::flush_dependents_on_method(mh);
2027 }
2028 }
2029
2030 void BreakpointInfo::clear(Method* method) {
2031 *method->bcp_from(_bci) = orig_bytecode();
2032 assert(method->number_of_breakpoints() > 0, "must not go negative");
2033 method->decr_number_of_breakpoints(Thread::current());
2034 }
2035
2036 #endif // INCLUDE_JVMTI
2037
2038 // jmethodID handling
2039
2040 // This is a block allocating object, sort of like JNIHandleBlock, only a
2041 // lot simpler.
2042 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2043 // never get rid of it.
2044
2045 static const int min_block_size = 8;
2046
2047 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2048 friend class JNIMethodBlock;
2049 Method** _methods;
2050 int _number_of_methods;
2051 int _top;
2052 JNIMethodBlockNode* _next;
2053
2054 public:
2055
2056 JNIMethodBlockNode(int num_methods = min_block_size);
2057
2058 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2059
2060 void ensure_methods(int num_addl_methods) {
2061 if (_top < _number_of_methods) {
2062 num_addl_methods -= _number_of_methods - _top;
2063 if (num_addl_methods <= 0) {
2064 return;
2065 }
2066 }
2067 if (_next == NULL) {
2068 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2069 } else {
2070 _next->ensure_methods(num_addl_methods);
2071 }
2072 }
2073 };
2074
2075 class JNIMethodBlock : public CHeapObj<mtClass> {
2076 JNIMethodBlockNode _head;
2077 JNIMethodBlockNode *_last_free;
2078 public:
2079 static Method* const _free_method;
2080
2081 JNIMethodBlock(int initial_capacity = min_block_size)
2082 : _head(initial_capacity), _last_free(&_head) {}
2083
2084 void ensure_methods(int num_addl_methods) {
2085 _last_free->ensure_methods(num_addl_methods);
2086 }
2087
2088 Method** add_method(Method* m) {
2089 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2090 if (b->_top < b->_number_of_methods) {
2091 // top points to the next free entry.
2092 int i = b->_top;
2093 b->_methods[i] = m;
2094 b->_top++;
2095 _last_free = b;
2096 return &(b->_methods[i]);
2097 } else if (b->_top == b->_number_of_methods) {
2098 // if the next free entry ran off the block see if there's a free entry
2099 for (int i = 0; i < b->_number_of_methods; i++) {
2100 if (b->_methods[i] == _free_method) {
2101 b->_methods[i] = m;
2102 _last_free = b;
2103 return &(b->_methods[i]);
2104 }
2105 }
2106 // Only check each block once for frees. They're very unlikely.
2107 // Increment top past the end of the block.
2108 b->_top++;
2109 }
2110 // need to allocate a next block.
2111 if (b->_next == NULL) {
2112 b->_next = _last_free = new JNIMethodBlockNode();
2113 }
2114 }
2115 guarantee(false, "Should always allocate a free block");
2116 return NULL;
2117 }
2118
2119 bool contains(Method** m) {
2120 if (m == NULL) return false;
2121 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2122 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2123 // This is a bit of extra checking, for two reasons. One is
2124 // that contains() deals with pointers that are passed in by
2125 // JNI code, so making sure that the pointer is aligned
2126 // correctly is valuable. The other is that <= and > are
2127 // technically not defined on pointers, so the if guard can
2128 // pass spuriously; no modern compiler is likely to make that
2129 // a problem, though (and if one did, the guard could also
2130 // fail spuriously, which would be bad).
2131 ptrdiff_t idx = m - b->_methods;
2132 if (b->_methods + idx == m) {
2133 return true;
2134 }
2135 }
2136 }
2137 return false; // not found
2138 }
2139
2140 // Doesn't really destroy it, just marks it as free so it can be reused.
2141 void destroy_method(Method** m) {
2142 #ifdef ASSERT
2143 assert(contains(m), "should be a methodID");
2144 #endif // ASSERT
2145 *m = _free_method;
2146 }
2147
2148 // During class unloading the methods are cleared, which is different
2149 // than freed.
2150 void clear_all_methods() {
2151 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2152 for (int i = 0; i< b->_number_of_methods; i++) {
2153 b->_methods[i] = NULL;
2154 }
2155 }
2156 }
2157 #ifndef PRODUCT
2158 int count_methods() {
2159 // count all allocated methods
2160 int count = 0;
2161 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2162 for (int i = 0; i< b->_number_of_methods; i++) {
2163 if (b->_methods[i] != _free_method) count++;
2164 }
2165 }
2166 return count;
2167 }
2168 #endif // PRODUCT
2169 };
2170
2171 // Something that can't be mistaken for an address or a markWord
2172 Method* const JNIMethodBlock::_free_method = (Method*)55;
2173
2174 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2175 _number_of_methods = MAX2(num_methods, min_block_size);
2176 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2177 for (int i = 0; i < _number_of_methods; i++) {
2178 _methods[i] = JNIMethodBlock::_free_method;
2179 }
2180 }
2181
2182 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2183 ClassLoaderData* cld = loader_data;
2184 if (!SafepointSynchronize::is_at_safepoint()) {
2185 // Have to add jmethod_ids() to class loader data thread-safely.
2186 // Also have to add the method to the list safely, which the cld lock
2187 // protects as well.
2188 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2189 if (cld->jmethod_ids() == NULL) {
2190 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2191 } else {
2192 cld->jmethod_ids()->ensure_methods(capacity);
2193 }
2194 } else {
2195 // At safepoint, we are single threaded and can set this.
2196 if (cld->jmethod_ids() == NULL) {
2197 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2198 } else {
2199 cld->jmethod_ids()->ensure_methods(capacity);
2200 }
2201 }
2202 }
2203
2204 // Add a method id to the jmethod_ids
2205 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2206 ClassLoaderData* cld = loader_data;
2207
2208 if (!SafepointSynchronize::is_at_safepoint()) {
2209 // Have to add jmethod_ids() to class loader data thread-safely.
2210 // Also have to add the method to the list safely, which the cld lock
2211 // protects as well.
2212 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2213 if (cld->jmethod_ids() == NULL) {
2214 cld->set_jmethod_ids(new JNIMethodBlock());
2215 }
2216 // jmethodID is a pointer to Method*
2217 return (jmethodID)cld->jmethod_ids()->add_method(m);
2218 } else {
2219 // At safepoint, we are single threaded and can set this.
2220 if (cld->jmethod_ids() == NULL) {
2221 cld->set_jmethod_ids(new JNIMethodBlock());
2222 }
2223 // jmethodID is a pointer to Method*
2224 return (jmethodID)cld->jmethod_ids()->add_method(m);
2225 }
2226 }
2227
2228 jmethodID Method::jmethod_id() {
2229 methodHandle mh(Thread::current(), this);
2230 return method_holder()->get_jmethod_id(mh);
2231 }
2232
2233 // Mark a jmethodID as free. This is called when there is a data race in
2234 // InstanceKlass while creating the jmethodID cache.
2235 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2236 ClassLoaderData* cld = loader_data;
2237 Method** ptr = (Method**)m;
2238 assert(cld->jmethod_ids() != NULL, "should have method handles");
2239 cld->jmethod_ids()->destroy_method(ptr);
2240 }
2241
2242 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2243 // Can't assert the method_holder is the same because the new method has the
2244 // scratch method holder.
2245 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2246 == new_method->method_holder()->class_loader() ||
2247 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2248 "changing to a different class loader");
2249 // Just change the method in place, jmethodID pointer doesn't change.
2250 *((Method**)jmid) = new_method;
2251 }
2252
2253 bool Method::is_method_id(jmethodID mid) {
2254 Method* m = resolve_jmethod_id(mid);
2255 assert(m != NULL, "should be called with non-null method");
2256 InstanceKlass* ik = m->method_holder();
2257 ClassLoaderData* cld = ik->class_loader_data();
2258 if (cld->jmethod_ids() == NULL) return false;
2259 return (cld->jmethod_ids()->contains((Method**)mid));
2260 }
2261
2262 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2263 if (mid == NULL) return NULL;
2264 Method* o = resolve_jmethod_id(mid);
2265 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2266 return NULL;
2267 }
2268 return o;
2269 };
2270
2271 void Method::set_on_stack(const bool value) {
2272 // Set both the method itself and its constant pool. The constant pool
2273 // on stack means some method referring to it is also on the stack.
2274 constants()->set_on_stack(value);
2275
2276 bool already_set = on_stack();
2277 _access_flags.set_on_stack(value);
2278 if (value && !already_set) {
2279 MetadataOnStackMark::record(this);
2280 }
2281 assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2282 "emcp methods cannot run after emcp bit is cleared");
2283 }
2284
2285 // Called when the class loader is unloaded to make all methods weak.
2286 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2287 loader_data->jmethod_ids()->clear_all_methods();
2288 }
2289
2290 bool Method::has_method_vptr(const void* ptr) {
2291 Method m;
2292 // This assumes that the vtbl pointer is the first word of a C++ object.
2293 return dereference_vptr(&m) == dereference_vptr(ptr);
2294 }
2295
2296 // Check that this pointer is valid by checking that the vtbl pointer matches
2297 bool Method::is_valid_method(const Method* m) {
2298 if (m == NULL) {
2299 return false;
2300 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2301 // Quick sanity check on pointer.
2302 return false;
2303 } else if (m->is_shared()) {
2304 return MetaspaceShared::is_valid_shared_method(m);
2305 } else if (Metaspace::contains_non_shared(m)) {
2306 return has_method_vptr((const void*)m);
2307 } else {
2308 return false;
2309 }
2310 }
2311
2312 #ifndef PRODUCT
2313 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2314 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2315 }
2316 #endif // PRODUCT
2317
2318
2319 // Printing
2320
2321 #ifndef PRODUCT
2322
2323 void Method::print_on(outputStream* st) const {
2324 ResourceMark rm;
2325 assert(is_method(), "must be method");
2326 st->print_cr("%s", internal_name());
2327 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2328 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2329 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2330 constants()->print_value_on(st); st->cr();
2331 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2332 st->print (" - name: "); name()->print_value_on(st); st->cr();
2333 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2334 st->print_cr(" - max stack: %d", max_stack());
2335 st->print_cr(" - max locals: %d", max_locals());
2336 st->print_cr(" - size of params: %d", size_of_parameters());
2337 st->print_cr(" - method size: %d", method_size());
2338 if (intrinsic_id() != vmIntrinsics::_none)
2339 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2340 if (highest_comp_level() != CompLevel_none)
2341 st->print_cr(" - highest level: %d", highest_comp_level());
2342 st->print_cr(" - vtable index: %d", _vtable_index);
2343 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2344 st->print( " - adapters: ");
2345 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2346 if (a == NULL)
2347 st->print_cr(INTPTR_FORMAT, p2i(a));
2348 else
2349 a->print_adapter_on(st);
2350 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2351 st->print_cr(" - code size: %d", code_size());
2352 if (code_size() != 0) {
2353 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2354 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2355 }
2356 if (method_data() != NULL) {
2357 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2358 }
2359 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2360 if (checked_exceptions_length() > 0) {
2361 CheckedExceptionElement* table = checked_exceptions_start();
2362 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2363 if (Verbose) {
2364 for (int i = 0; i < checked_exceptions_length(); i++) {
2365 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2366 }
2367 }
2368 }
2369 if (has_linenumber_table()) {
2370 u_char* table = compressed_linenumber_table();
2371 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2372 if (Verbose) {
2373 CompressedLineNumberReadStream stream(table);
2374 while (stream.read_pair()) {
2375 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2376 }
2377 }
2378 }
2379 st->print_cr(" - localvar length: %d", localvariable_table_length());
2380 if (localvariable_table_length() > 0) {
2381 LocalVariableTableElement* table = localvariable_table_start();
2382 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2383 if (Verbose) {
2384 for (int i = 0; i < localvariable_table_length(); i++) {
2385 int bci = table[i].start_bci;
2386 int len = table[i].length;
2387 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2388 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2389 int slot = table[i].slot;
2390 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2391 }
2392 }
2393 }
2394 if (code() != NULL) {
2395 st->print (" - compiled code: ");
2396 code()->print_value_on(st);
2397 }
2398 if (is_native()) {
2399 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2400 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2401 }
2402 }
2403
2404 void Method::print_linkage_flags(outputStream* st) {
2405 access_flags().print_on(st);
2406 if (is_default_method()) {
2407 st->print("default ");
2408 }
2409 if (is_overpass()) {
2410 st->print("overpass ");
2411 }
2412 }
2413 #endif //PRODUCT
2414
2415 void Method::print_value_on(outputStream* st) const {
2416 assert(is_method(), "must be method");
2417 st->print("%s", internal_name());
2418 print_address_on(st);
2419 st->print(" ");
2420 name()->print_value_on(st);
2421 st->print(" ");
2422 signature()->print_value_on(st);
2423 st->print(" in ");
2424 method_holder()->print_value_on(st);
2425 if (WizardMode) st->print("#%d", _vtable_index);
2426 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2427 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2428 }
2429
2430 // LogTouchedMethods and PrintTouchedMethods
2431
2432 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2433 // the Method may be garbage collected. Let's roll our own hash table.
2434 class TouchedMethodRecord : CHeapObj<mtTracing> {
2435 public:
2436 // It's OK to store Symbols here because they will NOT be GC'ed if
2437 // LogTouchedMethods is enabled.
2438 TouchedMethodRecord* _next;
2439 Symbol* _class_name;
2440 Symbol* _method_name;
2441 Symbol* _method_signature;
2442 };
2443
2444 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2445 static TouchedMethodRecord** _touched_method_table = NULL;
2446
2447 void Method::log_touched(TRAPS) {
2448
2449 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2450 Symbol* my_class = klass_name();
2451 Symbol* my_name = name();
2452 Symbol* my_sig = signature();
2453
2454 unsigned int hash = my_class->identity_hash() +
2455 my_name->identity_hash() +
2456 my_sig->identity_hash();
2457 juint index = juint(hash) % table_size;
2458
2459 MutexLocker ml(THREAD, TouchedMethodLog_lock);
2460 if (_touched_method_table == NULL) {
2461 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2462 mtTracing, CURRENT_PC);
2463 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2464 }
2465
2466 TouchedMethodRecord* ptr = _touched_method_table[index];
2467 while (ptr) {
2468 if (ptr->_class_name == my_class &&
2469 ptr->_method_name == my_name &&
2470 ptr->_method_signature == my_sig) {
2471 return;
2472 }
2473 if (ptr->_next == NULL) break;
2474 ptr = ptr->_next;
2475 }
2476 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2477 my_class->increment_refcount();
2478 my_name->increment_refcount();
2479 my_sig->increment_refcount();
2480 nptr->_class_name = my_class;
2481 nptr->_method_name = my_name;
2482 nptr->_method_signature = my_sig;
2483 nptr->_next = NULL;
2484
2485 if (ptr == NULL) {
2486 // first
2487 _touched_method_table[index] = nptr;
2488 } else {
2489 ptr->_next = nptr;
2490 }
2491 }
2492
2493 void Method::print_touched_methods(outputStream* out) {
2494 MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2495 out->print_cr("# Method::print_touched_methods version 1");
2496 if (_touched_method_table) {
2497 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2498 TouchedMethodRecord* ptr = _touched_method_table[i];
2499 while(ptr) {
2500 ptr->_class_name->print_symbol_on(out); out->print(".");
2501 ptr->_method_name->print_symbol_on(out); out->print(":");
2502 ptr->_method_signature->print_symbol_on(out); out->cr();
2503 ptr = ptr->_next;
2504 }
2505 }
2506 }
2507 }
2508
2509 // Verification
2510
2511 void Method::verify_on(outputStream* st) {
2512 guarantee(is_method(), "object must be method");
2513 guarantee(constants()->is_constantPool(), "should be constant pool");
2514 MethodData* md = method_data();
2515 guarantee(md == NULL ||
2516 md->is_methodData(), "should be method data");
2517 }