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 void 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;
427 stringStream st;
428 st.print("Method '");
429 Method::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());
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;
438 stringStream st;
439 st.print("Method '");
440 Method::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());
443 }
444 }
445
446 if (entry != NULL) {
447 method->set_native_function(entry,
448 Method::native_bind_event_is_interesting);
449 } else {
450 method->clear_native_function();
451 }
452 if (PrintJNIResolving) {
453 ResourceMark rm(THREAD);
454 tty->print_cr("[Registering JNI native method %s.%s]",
455 method->method_holder()->external_name(),
456 method->name()->as_C_string());
457 }
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
576 void Method::compute_size_of_parameters(Thread *thread) {
577 ArgumentSizeComputer asc(signature());
578 set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
579 }
580
581 BasicType Method::result_type() const {
582 ResultTypeFinder rtf(signature());
583 return rtf.type();
584 }
585
586
587 bool Method::is_empty_method() const {
588 return code_size() == 1
589 && *code_base() == Bytecodes::_return;
590 }
591
592
593 bool Method::is_vanilla_constructor() const {
594 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
595 // which only calls the superclass vanilla constructor and possibly does stores of
596 // zero constants to local fields:
597 //
598 // aload_0
599 // invokespecial
600 // indexbyte1
601 // indexbyte2
602 //
603 // followed by an (optional) sequence of:
604 //
605 // aload_0
606 // aconst_null / iconst_0 / fconst_0 / dconst_0
607 // putfield
608 // indexbyte1
609 // indexbyte2
610 //
611 // followed by:
612 //
613 // return
614
615 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
616 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
617 int size = code_size();
618 // Check if size match
619 if (size == 0 || size % 5 != 0) return false;
620 address cb = code_base();
621 int last = size - 1;
622 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
623 // Does not call superclass default constructor
624 return false;
625 }
626 // Check optional sequence
627 for (int i = 4; i < last; i += 5) {
628 if (cb[i] != Bytecodes::_aload_0) return false;
629 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
630 if (cb[i+2] != Bytecodes::_putfield) return false;
631 }
632 return true;
633 }
634
635
636 bool Method::compute_has_loops_flag() {
637 BytecodeStream bcs(this);
638 Bytecodes::Code bc;
639
640 while ((bc = bcs.next()) >= 0) {
641 switch( bc ) {
642 case Bytecodes::_ifeq:
643 case Bytecodes::_ifnull:
644 case Bytecodes::_iflt:
645 case Bytecodes::_ifle:
646 case Bytecodes::_ifne:
647 case Bytecodes::_ifnonnull:
648 case Bytecodes::_ifgt:
649 case Bytecodes::_ifge:
650 case Bytecodes::_if_icmpeq:
651 case Bytecodes::_if_icmpne:
652 case Bytecodes::_if_icmplt:
653 case Bytecodes::_if_icmpgt:
654 case Bytecodes::_if_icmple:
655 case Bytecodes::_if_icmpge:
656 case Bytecodes::_if_acmpeq:
657 case Bytecodes::_if_acmpne:
658 case Bytecodes::_goto:
659 case Bytecodes::_jsr:
660 if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
661 break;
662
663 case Bytecodes::_goto_w:
664 case Bytecodes::_jsr_w:
665 if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
666 break;
667
668 default:
669 break;
670 }
671 }
672 _access_flags.set_loops_flag_init();
673 return _access_flags.has_loops();
674 }
675
676 bool Method::is_final_method(AccessFlags class_access_flags) const {
677 // or "does_not_require_vtable_entry"
678 // default method or overpass can occur, is not final (reuses vtable entry)
679 // private methods in classes get vtable entries for backward class compatibility.
680 if (is_overpass() || is_default_method()) return false;
681 return is_final() || class_access_flags.is_final();
682 }
683
684 bool Method::is_final_method() const {
685 return is_final_method(method_holder()->access_flags());
686 }
687
688 bool Method::is_default_method() const {
689 if (method_holder() != NULL &&
690 method_holder()->is_interface() &&
691 !is_abstract() && !is_private()) {
692 return true;
693 } else {
694 return false;
695 }
696 }
697
698 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
699 if (is_final_method(class_access_flags)) return true;
700 #ifdef ASSERT
701 ResourceMark rm;
702 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
703 if (class_access_flags.is_interface()) {
704 assert(is_nonv == is_static() || is_nonv == is_private(),
705 "nonvirtual unexpected for non-static, non-private: %s",
706 name_and_sig_as_C_string());
707 }
708 #endif
709 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
710 return vtable_index() == nonvirtual_vtable_index;
711 }
712
713 bool Method::can_be_statically_bound() const {
714 return can_be_statically_bound(method_holder()->access_flags());
715 }
716
717 bool Method::can_be_statically_bound(InstanceKlass* context) const {
718 return (method_holder() == context) && can_be_statically_bound();
719 }
720
721 bool Method::is_accessor() const {
722 return is_getter() || is_setter();
723 }
724
725 bool Method::is_getter() const {
726 if (code_size() != 5) return false;
727 if (size_of_parameters() != 1) return false;
728 if (java_code_at(0) != Bytecodes::_aload_0) return false;
729 if (java_code_at(1) != Bytecodes::_getfield) return false;
730 switch (java_code_at(4)) {
731 case Bytecodes::_ireturn:
732 case Bytecodes::_lreturn:
733 case Bytecodes::_freturn:
734 case Bytecodes::_dreturn:
735 case Bytecodes::_areturn:
736 break;
737 default:
738 return false;
739 }
740 return true;
741 }
742
743 bool Method::is_setter() const {
744 if (code_size() != 6) return false;
745 if (java_code_at(0) != Bytecodes::_aload_0) return false;
746 switch (java_code_at(1)) {
747 case Bytecodes::_iload_1:
748 case Bytecodes::_aload_1:
749 case Bytecodes::_fload_1:
750 if (size_of_parameters() != 2) return false;
751 break;
752 case Bytecodes::_dload_1:
753 case Bytecodes::_lload_1:
754 if (size_of_parameters() != 3) return false;
755 break;
756 default:
757 return false;
758 }
759 if (java_code_at(2) != Bytecodes::_putfield) return false;
760 if (java_code_at(5) != Bytecodes::_return) return false;
761 return true;
762 }
763
764 bool Method::is_constant_getter() const {
765 int last_index = code_size() - 1;
766 // Check if the first 1-3 bytecodes are a constant push
767 // and the last bytecode is a return.
768 return (2 <= code_size() && code_size() <= 4 &&
769 Bytecodes::is_const(java_code_at(0)) &&
770 Bytecodes::length_for(java_code_at(0)) == last_index &&
771 Bytecodes::is_return(java_code_at(last_index)));
772 }
773
774 bool Method::is_initializer() const {
775 return is_object_initializer() || is_static_initializer();
776 }
777
778 bool Method::has_valid_initializer_flags() const {
779 return (is_static() ||
780 method_holder()->major_version() < 51);
781 }
782
783 bool Method::is_static_initializer() const {
784 // For classfiles version 51 or greater, ensure that the clinit method is
785 // static. Non-static methods with the name "<clinit>" are not static
786 // initializers. (older classfiles exempted for backward compatibility)
787 return name() == vmSymbols::class_initializer_name() &&
788 has_valid_initializer_flags();
789 }
790
791 bool Method::is_object_initializer() const {
792 return name() == vmSymbols::object_initializer_name();
793 }
794
795 bool Method::needs_clinit_barrier() const {
796 return is_static() && !method_holder()->is_initialized();
797 }
798
799 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
800 int length = method->checked_exceptions_length();
801 if (length == 0) { // common case
802 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
803 } else {
804 methodHandle h_this(THREAD, method);
805 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
806 objArrayHandle mirrors (THREAD, m_oop);
807 for (int i = 0; i < length; i++) {
808 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
809 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
810 assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
811 mirrors->obj_at_put(i, k->java_mirror());
812 }
813 return mirrors;
814 }
815 };
816
817
818 int Method::line_number_from_bci(int bci) const {
819 int best_bci = 0;
820 int best_line = -1;
821 if (bci == SynchronizationEntryBCI) bci = 0;
822 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
823 // The line numbers are a short array of 2-tuples [start_pc, line_number].
824 // Not necessarily sorted and not necessarily one-to-one.
825 CompressedLineNumberReadStream stream(compressed_linenumber_table());
826 while (stream.read_pair()) {
827 if (stream.bci() == bci) {
828 // perfect match
829 return stream.line();
830 } else {
831 // update best_bci/line
832 if (stream.bci() < bci && stream.bci() >= best_bci) {
833 best_bci = stream.bci();
834 best_line = stream.line();
835 }
836 }
837 }
838 }
839 return best_line;
840 }
841
842
843 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
844 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
845 Thread *thread = Thread::current();
846 Symbol* klass_name = constants()->klass_name_at(klass_index);
847 Handle loader(thread, method_holder()->class_loader());
848 Handle prot (thread, method_holder()->protection_domain());
849 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
850 } else {
851 return true;
852 }
853 }
854
855
856 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
857 int klass_index = constants()->klass_ref_index_at(refinfo_index);
858 if (must_be_resolved) {
859 // Make sure klass is resolved in constantpool.
860 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
861 }
862 return is_klass_loaded_by_klass_index(klass_index);
863 }
864
865
866 void Method::set_native_function(address function, bool post_event_flag) {
867 assert(function != NULL, "use clear_native_function to unregister natives");
868 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
869 address* native_function = native_function_addr();
870
871 // We can see racers trying to place the same native function into place. Once
872 // is plenty.
873 address current = *native_function;
874 if (current == function) return;
875 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
876 function != NULL) {
877 // native_method_throw_unsatisfied_link_error_entry() should only
878 // be passed when post_event_flag is false.
879 assert(function !=
880 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
881 "post_event_flag mis-match");
882
883 // post the bind event, and possible change the bind function
884 JvmtiExport::post_native_method_bind(this, &function);
885 }
886 *native_function = function;
887 // This function can be called more than once. We must make sure that we always
888 // use the latest registered method -> check if a stub already has been generated.
889 // If so, we have to make it not_entrant.
890 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
891 if (nm != NULL) {
892 nm->make_not_entrant();
893 }
894 }
895
896
897 bool Method::has_native_function() const {
898 if (is_method_handle_intrinsic())
899 return false; // special-cased in SharedRuntime::generate_native_wrapper
900 address func = native_function();
901 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
902 }
903
904
905 void Method::clear_native_function() {
906 // Note: is_method_handle_intrinsic() is allowed here.
907 set_native_function(
908 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
909 !native_bind_event_is_interesting);
910 this->unlink_code();
911 }
912
913
914 void Method::set_signature_handler(address handler) {
915 address* signature_handler = signature_handler_addr();
916 *signature_handler = handler;
917 }
918
919
920 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
921 assert(reason != NULL, "must provide a reason");
922 if (PrintCompilation && report) {
923 ttyLocker ttyl;
924 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
925 if (comp_level == CompLevel_all) {
926 tty->print("all levels ");
927 } else {
928 tty->print("level %d ", comp_level);
929 }
930 this->print_short_name(tty);
931 int size = this->code_size();
932 if (size > 0) {
933 tty->print(" (%d bytes)", size);
934 }
935 if (reason != NULL) {
936 tty->print(" %s", reason);
937 }
938 tty->cr();
939 }
940 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
941 ttyLocker ttyl;
942 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
943 os::current_thread_id(), is_osr, comp_level);
944 if (reason != NULL) {
945 xtty->print(" reason=\'%s\'", reason);
946 }
947 xtty->method(this);
948 xtty->stamp();
949 xtty->end_elem();
950 }
951 }
952
953 bool Method::is_always_compilable() const {
954 // Generated adapters must be compiled
955 if (is_method_handle_intrinsic() && is_synthetic()) {
956 assert(!is_not_c1_compilable(), "sanity check");
957 assert(!is_not_c2_compilable(), "sanity check");
958 return true;
959 }
960
961 return false;
962 }
963
964 bool Method::is_not_compilable(int comp_level) const {
965 if (number_of_breakpoints() > 0)
966 return true;
967 if (is_always_compilable())
968 return false;
969 if (comp_level == CompLevel_any)
970 return is_not_c1_compilable() || is_not_c2_compilable();
971 if (is_c1_compile(comp_level))
972 return is_not_c1_compilable();
973 if (is_c2_compile(comp_level))
974 return is_not_c2_compilable();
975 return false;
976 }
977
978 // call this when compiler finds that this method is not compilable
979 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
980 if (is_always_compilable()) {
981 // Don't mark a method which should be always compilable
982 return;
983 }
984 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
985 if (comp_level == CompLevel_all) {
986 set_not_c1_compilable();
987 set_not_c2_compilable();
988 } else {
989 if (is_c1_compile(comp_level))
990 set_not_c1_compilable();
991 if (is_c2_compile(comp_level))
992 set_not_c2_compilable();
993 }
994 CompilationPolicy::policy()->disable_compilation(this);
995 assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
996 }
997
998 bool Method::is_not_osr_compilable(int comp_level) const {
999 if (is_not_compilable(comp_level))
1000 return true;
1001 if (comp_level == CompLevel_any)
1002 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
1003 if (is_c1_compile(comp_level))
1004 return is_not_c1_osr_compilable();
1005 if (is_c2_compile(comp_level))
1006 return is_not_c2_osr_compilable();
1007 return false;
1008 }
1009
1010 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1011 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1012 if (comp_level == CompLevel_all) {
1013 set_not_c1_osr_compilable();
1014 set_not_c2_osr_compilable();
1015 } else {
1016 if (is_c1_compile(comp_level))
1017 set_not_c1_osr_compilable();
1018 if (is_c2_compile(comp_level))
1019 set_not_c2_osr_compilable();
1020 }
1021 CompilationPolicy::policy()->disable_compilation(this);
1022 assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
1023 }
1024
1025 // Revert to using the interpreter and clear out the nmethod
1026 void Method::clear_code() {
1027 // this may be NULL if c2i adapters have not been made yet
1028 // Only should happen at allocate time.
1029 if (adapter() == NULL) {
1030 _from_compiled_entry = NULL;
1031 } else {
1032 _from_compiled_entry = adapter()->get_c2i_entry();
1033 }
1034 OrderAccess::storestore();
1035 _from_interpreted_entry = _i2i_entry;
1036 OrderAccess::storestore();
1037 _code = NULL;
1038 }
1039
1040 void Method::unlink_code(CompiledMethod *compare) {
1041 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1042 // We need to check if either the _code or _from_compiled_code_entry_point
1043 // refer to this nmethod because there is a race in setting these two fields
1044 // in Method* as seen in bugid 4947125.
1045 // If the vep() points to the zombie nmethod, the memory for the nmethod
1046 // could be flushed and the compiler and vtable stubs could still call
1047 // through it.
1048 if (code() == compare ||
1049 from_compiled_entry() == compare->verified_entry_point()) {
1050 clear_code();
1051 }
1052 }
1053
1054 void Method::unlink_code() {
1055 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1056 clear_code();
1057 }
1058
1059 #if INCLUDE_CDS
1060 // Called by class data sharing to remove any entry points (which are not shared)
1061 void Method::unlink_method() {
1062 _code = NULL;
1063
1064 Arguments::assert_is_dumping_archive();
1065 // Set the values to what they should be at run time. Note that
1066 // this Method can no longer be executed during dump time.
1067 _i2i_entry = Interpreter::entry_for_cds_method(this);
1068 _from_interpreted_entry = _i2i_entry;
1069
1070 if (DynamicDumpSharedSpaces) {
1071 assert(_from_compiled_entry != NULL, "sanity");
1072 } else {
1073 // TODO: Simplify the adapter trampoline allocation for static archiving.
1074 // Remove the use of CDSAdapterHandlerEntry.
1075 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
1076 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
1077 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
1078 assert(*((int*)_from_compiled_entry) == 0,
1079 "must be NULL during dump time, to be initialized at run time");
1080 }
1081
1082 if (is_native()) {
1083 *native_function_addr() = NULL;
1084 set_signature_handler(NULL);
1085 }
1086 NOT_PRODUCT(set_compiled_invocation_count(0);)
1087
1088 set_method_data(NULL);
1089 clear_method_counters();
1090 }
1091 #endif
1092
1093 /****************************************************************************
1094 // The following illustrates how the entries work for CDS shared Methods:
1095 //
1096 // Our goal is to delay writing into a shared Method until it's compiled.
1097 // Hence, we want to determine the initial values for _i2i_entry,
1098 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1099 //
1100 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1101 // They also have similar signatures so that they will share the same
1102 // AdapterHandlerEntry.
1103 //
1104 // _adapter_trampoline points to a fixed location in the RW section of
1105 // the CDS archive. This location initially contains a NULL pointer. When the
1106 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1107 // dynamically, and its c2i/i2c entries are generated.
1108 //
1109 // _i2i_entry and _from_interpreted_entry initially points to the same
1110 // (fixed) location in the CODE section of the CDS archive. This contains
1111 // an unconditional branch to the actual entry for "zero_locals", which is
1112 // generated at run time and may be on an arbitrary address. Thus, the
1113 // unconditional branch is also generated at run time to jump to the correct
1114 // address.
1115 //
1116 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1117 // section. This address has enough space for an unconditional branch
1118 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1119 // initialized, and the address for the actual c2i_entry is known, we emit a
1120 // branch instruction here to branch to the actual c2i_entry.
1121 //
1122 // The effect of the extra branch on the i2i and c2i entries is negligible.
1123 //
1124 // The reason for putting _adapter_trampoline in RO is many shared Methods
1125 // share the same AdapterHandlerEntry, so we can save space in the RW section
1126 // by having the extra indirection.
1127
1128
1129 [Method A: RW]
1130 _constMethod ----> [ConstMethod: RO]
1131 _adapter_trampoline -----------+
1132 |
1133 _i2i_entry (same value as method B) |
1134 _from_interpreted_entry (same value as method B) |
1135 _from_compiled_entry (same value as method B) |
1136 |
1137 |
1138 [Method B: RW] +--------+
1139 _constMethod ----> [ConstMethod: RO] |
1140 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1141 |
1142 +-------------------------------+
1143 |
1144 +----> [AdapterHandlerEntry] (allocated at run time)
1145 _fingerprint
1146 _c2i_entry ---------------------------------+->[c2i entry..]
1147 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1148 _from_interpreted_entry | _c2i_unverified_entry | |
1149 | | _c2i_no_clinit_check_entry| |
1150 | | (_cds_entry_table: CODE) | |
1151 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1152 | | (allocated at run time) | |
1153 | | ... [asm code ...] | |
1154 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1155 | | |
1156 | | |
1157 +-[compiled]-------------------------------------------------------------------+ |
1158 |
1159 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1160 [jmp c2i_entry] ------------------------------------------------------+
1161
1162 ***/
1163
1164 // Called when the method_holder is getting linked. Setup entrypoints so the method
1165 // is ready to be called from interpreter, compiler, and vtables.
1166 void Method::link_method(const methodHandle& h_method, TRAPS) {
1167 // If the code cache is full, we may reenter this function for the
1168 // leftover methods that weren't linked.
1169 if (is_shared()) {
1170 address entry = Interpreter::entry_for_cds_method(h_method);
1171 assert(entry != NULL && entry == _i2i_entry,
1172 "should be correctly set during dump time");
1173 if (adapter() != NULL) {
1174 return;
1175 }
1176 assert(entry == _from_interpreted_entry,
1177 "should be correctly set during dump time");
1178 } else if (_i2i_entry != NULL) {
1179 return;
1180 }
1181 assert( _code == NULL, "nothing compiled yet" );
1182
1183 // Setup interpreter entrypoint
1184 assert(this == h_method(), "wrong h_method()" );
1185
1186 if (!is_shared()) {
1187 assert(adapter() == NULL, "init'd to NULL");
1188 address entry = Interpreter::entry_for_method(h_method);
1189 assert(entry != NULL, "interpreter entry must be non-null");
1190 // Sets both _i2i_entry and _from_interpreted_entry
1191 set_interpreter_entry(entry);
1192 }
1193
1194 // Don't overwrite already registered native entries.
1195 if (is_native() && !has_native_function()) {
1196 set_native_function(
1197 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1198 !native_bind_event_is_interesting);
1199 }
1200
1201 // Setup compiler entrypoint. This is made eagerly, so we do not need
1202 // special handling of vtables. An alternative is to make adapters more
1203 // lazily by calling make_adapter() from from_compiled_entry() for the
1204 // normal calls. For vtable calls life gets more complicated. When a
1205 // call-site goes mega-morphic we need adapters in all methods which can be
1206 // called from the vtable. We need adapters on such methods that get loaded
1207 // later. Ditto for mega-morphic itable calls. If this proves to be a
1208 // problem we'll make these lazily later.
1209 (void) make_adapters(h_method, CHECK);
1210
1211 // ONLY USE the h_method now as make_adapter may have blocked
1212
1213 }
1214
1215 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1216 // Adapters for compiled code are made eagerly here. They are fairly
1217 // small (generally < 100 bytes) and quick to make (and cached and shared)
1218 // so making them eagerly shouldn't be too expensive.
1219 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1220 if (adapter == NULL ) {
1221 if (!is_init_completed()) {
1222 // Don't throw exceptions during VM initialization because java.lang.* classes
1223 // might not have been initialized, causing problems when constructing the
1224 // Java exception object.
1225 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1226 } else {
1227 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1228 }
1229 }
1230
1231 if (mh->is_shared()) {
1232 assert(mh->adapter() == adapter, "must be");
1233 assert(mh->_from_compiled_entry != NULL, "must be");
1234 } else {
1235 mh->set_adapter_entry(adapter);
1236 mh->_from_compiled_entry = adapter->get_c2i_entry();
1237 }
1238 return adapter->get_c2i_entry();
1239 }
1240
1241 void Method::restore_unshareable_info(TRAPS) {
1242 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1243
1244 // Since restore_unshareable_info can be called more than once for a method, don't
1245 // redo any work.
1246 if (adapter() == NULL) {
1247 methodHandle mh(THREAD, this);
1248 link_method(mh, CHECK);
1249 }
1250 }
1251
1252 address Method::from_compiled_entry_no_trampoline() const {
1253 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1254 if (code) {
1255 return code->verified_entry_point();
1256 } else {
1257 return adapter()->get_c2i_entry();
1258 }
1259 }
1260
1261 // The verified_code_entry() must be called when a invoke is resolved
1262 // on this method.
1263
1264 // It returns the compiled code entry point, after asserting not null.
1265 // This function is called after potential safepoints so that nmethod
1266 // or adapter that it points to is still live and valid.
1267 // This function must not hit a safepoint!
1268 address Method::verified_code_entry() {
1269 debug_only(NoSafepointVerifier nsv;)
1270 assert(_from_compiled_entry != NULL, "must be set");
1271 return _from_compiled_entry;
1272 }
1273
1274 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1275 // (could be racing a deopt).
1276 // Not inline to avoid circular ref.
1277 bool Method::check_code() const {
1278 // cached in a register or local. There's a race on the value of the field.
1279 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1280 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1281 }
1282
1283 // Install compiled code. Instantly it can execute.
1284 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1285 assert_lock_strong(CompiledMethod_lock);
1286 assert( code, "use clear_code to remove code" );
1287 assert( mh->check_code(), "" );
1288
1289 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1290
1291 // These writes must happen in this order, because the interpreter will
1292 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1293 // which jumps to _from_compiled_entry.
1294 mh->_code = code; // Assign before allowing compiled code to exec
1295
1296 int comp_level = code->comp_level();
1297 // In theory there could be a race here. In practice it is unlikely
1298 // and not worth worrying about.
1299 if (comp_level > mh->highest_comp_level()) {
1300 mh->set_highest_comp_level(comp_level);
1301 }
1302
1303 OrderAccess::storestore();
1304 mh->_from_compiled_entry = code->verified_entry_point();
1305 OrderAccess::storestore();
1306 // Instantly compiled code can execute.
1307 if (!mh->is_method_handle_intrinsic())
1308 mh->_from_interpreted_entry = mh->get_i2c_entry();
1309 }
1310
1311
1312 bool Method::is_overridden_in(Klass* k) const {
1313 InstanceKlass* ik = InstanceKlass::cast(k);
1314
1315 if (ik->is_interface()) return false;
1316
1317 // If method is an interface, we skip it - except if it
1318 // is a miranda method
1319 if (method_holder()->is_interface()) {
1320 // Check that method is not a miranda method
1321 if (ik->lookup_method(name(), signature()) == NULL) {
1322 // No implementation exist - so miranda method
1323 return false;
1324 }
1325 return true;
1326 }
1327
1328 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1329 if (!has_vtable_index()) {
1330 return false;
1331 } else {
1332 Method* vt_m = ik->method_at_vtable(vtable_index());
1333 return vt_m != this;
1334 }
1335 }
1336
1337
1338 // give advice about whether this Method* should be cached or not
1339 bool Method::should_not_be_cached() const {
1340 if (is_old()) {
1341 // This method has been redefined. It is either EMCP or obsolete
1342 // and we don't want to cache it because that would pin the method
1343 // down and prevent it from being collectible if and when it
1344 // finishes executing.
1345 return true;
1346 }
1347
1348 // caching this method should be just fine
1349 return false;
1350 }
1351
1352
1353 /**
1354 * Returns true if this is one of the specially treated methods for
1355 * security related stack walks (like Reflection.getCallerClass).
1356 */
1357 bool Method::is_ignored_by_security_stack_walk() const {
1358 if (intrinsic_id() == vmIntrinsics::_invoke) {
1359 // This is Method.invoke() -- ignore it
1360 return true;
1361 }
1362 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1363 // This is an auxilary frame -- ignore it
1364 return true;
1365 }
1366 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1367 // This is an internal adapter frame for method handles -- ignore it
1368 return true;
1369 }
1370 return false;
1371 }
1372
1373
1374 // Constant pool structure for invoke methods:
1375 enum {
1376 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1377 _imcp_invoke_signature, // utf8: (variable Symbol*)
1378 _imcp_limit
1379 };
1380
1381 // Test if this method is an MH adapter frame generated by Java code.
1382 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1383 bool Method::is_compiled_lambda_form() const {
1384 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1385 }
1386
1387 // Test if this method is an internal MH primitive method.
1388 bool Method::is_method_handle_intrinsic() const {
1389 vmIntrinsics::ID iid = intrinsic_id();
1390 return (MethodHandles::is_signature_polymorphic(iid) &&
1391 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1392 }
1393
1394 bool Method::has_member_arg() const {
1395 vmIntrinsics::ID iid = intrinsic_id();
1396 return (MethodHandles::is_signature_polymorphic(iid) &&
1397 MethodHandles::has_member_arg(iid));
1398 }
1399
1400 // Make an instance of a signature-polymorphic internal MH primitive.
1401 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1402 Symbol* signature,
1403 TRAPS) {
1404 ResourceMark rm;
1405 methodHandle empty;
1406
1407 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1408 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1409 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1410 if (TraceMethodHandles) {
1411 tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1412 }
1413
1414 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1415 name->increment_refcount();
1416 signature->increment_refcount();
1417
1418 int cp_length = _imcp_limit;
1419 ClassLoaderData* loader_data = holder->class_loader_data();
1420 constantPoolHandle cp;
1421 {
1422 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1423 cp = constantPoolHandle(THREAD, cp_oop);
1424 }
1425 cp->set_pool_holder(holder);
1426 cp->symbol_at_put(_imcp_invoke_name, name);
1427 cp->symbol_at_put(_imcp_invoke_signature, signature);
1428 cp->set_has_preresolution();
1429
1430 // decide on access bits: public or not?
1431 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1432 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1433 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1434 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1435
1436 methodHandle m;
1437 {
1438 InlineTableSizes sizes;
1439 Method* m_oop = Method::allocate(loader_data, 0,
1440 accessFlags_from(flags_bits), &sizes,
1441 ConstMethod::NORMAL, CHECK_(empty));
1442 m = methodHandle(THREAD, m_oop);
1443 }
1444 m->set_constants(cp());
1445 m->set_name_index(_imcp_invoke_name);
1446 m->set_signature_index(_imcp_invoke_signature);
1447 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1448 assert(m->signature() == signature, "");
1449 ResultTypeFinder rtf(signature);
1450 m->constMethod()->set_result_type(rtf.type());
1451 m->compute_size_of_parameters(THREAD);
1452 m->init_intrinsic_id();
1453 assert(m->is_method_handle_intrinsic(), "");
1454 #ifdef ASSERT
1455 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1456 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1457 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1458 #endif //ASSERT
1459
1460 // Finally, set up its entry points.
1461 assert(m->can_be_statically_bound(), "");
1462 m->set_vtable_index(Method::nonvirtual_vtable_index);
1463 m->link_method(m, CHECK_(empty));
1464
1465 if (TraceMethodHandles && (Verbose || WizardMode)) {
1466 ttyLocker ttyl;
1467 m->print_on(tty);
1468 }
1469
1470 return m;
1471 }
1472
1473 Klass* Method::check_non_bcp_klass(Klass* klass) {
1474 if (klass != NULL && klass->class_loader() != NULL) {
1475 if (klass->is_objArray_klass())
1476 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1477 return klass;
1478 }
1479 return NULL;
1480 }
1481
1482
1483 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1484 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1485 // Code below does not work for native methods - they should never get rewritten anyway
1486 assert(!m->is_native(), "cannot rewrite native methods");
1487 // Allocate new Method*
1488 AccessFlags flags = m->access_flags();
1489
1490 ConstMethod* cm = m->constMethod();
1491 int checked_exceptions_len = cm->checked_exceptions_length();
1492 int localvariable_len = cm->localvariable_table_length();
1493 int exception_table_len = cm->exception_table_length();
1494 int method_parameters_len = cm->method_parameters_length();
1495 int method_annotations_len = cm->method_annotations_length();
1496 int parameter_annotations_len = cm->parameter_annotations_length();
1497 int type_annotations_len = cm->type_annotations_length();
1498 int default_annotations_len = cm->default_annotations_length();
1499
1500 InlineTableSizes sizes(
1501 localvariable_len,
1502 new_compressed_linenumber_size,
1503 exception_table_len,
1504 checked_exceptions_len,
1505 method_parameters_len,
1506 cm->generic_signature_index(),
1507 method_annotations_len,
1508 parameter_annotations_len,
1509 type_annotations_len,
1510 default_annotations_len,
1511 0);
1512
1513 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1514 Method* newm_oop = Method::allocate(loader_data,
1515 new_code_length,
1516 flags,
1517 &sizes,
1518 m->method_type(),
1519 CHECK_(methodHandle()));
1520 methodHandle newm (THREAD, newm_oop);
1521
1522 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1523 ConstMethod* newcm = newm->constMethod();
1524 int new_const_method_size = newm->constMethod()->size();
1525
1526 // This works because the source and target are both Methods. Some compilers
1527 // (e.g., clang) complain that the target vtable pointer will be stomped,
1528 // so cast away newm()'s and m()'s Methodness.
1529 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1530
1531 // Create shallow copy of ConstMethod.
1532 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1533
1534 // Reset correct method/const method, method size, and parameter info
1535 newm->set_constMethod(newcm);
1536 newm->constMethod()->set_code_size(new_code_length);
1537 newm->constMethod()->set_constMethod_size(new_const_method_size);
1538 assert(newm->code_size() == new_code_length, "check");
1539 assert(newm->method_parameters_length() == method_parameters_len, "check");
1540 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1541 assert(newm->exception_table_length() == exception_table_len, "check");
1542 assert(newm->localvariable_table_length() == localvariable_len, "check");
1543 // Copy new byte codes
1544 memcpy(newm->code_base(), new_code, new_code_length);
1545 // Copy line number table
1546 if (new_compressed_linenumber_size > 0) {
1547 memcpy(newm->compressed_linenumber_table(),
1548 new_compressed_linenumber_table,
1549 new_compressed_linenumber_size);
1550 }
1551 // Copy method_parameters
1552 if (method_parameters_len > 0) {
1553 memcpy(newm->method_parameters_start(),
1554 m->method_parameters_start(),
1555 method_parameters_len * sizeof(MethodParametersElement));
1556 }
1557 // Copy checked_exceptions
1558 if (checked_exceptions_len > 0) {
1559 memcpy(newm->checked_exceptions_start(),
1560 m->checked_exceptions_start(),
1561 checked_exceptions_len * sizeof(CheckedExceptionElement));
1562 }
1563 // Copy exception table
1564 if (exception_table_len > 0) {
1565 memcpy(newm->exception_table_start(),
1566 m->exception_table_start(),
1567 exception_table_len * sizeof(ExceptionTableElement));
1568 }
1569 // Copy local variable number table
1570 if (localvariable_len > 0) {
1571 memcpy(newm->localvariable_table_start(),
1572 m->localvariable_table_start(),
1573 localvariable_len * sizeof(LocalVariableTableElement));
1574 }
1575 // Copy stackmap table
1576 if (m->has_stackmap_table()) {
1577 int code_attribute_length = m->stackmap_data()->length();
1578 Array<u1>* stackmap_data =
1579 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1580 memcpy((void*)stackmap_data->adr_at(0),
1581 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1582 newm->set_stackmap_data(stackmap_data);
1583 }
1584
1585 // copy annotations over to new method
1586 newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1587 return newm;
1588 }
1589
1590 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1591 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1592 // because we are not loading from core libraries
1593 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1594 // which does not use the class default class loader so we check for its loader here
1595 const InstanceKlass* ik = InstanceKlass::cast(holder);
1596 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1597 return vmSymbols::NO_SID; // regardless of name, no intrinsics here
1598 }
1599
1600 // see if the klass name is well-known:
1601 Symbol* klass_name = ik->name();
1602 return vmSymbols::find_sid(klass_name);
1603 }
1604
1605 void Method::init_intrinsic_id() {
1606 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1607 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1608 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1609 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1610
1611 // the klass name is well-known:
1612 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1613 assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1614
1615 // ditto for method and signature:
1616 vmSymbols::SID name_id = vmSymbols::find_sid(name());
1617 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1618 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1619 && name_id == vmSymbols::NO_SID) {
1620 return;
1621 }
1622 vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
1623 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1624 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1625 && sig_id == vmSymbols::NO_SID) {
1626 return;
1627 }
1628 jshort flags = access_flags().as_short();
1629
1630 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1631 if (id != vmIntrinsics::_none) {
1632 set_intrinsic_id(id);
1633 if (id == vmIntrinsics::_Class_cast) {
1634 // Even if the intrinsic is rejected, we want to inline this simple method.
1635 set_force_inline(true);
1636 }
1637 return;
1638 }
1639
1640 // A few slightly irregular cases:
1641 switch (klass_id) {
1642 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1643 // Second chance: check in regular Math.
1644 switch (name_id) {
1645 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1646 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1647 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1648 // pretend it is the corresponding method in the non-strict class:
1649 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1650 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1651 break;
1652 default:
1653 break;
1654 }
1655 break;
1656
1657 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1658 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1659 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1660 if (!is_native()) break;
1661 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1662 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1663 id = vmIntrinsics::_none;
1664 break;
1665
1666 default:
1667 break;
1668 }
1669
1670 if (id != vmIntrinsics::_none) {
1671 // Set up its iid. It is an alias method.
1672 set_intrinsic_id(id);
1673 return;
1674 }
1675 }
1676
1677 // These two methods are static since a GC may move the Method
1678 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1679 if (!THREAD->can_call_java()) {
1680 // There is nothing useful this routine can do from within the Compile thread.
1681 // Hopefully, the signature contains only well-known classes.
1682 // We could scan for this and return true/false, but the caller won't care.
1683 return false;
1684 }
1685 bool sig_is_loaded = true;
1686 Handle class_loader(THREAD, m->method_holder()->class_loader());
1687 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1688 ResourceMark rm(THREAD);
1689 Symbol* signature = m->signature();
1690 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1691 if (ss.is_object()) {
1692 Symbol* sym = ss.as_symbol();
1693 Symbol* name = sym;
1694 Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1695 protection_domain, THREAD);
1696 // We are loading classes eagerly. If a ClassNotFoundException or
1697 // a LinkageError was generated, be sure to ignore it.
1698 if (HAS_PENDING_EXCEPTION) {
1699 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1700 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1701 CLEAR_PENDING_EXCEPTION;
1702 } else {
1703 return false;
1704 }
1705 }
1706 if( klass == NULL) { sig_is_loaded = false; }
1707 }
1708 }
1709 return sig_is_loaded;
1710 }
1711
1712 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1713 Handle class_loader(THREAD, m->method_holder()->class_loader());
1714 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1715 ResourceMark rm(THREAD);
1716 Symbol* signature = m->signature();
1717 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1718 if (ss.type() == T_OBJECT) {
1719 Symbol* name = ss.as_symbol_or_null();
1720 if (name == NULL) return true;
1721 Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1722 if (klass == NULL) return true;
1723 }
1724 }
1725 return false;
1726 }
1727
1728 // Exposed so field engineers can debug VM
1729 void Method::print_short_name(outputStream* st) {
1730 ResourceMark rm;
1731 #ifdef PRODUCT
1732 st->print(" %s::", method_holder()->external_name());
1733 #else
1734 st->print(" %s::", method_holder()->internal_name());
1735 #endif
1736 name()->print_symbol_on(st);
1737 if (WizardMode) signature()->print_symbol_on(st);
1738 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1739 MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1740 }
1741
1742 // Comparer for sorting an object array containing
1743 // Method*s.
1744 static int method_comparator(Method* a, Method* b) {
1745 return a->name()->fast_compare(b->name());
1746 }
1747
1748 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1749 // default_methods also uses this without the ordering for fast find_method
1750 void Method::sort_methods(Array<Method*>* methods, bool set_idnums) {
1751 int length = methods->length();
1752 if (length > 1) {
1753 {
1754 NoSafepointVerifier nsv;
1755 QuickSort::sort(methods->data(), length, method_comparator, /*idempotent=*/false);
1756 }
1757 // Reset method ordering
1758 if (set_idnums) {
1759 for (int i = 0; i < length; i++) {
1760 Method* m = methods->at(i);
1761 m->set_method_idnum(i);
1762 m->set_orig_method_idnum(i);
1763 }
1764 }
1765 }
1766 }
1767
1768 //-----------------------------------------------------------------------------------
1769 // Non-product code unless JVM/TI needs it
1770
1771 #if !defined(PRODUCT) || INCLUDE_JVMTI
1772 class SignatureTypePrinter : public SignatureTypeNames {
1773 private:
1774 outputStream* _st;
1775 bool _use_separator;
1776
1777 void type_name(const char* name) {
1778 if (_use_separator) _st->print(", ");
1779 _st->print("%s", name);
1780 _use_separator = true;
1781 }
1782
1783 public:
1784 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1785 _st = st;
1786 _use_separator = false;
1787 }
1788
1789 void print_parameters() { _use_separator = false; iterate_parameters(); }
1790 void print_returntype() { _use_separator = false; iterate_returntype(); }
1791 };
1792
1793
1794 void Method::print_name(outputStream* st) {
1795 Thread *thread = Thread::current();
1796 ResourceMark rm(thread);
1797 st->print("%s ", is_static() ? "static" : "virtual");
1798 if (WizardMode) {
1799 st->print("%s.", method_holder()->internal_name());
1800 name()->print_symbol_on(st);
1801 signature()->print_symbol_on(st);
1802 } else {
1803 SignatureTypePrinter sig(signature(), st);
1804 sig.print_returntype();
1805 st->print(" %s.", method_holder()->internal_name());
1806 name()->print_symbol_on(st);
1807 st->print("(");
1808 sig.print_parameters();
1809 st->print(")");
1810 }
1811 }
1812 #endif // !PRODUCT || INCLUDE_JVMTI
1813
1814
1815 void Method::print_codes_on(outputStream* st) const {
1816 print_codes_on(0, code_size(), st);
1817 }
1818
1819 void Method::print_codes_on(int from, int to, outputStream* st) const {
1820 Thread *thread = Thread::current();
1821 ResourceMark rm(thread);
1822 methodHandle mh (thread, (Method*)this);
1823 BytecodeStream s(mh);
1824 s.set_interval(from, to);
1825 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1826 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1827 }
1828
1829 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1830 _bci = 0;
1831 _line = 0;
1832 };
1833
1834 bool CompressedLineNumberReadStream::read_pair() {
1835 jubyte next = read_byte();
1836 // Check for terminator
1837 if (next == 0) return false;
1838 if (next == 0xFF) {
1839 // Escape character, regular compression used
1840 _bci += read_signed_int();
1841 _line += read_signed_int();
1842 } else {
1843 // Single byte compression used
1844 _bci += next >> 3;
1845 _line += next & 0x7;
1846 }
1847 return true;
1848 }
1849
1850 #if INCLUDE_JVMTI
1851
1852 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1853 BreakpointInfo* bp = method_holder()->breakpoints();
1854 for (; bp != NULL; bp = bp->next()) {
1855 if (bp->match(this, bci)) {
1856 return bp->orig_bytecode();
1857 }
1858 }
1859 {
1860 ResourceMark rm;
1861 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1862 }
1863 return Bytecodes::_shouldnotreachhere;
1864 }
1865
1866 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1867 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1868 BreakpointInfo* bp = method_holder()->breakpoints();
1869 for (; bp != NULL; bp = bp->next()) {
1870 if (bp->match(this, bci)) {
1871 bp->set_orig_bytecode(code);
1872 // and continue, in case there is more than one
1873 }
1874 }
1875 }
1876
1877 void Method::set_breakpoint(int bci) {
1878 InstanceKlass* ik = method_holder();
1879 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1880 bp->set_next(ik->breakpoints());
1881 ik->set_breakpoints(bp);
1882 // do this last:
1883 bp->set(this);
1884 }
1885
1886 static void clear_matches(Method* m, int bci) {
1887 InstanceKlass* ik = m->method_holder();
1888 BreakpointInfo* prev_bp = NULL;
1889 BreakpointInfo* next_bp;
1890 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1891 next_bp = bp->next();
1892 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1893 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1894 // do this first:
1895 bp->clear(m);
1896 // unhook it
1897 if (prev_bp != NULL)
1898 prev_bp->set_next(next_bp);
1899 else
1900 ik->set_breakpoints(next_bp);
1901 delete bp;
1902 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1903 // at same location. So we have multiple matching (method_index and bci)
1904 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1905 // breakpoint for clear_breakpoint request and keep all other method versions
1906 // BreakpointInfo for future clear_breakpoint request.
1907 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1908 // which is being called when class is unloaded. We delete all the Breakpoint
1909 // information for all versions of method. We may not correctly restore the original
1910 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1911 // so these methods won't be used anymore.
1912 if (bci >= 0) {
1913 break;
1914 }
1915 } else {
1916 // This one is a keeper.
1917 prev_bp = bp;
1918 }
1919 }
1920 }
1921
1922 void Method::clear_breakpoint(int bci) {
1923 assert(bci >= 0, "");
1924 clear_matches(this, bci);
1925 }
1926
1927 void Method::clear_all_breakpoints() {
1928 clear_matches(this, -1);
1929 }
1930
1931 #endif // INCLUDE_JVMTI
1932
1933 int Method::invocation_count() {
1934 MethodCounters *mcs = method_counters();
1935 if (TieredCompilation) {
1936 MethodData* const mdo = method_data();
1937 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1938 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1939 return InvocationCounter::count_limit;
1940 } else {
1941 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1942 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1943 }
1944 } else {
1945 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1946 }
1947 }
1948
1949 int Method::backedge_count() {
1950 MethodCounters *mcs = method_counters();
1951 if (TieredCompilation) {
1952 MethodData* const mdo = method_data();
1953 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1954 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1955 return InvocationCounter::count_limit;
1956 } else {
1957 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1958 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1959 }
1960 } else {
1961 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1962 }
1963 }
1964
1965 int Method::highest_comp_level() const {
1966 const MethodCounters* mcs = method_counters();
1967 if (mcs != NULL) {
1968 return mcs->highest_comp_level();
1969 } else {
1970 return CompLevel_none;
1971 }
1972 }
1973
1974 int Method::highest_osr_comp_level() const {
1975 const MethodCounters* mcs = method_counters();
1976 if (mcs != NULL) {
1977 return mcs->highest_osr_comp_level();
1978 } else {
1979 return CompLevel_none;
1980 }
1981 }
1982
1983 void Method::set_highest_comp_level(int level) {
1984 MethodCounters* mcs = method_counters();
1985 if (mcs != NULL) {
1986 mcs->set_highest_comp_level(level);
1987 }
1988 }
1989
1990 void Method::set_highest_osr_comp_level(int level) {
1991 MethodCounters* mcs = method_counters();
1992 if (mcs != NULL) {
1993 mcs->set_highest_osr_comp_level(level);
1994 }
1995 }
1996
1997 #if INCLUDE_JVMTI
1998
1999 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
2000 _bci = bci;
2001 _name_index = m->name_index();
2002 _signature_index = m->signature_index();
2003 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
2004 if (_orig_bytecode == Bytecodes::_breakpoint)
2005 _orig_bytecode = m->orig_bytecode_at(_bci);
2006 _next = NULL;
2007 }
2008
2009 void BreakpointInfo::set(Method* method) {
2010 #ifdef ASSERT
2011 {
2012 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2013 if (code == Bytecodes::_breakpoint)
2014 code = method->orig_bytecode_at(_bci);
2015 assert(orig_bytecode() == code, "original bytecode must be the same");
2016 }
2017 #endif
2018 Thread *thread = Thread::current();
2019 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2020 method->incr_number_of_breakpoints(thread);
2021 {
2022 // Deoptimize all dependents on this method
2023 HandleMark hm(thread);
2024 methodHandle mh(thread, method);
2025 CodeCache::flush_dependents_on_method(mh);
2026 }
2027 }
2028
2029 void BreakpointInfo::clear(Method* method) {
2030 *method->bcp_from(_bci) = orig_bytecode();
2031 assert(method->number_of_breakpoints() > 0, "must not go negative");
2032 method->decr_number_of_breakpoints(Thread::current());
2033 }
2034
2035 #endif // INCLUDE_JVMTI
2036
2037 // jmethodID handling
2038
2039 // This is a block allocating object, sort of like JNIHandleBlock, only a
2040 // lot simpler.
2041 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2042 // never get rid of it.
2043
2044 static const int min_block_size = 8;
2045
2046 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2047 friend class JNIMethodBlock;
2048 Method** _methods;
2049 int _number_of_methods;
2050 int _top;
2051 JNIMethodBlockNode* _next;
2052
2053 public:
2054
2055 JNIMethodBlockNode(int num_methods = min_block_size);
2056
2057 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2058
2059 void ensure_methods(int num_addl_methods) {
2060 if (_top < _number_of_methods) {
2061 num_addl_methods -= _number_of_methods - _top;
2062 if (num_addl_methods <= 0) {
2063 return;
2064 }
2065 }
2066 if (_next == NULL) {
2067 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2068 } else {
2069 _next->ensure_methods(num_addl_methods);
2070 }
2071 }
2072 };
2073
2074 class JNIMethodBlock : public CHeapObj<mtClass> {
2075 JNIMethodBlockNode _head;
2076 JNIMethodBlockNode *_last_free;
2077 public:
2078 static Method* const _free_method;
2079
2080 JNIMethodBlock(int initial_capacity = min_block_size)
2081 : _head(initial_capacity), _last_free(&_head) {}
2082
2083 void ensure_methods(int num_addl_methods) {
2084 _last_free->ensure_methods(num_addl_methods);
2085 }
2086
2087 Method** add_method(Method* m) {
2088 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2089 if (b->_top < b->_number_of_methods) {
2090 // top points to the next free entry.
2091 int i = b->_top;
2092 b->_methods[i] = m;
2093 b->_top++;
2094 _last_free = b;
2095 return &(b->_methods[i]);
2096 } else if (b->_top == b->_number_of_methods) {
2097 // if the next free entry ran off the block see if there's a free entry
2098 for (int i = 0; i < b->_number_of_methods; i++) {
2099 if (b->_methods[i] == _free_method) {
2100 b->_methods[i] = m;
2101 _last_free = b;
2102 return &(b->_methods[i]);
2103 }
2104 }
2105 // Only check each block once for frees. They're very unlikely.
2106 // Increment top past the end of the block.
2107 b->_top++;
2108 }
2109 // need to allocate a next block.
2110 if (b->_next == NULL) {
2111 b->_next = _last_free = new JNIMethodBlockNode();
2112 }
2113 }
2114 guarantee(false, "Should always allocate a free block");
2115 return NULL;
2116 }
2117
2118 bool contains(Method** m) {
2119 if (m == NULL) return false;
2120 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2121 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2122 // This is a bit of extra checking, for two reasons. One is
2123 // that contains() deals with pointers that are passed in by
2124 // JNI code, so making sure that the pointer is aligned
2125 // correctly is valuable. The other is that <= and > are
2126 // technically not defined on pointers, so the if guard can
2127 // pass spuriously; no modern compiler is likely to make that
2128 // a problem, though (and if one did, the guard could also
2129 // fail spuriously, which would be bad).
2130 ptrdiff_t idx = m - b->_methods;
2131 if (b->_methods + idx == m) {
2132 return true;
2133 }
2134 }
2135 }
2136 return false; // not found
2137 }
2138
2139 // Doesn't really destroy it, just marks it as free so it can be reused.
2140 void destroy_method(Method** m) {
2141 #ifdef ASSERT
2142 assert(contains(m), "should be a methodID");
2143 #endif // ASSERT
2144 *m = _free_method;
2145 }
2146
2147 // During class unloading the methods are cleared, which is different
2148 // than freed.
2149 void clear_all_methods() {
2150 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2151 for (int i = 0; i< b->_number_of_methods; i++) {
2152 b->_methods[i] = NULL;
2153 }
2154 }
2155 }
2156 #ifndef PRODUCT
2157 int count_methods() {
2158 // count all allocated methods
2159 int count = 0;
2160 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2161 for (int i = 0; i< b->_number_of_methods; i++) {
2162 if (b->_methods[i] != _free_method) count++;
2163 }
2164 }
2165 return count;
2166 }
2167 #endif // PRODUCT
2168 };
2169
2170 // Something that can't be mistaken for an address or a markWord
2171 Method* const JNIMethodBlock::_free_method = (Method*)55;
2172
2173 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2174 _number_of_methods = MAX2(num_methods, min_block_size);
2175 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2176 for (int i = 0; i < _number_of_methods; i++) {
2177 _methods[i] = JNIMethodBlock::_free_method;
2178 }
2179 }
2180
2181 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2182 ClassLoaderData* cld = loader_data;
2183 if (!SafepointSynchronize::is_at_safepoint()) {
2184 // Have to add jmethod_ids() to class loader data thread-safely.
2185 // Also have to add the method to the list safely, which the cld lock
2186 // protects as well.
2187 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2188 if (cld->jmethod_ids() == NULL) {
2189 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2190 } else {
2191 cld->jmethod_ids()->ensure_methods(capacity);
2192 }
2193 } else {
2194 // At safepoint, we are single threaded and can set this.
2195 if (cld->jmethod_ids() == NULL) {
2196 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2197 } else {
2198 cld->jmethod_ids()->ensure_methods(capacity);
2199 }
2200 }
2201 }
2202
2203 // Add a method id to the jmethod_ids
2204 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2205 ClassLoaderData* cld = loader_data;
2206
2207 if (!SafepointSynchronize::is_at_safepoint()) {
2208 // Have to add jmethod_ids() to class loader data thread-safely.
2209 // Also have to add the method to the list safely, which the cld lock
2210 // protects as well.
2211 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2212 if (cld->jmethod_ids() == NULL) {
2213 cld->set_jmethod_ids(new JNIMethodBlock());
2214 }
2215 // jmethodID is a pointer to Method*
2216 return (jmethodID)cld->jmethod_ids()->add_method(m);
2217 } else {
2218 // At safepoint, we are single threaded and can set this.
2219 if (cld->jmethod_ids() == NULL) {
2220 cld->set_jmethod_ids(new JNIMethodBlock());
2221 }
2222 // jmethodID is a pointer to Method*
2223 return (jmethodID)cld->jmethod_ids()->add_method(m);
2224 }
2225 }
2226
2227 // Mark a jmethodID as free. This is called when there is a data race in
2228 // InstanceKlass while creating the jmethodID cache.
2229 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2230 ClassLoaderData* cld = loader_data;
2231 Method** ptr = (Method**)m;
2232 assert(cld->jmethod_ids() != NULL, "should have method handles");
2233 cld->jmethod_ids()->destroy_method(ptr);
2234 }
2235
2236 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2237 // Can't assert the method_holder is the same because the new method has the
2238 // scratch method holder.
2239 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2240 == new_method->method_holder()->class_loader() ||
2241 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2242 "changing to a different class loader");
2243 // Just change the method in place, jmethodID pointer doesn't change.
2244 *((Method**)jmid) = new_method;
2245 }
2246
2247 bool Method::is_method_id(jmethodID mid) {
2248 Method* m = resolve_jmethod_id(mid);
2249 assert(m != NULL, "should be called with non-null method");
2250 InstanceKlass* ik = m->method_holder();
2251 ClassLoaderData* cld = ik->class_loader_data();
2252 if (cld->jmethod_ids() == NULL) return false;
2253 return (cld->jmethod_ids()->contains((Method**)mid));
2254 }
2255
2256 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2257 if (mid == NULL) return NULL;
2258 Method* o = resolve_jmethod_id(mid);
2259 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2260 return NULL;
2261 }
2262 return o;
2263 };
2264
2265 void Method::set_on_stack(const bool value) {
2266 // Set both the method itself and its constant pool. The constant pool
2267 // on stack means some method referring to it is also on the stack.
2268 constants()->set_on_stack(value);
2269
2270 bool already_set = on_stack();
2271 _access_flags.set_on_stack(value);
2272 if (value && !already_set) {
2273 MetadataOnStackMark::record(this);
2274 }
2275 assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2276 "emcp methods cannot run after emcp bit is cleared");
2277 }
2278
2279 // Called when the class loader is unloaded to make all methods weak.
2280 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2281 loader_data->jmethod_ids()->clear_all_methods();
2282 }
2283
2284 bool Method::has_method_vptr(const void* ptr) {
2285 Method m;
2286 // This assumes that the vtbl pointer is the first word of a C++ object.
2287 return dereference_vptr(&m) == dereference_vptr(ptr);
2288 }
2289
2290 // Check that this pointer is valid by checking that the vtbl pointer matches
2291 bool Method::is_valid_method(const Method* m) {
2292 if (m == NULL) {
2293 return false;
2294 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2295 // Quick sanity check on pointer.
2296 return false;
2297 } else if (m->is_shared()) {
2298 return MetaspaceShared::is_valid_shared_method(m);
2299 } else if (Metaspace::contains_non_shared(m)) {
2300 return has_method_vptr((const void*)m);
2301 } else {
2302 return false;
2303 }
2304 }
2305
2306 #ifndef PRODUCT
2307 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2308 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2309 }
2310 #endif // PRODUCT
2311
2312
2313 // Printing
2314
2315 #ifndef PRODUCT
2316
2317 void Method::print_on(outputStream* st) const {
2318 ResourceMark rm;
2319 assert(is_method(), "must be method");
2320 st->print_cr("%s", internal_name());
2321 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2322 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2323 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2324 constants()->print_value_on(st); st->cr();
2325 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2326 st->print (" - name: "); name()->print_value_on(st); st->cr();
2327 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2328 st->print_cr(" - max stack: %d", max_stack());
2329 st->print_cr(" - max locals: %d", max_locals());
2330 st->print_cr(" - size of params: %d", size_of_parameters());
2331 st->print_cr(" - method size: %d", method_size());
2332 if (intrinsic_id() != vmIntrinsics::_none)
2333 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2334 if (highest_comp_level() != CompLevel_none)
2335 st->print_cr(" - highest level: %d", highest_comp_level());
2336 st->print_cr(" - vtable index: %d", _vtable_index);
2337 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2338 st->print( " - adapters: ");
2339 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2340 if (a == NULL)
2341 st->print_cr(INTPTR_FORMAT, p2i(a));
2342 else
2343 a->print_adapter_on(st);
2344 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2345 st->print_cr(" - code size: %d", code_size());
2346 if (code_size() != 0) {
2347 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2348 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2349 }
2350 if (method_data() != NULL) {
2351 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2352 }
2353 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2354 if (checked_exceptions_length() > 0) {
2355 CheckedExceptionElement* table = checked_exceptions_start();
2356 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2357 if (Verbose) {
2358 for (int i = 0; i < checked_exceptions_length(); i++) {
2359 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2360 }
2361 }
2362 }
2363 if (has_linenumber_table()) {
2364 u_char* table = compressed_linenumber_table();
2365 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2366 if (Verbose) {
2367 CompressedLineNumberReadStream stream(table);
2368 while (stream.read_pair()) {
2369 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2370 }
2371 }
2372 }
2373 st->print_cr(" - localvar length: %d", localvariable_table_length());
2374 if (localvariable_table_length() > 0) {
2375 LocalVariableTableElement* table = localvariable_table_start();
2376 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2377 if (Verbose) {
2378 for (int i = 0; i < localvariable_table_length(); i++) {
2379 int bci = table[i].start_bci;
2380 int len = table[i].length;
2381 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2382 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2383 int slot = table[i].slot;
2384 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2385 }
2386 }
2387 }
2388 if (code() != NULL) {
2389 st->print (" - compiled code: ");
2390 code()->print_value_on(st);
2391 }
2392 if (is_native()) {
2393 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2394 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2395 }
2396 }
2397
2398 void Method::print_linkage_flags(outputStream* st) {
2399 access_flags().print_on(st);
2400 if (is_default_method()) {
2401 st->print("default ");
2402 }
2403 if (is_overpass()) {
2404 st->print("overpass ");
2405 }
2406 }
2407 #endif //PRODUCT
2408
2409 void Method::print_value_on(outputStream* st) const {
2410 assert(is_method(), "must be method");
2411 st->print("%s", internal_name());
2412 print_address_on(st);
2413 st->print(" ");
2414 name()->print_value_on(st);
2415 st->print(" ");
2416 signature()->print_value_on(st);
2417 st->print(" in ");
2418 method_holder()->print_value_on(st);
2419 if (WizardMode) st->print("#%d", _vtable_index);
2420 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2421 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2422 }
2423
2424 #if INCLUDE_SERVICES
2425 // Size Statistics
2426 void Method::collect_statistics(KlassSizeStats *sz) const {
2427 int mysize = sz->count(this);
2428 sz->_method_bytes += mysize;
2429 sz->_method_all_bytes += mysize;
2430 sz->_rw_bytes += mysize;
2431
2432 if (constMethod()) {
2433 constMethod()->collect_statistics(sz);
2434 }
2435 if (method_data()) {
2436 method_data()->collect_statistics(sz);
2437 }
2438 }
2439 #endif // INCLUDE_SERVICES
2440
2441 // LogTouchedMethods and PrintTouchedMethods
2442
2443 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2444 // the Method may be garbage collected. Let's roll our own hash table.
2445 class TouchedMethodRecord : CHeapObj<mtTracing> {
2446 public:
2447 // It's OK to store Symbols here because they will NOT be GC'ed if
2448 // LogTouchedMethods is enabled.
2449 TouchedMethodRecord* _next;
2450 Symbol* _class_name;
2451 Symbol* _method_name;
2452 Symbol* _method_signature;
2453 };
2454
2455 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2456 static TouchedMethodRecord** _touched_method_table = NULL;
2457
2458 void Method::log_touched(TRAPS) {
2459
2460 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2461 Symbol* my_class = klass_name();
2462 Symbol* my_name = name();
2463 Symbol* my_sig = signature();
2464
2465 unsigned int hash = my_class->identity_hash() +
2466 my_name->identity_hash() +
2467 my_sig->identity_hash();
2468 juint index = juint(hash) % table_size;
2469
2470 MutexLocker ml(TouchedMethodLog_lock, THREAD);
2471 if (_touched_method_table == NULL) {
2472 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2473 mtTracing, CURRENT_PC);
2474 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2475 }
2476
2477 TouchedMethodRecord* ptr = _touched_method_table[index];
2478 while (ptr) {
2479 if (ptr->_class_name == my_class &&
2480 ptr->_method_name == my_name &&
2481 ptr->_method_signature == my_sig) {
2482 return;
2483 }
2484 if (ptr->_next == NULL) break;
2485 ptr = ptr->_next;
2486 }
2487 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2488 my_class->increment_refcount();
2489 my_name->increment_refcount();
2490 my_sig->increment_refcount();
2491 nptr->_class_name = my_class;
2492 nptr->_method_name = my_name;
2493 nptr->_method_signature = my_sig;
2494 nptr->_next = NULL;
2495
2496 if (ptr == NULL) {
2497 // first
2498 _touched_method_table[index] = nptr;
2499 } else {
2500 ptr->_next = nptr;
2501 }
2502 }
2503
2504 void Method::print_touched_methods(outputStream* out) {
2505 MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2506 out->print_cr("# Method::print_touched_methods version 1");
2507 if (_touched_method_table) {
2508 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2509 TouchedMethodRecord* ptr = _touched_method_table[i];
2510 while(ptr) {
2511 ptr->_class_name->print_symbol_on(out); out->print(".");
2512 ptr->_method_name->print_symbol_on(out); out->print(":");
2513 ptr->_method_signature->print_symbol_on(out); out->cr();
2514 ptr = ptr->_next;
2515 }
2516 }
2517 }
2518 }
2519
2520 // Verification
2521
2522 void Method::verify_on(outputStream* st) {
2523 guarantee(is_method(), "object must be method");
2524 guarantee(constants()->is_constantPool(), "should be constant pool");
2525 MethodData* md = method_data();
2526 guarantee(md == NULL ||
2527 md->is_methodData(), "should be method data");
2528 }