1 /*
2 * Copyright (c) 1997, 2019, 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 "memory/allocation.inline.hpp"
40 #include "memory/heapInspection.hpp"
41 #include "memory/metadataFactory.hpp"
42 #include "memory/metaspaceClosure.hpp"
43 #include "memory/metaspaceShared.hpp"
44 #include "memory/oopFactory.hpp"
45 #include "memory/resourceArea.hpp"
46 #include "memory/universe.hpp"
47 #include "oops/constMethod.hpp"
48 #include "oops/constantPool.hpp"
49 #include "oops/method.inline.hpp"
50 #include "oops/methodData.hpp"
51 #include "oops/objArrayKlass.hpp"
52 #include "oops/objArrayOop.inline.hpp"
53 #include "oops/oop.inline.hpp"
54 #include "oops/symbol.hpp"
55 #include "prims/jvmtiExport.hpp"
56 #include "prims/methodHandles.hpp"
57 #include "prims/nativeLookup.hpp"
58 #include "runtime/arguments.hpp"
59 #include "runtime/frame.inline.hpp"
60 #include "runtime/handles.inline.hpp"
61 #include "runtime/init.hpp"
62 #include "runtime/orderAccess.hpp"
63 #include "runtime/relocator.hpp"
64 #include "runtime/safepointVerifiers.hpp"
65 #include "runtime/sharedRuntime.hpp"
66 #include "runtime/signature.hpp"
67 #include "utilities/align.hpp"
68 #include "utilities/quickSort.hpp"
69 #include "utilities/vmError.hpp"
70 #include "utilities/xmlstream.hpp"
71
72 // Implementation of Method
73
74 Method* Method::allocate(ClassLoaderData* loader_data,
75 int byte_code_size,
76 AccessFlags access_flags,
77 InlineTableSizes* sizes,
78 ConstMethod::MethodType method_type,
79 TRAPS) {
80 assert(!access_flags.is_native() || byte_code_size == 0,
81 "native methods should not contain byte codes");
82 ConstMethod* cm = ConstMethod::allocate(loader_data,
83 byte_code_size,
84 sizes,
85 method_type,
86 CHECK_NULL);
87 int size = Method::size(access_flags.is_native());
88 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
89 }
90
91 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
92 NoSafepointVerifier no_safepoint;
93 set_constMethod(xconst);
94 set_access_flags(access_flags);
95 set_intrinsic_id(vmIntrinsics::_none);
96 set_force_inline(false);
97 set_hidden(false);
98 set_dont_inline(false);
99 set_has_injected_profile(false);
100 set_method_data(NULL);
101 clear_method_counters();
102 set_vtable_index(Method::garbage_vtable_index);
103
104 // Fix and bury in Method*
105 set_interpreter_entry(NULL); // sets i2i entry and from_int
106 set_adapter_entry(NULL);
107 Method::clear_code(); // from_c/from_i get set to c2i/i2i
108
109 if (access_flags.is_native()) {
110 clear_native_function();
111 set_signature_handler(NULL);
112 }
113
114 NOT_PRODUCT(set_compiled_invocation_count(0);)
115 }
116
117 // Release Method*. The nmethod will be gone when we get here because
118 // we've walked the code cache.
119 void Method::deallocate_contents(ClassLoaderData* loader_data) {
120 MetadataFactory::free_metadata(loader_data, constMethod());
121 set_constMethod(NULL);
122 MetadataFactory::free_metadata(loader_data, method_data());
123 set_method_data(NULL);
124 MetadataFactory::free_metadata(loader_data, method_counters());
125 clear_method_counters();
126 // The nmethod will be gone when we get here.
127 if (code() != NULL) _code = NULL;
128 }
129
130 void Method::release_C_heap_structures() {
131 if (method_data()) {
132 #if INCLUDE_JVMCI
133 FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
134 #endif
135 // Destroy MethodData
136 method_data()->~MethodData();
137 }
138 }
139
140 address Method::get_i2c_entry() {
141 assert(adapter() != NULL, "must have");
142 return adapter()->get_i2c_entry();
143 }
144
145 address Method::get_c2i_entry() {
146 assert(adapter() != NULL, "must have");
147 return adapter()->get_c2i_entry();
148 }
149
150 address Method::get_c2i_unverified_entry() {
151 assert(adapter() != NULL, "must have");
152 return adapter()->get_c2i_unverified_entry();
153 }
154
155 address Method::get_c2i_no_clinit_check_entry() {
156 assert(VM_Version::supports_fast_class_init_checks(), "");
157 assert(adapter() != NULL, "must have");
158 return adapter()->get_c2i_no_clinit_check_entry();
159 }
160
161 char* Method::name_and_sig_as_C_string() const {
162 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
163 }
164
165 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
166 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
167 }
168
169 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
170 const char* klass_name = klass->external_name();
171 int klass_name_len = (int)strlen(klass_name);
172 int method_name_len = method_name->utf8_length();
173 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
174 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
175 strcpy(dest, klass_name);
176 dest[klass_name_len] = '.';
177 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
178 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
179 dest[len] = 0;
180 return dest;
181 }
182
183 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
184 Symbol* klass_name = klass->name();
185 klass_name->as_klass_external_name(buf, size);
186 int len = (int)strlen(buf);
187
188 if (len < size - 1) {
189 buf[len++] = '.';
190
191 method_name->as_C_string(&(buf[len]), size - len);
192 len = (int)strlen(buf);
193
194 signature->as_C_string(&(buf[len]), size - len);
195 }
196
197 return buf;
198 }
199
200 const char* Method::external_name() const {
201 return external_name(constants()->pool_holder(), name(), signature());
202 }
203
204 void Method::print_external_name(outputStream *os) const {
205 print_external_name(os, constants()->pool_holder(), name(), signature());
206 }
207
208 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
209 stringStream ss;
210 print_external_name(&ss, klass, method_name, signature);
211 return ss.as_string();
212 }
213
214 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
215 signature->print_as_signature_external_return_type(os);
216 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
217 signature->print_as_signature_external_parameters(os);
218 os->print(")");
219 }
220
221 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
222 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
223 // access exception table
224 ExceptionTable table(mh());
225 int length = table.length();
226 // iterate through all entries sequentially
227 constantPoolHandle pool(THREAD, mh->constants());
228 for (int i = 0; i < length; i ++) {
229 //reacquire the table in case a GC happened
230 ExceptionTable table(mh());
231 int beg_bci = table.start_pc(i);
232 int end_bci = table.end_pc(i);
233 assert(beg_bci <= end_bci, "inconsistent exception table");
234 if (beg_bci <= throw_bci && throw_bci < end_bci) {
235 // exception handler bci range covers throw_bci => investigate further
236 int handler_bci = table.handler_pc(i);
237 int klass_index = table.catch_type_index(i);
238 if (klass_index == 0) {
239 return handler_bci;
240 } else if (ex_klass == NULL) {
241 return handler_bci;
242 } else {
243 // we know the exception class => get the constraint class
244 // this may require loading of the constraint class; if verification
245 // fails or some other exception occurs, return handler_bci
246 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
247 assert(k != NULL, "klass not loaded");
248 if (ex_klass->is_subtype_of(k)) {
249 return handler_bci;
250 }
251 }
252 }
253 }
254
255 return -1;
256 }
257
258 void Method::mask_for(int bci, InterpreterOopMap* mask) {
259 methodHandle h_this(Thread::current(), this);
260 // Only GC uses the OopMapCache during thread stack root scanning
261 // any other uses generate an oopmap but do not save it in the cache.
262 if (Universe::heap()->is_gc_active()) {
263 method_holder()->mask_for(h_this, bci, mask);
264 } else {
265 OopMapCache::compute_one_oop_map(h_this, bci, mask);
266 }
267 return;
268 }
269
270
271 int Method::bci_from(address bcp) const {
272 if (is_native() && bcp == 0) {
273 return 0;
274 }
275 #ifdef ASSERT
276 {
277 ResourceMark rm;
278 assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
279 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
280 p2i(bcp), name_and_sig_as_C_string());
281 }
282 #endif
283 return bcp - code_base();
284 }
285
286
287 int Method::validate_bci(int bci) const {
288 return (bci == 0 || bci < code_size()) ? bci : -1;
289 }
290
291 // Return bci if it appears to be a valid bcp
292 // Return -1 otherwise.
293 // Used by profiling code, when invalid data is a possibility.
294 // The caller is responsible for validating the Method* itself.
295 int Method::validate_bci_from_bcp(address bcp) const {
296 // keep bci as -1 if not a valid bci
297 int bci = -1;
298 if (bcp == 0 || bcp == code_base()) {
299 // code_size() may return 0 and we allow 0 here
300 // the method may be native
301 bci = 0;
302 } else if (contains(bcp)) {
303 bci = bcp - code_base();
304 }
305 // Assert that if we have dodged any asserts, bci is negative.
306 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
307 return bci;
308 }
309
310 address Method::bcp_from(int bci) const {
311 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
312 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
313 address bcp = code_base() + bci;
314 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
315 return bcp;
316 }
317
318 address Method::bcp_from(address bcp) const {
319 if (is_native() && bcp == NULL) {
320 return code_base();
321 } else {
322 return bcp;
323 }
324 }
325
326 int Method::size(bool is_native) {
327 // If native, then include pointers for native_function and signature_handler
328 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
329 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
330 return align_metadata_size(header_size() + extra_words);
331 }
332
333
334 Symbol* Method::klass_name() const {
335 return method_holder()->name();
336 }
337
338
339 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
340 log_trace(cds)("Iter(Method): %p", this);
341
342 it->push(&_constMethod);
343 it->push(&_method_data);
344 it->push(&_method_counters);
345 }
346
347 // Attempt to return method oop to original state. Clear any pointers
348 // (to objects outside the shared spaces). We won't be able to predict
349 // where they should point in a new JVM. Further initialize some
350 // entries now in order allow them to be write protected later.
351
352 void Method::remove_unshareable_info() {
353 unlink_method();
354 }
355
356 void Method::set_vtable_index(int index) {
357 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
358 // At runtime initialize_vtable is rerun as part of link_class_impl()
359 // for a shared class loaded by the non-boot loader to obtain the loader
360 // constraints based on the runtime classloaders' context.
361 return; // don't write into the shared class
362 } else {
363 _vtable_index = index;
364 }
365 }
366
367 void Method::set_itable_index(int index) {
368 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
369 // At runtime initialize_itable is rerun as part of link_class_impl()
370 // for a shared class loaded by the non-boot loader to obtain the loader
371 // constraints based on the runtime classloaders' context. The dumptime
372 // itable index should be the same as the runtime index.
373 assert(_vtable_index == itable_index_max - index,
374 "archived itable index is different from runtime index");
375 return; // don’t write into the shared class
376 } else {
377 _vtable_index = itable_index_max - index;
378 }
379 assert(valid_itable_index(), "");
380 }
381
382 // The RegisterNatives call being attempted tried to register with a method that
383 // is not native. Ask JVM TI what prefixes have been specified. Then check
384 // to see if the native method is now wrapped with the prefixes. See the
385 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
386 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
387 #if INCLUDE_JVMTI
388 ResourceMark rm(THREAD);
389 Method* method;
390 int name_len = name->utf8_length();
391 char* name_str = name->as_utf8();
392 int prefix_count;
393 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
394 for (int i = 0; i < prefix_count; i++) {
395 char* prefix = prefixes[i];
396 int prefix_len = (int)strlen(prefix);
397
398 // try adding this prefix to the method name and see if it matches another method name
399 int trial_len = name_len + prefix_len;
400 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
401 strcpy(trial_name_str, prefix);
402 strcat(trial_name_str, name_str);
403 TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
404 if (trial_name == NULL) {
405 continue; // no such symbol, so this prefix wasn't used, try the next prefix
406 }
407 method = k->lookup_method(trial_name, signature);
408 if (method == NULL) {
409 continue; // signature doesn't match, try the next prefix
410 }
411 if (method->is_native()) {
412 method->set_is_prefixed_native();
413 return method; // wahoo, we found a prefixed version of the method, return it
414 }
415 // found as non-native, so prefix is good, add it, probably just need more prefixes
416 name_len = trial_len;
417 name_str = trial_name_str;
418 }
419 #endif // INCLUDE_JVMTI
420 return NULL; // not found
421 }
422
423 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
424 Method* method = k->lookup_method(name, signature);
425 if (method == NULL) {
426 ResourceMark rm(THREAD);
427 stringStream st;
428 st.print("Method '");
429 print_external_name(&st, k, name, signature);
430 st.print("' name or signature does not match");
431 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
432 }
433 if (!method->is_native()) {
434 // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
435 method = find_prefixed_native(k, name, signature, THREAD);
436 if (method == NULL) {
437 ResourceMark rm(THREAD);
438 stringStream st;
439 st.print("Method '");
440 print_external_name(&st, k, name, signature);
441 st.print("' is not declared as native");
442 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
443 }
444 }
445
446 if (entry != NULL) {
447 method->set_native_function(entry, native_bind_event_is_interesting);
448 } else {
449 method->clear_native_function();
450 }
451 if (PrintJNIResolving) {
452 ResourceMark rm(THREAD);
453 tty->print_cr("[Registering JNI native method %s.%s]",
454 method->method_holder()->external_name(),
455 method->name()->as_C_string());
456 }
457 return true;
458 }
459
460 bool Method::was_executed_more_than(int n) {
461 // Invocation counter is reset when the Method* is compiled.
462 // If the method has compiled code we therefore assume it has
463 // be excuted more than n times.
464 if (is_accessor() || is_empty_method() || (code() != NULL)) {
465 // interpreter doesn't bump invocation counter of trivial methods
466 // compiler does not bump invocation counter of compiled methods
467 return true;
468 }
469 else if ((method_counters() != NULL &&
470 method_counters()->invocation_counter()->carry()) ||
471 (method_data() != NULL &&
472 method_data()->invocation_counter()->carry())) {
473 // The carry bit is set when the counter overflows and causes
474 // a compilation to occur. We don't know how many times
475 // the counter has been reset, so we simply assume it has
476 // been executed more than n times.
477 return true;
478 } else {
479 return invocation_count() > n;
480 }
481 }
482
483 void Method::print_invocation_count() {
484 if (is_static()) tty->print("static ");
485 if (is_final()) tty->print("final ");
486 if (is_synchronized()) tty->print("synchronized ");
487 if (is_native()) tty->print("native ");
488 tty->print("%s::", method_holder()->external_name());
489 name()->print_symbol_on(tty);
490 signature()->print_symbol_on(tty);
491
492 if (WizardMode) {
493 // dump the size of the byte codes
494 tty->print(" {%d}", code_size());
495 }
496 tty->cr();
497
498 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
499 tty->print_cr (" invocation_counter: %8d ", invocation_count());
500 tty->print_cr (" backedge_counter: %8d ", backedge_count());
501 #ifndef PRODUCT
502 if (CountCompiledCalls) {
503 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
504 }
505 #endif
506 }
507
508 // Build a MethodData* object to hold information about this method
509 // collected in the interpreter.
510 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
511 // Do not profile the method if metaspace has hit an OOM previously
512 // allocating profiling data. Callers clear pending exception so don't
513 // add one here.
514 if (ClassLoaderDataGraph::has_metaspace_oom()) {
515 return;
516 }
517
518 // Grab a lock here to prevent multiple
519 // MethodData*s from being created.
520 MutexLocker ml(MethodData_lock, THREAD);
521 if (method->method_data() == NULL) {
522 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
523 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
524 if (HAS_PENDING_EXCEPTION) {
525 CompileBroker::log_metaspace_failure();
526 ClassLoaderDataGraph::set_metaspace_oom(true);
527 return; // return the exception (which is cleared)
528 }
529
530 method->set_method_data(method_data);
531 if (PrintMethodData && (Verbose || WizardMode)) {
532 ResourceMark rm(THREAD);
533 tty->print("build_interpreter_method_data for ");
534 method->print_name(tty);
535 tty->cr();
536 // At the end of the run, the MDO, full of data, will be dumped.
537 }
538 }
539 }
540
541 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
542 // Do not profile the method if metaspace has hit an OOM previously
543 if (ClassLoaderDataGraph::has_metaspace_oom()) {
544 return NULL;
545 }
546
547 methodHandle mh(m);
548 MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
549 if (HAS_PENDING_EXCEPTION) {
550 CompileBroker::log_metaspace_failure();
551 ClassLoaderDataGraph::set_metaspace_oom(true);
552 return NULL; // return the exception (which is cleared)
553 }
554 if (!mh->init_method_counters(counters)) {
555 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
556 }
557
558 if (LogTouchedMethods) {
559 mh->log_touched(CHECK_NULL);
560 }
561
562 return mh->method_counters();
563 }
564
565 bool Method::init_method_counters(MethodCounters* counters) {
566 // Try to install a pointer to MethodCounters, return true on success.
567 return Atomic::replace_if_null(counters, &_method_counters);
568 }
569
570 int Method::extra_stack_words() {
571 // not an inline function, to avoid a header dependency on Interpreter
572 return extra_stack_entries() * Interpreter::stackElementSize;
573 }
574
575 void Method::compute_size_of_parameters(Thread *thread) {
576 ArgumentSizeComputer asc(signature());
577 set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
578 }
579
580 bool Method::is_empty_method() const {
581 return code_size() == 1
582 && *code_base() == Bytecodes::_return;
583 }
584
585 bool Method::is_vanilla_constructor() const {
586 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
587 // which only calls the superclass vanilla constructor and possibly does stores of
588 // zero constants to local fields:
589 //
590 // aload_0
591 // invokespecial
592 // indexbyte1
593 // indexbyte2
594 //
595 // followed by an (optional) sequence of:
596 //
597 // aload_0
598 // aconst_null / iconst_0 / fconst_0 / dconst_0
599 // putfield
600 // indexbyte1
601 // indexbyte2
602 //
603 // followed by:
604 //
605 // return
606
607 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
608 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
609 int size = code_size();
610 // Check if size match
611 if (size == 0 || size % 5 != 0) return false;
612 address cb = code_base();
613 int last = size - 1;
614 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
615 // Does not call superclass default constructor
616 return false;
617 }
618 // Check optional sequence
619 for (int i = 4; i < last; i += 5) {
620 if (cb[i] != Bytecodes::_aload_0) return false;
621 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
622 if (cb[i+2] != Bytecodes::_putfield) return false;
623 }
624 return true;
625 }
626
627
628 bool Method::compute_has_loops_flag() {
629 BytecodeStream bcs(this);
630 Bytecodes::Code bc;
631
632 while ((bc = bcs.next()) >= 0) {
633 switch( bc ) {
634 case Bytecodes::_ifeq:
635 case Bytecodes::_ifnull:
636 case Bytecodes::_iflt:
637 case Bytecodes::_ifle:
638 case Bytecodes::_ifne:
639 case Bytecodes::_ifnonnull:
640 case Bytecodes::_ifgt:
641 case Bytecodes::_ifge:
642 case Bytecodes::_if_icmpeq:
643 case Bytecodes::_if_icmpne:
644 case Bytecodes::_if_icmplt:
645 case Bytecodes::_if_icmpgt:
646 case Bytecodes::_if_icmple:
647 case Bytecodes::_if_icmpge:
648 case Bytecodes::_if_acmpeq:
649 case Bytecodes::_if_acmpne:
650 case Bytecodes::_goto:
651 case Bytecodes::_jsr:
652 if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
653 break;
654
655 case Bytecodes::_goto_w:
656 case Bytecodes::_jsr_w:
657 if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
658 break;
659
660 default:
661 break;
662 }
663 }
664 _access_flags.set_loops_flag_init();
665 return _access_flags.has_loops();
666 }
667
668 bool Method::is_final_method(AccessFlags class_access_flags) const {
669 // or "does_not_require_vtable_entry"
670 // default method or overpass can occur, is not final (reuses vtable entry)
671 // private methods in classes get vtable entries for backward class compatibility.
672 if (is_overpass() || is_default_method()) return false;
673 return is_final() || class_access_flags.is_final();
674 }
675
676 bool Method::is_final_method() const {
677 return is_final_method(method_holder()->access_flags());
678 }
679
680 bool Method::is_default_method() const {
681 if (method_holder() != NULL &&
682 method_holder()->is_interface() &&
683 !is_abstract() && !is_private()) {
684 return true;
685 } else {
686 return false;
687 }
688 }
689
690 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
691 if (is_final_method(class_access_flags)) return true;
692 #ifdef ASSERT
693 ResourceMark rm;
694 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
695 if (class_access_flags.is_interface()) {
696 assert(is_nonv == is_static() || is_nonv == is_private(),
697 "nonvirtual unexpected for non-static, non-private: %s",
698 name_and_sig_as_C_string());
699 }
700 #endif
701 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
702 return vtable_index() == nonvirtual_vtable_index;
703 }
704
705 bool Method::can_be_statically_bound() const {
706 return can_be_statically_bound(method_holder()->access_flags());
707 }
708
709 bool Method::can_be_statically_bound(InstanceKlass* context) const {
710 return (method_holder() == context) && can_be_statically_bound();
711 }
712
713 bool Method::is_accessor() const {
714 return is_getter() || is_setter();
715 }
716
717 bool Method::is_getter() const {
718 if (code_size() != 5) return false;
719 if (size_of_parameters() != 1) return false;
720 if (java_code_at(0) != Bytecodes::_aload_0) return false;
721 if (java_code_at(1) != Bytecodes::_getfield) return false;
722 switch (java_code_at(4)) {
723 case Bytecodes::_ireturn:
724 case Bytecodes::_lreturn:
725 case Bytecodes::_freturn:
726 case Bytecodes::_dreturn:
727 case Bytecodes::_areturn:
728 break;
729 default:
730 return false;
731 }
732 return true;
733 }
734
735 bool Method::is_setter() const {
736 if (code_size() != 6) return false;
737 if (java_code_at(0) != Bytecodes::_aload_0) return false;
738 switch (java_code_at(1)) {
739 case Bytecodes::_iload_1:
740 case Bytecodes::_aload_1:
741 case Bytecodes::_fload_1:
742 if (size_of_parameters() != 2) return false;
743 break;
744 case Bytecodes::_dload_1:
745 case Bytecodes::_lload_1:
746 if (size_of_parameters() != 3) return false;
747 break;
748 default:
749 return false;
750 }
751 if (java_code_at(2) != Bytecodes::_putfield) return false;
752 if (java_code_at(5) != Bytecodes::_return) return false;
753 return true;
754 }
755
756 bool Method::is_constant_getter() const {
757 int last_index = code_size() - 1;
758 // Check if the first 1-3 bytecodes are a constant push
759 // and the last bytecode is a return.
760 return (2 <= code_size() && code_size() <= 4 &&
761 Bytecodes::is_const(java_code_at(0)) &&
762 Bytecodes::length_for(java_code_at(0)) == last_index &&
763 Bytecodes::is_return(java_code_at(last_index)));
764 }
765
766 bool Method::is_initializer() const {
767 return is_object_initializer() || is_static_initializer();
768 }
769
770 bool Method::has_valid_initializer_flags() const {
771 return (is_static() ||
772 method_holder()->major_version() < 51);
773 }
774
775 bool Method::is_static_initializer() const {
776 // For classfiles version 51 or greater, ensure that the clinit method is
777 // static. Non-static methods with the name "<clinit>" are not static
778 // initializers. (older classfiles exempted for backward compatibility)
779 return name() == vmSymbols::class_initializer_name() &&
780 has_valid_initializer_flags();
781 }
782
783 bool Method::is_object_initializer() const {
784 return name() == vmSymbols::object_initializer_name();
785 }
786
787 bool Method::needs_clinit_barrier() const {
788 return is_static() && !method_holder()->is_initialized();
789 }
790
791 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
792 int length = method->checked_exceptions_length();
793 if (length == 0) { // common case
794 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
795 } else {
796 methodHandle h_this(THREAD, method);
797 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
798 objArrayHandle mirrors (THREAD, m_oop);
799 for (int i = 0; i < length; i++) {
800 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
801 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
802 assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
803 mirrors->obj_at_put(i, k->java_mirror());
804 }
805 return mirrors;
806 }
807 };
808
809
810 int Method::line_number_from_bci(int bci) const {
811 int best_bci = 0;
812 int best_line = -1;
813 if (bci == SynchronizationEntryBCI) bci = 0;
814 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
815 // The line numbers are a short array of 2-tuples [start_pc, line_number].
816 // Not necessarily sorted and not necessarily one-to-one.
817 CompressedLineNumberReadStream stream(compressed_linenumber_table());
818 while (stream.read_pair()) {
819 if (stream.bci() == bci) {
820 // perfect match
821 return stream.line();
822 } else {
823 // update best_bci/line
824 if (stream.bci() < bci && stream.bci() >= best_bci) {
825 best_bci = stream.bci();
826 best_line = stream.line();
827 }
828 }
829 }
830 }
831 return best_line;
832 }
833
834
835 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
836 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
837 Thread *thread = Thread::current();
838 Symbol* klass_name = constants()->klass_name_at(klass_index);
839 Handle loader(thread, method_holder()->class_loader());
840 Handle prot (thread, method_holder()->protection_domain());
841 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
842 } else {
843 return true;
844 }
845 }
846
847
848 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
849 int klass_index = constants()->klass_ref_index_at(refinfo_index);
850 if (must_be_resolved) {
851 // Make sure klass is resolved in constantpool.
852 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
853 }
854 return is_klass_loaded_by_klass_index(klass_index);
855 }
856
857
858 void Method::set_native_function(address function, bool post_event_flag) {
859 assert(function != NULL, "use clear_native_function to unregister natives");
860 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
861 address* native_function = native_function_addr();
862
863 // We can see racers trying to place the same native function into place. Once
864 // is plenty.
865 address current = *native_function;
866 if (current == function) return;
867 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
868 function != NULL) {
869 // native_method_throw_unsatisfied_link_error_entry() should only
870 // be passed when post_event_flag is false.
871 assert(function !=
872 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
873 "post_event_flag mis-match");
874
875 // post the bind event, and possible change the bind function
876 JvmtiExport::post_native_method_bind(this, &function);
877 }
878 *native_function = function;
879 // This function can be called more than once. We must make sure that we always
880 // use the latest registered method -> check if a stub already has been generated.
881 // If so, we have to make it not_entrant.
882 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
883 if (nm != NULL) {
884 nm->make_not_entrant();
885 }
886 }
887
888
889 bool Method::has_native_function() const {
890 if (is_method_handle_intrinsic())
891 return false; // special-cased in SharedRuntime::generate_native_wrapper
892 address func = native_function();
893 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
894 }
895
896
897 void Method::clear_native_function() {
898 // Note: is_method_handle_intrinsic() is allowed here.
899 set_native_function(
900 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
901 !native_bind_event_is_interesting);
902 this->unlink_code();
903 }
904
905
906 void Method::set_signature_handler(address handler) {
907 address* signature_handler = signature_handler_addr();
908 *signature_handler = handler;
909 }
910
911
912 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
913 assert(reason != NULL, "must provide a reason");
914 if (PrintCompilation && report) {
915 ttyLocker ttyl;
916 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
917 if (comp_level == CompLevel_all) {
918 tty->print("all levels ");
919 } else {
920 tty->print("level %d ", comp_level);
921 }
922 this->print_short_name(tty);
923 int size = this->code_size();
924 if (size > 0) {
925 tty->print(" (%d bytes)", size);
926 }
927 if (reason != NULL) {
928 tty->print(" %s", reason);
929 }
930 tty->cr();
931 }
932 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
933 ttyLocker ttyl;
934 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
935 os::current_thread_id(), is_osr, comp_level);
936 if (reason != NULL) {
937 xtty->print(" reason=\'%s\'", reason);
938 }
939 xtty->method(this);
940 xtty->stamp();
941 xtty->end_elem();
942 }
943 }
944
945 bool Method::is_always_compilable() const {
946 // Generated adapters must be compiled
947 if (is_method_handle_intrinsic() && is_synthetic()) {
948 assert(!is_not_c1_compilable(), "sanity check");
949 assert(!is_not_c2_compilable(), "sanity check");
950 return true;
951 }
952
953 return false;
954 }
955
956 bool Method::is_not_compilable(int comp_level) const {
957 if (number_of_breakpoints() > 0)
958 return true;
959 if (is_always_compilable())
960 return false;
961 if (comp_level == CompLevel_any)
962 return is_not_c1_compilable() || is_not_c2_compilable();
963 if (is_c1_compile(comp_level))
964 return is_not_c1_compilable();
965 if (is_c2_compile(comp_level))
966 return is_not_c2_compilable();
967 return false;
968 }
969
970 // call this when compiler finds that this method is not compilable
971 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
972 if (is_always_compilable()) {
973 // Don't mark a method which should be always compilable
974 return;
975 }
976 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
977 if (comp_level == CompLevel_all) {
978 set_not_c1_compilable();
979 set_not_c2_compilable();
980 } else {
981 if (is_c1_compile(comp_level))
982 set_not_c1_compilable();
983 if (is_c2_compile(comp_level))
984 set_not_c2_compilable();
985 }
986 CompilationPolicy::policy()->disable_compilation(this);
987 assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
988 }
989
990 bool Method::is_not_osr_compilable(int comp_level) const {
991 if (is_not_compilable(comp_level))
992 return true;
993 if (comp_level == CompLevel_any)
994 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
995 if (is_c1_compile(comp_level))
996 return is_not_c1_osr_compilable();
997 if (is_c2_compile(comp_level))
998 return is_not_c2_osr_compilable();
999 return false;
1000 }
1001
1002 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1003 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1004 if (comp_level == CompLevel_all) {
1005 set_not_c1_osr_compilable();
1006 set_not_c2_osr_compilable();
1007 } else {
1008 if (is_c1_compile(comp_level))
1009 set_not_c1_osr_compilable();
1010 if (is_c2_compile(comp_level))
1011 set_not_c2_osr_compilable();
1012 }
1013 CompilationPolicy::policy()->disable_compilation(this);
1014 assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
1015 }
1016
1017 // Revert to using the interpreter and clear out the nmethod
1018 void Method::clear_code() {
1019 // this may be NULL if c2i adapters have not been made yet
1020 // Only should happen at allocate time.
1021 if (adapter() == NULL) {
1022 _from_compiled_entry = NULL;
1023 } else {
1024 _from_compiled_entry = adapter()->get_c2i_entry();
1025 }
1026 OrderAccess::storestore();
1027 _from_interpreted_entry = _i2i_entry;
1028 OrderAccess::storestore();
1029 _code = NULL;
1030 }
1031
1032 void Method::unlink_code(CompiledMethod *compare) {
1033 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1034 // We need to check if either the _code or _from_compiled_code_entry_point
1035 // refer to this nmethod because there is a race in setting these two fields
1036 // in Method* as seen in bugid 4947125.
1037 // If the vep() points to the zombie nmethod, the memory for the nmethod
1038 // could be flushed and the compiler and vtable stubs could still call
1039 // through it.
1040 if (code() == compare ||
1041 from_compiled_entry() == compare->verified_entry_point()) {
1042 clear_code();
1043 }
1044 }
1045
1046 void Method::unlink_code() {
1047 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1048 clear_code();
1049 }
1050
1051 #if INCLUDE_CDS
1052 // Called by class data sharing to remove any entry points (which are not shared)
1053 void Method::unlink_method() {
1054 _code = NULL;
1055
1056 Arguments::assert_is_dumping_archive();
1057 // Set the values to what they should be at run time. Note that
1058 // this Method can no longer be executed during dump time.
1059 _i2i_entry = Interpreter::entry_for_cds_method(this);
1060 _from_interpreted_entry = _i2i_entry;
1061
1062 if (DynamicDumpSharedSpaces) {
1063 assert(_from_compiled_entry != NULL, "sanity");
1064 } else {
1065 // TODO: Simplify the adapter trampoline allocation for static archiving.
1066 // Remove the use of CDSAdapterHandlerEntry.
1067 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
1068 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
1069 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
1070 assert(*((int*)_from_compiled_entry) == 0,
1071 "must be NULL during dump time, to be initialized at run time");
1072 }
1073
1074 if (is_native()) {
1075 *native_function_addr() = NULL;
1076 set_signature_handler(NULL);
1077 }
1078 NOT_PRODUCT(set_compiled_invocation_count(0);)
1079
1080 set_method_data(NULL);
1081 clear_method_counters();
1082 }
1083 #endif
1084
1085 /****************************************************************************
1086 // The following illustrates how the entries work for CDS shared Methods:
1087 //
1088 // Our goal is to delay writing into a shared Method until it's compiled.
1089 // Hence, we want to determine the initial values for _i2i_entry,
1090 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1091 //
1092 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1093 // They also have similar signatures so that they will share the same
1094 // AdapterHandlerEntry.
1095 //
1096 // _adapter_trampoline points to a fixed location in the RW section of
1097 // the CDS archive. This location initially contains a NULL pointer. When the
1098 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1099 // dynamically, and its c2i/i2c entries are generated.
1100 //
1101 // _i2i_entry and _from_interpreted_entry initially points to the same
1102 // (fixed) location in the CODE section of the CDS archive. This contains
1103 // an unconditional branch to the actual entry for "zero_locals", which is
1104 // generated at run time and may be on an arbitrary address. Thus, the
1105 // unconditional branch is also generated at run time to jump to the correct
1106 // address.
1107 //
1108 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1109 // section. This address has enough space for an unconditional branch
1110 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1111 // initialized, and the address for the actual c2i_entry is known, we emit a
1112 // branch instruction here to branch to the actual c2i_entry.
1113 //
1114 // The effect of the extra branch on the i2i and c2i entries is negligible.
1115 //
1116 // The reason for putting _adapter_trampoline in RO is many shared Methods
1117 // share the same AdapterHandlerEntry, so we can save space in the RW section
1118 // by having the extra indirection.
1119
1120
1121 [Method A: RW]
1122 _constMethod ----> [ConstMethod: RO]
1123 _adapter_trampoline -----------+
1124 |
1125 _i2i_entry (same value as method B) |
1126 _from_interpreted_entry (same value as method B) |
1127 _from_compiled_entry (same value as method B) |
1128 |
1129 |
1130 [Method B: RW] +--------+
1131 _constMethod ----> [ConstMethod: RO] |
1132 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1133 |
1134 +-------------------------------+
1135 |
1136 +----> [AdapterHandlerEntry] (allocated at run time)
1137 _fingerprint
1138 _c2i_entry ---------------------------------+->[c2i entry..]
1139 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1140 _from_interpreted_entry | _c2i_unverified_entry | |
1141 | | _c2i_no_clinit_check_entry| |
1142 | | (_cds_entry_table: CODE) | |
1143 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1144 | | (allocated at run time) | |
1145 | | ... [asm code ...] | |
1146 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1147 | | |
1148 | | |
1149 +-[compiled]-------------------------------------------------------------------+ |
1150 |
1151 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1152 [jmp c2i_entry] ------------------------------------------------------+
1153
1154 ***/
1155
1156 // Called when the method_holder is getting linked. Setup entrypoints so the method
1157 // is ready to be called from interpreter, compiler, and vtables.
1158 void Method::link_method(const methodHandle& h_method, TRAPS) {
1159 // If the code cache is full, we may reenter this function for the
1160 // leftover methods that weren't linked.
1161 if (is_shared()) {
1162 address entry = Interpreter::entry_for_cds_method(h_method);
1163 assert(entry != NULL && entry == _i2i_entry,
1164 "should be correctly set during dump time");
1165 if (adapter() != NULL) {
1166 return;
1167 }
1168 assert(entry == _from_interpreted_entry,
1169 "should be correctly set during dump time");
1170 } else if (_i2i_entry != NULL) {
1171 return;
1172 }
1173 assert( _code == NULL, "nothing compiled yet" );
1174
1175 // Setup interpreter entrypoint
1176 assert(this == h_method(), "wrong h_method()" );
1177
1178 if (!is_shared()) {
1179 assert(adapter() == NULL, "init'd to NULL");
1180 address entry = Interpreter::entry_for_method(h_method);
1181 assert(entry != NULL, "interpreter entry must be non-null");
1182 // Sets both _i2i_entry and _from_interpreted_entry
1183 set_interpreter_entry(entry);
1184 }
1185
1186 // Don't overwrite already registered native entries.
1187 if (is_native() && !has_native_function()) {
1188 set_native_function(
1189 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1190 !native_bind_event_is_interesting);
1191 }
1192
1193 // Setup compiler entrypoint. This is made eagerly, so we do not need
1194 // special handling of vtables. An alternative is to make adapters more
1195 // lazily by calling make_adapter() from from_compiled_entry() for the
1196 // normal calls. For vtable calls life gets more complicated. When a
1197 // call-site goes mega-morphic we need adapters in all methods which can be
1198 // called from the vtable. We need adapters on such methods that get loaded
1199 // later. Ditto for mega-morphic itable calls. If this proves to be a
1200 // problem we'll make these lazily later.
1201 (void) make_adapters(h_method, CHECK);
1202
1203 // ONLY USE the h_method now as make_adapter may have blocked
1204
1205 }
1206
1207 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1208 // Adapters for compiled code are made eagerly here. They are fairly
1209 // small (generally < 100 bytes) and quick to make (and cached and shared)
1210 // so making them eagerly shouldn't be too expensive.
1211 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1212 if (adapter == NULL ) {
1213 if (!is_init_completed()) {
1214 // Don't throw exceptions during VM initialization because java.lang.* classes
1215 // might not have been initialized, causing problems when constructing the
1216 // Java exception object.
1217 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1218 } else {
1219 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1220 }
1221 }
1222
1223 if (mh->is_shared()) {
1224 assert(mh->adapter() == adapter, "must be");
1225 assert(mh->_from_compiled_entry != NULL, "must be");
1226 } else {
1227 mh->set_adapter_entry(adapter);
1228 mh->_from_compiled_entry = adapter->get_c2i_entry();
1229 }
1230 return adapter->get_c2i_entry();
1231 }
1232
1233 void Method::restore_unshareable_info(TRAPS) {
1234 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1235
1236 // Since restore_unshareable_info can be called more than once for a method, don't
1237 // redo any work.
1238 if (adapter() == NULL) {
1239 methodHandle mh(THREAD, this);
1240 link_method(mh, CHECK);
1241 }
1242 }
1243
1244 address Method::from_compiled_entry_no_trampoline() const {
1245 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1246 if (code) {
1247 return code->verified_entry_point();
1248 } else {
1249 return adapter()->get_c2i_entry();
1250 }
1251 }
1252
1253 // The verified_code_entry() must be called when a invoke is resolved
1254 // on this method.
1255
1256 // It returns the compiled code entry point, after asserting not null.
1257 // This function is called after potential safepoints so that nmethod
1258 // or adapter that it points to is still live and valid.
1259 // This function must not hit a safepoint!
1260 address Method::verified_code_entry() {
1261 debug_only(NoSafepointVerifier nsv;)
1262 assert(_from_compiled_entry != NULL, "must be set");
1263 return _from_compiled_entry;
1264 }
1265
1266 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1267 // (could be racing a deopt).
1268 // Not inline to avoid circular ref.
1269 bool Method::check_code() const {
1270 // cached in a register or local. There's a race on the value of the field.
1271 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1272 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1273 }
1274
1275 // Install compiled code. Instantly it can execute.
1276 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1277 assert_lock_strong(CompiledMethod_lock);
1278 assert( code, "use clear_code to remove code" );
1279 assert( mh->check_code(), "" );
1280
1281 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1282
1283 // These writes must happen in this order, because the interpreter will
1284 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1285 // which jumps to _from_compiled_entry.
1286 mh->_code = code; // Assign before allowing compiled code to exec
1287
1288 int comp_level = code->comp_level();
1289 // In theory there could be a race here. In practice it is unlikely
1290 // and not worth worrying about.
1291 if (comp_level > mh->highest_comp_level()) {
1292 mh->set_highest_comp_level(comp_level);
1293 }
1294
1295 OrderAccess::storestore();
1296 mh->_from_compiled_entry = code->verified_entry_point();
1297 OrderAccess::storestore();
1298 // Instantly compiled code can execute.
1299 if (!mh->is_method_handle_intrinsic())
1300 mh->_from_interpreted_entry = mh->get_i2c_entry();
1301 }
1302
1303
1304 bool Method::is_overridden_in(Klass* k) const {
1305 InstanceKlass* ik = InstanceKlass::cast(k);
1306
1307 if (ik->is_interface()) return false;
1308
1309 // If method is an interface, we skip it - except if it
1310 // is a miranda method
1311 if (method_holder()->is_interface()) {
1312 // Check that method is not a miranda method
1313 if (ik->lookup_method(name(), signature()) == NULL) {
1314 // No implementation exist - so miranda method
1315 return false;
1316 }
1317 return true;
1318 }
1319
1320 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1321 if (!has_vtable_index()) {
1322 return false;
1323 } else {
1324 Method* vt_m = ik->method_at_vtable(vtable_index());
1325 return vt_m != this;
1326 }
1327 }
1328
1329
1330 // give advice about whether this Method* should be cached or not
1331 bool Method::should_not_be_cached() const {
1332 if (is_old()) {
1333 // This method has been redefined. It is either EMCP or obsolete
1334 // and we don't want to cache it because that would pin the method
1335 // down and prevent it from being collectible if and when it
1336 // finishes executing.
1337 return true;
1338 }
1339
1340 // caching this method should be just fine
1341 return false;
1342 }
1343
1344
1345 /**
1346 * Returns true if this is one of the specially treated methods for
1347 * security related stack walks (like Reflection.getCallerClass).
1348 */
1349 bool Method::is_ignored_by_security_stack_walk() const {
1350 if (intrinsic_id() == vmIntrinsics::_invoke) {
1351 // This is Method.invoke() -- ignore it
1352 return true;
1353 }
1354 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1355 // This is an auxilary frame -- ignore it
1356 return true;
1357 }
1358 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1359 // This is an internal adapter frame for method handles -- ignore it
1360 return true;
1361 }
1362 return false;
1363 }
1364
1365
1366 // Constant pool structure for invoke methods:
1367 enum {
1368 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1369 _imcp_invoke_signature, // utf8: (variable Symbol*)
1370 _imcp_limit
1371 };
1372
1373 // Test if this method is an MH adapter frame generated by Java code.
1374 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1375 bool Method::is_compiled_lambda_form() const {
1376 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1377 }
1378
1379 // Test if this method is an internal MH primitive method.
1380 bool Method::is_method_handle_intrinsic() const {
1381 vmIntrinsics::ID iid = intrinsic_id();
1382 return (MethodHandles::is_signature_polymorphic(iid) &&
1383 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1384 }
1385
1386 bool Method::has_member_arg() const {
1387 vmIntrinsics::ID iid = intrinsic_id();
1388 return (MethodHandles::is_signature_polymorphic(iid) &&
1389 MethodHandles::has_member_arg(iid));
1390 }
1391
1392 // Make an instance of a signature-polymorphic internal MH primitive.
1393 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1394 Symbol* signature,
1395 TRAPS) {
1396 ResourceMark rm;
1397 methodHandle empty;
1398
1399 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1400 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1401 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1402 if (TraceMethodHandles) {
1403 tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1404 }
1405
1406 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1407 name->increment_refcount();
1408 signature->increment_refcount();
1409
1410 int cp_length = _imcp_limit;
1411 ClassLoaderData* loader_data = holder->class_loader_data();
1412 constantPoolHandle cp;
1413 {
1414 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1415 cp = constantPoolHandle(THREAD, cp_oop);
1416 }
1417 cp->set_pool_holder(holder);
1418 cp->symbol_at_put(_imcp_invoke_name, name);
1419 cp->symbol_at_put(_imcp_invoke_signature, signature);
1420 cp->set_has_preresolution();
1421
1422 // decide on access bits: public or not?
1423 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1424 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1425 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1426 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1427
1428 methodHandle m;
1429 {
1430 InlineTableSizes sizes;
1431 Method* m_oop = Method::allocate(loader_data, 0,
1432 accessFlags_from(flags_bits), &sizes,
1433 ConstMethod::NORMAL, CHECK_(empty));
1434 m = methodHandle(THREAD, m_oop);
1435 }
1436 m->set_constants(cp());
1437 m->set_name_index(_imcp_invoke_name);
1438 m->set_signature_index(_imcp_invoke_signature);
1439 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1440 assert(m->signature() == signature, "");
1441 ResultTypeFinder rtf(signature);
1442 m->constMethod()->set_result_type(rtf.type());
1443 m->compute_size_of_parameters(THREAD);
1444 m->init_intrinsic_id();
1445 assert(m->is_method_handle_intrinsic(), "");
1446 #ifdef ASSERT
1447 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1448 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1449 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1450 #endif //ASSERT
1451
1452 // Finally, set up its entry points.
1453 assert(m->can_be_statically_bound(), "");
1454 m->set_vtable_index(Method::nonvirtual_vtable_index);
1455 m->link_method(m, CHECK_(empty));
1456
1457 if (TraceMethodHandles && (Verbose || WizardMode)) {
1458 ttyLocker ttyl;
1459 m->print_on(tty);
1460 }
1461
1462 return m;
1463 }
1464
1465 Klass* Method::check_non_bcp_klass(Klass* klass) {
1466 if (klass != NULL && klass->class_loader() != NULL) {
1467 if (klass->is_objArray_klass())
1468 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1469 return klass;
1470 }
1471 return NULL;
1472 }
1473
1474
1475 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1476 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1477 // Code below does not work for native methods - they should never get rewritten anyway
1478 assert(!m->is_native(), "cannot rewrite native methods");
1479 // Allocate new Method*
1480 AccessFlags flags = m->access_flags();
1481
1482 ConstMethod* cm = m->constMethod();
1483 int checked_exceptions_len = cm->checked_exceptions_length();
1484 int localvariable_len = cm->localvariable_table_length();
1485 int exception_table_len = cm->exception_table_length();
1486 int method_parameters_len = cm->method_parameters_length();
1487 int method_annotations_len = cm->method_annotations_length();
1488 int parameter_annotations_len = cm->parameter_annotations_length();
1489 int type_annotations_len = cm->type_annotations_length();
1490 int default_annotations_len = cm->default_annotations_length();
1491
1492 InlineTableSizes sizes(
1493 localvariable_len,
1494 new_compressed_linenumber_size,
1495 exception_table_len,
1496 checked_exceptions_len,
1497 method_parameters_len,
1498 cm->generic_signature_index(),
1499 method_annotations_len,
1500 parameter_annotations_len,
1501 type_annotations_len,
1502 default_annotations_len,
1503 0);
1504
1505 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1506 Method* newm_oop = Method::allocate(loader_data,
1507 new_code_length,
1508 flags,
1509 &sizes,
1510 m->method_type(),
1511 CHECK_(methodHandle()));
1512 methodHandle newm (THREAD, newm_oop);
1513
1514 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1515 ConstMethod* newcm = newm->constMethod();
1516 int new_const_method_size = newm->constMethod()->size();
1517
1518 // This works because the source and target are both Methods. Some compilers
1519 // (e.g., clang) complain that the target vtable pointer will be stomped,
1520 // so cast away newm()'s and m()'s Methodness.
1521 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1522
1523 // Create shallow copy of ConstMethod.
1524 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1525
1526 // Reset correct method/const method, method size, and parameter info
1527 newm->set_constMethod(newcm);
1528 newm->constMethod()->set_code_size(new_code_length);
1529 newm->constMethod()->set_constMethod_size(new_const_method_size);
1530 assert(newm->code_size() == new_code_length, "check");
1531 assert(newm->method_parameters_length() == method_parameters_len, "check");
1532 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1533 assert(newm->exception_table_length() == exception_table_len, "check");
1534 assert(newm->localvariable_table_length() == localvariable_len, "check");
1535 // Copy new byte codes
1536 memcpy(newm->code_base(), new_code, new_code_length);
1537 // Copy line number table
1538 if (new_compressed_linenumber_size > 0) {
1539 memcpy(newm->compressed_linenumber_table(),
1540 new_compressed_linenumber_table,
1541 new_compressed_linenumber_size);
1542 }
1543 // Copy method_parameters
1544 if (method_parameters_len > 0) {
1545 memcpy(newm->method_parameters_start(),
1546 m->method_parameters_start(),
1547 method_parameters_len * sizeof(MethodParametersElement));
1548 }
1549 // Copy checked_exceptions
1550 if (checked_exceptions_len > 0) {
1551 memcpy(newm->checked_exceptions_start(),
1552 m->checked_exceptions_start(),
1553 checked_exceptions_len * sizeof(CheckedExceptionElement));
1554 }
1555 // Copy exception table
1556 if (exception_table_len > 0) {
1557 memcpy(newm->exception_table_start(),
1558 m->exception_table_start(),
1559 exception_table_len * sizeof(ExceptionTableElement));
1560 }
1561 // Copy local variable number table
1562 if (localvariable_len > 0) {
1563 memcpy(newm->localvariable_table_start(),
1564 m->localvariable_table_start(),
1565 localvariable_len * sizeof(LocalVariableTableElement));
1566 }
1567 // Copy stackmap table
1568 if (m->has_stackmap_table()) {
1569 int code_attribute_length = m->stackmap_data()->length();
1570 Array<u1>* stackmap_data =
1571 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1572 memcpy((void*)stackmap_data->adr_at(0),
1573 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1574 newm->set_stackmap_data(stackmap_data);
1575 }
1576
1577 // copy annotations over to new method
1578 newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1579 return newm;
1580 }
1581
1582 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1583 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1584 // because we are not loading from core libraries
1585 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1586 // which does not use the class default class loader so we check for its loader here
1587 const InstanceKlass* ik = InstanceKlass::cast(holder);
1588 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1589 return vmSymbols::NO_SID; // regardless of name, no intrinsics here
1590 }
1591
1592 // see if the klass name is well-known:
1593 Symbol* klass_name = ik->name();
1594 return vmSymbols::find_sid(klass_name);
1595 }
1596
1597 void Method::init_intrinsic_id() {
1598 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1599 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1600 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1601 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1602
1603 // the klass name is well-known:
1604 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1605 assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1606
1607 // ditto for method and signature:
1608 vmSymbols::SID name_id = vmSymbols::find_sid(name());
1609 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1610 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1611 && name_id == vmSymbols::NO_SID) {
1612 return;
1613 }
1614 vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
1615 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1616 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1617 && sig_id == vmSymbols::NO_SID) {
1618 return;
1619 }
1620 jshort flags = access_flags().as_short();
1621
1622 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1623 if (id != vmIntrinsics::_none) {
1624 set_intrinsic_id(id);
1625 if (id == vmIntrinsics::_Class_cast) {
1626 // Even if the intrinsic is rejected, we want to inline this simple method.
1627 set_force_inline(true);
1628 }
1629 return;
1630 }
1631
1632 // A few slightly irregular cases:
1633 switch (klass_id) {
1634 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1635 // Second chance: check in regular Math.
1636 switch (name_id) {
1637 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1638 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1639 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1640 // pretend it is the corresponding method in the non-strict class:
1641 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1642 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1643 break;
1644 default:
1645 break;
1646 }
1647 break;
1648
1649 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1650 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1651 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1652 if (!is_native()) break;
1653 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1654 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1655 id = vmIntrinsics::_none;
1656 break;
1657
1658 default:
1659 break;
1660 }
1661
1662 if (id != vmIntrinsics::_none) {
1663 // Set up its iid. It is an alias method.
1664 set_intrinsic_id(id);
1665 return;
1666 }
1667 }
1668
1669 // These two methods are static since a GC may move the Method
1670 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1671 if (!THREAD->can_call_java()) {
1672 // There is nothing useful this routine can do from within the Compile thread.
1673 // Hopefully, the signature contains only well-known classes.
1674 // We could scan for this and return true/false, but the caller won't care.
1675 return false;
1676 }
1677 bool sig_is_loaded = true;
1678 Handle class_loader(THREAD, m->method_holder()->class_loader());
1679 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1680 ResourceMark rm(THREAD);
1681 Symbol* signature = m->signature();
1682 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1683 if (ss.is_object()) {
1684 Symbol* sym = ss.as_symbol();
1685 Symbol* name = sym;
1686 Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1687 protection_domain, THREAD);
1688 // We are loading classes eagerly. If a ClassNotFoundException or
1689 // a LinkageError was generated, be sure to ignore it.
1690 if (HAS_PENDING_EXCEPTION) {
1691 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1692 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1693 CLEAR_PENDING_EXCEPTION;
1694 } else {
1695 return false;
1696 }
1697 }
1698 if( klass == NULL) { sig_is_loaded = false; }
1699 }
1700 }
1701 return sig_is_loaded;
1702 }
1703
1704 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1705 Handle class_loader(THREAD, m->method_holder()->class_loader());
1706 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1707 ResourceMark rm(THREAD);
1708 Symbol* signature = m->signature();
1709 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1710 if (ss.type() == T_OBJECT) {
1711 Symbol* name = ss.as_symbol_or_null();
1712 if (name == NULL) return true;
1713 Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1714 if (klass == NULL) return true;
1715 }
1716 }
1717 return false;
1718 }
1719
1720 // Exposed so field engineers can debug VM
1721 void Method::print_short_name(outputStream* st) {
1722 ResourceMark rm;
1723 #ifdef PRODUCT
1724 st->print(" %s::", method_holder()->external_name());
1725 #else
1726 st->print(" %s::", method_holder()->internal_name());
1727 #endif
1728 name()->print_symbol_on(st);
1729 if (WizardMode) signature()->print_symbol_on(st);
1730 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1731 MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1732 }
1733
1734 // Comparer for sorting an object array containing
1735 // Method*s.
1736 static int method_comparator(Method* a, Method* b) {
1737 return a->name()->fast_compare(b->name());
1738 }
1739
1740 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1741 // default_methods also uses this without the ordering for fast find_method
1742 void Method::sort_methods(Array<Method*>* methods, bool set_idnums) {
1743 int length = methods->length();
1744 if (length > 1) {
1745 {
1746 NoSafepointVerifier nsv;
1747 QuickSort::sort(methods->data(), length, method_comparator, /*idempotent=*/false);
1748 }
1749 // Reset method ordering
1750 if (set_idnums) {
1751 for (int i = 0; i < length; i++) {
1752 Method* m = methods->at(i);
1753 m->set_method_idnum(i);
1754 m->set_orig_method_idnum(i);
1755 }
1756 }
1757 }
1758 }
1759
1760 //-----------------------------------------------------------------------------------
1761 // Non-product code unless JVM/TI needs it
1762
1763 #if !defined(PRODUCT) || INCLUDE_JVMTI
1764 class SignatureTypePrinter : public SignatureTypeNames {
1765 private:
1766 outputStream* _st;
1767 bool _use_separator;
1768
1769 void type_name(const char* name) {
1770 if (_use_separator) _st->print(", ");
1771 _st->print("%s", name);
1772 _use_separator = true;
1773 }
1774
1775 public:
1776 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1777 _st = st;
1778 _use_separator = false;
1779 }
1780
1781 void print_parameters() { _use_separator = false; iterate_parameters(); }
1782 void print_returntype() { _use_separator = false; iterate_returntype(); }
1783 };
1784
1785
1786 void Method::print_name(outputStream* st) {
1787 Thread *thread = Thread::current();
1788 ResourceMark rm(thread);
1789 st->print("%s ", is_static() ? "static" : "virtual");
1790 if (WizardMode) {
1791 st->print("%s.", method_holder()->internal_name());
1792 name()->print_symbol_on(st);
1793 signature()->print_symbol_on(st);
1794 } else {
1795 SignatureTypePrinter sig(signature(), st);
1796 sig.print_returntype();
1797 st->print(" %s.", method_holder()->internal_name());
1798 name()->print_symbol_on(st);
1799 st->print("(");
1800 sig.print_parameters();
1801 st->print(")");
1802 }
1803 }
1804 #endif // !PRODUCT || INCLUDE_JVMTI
1805
1806
1807 void Method::print_codes_on(outputStream* st) const {
1808 print_codes_on(0, code_size(), st);
1809 }
1810
1811 void Method::print_codes_on(int from, int to, outputStream* st) const {
1812 Thread *thread = Thread::current();
1813 ResourceMark rm(thread);
1814 methodHandle mh (thread, (Method*)this);
1815 BytecodeStream s(mh);
1816 s.set_interval(from, to);
1817 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1818 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1819 }
1820
1821 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1822 _bci = 0;
1823 _line = 0;
1824 };
1825
1826 bool CompressedLineNumberReadStream::read_pair() {
1827 jubyte next = read_byte();
1828 // Check for terminator
1829 if (next == 0) return false;
1830 if (next == 0xFF) {
1831 // Escape character, regular compression used
1832 _bci += read_signed_int();
1833 _line += read_signed_int();
1834 } else {
1835 // Single byte compression used
1836 _bci += next >> 3;
1837 _line += next & 0x7;
1838 }
1839 return true;
1840 }
1841
1842 #if INCLUDE_JVMTI
1843
1844 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1845 BreakpointInfo* bp = method_holder()->breakpoints();
1846 for (; bp != NULL; bp = bp->next()) {
1847 if (bp->match(this, bci)) {
1848 return bp->orig_bytecode();
1849 }
1850 }
1851 {
1852 ResourceMark rm;
1853 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1854 }
1855 return Bytecodes::_shouldnotreachhere;
1856 }
1857
1858 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1859 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1860 BreakpointInfo* bp = method_holder()->breakpoints();
1861 for (; bp != NULL; bp = bp->next()) {
1862 if (bp->match(this, bci)) {
1863 bp->set_orig_bytecode(code);
1864 // and continue, in case there is more than one
1865 }
1866 }
1867 }
1868
1869 void Method::set_breakpoint(int bci) {
1870 InstanceKlass* ik = method_holder();
1871 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1872 bp->set_next(ik->breakpoints());
1873 ik->set_breakpoints(bp);
1874 // do this last:
1875 bp->set(this);
1876 }
1877
1878 static void clear_matches(Method* m, int bci) {
1879 InstanceKlass* ik = m->method_holder();
1880 BreakpointInfo* prev_bp = NULL;
1881 BreakpointInfo* next_bp;
1882 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1883 next_bp = bp->next();
1884 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1885 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1886 // do this first:
1887 bp->clear(m);
1888 // unhook it
1889 if (prev_bp != NULL)
1890 prev_bp->set_next(next_bp);
1891 else
1892 ik->set_breakpoints(next_bp);
1893 delete bp;
1894 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1895 // at same location. So we have multiple matching (method_index and bci)
1896 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1897 // breakpoint for clear_breakpoint request and keep all other method versions
1898 // BreakpointInfo for future clear_breakpoint request.
1899 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1900 // which is being called when class is unloaded. We delete all the Breakpoint
1901 // information for all versions of method. We may not correctly restore the original
1902 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1903 // so these methods won't be used anymore.
1904 if (bci >= 0) {
1905 break;
1906 }
1907 } else {
1908 // This one is a keeper.
1909 prev_bp = bp;
1910 }
1911 }
1912 }
1913
1914 void Method::clear_breakpoint(int bci) {
1915 assert(bci >= 0, "");
1916 clear_matches(this, bci);
1917 }
1918
1919 void Method::clear_all_breakpoints() {
1920 clear_matches(this, -1);
1921 }
1922
1923 #endif // INCLUDE_JVMTI
1924
1925 int Method::invocation_count() {
1926 MethodCounters *mcs = method_counters();
1927 if (TieredCompilation) {
1928 MethodData* const mdo = method_data();
1929 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1930 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1931 return InvocationCounter::count_limit;
1932 } else {
1933 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1934 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1935 }
1936 } else {
1937 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1938 }
1939 }
1940
1941 int Method::backedge_count() {
1942 MethodCounters *mcs = method_counters();
1943 if (TieredCompilation) {
1944 MethodData* const mdo = method_data();
1945 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1946 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1947 return InvocationCounter::count_limit;
1948 } else {
1949 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1950 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1951 }
1952 } else {
1953 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1954 }
1955 }
1956
1957 int Method::highest_comp_level() const {
1958 const MethodCounters* mcs = method_counters();
1959 if (mcs != NULL) {
1960 return mcs->highest_comp_level();
1961 } else {
1962 return CompLevel_none;
1963 }
1964 }
1965
1966 int Method::highest_osr_comp_level() const {
1967 const MethodCounters* mcs = method_counters();
1968 if (mcs != NULL) {
1969 return mcs->highest_osr_comp_level();
1970 } else {
1971 return CompLevel_none;
1972 }
1973 }
1974
1975 void Method::set_highest_comp_level(int level) {
1976 MethodCounters* mcs = method_counters();
1977 if (mcs != NULL) {
1978 mcs->set_highest_comp_level(level);
1979 }
1980 }
1981
1982 void Method::set_highest_osr_comp_level(int level) {
1983 MethodCounters* mcs = method_counters();
1984 if (mcs != NULL) {
1985 mcs->set_highest_osr_comp_level(level);
1986 }
1987 }
1988
1989 #if INCLUDE_JVMTI
1990
1991 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1992 _bci = bci;
1993 _name_index = m->name_index();
1994 _signature_index = m->signature_index();
1995 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1996 if (_orig_bytecode == Bytecodes::_breakpoint)
1997 _orig_bytecode = m->orig_bytecode_at(_bci);
1998 _next = NULL;
1999 }
2000
2001 void BreakpointInfo::set(Method* method) {
2002 #ifdef ASSERT
2003 {
2004 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2005 if (code == Bytecodes::_breakpoint)
2006 code = method->orig_bytecode_at(_bci);
2007 assert(orig_bytecode() == code, "original bytecode must be the same");
2008 }
2009 #endif
2010 Thread *thread = Thread::current();
2011 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2012 method->incr_number_of_breakpoints(thread);
2013 {
2014 // Deoptimize all dependents on this method
2015 HandleMark hm(thread);
2016 methodHandle mh(thread, method);
2017 CodeCache::flush_dependents_on_method(mh);
2018 }
2019 }
2020
2021 void BreakpointInfo::clear(Method* method) {
2022 *method->bcp_from(_bci) = orig_bytecode();
2023 assert(method->number_of_breakpoints() > 0, "must not go negative");
2024 method->decr_number_of_breakpoints(Thread::current());
2025 }
2026
2027 #endif // INCLUDE_JVMTI
2028
2029 // jmethodID handling
2030
2031 // This is a block allocating object, sort of like JNIHandleBlock, only a
2032 // lot simpler.
2033 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2034 // never get rid of it.
2035
2036 static const int min_block_size = 8;
2037
2038 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2039 friend class JNIMethodBlock;
2040 Method** _methods;
2041 int _number_of_methods;
2042 int _top;
2043 JNIMethodBlockNode* _next;
2044
2045 public:
2046
2047 JNIMethodBlockNode(int num_methods = min_block_size);
2048
2049 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2050
2051 void ensure_methods(int num_addl_methods) {
2052 if (_top < _number_of_methods) {
2053 num_addl_methods -= _number_of_methods - _top;
2054 if (num_addl_methods <= 0) {
2055 return;
2056 }
2057 }
2058 if (_next == NULL) {
2059 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2060 } else {
2061 _next->ensure_methods(num_addl_methods);
2062 }
2063 }
2064 };
2065
2066 class JNIMethodBlock : public CHeapObj<mtClass> {
2067 JNIMethodBlockNode _head;
2068 JNIMethodBlockNode *_last_free;
2069 public:
2070 static Method* const _free_method;
2071
2072 JNIMethodBlock(int initial_capacity = min_block_size)
2073 : _head(initial_capacity), _last_free(&_head) {}
2074
2075 void ensure_methods(int num_addl_methods) {
2076 _last_free->ensure_methods(num_addl_methods);
2077 }
2078
2079 Method** add_method(Method* m) {
2080 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2081 if (b->_top < b->_number_of_methods) {
2082 // top points to the next free entry.
2083 int i = b->_top;
2084 b->_methods[i] = m;
2085 b->_top++;
2086 _last_free = b;
2087 return &(b->_methods[i]);
2088 } else if (b->_top == b->_number_of_methods) {
2089 // if the next free entry ran off the block see if there's a free entry
2090 for (int i = 0; i < b->_number_of_methods; i++) {
2091 if (b->_methods[i] == _free_method) {
2092 b->_methods[i] = m;
2093 _last_free = b;
2094 return &(b->_methods[i]);
2095 }
2096 }
2097 // Only check each block once for frees. They're very unlikely.
2098 // Increment top past the end of the block.
2099 b->_top++;
2100 }
2101 // need to allocate a next block.
2102 if (b->_next == NULL) {
2103 b->_next = _last_free = new JNIMethodBlockNode();
2104 }
2105 }
2106 guarantee(false, "Should always allocate a free block");
2107 return NULL;
2108 }
2109
2110 bool contains(Method** m) {
2111 if (m == NULL) return false;
2112 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2113 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2114 // This is a bit of extra checking, for two reasons. One is
2115 // that contains() deals with pointers that are passed in by
2116 // JNI code, so making sure that the pointer is aligned
2117 // correctly is valuable. The other is that <= and > are
2118 // technically not defined on pointers, so the if guard can
2119 // pass spuriously; no modern compiler is likely to make that
2120 // a problem, though (and if one did, the guard could also
2121 // fail spuriously, which would be bad).
2122 ptrdiff_t idx = m - b->_methods;
2123 if (b->_methods + idx == m) {
2124 return true;
2125 }
2126 }
2127 }
2128 return false; // not found
2129 }
2130
2131 // Doesn't really destroy it, just marks it as free so it can be reused.
2132 void destroy_method(Method** m) {
2133 #ifdef ASSERT
2134 assert(contains(m), "should be a methodID");
2135 #endif // ASSERT
2136 *m = _free_method;
2137 }
2138
2139 // During class unloading the methods are cleared, which is different
2140 // than freed.
2141 void clear_all_methods() {
2142 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2143 for (int i = 0; i< b->_number_of_methods; i++) {
2144 b->_methods[i] = NULL;
2145 }
2146 }
2147 }
2148 #ifndef PRODUCT
2149 int count_methods() {
2150 // count all allocated methods
2151 int count = 0;
2152 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2153 for (int i = 0; i< b->_number_of_methods; i++) {
2154 if (b->_methods[i] != _free_method) count++;
2155 }
2156 }
2157 return count;
2158 }
2159 #endif // PRODUCT
2160 };
2161
2162 // Something that can't be mistaken for an address or a markWord
2163 Method* const JNIMethodBlock::_free_method = (Method*)55;
2164
2165 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2166 _number_of_methods = MAX2(num_methods, min_block_size);
2167 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2168 for (int i = 0; i < _number_of_methods; i++) {
2169 _methods[i] = JNIMethodBlock::_free_method;
2170 }
2171 }
2172
2173 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2174 ClassLoaderData* cld = loader_data;
2175 if (!SafepointSynchronize::is_at_safepoint()) {
2176 // Have to add jmethod_ids() to class loader data thread-safely.
2177 // Also have to add the method to the list safely, which the cld lock
2178 // protects as well.
2179 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2180 if (cld->jmethod_ids() == NULL) {
2181 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2182 } else {
2183 cld->jmethod_ids()->ensure_methods(capacity);
2184 }
2185 } else {
2186 // At safepoint, we are single threaded and can set this.
2187 if (cld->jmethod_ids() == NULL) {
2188 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2189 } else {
2190 cld->jmethod_ids()->ensure_methods(capacity);
2191 }
2192 }
2193 }
2194
2195 // Add a method id to the jmethod_ids
2196 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2197 ClassLoaderData* cld = loader_data;
2198
2199 if (!SafepointSynchronize::is_at_safepoint()) {
2200 // Have to add jmethod_ids() to class loader data thread-safely.
2201 // Also have to add the method to the list safely, which the cld lock
2202 // protects as well.
2203 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2204 if (cld->jmethod_ids() == NULL) {
2205 cld->set_jmethod_ids(new JNIMethodBlock());
2206 }
2207 // jmethodID is a pointer to Method*
2208 return (jmethodID)cld->jmethod_ids()->add_method(m);
2209 } else {
2210 // At safepoint, we are single threaded and can set this.
2211 if (cld->jmethod_ids() == NULL) {
2212 cld->set_jmethod_ids(new JNIMethodBlock());
2213 }
2214 // jmethodID is a pointer to Method*
2215 return (jmethodID)cld->jmethod_ids()->add_method(m);
2216 }
2217 }
2218
2219 // Mark a jmethodID as free. This is called when there is a data race in
2220 // InstanceKlass while creating the jmethodID cache.
2221 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2222 ClassLoaderData* cld = loader_data;
2223 Method** ptr = (Method**)m;
2224 assert(cld->jmethod_ids() != NULL, "should have method handles");
2225 cld->jmethod_ids()->destroy_method(ptr);
2226 }
2227
2228 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2229 // Can't assert the method_holder is the same because the new method has the
2230 // scratch method holder.
2231 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2232 == new_method->method_holder()->class_loader() ||
2233 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2234 "changing to a different class loader");
2235 // Just change the method in place, jmethodID pointer doesn't change.
2236 *((Method**)jmid) = new_method;
2237 }
2238
2239 bool Method::is_method_id(jmethodID mid) {
2240 Method* m = resolve_jmethod_id(mid);
2241 assert(m != NULL, "should be called with non-null method");
2242 InstanceKlass* ik = m->method_holder();
2243 ClassLoaderData* cld = ik->class_loader_data();
2244 if (cld->jmethod_ids() == NULL) return false;
2245 return (cld->jmethod_ids()->contains((Method**)mid));
2246 }
2247
2248 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2249 if (mid == NULL) return NULL;
2250 Method* o = resolve_jmethod_id(mid);
2251 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2252 return NULL;
2253 }
2254 return o;
2255 };
2256
2257 void Method::set_on_stack(const bool value) {
2258 // Set both the method itself and its constant pool. The constant pool
2259 // on stack means some method referring to it is also on the stack.
2260 constants()->set_on_stack(value);
2261
2262 bool already_set = on_stack();
2263 _access_flags.set_on_stack(value);
2264 if (value && !already_set) {
2265 MetadataOnStackMark::record(this);
2266 }
2267 assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2268 "emcp methods cannot run after emcp bit is cleared");
2269 }
2270
2271 // Called when the class loader is unloaded to make all methods weak.
2272 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2273 loader_data->jmethod_ids()->clear_all_methods();
2274 }
2275
2276 bool Method::has_method_vptr(const void* ptr) {
2277 Method m;
2278 // This assumes that the vtbl pointer is the first word of a C++ object.
2279 return dereference_vptr(&m) == dereference_vptr(ptr);
2280 }
2281
2282 // Check that this pointer is valid by checking that the vtbl pointer matches
2283 bool Method::is_valid_method(const Method* m) {
2284 if (m == NULL) {
2285 return false;
2286 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2287 // Quick sanity check on pointer.
2288 return false;
2289 } else if (m->is_shared()) {
2290 return MetaspaceShared::is_valid_shared_method(m);
2291 } else if (Metaspace::contains_non_shared(m)) {
2292 return has_method_vptr((const void*)m);
2293 } else {
2294 return false;
2295 }
2296 }
2297
2298 #ifndef PRODUCT
2299 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2300 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2301 }
2302 #endif // PRODUCT
2303
2304
2305 // Printing
2306
2307 #ifndef PRODUCT
2308
2309 void Method::print_on(outputStream* st) const {
2310 ResourceMark rm;
2311 assert(is_method(), "must be method");
2312 st->print_cr("%s", internal_name());
2313 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2314 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2315 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2316 constants()->print_value_on(st); st->cr();
2317 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2318 st->print (" - name: "); name()->print_value_on(st); st->cr();
2319 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2320 st->print_cr(" - max stack: %d", max_stack());
2321 st->print_cr(" - max locals: %d", max_locals());
2322 st->print_cr(" - size of params: %d", size_of_parameters());
2323 st->print_cr(" - method size: %d", method_size());
2324 if (intrinsic_id() != vmIntrinsics::_none)
2325 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2326 if (highest_comp_level() != CompLevel_none)
2327 st->print_cr(" - highest level: %d", highest_comp_level());
2328 st->print_cr(" - vtable index: %d", _vtable_index);
2329 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2330 st->print( " - adapters: ");
2331 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2332 if (a == NULL)
2333 st->print_cr(INTPTR_FORMAT, p2i(a));
2334 else
2335 a->print_adapter_on(st);
2336 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2337 st->print_cr(" - code size: %d", code_size());
2338 if (code_size() != 0) {
2339 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2340 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2341 }
2342 if (method_data() != NULL) {
2343 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2344 }
2345 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2346 if (checked_exceptions_length() > 0) {
2347 CheckedExceptionElement* table = checked_exceptions_start();
2348 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2349 if (Verbose) {
2350 for (int i = 0; i < checked_exceptions_length(); i++) {
2351 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2352 }
2353 }
2354 }
2355 if (has_linenumber_table()) {
2356 u_char* table = compressed_linenumber_table();
2357 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2358 if (Verbose) {
2359 CompressedLineNumberReadStream stream(table);
2360 while (stream.read_pair()) {
2361 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2362 }
2363 }
2364 }
2365 st->print_cr(" - localvar length: %d", localvariable_table_length());
2366 if (localvariable_table_length() > 0) {
2367 LocalVariableTableElement* table = localvariable_table_start();
2368 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2369 if (Verbose) {
2370 for (int i = 0; i < localvariable_table_length(); i++) {
2371 int bci = table[i].start_bci;
2372 int len = table[i].length;
2373 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2374 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2375 int slot = table[i].slot;
2376 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2377 }
2378 }
2379 }
2380 if (code() != NULL) {
2381 st->print (" - compiled code: ");
2382 code()->print_value_on(st);
2383 }
2384 if (is_native()) {
2385 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2386 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2387 }
2388 }
2389
2390 void Method::print_linkage_flags(outputStream* st) {
2391 access_flags().print_on(st);
2392 if (is_default_method()) {
2393 st->print("default ");
2394 }
2395 if (is_overpass()) {
2396 st->print("overpass ");
2397 }
2398 }
2399 #endif //PRODUCT
2400
2401 void Method::print_value_on(outputStream* st) const {
2402 assert(is_method(), "must be method");
2403 st->print("%s", internal_name());
2404 print_address_on(st);
2405 st->print(" ");
2406 name()->print_value_on(st);
2407 st->print(" ");
2408 signature()->print_value_on(st);
2409 st->print(" in ");
2410 method_holder()->print_value_on(st);
2411 if (WizardMode) st->print("#%d", _vtable_index);
2412 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2413 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2414 }
2415
2416 #if INCLUDE_SERVICES
2417 // Size Statistics
2418 void Method::collect_statistics(KlassSizeStats *sz) const {
2419 int mysize = sz->count(this);
2420 sz->_method_bytes += mysize;
2421 sz->_method_all_bytes += mysize;
2422 sz->_rw_bytes += mysize;
2423
2424 if (constMethod()) {
2425 constMethod()->collect_statistics(sz);
2426 }
2427 if (method_data()) {
2428 method_data()->collect_statistics(sz);
2429 }
2430 }
2431 #endif // INCLUDE_SERVICES
2432
2433 // LogTouchedMethods and PrintTouchedMethods
2434
2435 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2436 // the Method may be garbage collected. Let's roll our own hash table.
2437 class TouchedMethodRecord : CHeapObj<mtTracing> {
2438 public:
2439 // It's OK to store Symbols here because they will NOT be GC'ed if
2440 // LogTouchedMethods is enabled.
2441 TouchedMethodRecord* _next;
2442 Symbol* _class_name;
2443 Symbol* _method_name;
2444 Symbol* _method_signature;
2445 };
2446
2447 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2448 static TouchedMethodRecord** _touched_method_table = NULL;
2449
2450 void Method::log_touched(TRAPS) {
2451
2452 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2453 Symbol* my_class = klass_name();
2454 Symbol* my_name = name();
2455 Symbol* my_sig = signature();
2456
2457 unsigned int hash = my_class->identity_hash() +
2458 my_name->identity_hash() +
2459 my_sig->identity_hash();
2460 juint index = juint(hash) % table_size;
2461
2462 MutexLocker ml(TouchedMethodLog_lock, THREAD);
2463 if (_touched_method_table == NULL) {
2464 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2465 mtTracing, CURRENT_PC);
2466 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2467 }
2468
2469 TouchedMethodRecord* ptr = _touched_method_table[index];
2470 while (ptr) {
2471 if (ptr->_class_name == my_class &&
2472 ptr->_method_name == my_name &&
2473 ptr->_method_signature == my_sig) {
2474 return;
2475 }
2476 if (ptr->_next == NULL) break;
2477 ptr = ptr->_next;
2478 }
2479 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2480 my_class->increment_refcount();
2481 my_name->increment_refcount();
2482 my_sig->increment_refcount();
2483 nptr->_class_name = my_class;
2484 nptr->_method_name = my_name;
2485 nptr->_method_signature = my_sig;
2486 nptr->_next = NULL;
2487
2488 if (ptr == NULL) {
2489 // first
2490 _touched_method_table[index] = nptr;
2491 } else {
2492 ptr->_next = nptr;
2493 }
2494 }
2495
2496 void Method::print_touched_methods(outputStream* out) {
2497 MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2498 out->print_cr("# Method::print_touched_methods version 1");
2499 if (_touched_method_table) {
2500 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2501 TouchedMethodRecord* ptr = _touched_method_table[i];
2502 while(ptr) {
2503 ptr->_class_name->print_symbol_on(out); out->print(".");
2504 ptr->_method_name->print_symbol_on(out); out->print(":");
2505 ptr->_method_signature->print_symbol_on(out); out->cr();
2506 ptr = ptr->_next;
2507 }
2508 }
2509 }
2510 }
2511
2512 // Verification
2513
2514 void Method::verify_on(outputStream* st) {
2515 guarantee(is_method(), "object must be method");
2516 guarantee(constants()->is_constantPool(), "should be constant pool");
2517 MethodData* md = method_data();
2518 guarantee(md == NULL ||
2519 md->is_methodData(), "should be method data");
2520 }