1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderDataGraph.hpp"
27 #include "classfile/metadataOnStackMark.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/debugInfoRec.hpp"
32 #include "compiler/compilationPolicy.hpp"
33 #include "gc/shared/collectedHeap.inline.hpp"
34 #include "interpreter/bytecodeStream.hpp"
35 #include "interpreter/bytecodeTracer.hpp"
36 #include "interpreter/bytecodes.hpp"
37 #include "interpreter/interpreter.hpp"
38 #include "interpreter/oopMapCache.hpp"
39 #include "memory/allocation.inline.hpp"
40 #include "memory/heapInspection.hpp"
41 #include "memory/metadataFactory.hpp"
42 #include "memory/metaspaceClosure.hpp"
43 #include "memory/metaspaceShared.hpp"
44 #include "memory/oopFactory.hpp"
45 #include "memory/resourceArea.hpp"
46 #include "memory/universe.hpp"
47 #include "oops/constMethod.hpp"
48 #include "oops/constantPool.hpp"
49 #include "oops/method.inline.hpp"
50 #include "oops/methodData.hpp"
51 #include "oops/objArrayKlass.hpp"
52 #include "oops/objArrayOop.inline.hpp"
53 #include "oops/oop.inline.hpp"
54 #include "oops/symbol.hpp"
55 #include "prims/jvmtiExport.hpp"
56 #include "prims/methodHandles.hpp"
57 #include "prims/nativeLookup.hpp"
58 #include "runtime/arguments.hpp"
59 #include "runtime/frame.inline.hpp"
60 #include "runtime/handles.inline.hpp"
61 #include "runtime/init.hpp"
62 #include "runtime/orderAccess.hpp"
63 #include "runtime/relocator.hpp"
64 #include "runtime/safepointVerifiers.hpp"
65 #include "runtime/sharedRuntime.hpp"
66 #include "runtime/signature.hpp"
67 #include "utilities/align.hpp"
68 #include "utilities/quickSort.hpp"
69 #include "utilities/vmError.hpp"
70 #include "utilities/xmlstream.hpp"
71
72 // Implementation of Method
73
74 Method* Method::allocate(ClassLoaderData* loader_data,
75 int byte_code_size,
76 AccessFlags access_flags,
77 InlineTableSizes* sizes,
78 ConstMethod::MethodType method_type,
79 TRAPS) {
80 assert(!access_flags.is_native() || byte_code_size == 0,
81 "native methods should not contain byte codes");
82 ConstMethod* cm = ConstMethod::allocate(loader_data,
83 byte_code_size,
84 sizes,
85 method_type,
86 CHECK_NULL);
87 int size = Method::size(access_flags.is_native());
88 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
89 }
90
91 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
92 NoSafepointVerifier no_safepoint;
93 set_constMethod(xconst);
94 set_access_flags(access_flags);
95 set_intrinsic_id(vmIntrinsics::_none);
96 set_force_inline(false);
97 set_hidden(false);
98 set_dont_inline(false);
99 set_has_injected_profile(false);
100 set_method_data(NULL);
101 clear_method_counters();
102 set_vtable_index(Method::garbage_vtable_index);
103
104 // Fix and bury in Method*
105 set_interpreter_entry(NULL); // sets i2i entry and from_int
106 set_adapter_entry(NULL);
107 Method::clear_code(); // from_c/from_i get set to c2i/i2i
108
109 if (access_flags.is_native()) {
110 clear_native_function();
111 set_signature_handler(NULL);
112 }
113
114 NOT_PRODUCT(set_compiled_invocation_count(0);)
115 }
116
117 // Release Method*. The nmethod will be gone when we get here because
118 // we've walked the code cache.
119 void Method::deallocate_contents(ClassLoaderData* loader_data) {
120 MetadataFactory::free_metadata(loader_data, constMethod());
121 set_constMethod(NULL);
122 MetadataFactory::free_metadata(loader_data, method_data());
123 set_method_data(NULL);
124 MetadataFactory::free_metadata(loader_data, method_counters());
125 clear_method_counters();
126 // The nmethod will be gone when we get here.
127 if (code() != NULL) _code = NULL;
128 }
129
130 void Method::release_C_heap_structures() {
131 if (method_data()) {
132 #if INCLUDE_JVMCI
133 FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
134 #endif
135 // Destroy MethodData
136 method_data()->~MethodData();
137 }
138 }
139
140 address Method::get_i2c_entry() {
141 assert(adapter() != NULL, "must have");
142 return adapter()->get_i2c_entry();
143 }
144
145 address Method::get_c2i_entry() {
146 assert(adapter() != NULL, "must have");
147 return adapter()->get_c2i_entry();
148 }
149
150 address Method::get_c2i_unverified_entry() {
151 assert(adapter() != NULL, "must have");
152 return adapter()->get_c2i_unverified_entry();
153 }
154
155 address Method::get_c2i_no_clinit_check_entry() {
156 assert(VM_Version::supports_fast_class_init_checks(), "");
157 assert(adapter() != NULL, "must have");
158 return adapter()->get_c2i_no_clinit_check_entry();
159 }
160
161 char* Method::name_and_sig_as_C_string() const {
162 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
163 }
164
165 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
166 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
167 }
168
169 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
170 const char* klass_name = klass->external_name();
171 int klass_name_len = (int)strlen(klass_name);
172 int method_name_len = method_name->utf8_length();
173 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
174 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
175 strcpy(dest, klass_name);
176 dest[klass_name_len] = '.';
177 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
178 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
179 dest[len] = 0;
180 return dest;
181 }
182
183 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
184 Symbol* klass_name = klass->name();
185 klass_name->as_klass_external_name(buf, size);
186 int len = (int)strlen(buf);
187
188 if (len < size - 1) {
189 buf[len++] = '.';
190
191 method_name->as_C_string(&(buf[len]), size - len);
192 len = (int)strlen(buf);
193
194 signature->as_C_string(&(buf[len]), size - len);
195 }
196
197 return buf;
198 }
199
200 const char* Method::external_name() const {
201 return external_name(constants()->pool_holder(), name(), signature());
202 }
203
204 void Method::print_external_name(outputStream *os) const {
205 print_external_name(os, constants()->pool_holder(), name(), signature());
206 }
207
208 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
209 stringStream ss;
210 print_external_name(&ss, klass, method_name, signature);
211 return ss.as_string();
212 }
213
214 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
215 signature->print_as_signature_external_return_type(os);
216 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
217 signature->print_as_signature_external_parameters(os);
218 os->print(")");
219 }
220
221 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
222 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
223 // access exception table
224 ExceptionTable table(mh());
225 int length = table.length();
226 // iterate through all entries sequentially
227 constantPoolHandle pool(THREAD, mh->constants());
228 for (int i = 0; i < length; i ++) {
229 //reacquire the table in case a GC happened
230 ExceptionTable table(mh());
231 int beg_bci = table.start_pc(i);
232 int end_bci = table.end_pc(i);
233 assert(beg_bci <= end_bci, "inconsistent exception table");
234 if (beg_bci <= throw_bci && throw_bci < end_bci) {
235 // exception handler bci range covers throw_bci => investigate further
236 int handler_bci = table.handler_pc(i);
237 int klass_index = table.catch_type_index(i);
238 if (klass_index == 0) {
239 return handler_bci;
240 } else if (ex_klass == NULL) {
241 return handler_bci;
242 } else {
243 // we know the exception class => get the constraint class
244 // this may require loading of the constraint class; if verification
245 // fails or some other exception occurs, return handler_bci
246 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
247 assert(k != NULL, "klass not loaded");
248 if (ex_klass->is_subtype_of(k)) {
249 return handler_bci;
250 }
251 }
252 }
253 }
254
255 return -1;
256 }
257
258 void Method::mask_for(int bci, InterpreterOopMap* mask) {
259 methodHandle h_this(Thread::current(), this);
260 // Only GC uses the OopMapCache during thread stack root scanning
261 // any other uses generate an oopmap but do not save it in the cache.
262 if (Universe::heap()->is_gc_active()) {
263 method_holder()->mask_for(h_this, bci, mask);
264 } else {
265 OopMapCache::compute_one_oop_map(h_this, bci, mask);
266 }
267 return;
268 }
269
270
271 int Method::bci_from(address bcp) const {
272 if (is_native() && bcp == 0) {
273 return 0;
274 }
275 #ifdef ASSERT
276 {
277 ResourceMark rm;
278 assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
279 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
280 p2i(bcp), name_and_sig_as_C_string());
281 }
282 #endif
283 return bcp - code_base();
284 }
285
286
287 int Method::validate_bci(int bci) const {
288 return (bci == 0 || bci < code_size()) ? bci : -1;
289 }
290
291 // Return bci if it appears to be a valid bcp
292 // Return -1 otherwise.
293 // Used by profiling code, when invalid data is a possibility.
294 // The caller is responsible for validating the Method* itself.
295 int Method::validate_bci_from_bcp(address bcp) const {
296 // keep bci as -1 if not a valid bci
297 int bci = -1;
298 if (bcp == 0 || bcp == code_base()) {
299 // code_size() may return 0 and we allow 0 here
300 // the method may be native
301 bci = 0;
302 } else if (contains(bcp)) {
303 bci = bcp - code_base();
304 }
305 // Assert that if we have dodged any asserts, bci is negative.
306 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
307 return bci;
308 }
309
310 address Method::bcp_from(int bci) const {
311 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
312 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
313 address bcp = code_base() + bci;
314 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
315 return bcp;
316 }
317
318 address Method::bcp_from(address bcp) const {
319 if (is_native() && bcp == NULL) {
320 return code_base();
321 } else {
322 return bcp;
323 }
324 }
325
326 int Method::size(bool is_native) {
327 // If native, then include pointers for native_function and signature_handler
328 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
329 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
330 return align_metadata_size(header_size() + extra_words);
331 }
332
333
334 Symbol* Method::klass_name() const {
335 return method_holder()->name();
336 }
337
338
339 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
340 log_trace(cds)("Iter(Method): %p", this);
341
342 it->push(&_constMethod);
343 it->push(&_method_data);
344 it->push(&_method_counters);
345 }
346
347 // Attempt to return method oop to original state. Clear any pointers
348 // (to objects outside the shared spaces). We won't be able to predict
349 // where they should point in a new JVM. Further initialize some
350 // entries now in order allow them to be write protected later.
351
352 void Method::remove_unshareable_info() {
353 unlink_method();
354 }
355
356 void Method::set_vtable_index(int index) {
357 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
358 // At runtime initialize_vtable is rerun as part of link_class_impl()
359 // for a shared class loaded by the non-boot loader to obtain the loader
360 // constraints based on the runtime classloaders' context.
361 return; // don't write into the shared class
362 } else {
363 _vtable_index = index;
364 }
365 }
366
367 void Method::set_itable_index(int index) {
368 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
369 // At runtime initialize_itable is rerun as part of link_class_impl()
370 // for a shared class loaded by the non-boot loader to obtain the loader
371 // constraints based on the runtime classloaders' context. The dumptime
372 // itable index should be the same as the runtime index.
373 assert(_vtable_index == itable_index_max - index,
374 "archived itable index is different from runtime index");
375 return; // don’t write into the shared class
376 } else {
377 _vtable_index = itable_index_max - index;
378 }
379 assert(valid_itable_index(), "");
380 }
381
382 // The RegisterNatives call being attempted tried to register with a method that
383 // is not native. Ask JVM TI what prefixes have been specified. Then check
384 // to see if the native method is now wrapped with the prefixes. See the
385 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
386 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
387 #if INCLUDE_JVMTI
388 ResourceMark rm(THREAD);
389 Method* method;
390 int name_len = name->utf8_length();
391 char* name_str = name->as_utf8();
392 int prefix_count;
393 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
394 for (int i = 0; i < prefix_count; i++) {
395 char* prefix = prefixes[i];
396 int prefix_len = (int)strlen(prefix);
397
398 // try adding this prefix to the method name and see if it matches another method name
399 int trial_len = name_len + prefix_len;
400 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
401 strcpy(trial_name_str, prefix);
402 strcat(trial_name_str, name_str);
403 TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
404 if (trial_name == NULL) {
405 continue; // no such symbol, so this prefix wasn't used, try the next prefix
406 }
407 method = k->lookup_method(trial_name, signature);
408 if (method == NULL) {
409 continue; // signature doesn't match, try the next prefix
410 }
411 if (method->is_native()) {
412 method->set_is_prefixed_native();
413 return method; // wahoo, we found a prefixed version of the method, return it
414 }
415 // found as non-native, so prefix is good, add it, probably just need more prefixes
416 name_len = trial_len;
417 name_str = trial_name_str;
418 }
419 #endif // INCLUDE_JVMTI
420 return NULL; // not found
421 }
422
423 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
424 Method* method = k->lookup_method(name, signature);
425 if (method == NULL) {
426 ResourceMark rm;
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(), false);
432 }
433 if (!method->is_native()) {
434 // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
435 method = find_prefixed_native(k, name, signature, THREAD);
436 if (method == NULL) {
437 ResourceMark rm;
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(), false);
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 return true;
459 }
460
461 bool Method::was_executed_more_than(int n) {
462 // Invocation counter is reset when the Method* is compiled.
463 // If the method has compiled code we therefore assume it has
464 // be excuted more than n times.
465 if (is_accessor() || is_empty_method() || (code() != NULL)) {
466 // interpreter doesn't bump invocation counter of trivial methods
467 // compiler does not bump invocation counter of compiled methods
468 return true;
469 }
470 else if ((method_counters() != NULL &&
471 method_counters()->invocation_counter()->carry()) ||
472 (method_data() != NULL &&
473 method_data()->invocation_counter()->carry())) {
474 // The carry bit is set when the counter overflows and causes
475 // a compilation to occur. We don't know how many times
476 // the counter has been reset, so we simply assume it has
477 // been executed more than n times.
478 return true;
479 } else {
480 return invocation_count() > n;
481 }
482 }
483
484 void Method::print_invocation_count() {
485 if (is_static()) tty->print("static ");
486 if (is_final()) tty->print("final ");
487 if (is_synchronized()) tty->print("synchronized ");
488 if (is_native()) tty->print("native ");
489 tty->print("%s::", method_holder()->external_name());
490 name()->print_symbol_on(tty);
491 signature()->print_symbol_on(tty);
492
493 if (WizardMode) {
494 // dump the size of the byte codes
495 tty->print(" {%d}", code_size());
496 }
497 tty->cr();
498
499 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
500 tty->print_cr (" invocation_counter: %8d ", invocation_count());
501 tty->print_cr (" backedge_counter: %8d ", backedge_count());
502 #ifndef PRODUCT
503 if (CountCompiledCalls) {
504 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
505 }
506 #endif
507 }
508
509 // Build a MethodData* object to hold information about this method
510 // collected in the interpreter.
511 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
512 // Do not profile the method if metaspace has hit an OOM previously
513 // allocating profiling data. Callers clear pending exception so don't
514 // add one here.
515 if (ClassLoaderDataGraph::has_metaspace_oom()) {
516 return;
517 }
518
519 // Grab a lock here to prevent multiple
520 // MethodData*s from being created.
521 MutexLocker ml(MethodData_lock, THREAD);
522 if (method->method_data() == NULL) {
523 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
524 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
525 if (HAS_PENDING_EXCEPTION) {
526 CompileBroker::log_metaspace_failure();
527 ClassLoaderDataGraph::set_metaspace_oom(true);
528 return; // return the exception (which is cleared)
529 }
530
531 method->set_method_data(method_data);
532 if (PrintMethodData && (Verbose || WizardMode)) {
533 ResourceMark rm(THREAD);
534 tty->print("build_interpreter_method_data for ");
535 method->print_name(tty);
536 tty->cr();
537 // At the end of the run, the MDO, full of data, will be dumped.
538 }
539 }
540 }
541
542 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
543 // Do not profile the method if metaspace has hit an OOM previously
544 if (ClassLoaderDataGraph::has_metaspace_oom()) {
545 return NULL;
546 }
547
548 methodHandle mh(m);
549 MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
550 if (HAS_PENDING_EXCEPTION) {
551 CompileBroker::log_metaspace_failure();
552 ClassLoaderDataGraph::set_metaspace_oom(true);
553 return NULL; // return the exception (which is cleared)
554 }
555 if (!mh->init_method_counters(counters)) {
556 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
557 }
558
559 if (LogTouchedMethods) {
560 mh->log_touched(CHECK_NULL);
561 }
562
563 return mh->method_counters();
564 }
565
566 bool Method::init_method_counters(MethodCounters* counters) {
567 // Try to install a pointer to MethodCounters, return true on success.
568 return Atomic::replace_if_null(counters, &_method_counters);
569 }
570
571 int Method::extra_stack_words() {
572 // not an inline function, to avoid a header dependency on Interpreter
573 return extra_stack_entries() * Interpreter::stackElementSize;
574 }
575
576
577 void Method::compute_size_of_parameters(Thread *thread) {
578 ArgumentSizeComputer asc(signature());
579 set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
580 }
581
582 BasicType Method::result_type() const {
583 ResultTypeFinder rtf(signature());
584 return rtf.type();
585 }
586
587
588 bool Method::is_empty_method() const {
589 return code_size() == 1
590 && *code_base() == Bytecodes::_return;
591 }
592
593
594 bool Method::is_vanilla_constructor() const {
595 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
596 // which only calls the superclass vanilla constructor and possibly does stores of
597 // zero constants to local fields:
598 //
599 // aload_0
600 // invokespecial
601 // indexbyte1
602 // indexbyte2
603 //
604 // followed by an (optional) sequence of:
605 //
606 // aload_0
607 // aconst_null / iconst_0 / fconst_0 / dconst_0
608 // putfield
609 // indexbyte1
610 // indexbyte2
611 //
612 // followed by:
613 //
614 // return
615
616 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
617 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
618 int size = code_size();
619 // Check if size match
620 if (size == 0 || size % 5 != 0) return false;
621 address cb = code_base();
622 int last = size - 1;
623 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
624 // Does not call superclass default constructor
625 return false;
626 }
627 // Check optional sequence
628 for (int i = 4; i < last; i += 5) {
629 if (cb[i] != Bytecodes::_aload_0) return false;
630 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
631 if (cb[i+2] != Bytecodes::_putfield) return false;
632 }
633 return true;
634 }
635
636
637 bool Method::compute_has_loops_flag() {
638 BytecodeStream bcs(this);
639 Bytecodes::Code bc;
640
641 while ((bc = bcs.next()) >= 0) {
642 switch( bc ) {
643 case Bytecodes::_ifeq:
644 case Bytecodes::_ifnull:
645 case Bytecodes::_iflt:
646 case Bytecodes::_ifle:
647 case Bytecodes::_ifne:
648 case Bytecodes::_ifnonnull:
649 case Bytecodes::_ifgt:
650 case Bytecodes::_ifge:
651 case Bytecodes::_if_icmpeq:
652 case Bytecodes::_if_icmpne:
653 case Bytecodes::_if_icmplt:
654 case Bytecodes::_if_icmpgt:
655 case Bytecodes::_if_icmple:
656 case Bytecodes::_if_icmpge:
657 case Bytecodes::_if_acmpeq:
658 case Bytecodes::_if_acmpne:
659 case Bytecodes::_goto:
660 case Bytecodes::_jsr:
661 if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
662 break;
663
664 case Bytecodes::_goto_w:
665 case Bytecodes::_jsr_w:
666 if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
667 break;
668
669 default:
670 break;
671 }
672 }
673 _access_flags.set_loops_flag_init();
674 return _access_flags.has_loops();
675 }
676
677 bool Method::is_final_method(AccessFlags class_access_flags) const {
678 // or "does_not_require_vtable_entry"
679 // default method or overpass can occur, is not final (reuses vtable entry)
680 // private methods in classes get vtable entries for backward class compatibility.
681 if (is_overpass() || is_default_method()) return false;
682 return is_final() || class_access_flags.is_final();
683 }
684
685 bool Method::is_final_method() const {
686 return is_final_method(method_holder()->access_flags());
687 }
688
689 bool Method::is_default_method() const {
690 if (method_holder() != NULL &&
691 method_holder()->is_interface() &&
692 !is_abstract() && !is_private()) {
693 return true;
694 } else {
695 return false;
696 }
697 }
698
699 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
700 if (is_final_method(class_access_flags)) return true;
701 #ifdef ASSERT
702 ResourceMark rm;
703 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
704 if (class_access_flags.is_interface()) {
705 assert(is_nonv == is_static() || is_nonv == is_private(),
706 "nonvirtual unexpected for non-static, non-private: %s",
707 name_and_sig_as_C_string());
708 }
709 #endif
710 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
711 return vtable_index() == nonvirtual_vtable_index;
712 }
713
714 bool Method::can_be_statically_bound() const {
715 return can_be_statically_bound(method_holder()->access_flags());
716 }
717
718 bool Method::can_be_statically_bound(InstanceKlass* context) const {
719 return (method_holder() == context) && can_be_statically_bound();
720 }
721
722 bool Method::is_accessor() const {
723 return is_getter() || is_setter();
724 }
725
726 bool Method::is_getter() const {
727 if (code_size() != 5) return false;
728 if (size_of_parameters() != 1) return false;
729 if (java_code_at(0) != Bytecodes::_aload_0) return false;
730 if (java_code_at(1) != Bytecodes::_getfield) return false;
731 switch (java_code_at(4)) {
732 case Bytecodes::_ireturn:
733 case Bytecodes::_lreturn:
734 case Bytecodes::_freturn:
735 case Bytecodes::_dreturn:
736 case Bytecodes::_areturn:
737 break;
738 default:
739 return false;
740 }
741 return true;
742 }
743
744 bool Method::is_setter() const {
745 if (code_size() != 6) return false;
746 if (java_code_at(0) != Bytecodes::_aload_0) return false;
747 switch (java_code_at(1)) {
748 case Bytecodes::_iload_1:
749 case Bytecodes::_aload_1:
750 case Bytecodes::_fload_1:
751 if (size_of_parameters() != 2) return false;
752 break;
753 case Bytecodes::_dload_1:
754 case Bytecodes::_lload_1:
755 if (size_of_parameters() != 3) return false;
756 break;
757 default:
758 return false;
759 }
760 if (java_code_at(2) != Bytecodes::_putfield) return false;
761 if (java_code_at(5) != Bytecodes::_return) return false;
762 return true;
763 }
764
765 bool Method::is_constant_getter() const {
766 int last_index = code_size() - 1;
767 // Check if the first 1-3 bytecodes are a constant push
768 // and the last bytecode is a return.
769 return (2 <= code_size() && code_size() <= 4 &&
770 Bytecodes::is_const(java_code_at(0)) &&
771 Bytecodes::length_for(java_code_at(0)) == last_index &&
772 Bytecodes::is_return(java_code_at(last_index)));
773 }
774
775 bool Method::is_initializer() const {
776 return is_object_initializer() || is_static_initializer();
777 }
778
779 bool Method::has_valid_initializer_flags() const {
780 return (is_static() ||
781 method_holder()->major_version() < 51);
782 }
783
784 bool Method::is_static_initializer() const {
785 // For classfiles version 51 or greater, ensure that the clinit method is
786 // static. Non-static methods with the name "<clinit>" are not static
787 // initializers. (older classfiles exempted for backward compatibility)
788 return name() == vmSymbols::class_initializer_name() &&
789 has_valid_initializer_flags();
790 }
791
792 bool Method::is_object_initializer() const {
793 return name() == vmSymbols::object_initializer_name();
794 }
795
796 bool Method::needs_clinit_barrier() const {
797 return is_static() && !method_holder()->is_initialized();
798 }
799
800 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
801 int length = method->checked_exceptions_length();
802 if (length == 0) { // common case
803 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
804 } else {
805 methodHandle h_this(THREAD, method);
806 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
807 objArrayHandle mirrors (THREAD, m_oop);
808 for (int i = 0; i < length; i++) {
809 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
810 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
811 assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
812 mirrors->obj_at_put(i, k->java_mirror());
813 }
814 return mirrors;
815 }
816 };
817
818
819 int Method::line_number_from_bci(int bci) const {
820 int best_bci = 0;
821 int best_line = -1;
822 if (bci == SynchronizationEntryBCI) bci = 0;
823 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
824 // The line numbers are a short array of 2-tuples [start_pc, line_number].
825 // Not necessarily sorted and not necessarily one-to-one.
826 CompressedLineNumberReadStream stream(compressed_linenumber_table());
827 while (stream.read_pair()) {
828 if (stream.bci() == bci) {
829 // perfect match
830 return stream.line();
831 } else {
832 // update best_bci/line
833 if (stream.bci() < bci && stream.bci() >= best_bci) {
834 best_bci = stream.bci();
835 best_line = stream.line();
836 }
837 }
838 }
839 }
840 return best_line;
841 }
842
843
844 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
845 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
846 Thread *thread = Thread::current();
847 Symbol* klass_name = constants()->klass_name_at(klass_index);
848 Handle loader(thread, method_holder()->class_loader());
849 Handle prot (thread, method_holder()->protection_domain());
850 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
851 } else {
852 return true;
853 }
854 }
855
856
857 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
858 int klass_index = constants()->klass_ref_index_at(refinfo_index);
859 if (must_be_resolved) {
860 // Make sure klass is resolved in constantpool.
861 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
862 }
863 return is_klass_loaded_by_klass_index(klass_index);
864 }
865
866
867 void Method::set_native_function(address function, bool post_event_flag) {
868 assert(function != NULL, "use clear_native_function to unregister natives");
869 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
870 address* native_function = native_function_addr();
871
872 // We can see racers trying to place the same native function into place. Once
873 // is plenty.
874 address current = *native_function;
875 if (current == function) return;
876 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
877 function != NULL) {
878 // native_method_throw_unsatisfied_link_error_entry() should only
879 // be passed when post_event_flag is false.
880 assert(function !=
881 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
882 "post_event_flag mis-match");
883
884 // post the bind event, and possible change the bind function
885 JvmtiExport::post_native_method_bind(this, &function);
886 }
887 *native_function = function;
888 // This function can be called more than once. We must make sure that we always
889 // use the latest registered method -> check if a stub already has been generated.
890 // If so, we have to make it not_entrant.
891 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
892 if (nm != NULL) {
893 nm->make_not_entrant();
894 }
895 }
896
897
898 bool Method::has_native_function() const {
899 if (is_method_handle_intrinsic())
900 return false; // special-cased in SharedRuntime::generate_native_wrapper
901 address func = native_function();
902 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
903 }
904
905
906 void Method::clear_native_function() {
907 // Note: is_method_handle_intrinsic() is allowed here.
908 set_native_function(
909 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
910 !native_bind_event_is_interesting);
911 this->unlink_code();
912 }
913
914
915 void Method::set_signature_handler(address handler) {
916 address* signature_handler = signature_handler_addr();
917 *signature_handler = handler;
918 }
919
920
921 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
922 assert(reason != NULL, "must provide a reason");
923 if (PrintCompilation && report) {
924 ttyLocker ttyl;
925 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
926 if (comp_level == CompLevel_all) {
927 tty->print("all levels ");
928 } else {
929 tty->print("level %d ", comp_level);
930 }
931 this->print_short_name(tty);
932 int size = this->code_size();
933 if (size > 0) {
934 tty->print(" (%d bytes)", size);
935 }
936 if (reason != NULL) {
937 tty->print(" %s", reason);
938 }
939 tty->cr();
940 }
941 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
942 ttyLocker ttyl;
943 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
944 os::current_thread_id(), is_osr, comp_level);
945 if (reason != NULL) {
946 xtty->print(" reason=\'%s\'", reason);
947 }
948 xtty->method(this);
949 xtty->stamp();
950 xtty->end_elem();
951 }
952 }
953
954 bool Method::is_always_compilable() const {
955 // Generated adapters must be compiled
956 if (is_method_handle_intrinsic() && is_synthetic()) {
957 assert(!is_not_c1_compilable(), "sanity check");
958 assert(!is_not_c2_compilable(), "sanity check");
959 return true;
960 }
961
962 return false;
963 }
964
965 bool Method::is_not_compilable(int comp_level) const {
966 if (number_of_breakpoints() > 0)
967 return true;
968 if (is_always_compilable())
969 return false;
970 if (comp_level == CompLevel_any)
971 return is_not_c1_compilable() || is_not_c2_compilable();
972 if (is_c1_compile(comp_level))
973 return is_not_c1_compilable();
974 if (is_c2_compile(comp_level))
975 return is_not_c2_compilable();
976 return false;
977 }
978
979 // call this when compiler finds that this method is not compilable
980 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
981 if (is_always_compilable()) {
982 // Don't mark a method which should be always compilable
983 return;
984 }
985 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
986 if (comp_level == CompLevel_all) {
987 set_not_c1_compilable();
988 set_not_c2_compilable();
989 } else {
990 if (is_c1_compile(comp_level))
991 set_not_c1_compilable();
992 if (is_c2_compile(comp_level))
993 set_not_c2_compilable();
994 }
995 CompilationPolicy::policy()->disable_compilation(this);
996 assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
997 }
998
999 bool Method::is_not_osr_compilable(int comp_level) const {
1000 if (is_not_compilable(comp_level))
1001 return true;
1002 if (comp_level == CompLevel_any)
1003 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
1004 if (is_c1_compile(comp_level))
1005 return is_not_c1_osr_compilable();
1006 if (is_c2_compile(comp_level))
1007 return is_not_c2_osr_compilable();
1008 return false;
1009 }
1010
1011 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1012 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1013 if (comp_level == CompLevel_all) {
1014 set_not_c1_osr_compilable();
1015 set_not_c2_osr_compilable();
1016 } else {
1017 if (is_c1_compile(comp_level))
1018 set_not_c1_osr_compilable();
1019 if (is_c2_compile(comp_level))
1020 set_not_c2_osr_compilable();
1021 }
1022 CompilationPolicy::policy()->disable_compilation(this);
1023 assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
1024 }
1025
1026 // Revert to using the interpreter and clear out the nmethod
1027 void Method::clear_code() {
1028 // this may be NULL if c2i adapters have not been made yet
1029 // Only should happen at allocate time.
1030 if (adapter() == NULL) {
1031 _from_compiled_entry = NULL;
1032 } else {
1033 _from_compiled_entry = adapter()->get_c2i_entry();
1034 }
1035 OrderAccess::storestore();
1036 _from_interpreted_entry = _i2i_entry;
1037 OrderAccess::storestore();
1038 _code = NULL;
1039 }
1040
1041 void Method::unlink_code(CompiledMethod *compare) {
1042 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1043 // We need to check if either the _code or _from_compiled_code_entry_point
1044 // refer to this nmethod because there is a race in setting these two fields
1045 // in Method* as seen in bugid 4947125.
1046 // If the vep() points to the zombie nmethod, the memory for the nmethod
1047 // could be flushed and the compiler and vtable stubs could still call
1048 // through it.
1049 if (code() == compare ||
1050 from_compiled_entry() == compare->verified_entry_point()) {
1051 clear_code();
1052 }
1053 }
1054
1055 void Method::unlink_code() {
1056 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1057 clear_code();
1058 }
1059
1060 #if INCLUDE_CDS
1061 // Called by class data sharing to remove any entry points (which are not shared)
1062 void Method::unlink_method() {
1063 _code = NULL;
1064
1065 Arguments::assert_is_dumping_archive();
1066 // Set the values to what they should be at run time. Note that
1067 // this Method can no longer be executed during dump time.
1068 _i2i_entry = Interpreter::entry_for_cds_method(this);
1069 _from_interpreted_entry = _i2i_entry;
1070
1071 if (DynamicDumpSharedSpaces) {
1072 assert(_from_compiled_entry != NULL, "sanity");
1073 } else {
1074 // TODO: Simplify the adapter trampoline allocation for static archiving.
1075 // Remove the use of CDSAdapterHandlerEntry.
1076 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
1077 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
1078 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
1079 assert(*((int*)_from_compiled_entry) == 0,
1080 "must be NULL during dump time, to be initialized at run time");
1081 }
1082
1083 if (is_native()) {
1084 *native_function_addr() = NULL;
1085 set_signature_handler(NULL);
1086 }
1087 NOT_PRODUCT(set_compiled_invocation_count(0);)
1088
1089 set_method_data(NULL);
1090 clear_method_counters();
1091 }
1092 #endif
1093
1094 /****************************************************************************
1095 // The following illustrates how the entries work for CDS shared Methods:
1096 //
1097 // Our goal is to delay writing into a shared Method until it's compiled.
1098 // Hence, we want to determine the initial values for _i2i_entry,
1099 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1100 //
1101 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1102 // They also have similar signatures so that they will share the same
1103 // AdapterHandlerEntry.
1104 //
1105 // _adapter_trampoline points to a fixed location in the RW section of
1106 // the CDS archive. This location initially contains a NULL pointer. When the
1107 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1108 // dynamically, and its c2i/i2c entries are generated.
1109 //
1110 // _i2i_entry and _from_interpreted_entry initially points to the same
1111 // (fixed) location in the CODE section of the CDS archive. This contains
1112 // an unconditional branch to the actual entry for "zero_locals", which is
1113 // generated at run time and may be on an arbitrary address. Thus, the
1114 // unconditional branch is also generated at run time to jump to the correct
1115 // address.
1116 //
1117 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1118 // section. This address has enough space for an unconditional branch
1119 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1120 // initialized, and the address for the actual c2i_entry is known, we emit a
1121 // branch instruction here to branch to the actual c2i_entry.
1122 //
1123 // The effect of the extra branch on the i2i and c2i entries is negligible.
1124 //
1125 // The reason for putting _adapter_trampoline in RO is many shared Methods
1126 // share the same AdapterHandlerEntry, so we can save space in the RW section
1127 // by having the extra indirection.
1128
1129
1130 [Method A: RW]
1131 _constMethod ----> [ConstMethod: RO]
1132 _adapter_trampoline -----------+
1133 |
1134 _i2i_entry (same value as method B) |
1135 _from_interpreted_entry (same value as method B) |
1136 _from_compiled_entry (same value as method B) |
1137 |
1138 |
1139 [Method B: RW] +--------+
1140 _constMethod ----> [ConstMethod: RO] |
1141 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1142 |
1143 +-------------------------------+
1144 |
1145 +----> [AdapterHandlerEntry] (allocated at run time)
1146 _fingerprint
1147 _c2i_entry ---------------------------------+->[c2i entry..]
1148 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1149 _from_interpreted_entry | _c2i_unverified_entry | |
1150 | | _c2i_no_clinit_check_entry| |
1151 | | (_cds_entry_table: CODE) | |
1152 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1153 | | (allocated at run time) | |
1154 | | ... [asm code ...] | |
1155 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1156 | | |
1157 | | |
1158 +-[compiled]-------------------------------------------------------------------+ |
1159 |
1160 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1161 [jmp c2i_entry] ------------------------------------------------------+
1162
1163 ***/
1164
1165 // Called when the method_holder is getting linked. Setup entrypoints so the method
1166 // is ready to be called from interpreter, compiler, and vtables.
1167 void Method::link_method(const methodHandle& h_method, TRAPS) {
1168 // If the code cache is full, we may reenter this function for the
1169 // leftover methods that weren't linked.
1170 if (is_shared()) {
1171 address entry = Interpreter::entry_for_cds_method(h_method);
1172 assert(entry != NULL && entry == _i2i_entry,
1173 "should be correctly set during dump time");
1174 if (adapter() != NULL) {
1175 return;
1176 }
1177 assert(entry == _from_interpreted_entry,
1178 "should be correctly set during dump time");
1179 } else if (_i2i_entry != NULL) {
1180 return;
1181 }
1182 assert( _code == NULL, "nothing compiled yet" );
1183
1184 // Setup interpreter entrypoint
1185 assert(this == h_method(), "wrong h_method()" );
1186
1187 if (!is_shared()) {
1188 assert(adapter() == NULL, "init'd to NULL");
1189 address entry = Interpreter::entry_for_method(h_method);
1190 assert(entry != NULL, "interpreter entry must be non-null");
1191 // Sets both _i2i_entry and _from_interpreted_entry
1192 set_interpreter_entry(entry);
1193 }
1194
1195 // Don't overwrite already registered native entries.
1196 if (is_native() && !has_native_function()) {
1197 set_native_function(
1198 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1199 !native_bind_event_is_interesting);
1200 }
1201
1202 // Setup compiler entrypoint. This is made eagerly, so we do not need
1203 // special handling of vtables. An alternative is to make adapters more
1204 // lazily by calling make_adapter() from from_compiled_entry() for the
1205 // normal calls. For vtable calls life gets more complicated. When a
1206 // call-site goes mega-morphic we need adapters in all methods which can be
1207 // called from the vtable. We need adapters on such methods that get loaded
1208 // later. Ditto for mega-morphic itable calls. If this proves to be a
1209 // problem we'll make these lazily later.
1210 (void) make_adapters(h_method, CHECK);
1211
1212 // ONLY USE the h_method now as make_adapter may have blocked
1213
1214 }
1215
1216 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1217 // Adapters for compiled code are made eagerly here. They are fairly
1218 // small (generally < 100 bytes) and quick to make (and cached and shared)
1219 // so making them eagerly shouldn't be too expensive.
1220 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1221 if (adapter == NULL ) {
1222 if (!is_init_completed()) {
1223 // Don't throw exceptions during VM initialization because java.lang.* classes
1224 // might not have been initialized, causing problems when constructing the
1225 // Java exception object.
1226 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1227 } else {
1228 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1229 }
1230 }
1231
1232 if (mh->is_shared()) {
1233 assert(mh->adapter() == adapter, "must be");
1234 assert(mh->_from_compiled_entry != NULL, "must be");
1235 } else {
1236 mh->set_adapter_entry(adapter);
1237 mh->_from_compiled_entry = adapter->get_c2i_entry();
1238 }
1239 return adapter->get_c2i_entry();
1240 }
1241
1242 void Method::restore_unshareable_info(TRAPS) {
1243 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1244
1245 // Since restore_unshareable_info can be called more than once for a method, don't
1246 // redo any work.
1247 if (adapter() == NULL) {
1248 methodHandle mh(THREAD, this);
1249 link_method(mh, CHECK);
1250 }
1251 }
1252
1253 address Method::from_compiled_entry_no_trampoline() const {
1254 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1255 if (code) {
1256 return code->verified_entry_point();
1257 } else {
1258 return adapter()->get_c2i_entry();
1259 }
1260 }
1261
1262 // The verified_code_entry() must be called when a invoke is resolved
1263 // on this method.
1264
1265 // It returns the compiled code entry point, after asserting not null.
1266 // This function is called after potential safepoints so that nmethod
1267 // or adapter that it points to is still live and valid.
1268 // This function must not hit a safepoint!
1269 address Method::verified_code_entry() {
1270 debug_only(NoSafepointVerifier nsv;)
1271 assert(_from_compiled_entry != NULL, "must be set");
1272 return _from_compiled_entry;
1273 }
1274
1275 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1276 // (could be racing a deopt).
1277 // Not inline to avoid circular ref.
1278 bool Method::check_code() const {
1279 // cached in a register or local. There's a race on the value of the field.
1280 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1281 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1282 }
1283
1284 // Install compiled code. Instantly it can execute.
1285 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1286 assert_lock_strong(CompiledMethod_lock);
1287 assert( code, "use clear_code to remove code" );
1288 assert( mh->check_code(), "" );
1289
1290 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1291
1292 // These writes must happen in this order, because the interpreter will
1293 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1294 // which jumps to _from_compiled_entry.
1295 mh->_code = code; // Assign before allowing compiled code to exec
1296
1297 int comp_level = code->comp_level();
1298 // In theory there could be a race here. In practice it is unlikely
1299 // and not worth worrying about.
1300 if (comp_level > mh->highest_comp_level()) {
1301 mh->set_highest_comp_level(comp_level);
1302 }
1303
1304 OrderAccess::storestore();
1305 mh->_from_compiled_entry = code->verified_entry_point();
1306 OrderAccess::storestore();
1307 // Instantly compiled code can execute.
1308 if (!mh->is_method_handle_intrinsic())
1309 mh->_from_interpreted_entry = mh->get_i2c_entry();
1310 }
1311
1312
1313 bool Method::is_overridden_in(Klass* k) const {
1314 InstanceKlass* ik = InstanceKlass::cast(k);
1315
1316 if (ik->is_interface()) return false;
1317
1318 // If method is an interface, we skip it - except if it
1319 // is a miranda method
1320 if (method_holder()->is_interface()) {
1321 // Check that method is not a miranda method
1322 if (ik->lookup_method(name(), signature()) == NULL) {
1323 // No implementation exist - so miranda method
1324 return false;
1325 }
1326 return true;
1327 }
1328
1329 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1330 if (!has_vtable_index()) {
1331 return false;
1332 } else {
1333 Method* vt_m = ik->method_at_vtable(vtable_index());
1334 return vt_m != this;
1335 }
1336 }
1337
1338
1339 // give advice about whether this Method* should be cached or not
1340 bool Method::should_not_be_cached() const {
1341 if (is_old()) {
1342 // This method has been redefined. It is either EMCP or obsolete
1343 // and we don't want to cache it because that would pin the method
1344 // down and prevent it from being collectible if and when it
1345 // finishes executing.
1346 return true;
1347 }
1348
1349 // caching this method should be just fine
1350 return false;
1351 }
1352
1353
1354 /**
1355 * Returns true if this is one of the specially treated methods for
1356 * security related stack walks (like Reflection.getCallerClass).
1357 */
1358 bool Method::is_ignored_by_security_stack_walk() const {
1359 if (intrinsic_id() == vmIntrinsics::_invoke) {
1360 // This is Method.invoke() -- ignore it
1361 return true;
1362 }
1363 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1364 // This is an auxilary frame -- ignore it
1365 return true;
1366 }
1367 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1368 // This is an internal adapter frame for method handles -- ignore it
1369 return true;
1370 }
1371 return false;
1372 }
1373
1374
1375 // Constant pool structure for invoke methods:
1376 enum {
1377 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1378 _imcp_invoke_signature, // utf8: (variable Symbol*)
1379 _imcp_limit
1380 };
1381
1382 // Test if this method is an MH adapter frame generated by Java code.
1383 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1384 bool Method::is_compiled_lambda_form() const {
1385 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1386 }
1387
1388 // Test if this method is an internal MH primitive method.
1389 bool Method::is_method_handle_intrinsic() const {
1390 vmIntrinsics::ID iid = intrinsic_id();
1391 return (MethodHandles::is_signature_polymorphic(iid) &&
1392 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1393 }
1394
1395 bool Method::has_member_arg() const {
1396 vmIntrinsics::ID iid = intrinsic_id();
1397 return (MethodHandles::is_signature_polymorphic(iid) &&
1398 MethodHandles::has_member_arg(iid));
1399 }
1400
1401 // Make an instance of a signature-polymorphic internal MH primitive.
1402 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1403 Symbol* signature,
1404 TRAPS) {
1405 ResourceMark rm;
1406 methodHandle empty;
1407
1408 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1409 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1410 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1411 if (TraceMethodHandles) {
1412 tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1413 }
1414
1415 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1416 name->increment_refcount();
1417 signature->increment_refcount();
1418
1419 int cp_length = _imcp_limit;
1420 ClassLoaderData* loader_data = holder->class_loader_data();
1421 constantPoolHandle cp;
1422 {
1423 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1424 cp = constantPoolHandle(THREAD, cp_oop);
1425 }
1426 cp->set_pool_holder(holder);
1427 cp->symbol_at_put(_imcp_invoke_name, name);
1428 cp->symbol_at_put(_imcp_invoke_signature, signature);
1429 cp->set_has_preresolution();
1430
1431 // decide on access bits: public or not?
1432 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1433 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1434 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1435 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1436
1437 methodHandle m;
1438 {
1439 InlineTableSizes sizes;
1440 Method* m_oop = Method::allocate(loader_data, 0,
1441 accessFlags_from(flags_bits), &sizes,
1442 ConstMethod::NORMAL, CHECK_(empty));
1443 m = methodHandle(THREAD, m_oop);
1444 }
1445 m->set_constants(cp());
1446 m->set_name_index(_imcp_invoke_name);
1447 m->set_signature_index(_imcp_invoke_signature);
1448 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1449 assert(m->signature() == signature, "");
1450 ResultTypeFinder rtf(signature);
1451 m->constMethod()->set_result_type(rtf.type());
1452 m->compute_size_of_parameters(THREAD);
1453 m->init_intrinsic_id();
1454 assert(m->is_method_handle_intrinsic(), "");
1455 #ifdef ASSERT
1456 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1457 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1458 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1459 #endif //ASSERT
1460
1461 // Finally, set up its entry points.
1462 assert(m->can_be_statically_bound(), "");
1463 m->set_vtable_index(Method::nonvirtual_vtable_index);
1464 m->link_method(m, CHECK_(empty));
1465
1466 if (TraceMethodHandles && (Verbose || WizardMode)) {
1467 ttyLocker ttyl;
1468 m->print_on(tty);
1469 }
1470
1471 return m;
1472 }
1473
1474 Klass* Method::check_non_bcp_klass(Klass* klass) {
1475 if (klass != NULL && klass->class_loader() != NULL) {
1476 if (klass->is_objArray_klass())
1477 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1478 return klass;
1479 }
1480 return NULL;
1481 }
1482
1483
1484 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1485 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1486 // Code below does not work for native methods - they should never get rewritten anyway
1487 assert(!m->is_native(), "cannot rewrite native methods");
1488 // Allocate new Method*
1489 AccessFlags flags = m->access_flags();
1490
1491 ConstMethod* cm = m->constMethod();
1492 int checked_exceptions_len = cm->checked_exceptions_length();
1493 int localvariable_len = cm->localvariable_table_length();
1494 int exception_table_len = cm->exception_table_length();
1495 int method_parameters_len = cm->method_parameters_length();
1496 int method_annotations_len = cm->method_annotations_length();
1497 int parameter_annotations_len = cm->parameter_annotations_length();
1498 int type_annotations_len = cm->type_annotations_length();
1499 int default_annotations_len = cm->default_annotations_length();
1500
1501 InlineTableSizes sizes(
1502 localvariable_len,
1503 new_compressed_linenumber_size,
1504 exception_table_len,
1505 checked_exceptions_len,
1506 method_parameters_len,
1507 cm->generic_signature_index(),
1508 method_annotations_len,
1509 parameter_annotations_len,
1510 type_annotations_len,
1511 default_annotations_len,
1512 0);
1513
1514 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1515 Method* newm_oop = Method::allocate(loader_data,
1516 new_code_length,
1517 flags,
1518 &sizes,
1519 m->method_type(),
1520 CHECK_(methodHandle()));
1521 methodHandle newm (THREAD, newm_oop);
1522
1523 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1524 ConstMethod* newcm = newm->constMethod();
1525 int new_const_method_size = newm->constMethod()->size();
1526
1527 // This works because the source and target are both Methods. Some compilers
1528 // (e.g., clang) complain that the target vtable pointer will be stomped,
1529 // so cast away newm()'s and m()'s Methodness.
1530 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1531
1532 // Create shallow copy of ConstMethod.
1533 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1534
1535 // Reset correct method/const method, method size, and parameter info
1536 newm->set_constMethod(newcm);
1537 newm->constMethod()->set_code_size(new_code_length);
1538 newm->constMethod()->set_constMethod_size(new_const_method_size);
1539 assert(newm->code_size() == new_code_length, "check");
1540 assert(newm->method_parameters_length() == method_parameters_len, "check");
1541 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1542 assert(newm->exception_table_length() == exception_table_len, "check");
1543 assert(newm->localvariable_table_length() == localvariable_len, "check");
1544 // Copy new byte codes
1545 memcpy(newm->code_base(), new_code, new_code_length);
1546 // Copy line number table
1547 if (new_compressed_linenumber_size > 0) {
1548 memcpy(newm->compressed_linenumber_table(),
1549 new_compressed_linenumber_table,
1550 new_compressed_linenumber_size);
1551 }
1552 // Copy method_parameters
1553 if (method_parameters_len > 0) {
1554 memcpy(newm->method_parameters_start(),
1555 m->method_parameters_start(),
1556 method_parameters_len * sizeof(MethodParametersElement));
1557 }
1558 // Copy checked_exceptions
1559 if (checked_exceptions_len > 0) {
1560 memcpy(newm->checked_exceptions_start(),
1561 m->checked_exceptions_start(),
1562 checked_exceptions_len * sizeof(CheckedExceptionElement));
1563 }
1564 // Copy exception table
1565 if (exception_table_len > 0) {
1566 memcpy(newm->exception_table_start(),
1567 m->exception_table_start(),
1568 exception_table_len * sizeof(ExceptionTableElement));
1569 }
1570 // Copy local variable number table
1571 if (localvariable_len > 0) {
1572 memcpy(newm->localvariable_table_start(),
1573 m->localvariable_table_start(),
1574 localvariable_len * sizeof(LocalVariableTableElement));
1575 }
1576 // Copy stackmap table
1577 if (m->has_stackmap_table()) {
1578 int code_attribute_length = m->stackmap_data()->length();
1579 Array<u1>* stackmap_data =
1580 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1581 memcpy((void*)stackmap_data->adr_at(0),
1582 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1583 newm->set_stackmap_data(stackmap_data);
1584 }
1585
1586 // copy annotations over to new method
1587 newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1588 return newm;
1589 }
1590
1591 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1592 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1593 // because we are not loading from core libraries
1594 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1595 // which does not use the class default class loader so we check for its loader here
1596 const InstanceKlass* ik = InstanceKlass::cast(holder);
1597 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1598 return vmSymbols::NO_SID; // regardless of name, no intrinsics here
1599 }
1600
1601 // see if the klass name is well-known:
1602 Symbol* klass_name = ik->name();
1603 return vmSymbols::find_sid(klass_name);
1604 }
1605
1606 void Method::init_intrinsic_id() {
1607 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1608 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1609 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1610 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1611
1612 // the klass name is well-known:
1613 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1614 assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1615
1616 // ditto for method and signature:
1617 vmSymbols::SID name_id = vmSymbols::find_sid(name());
1618 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1619 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1620 && name_id == vmSymbols::NO_SID) {
1621 return;
1622 }
1623 vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
1624 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1625 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1626 && sig_id == vmSymbols::NO_SID) {
1627 return;
1628 }
1629 jshort flags = access_flags().as_short();
1630
1631 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1632 if (id != vmIntrinsics::_none) {
1633 set_intrinsic_id(id);
1634 if (id == vmIntrinsics::_Class_cast) {
1635 // Even if the intrinsic is rejected, we want to inline this simple method.
1636 set_force_inline(true);
1637 }
1638 return;
1639 }
1640
1641 // A few slightly irregular cases:
1642 switch (klass_id) {
1643 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1644 // Second chance: check in regular Math.
1645 switch (name_id) {
1646 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1647 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1648 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1649 // pretend it is the corresponding method in the non-strict class:
1650 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1651 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1652 break;
1653 default:
1654 break;
1655 }
1656 break;
1657
1658 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1659 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1660 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1661 if (!is_native()) break;
1662 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1663 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1664 id = vmIntrinsics::_none;
1665 break;
1666
1667 default:
1668 break;
1669 }
1670
1671 if (id != vmIntrinsics::_none) {
1672 // Set up its iid. It is an alias method.
1673 set_intrinsic_id(id);
1674 return;
1675 }
1676 }
1677
1678 // These two methods are static since a GC may move the Method
1679 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1680 if (!THREAD->can_call_java()) {
1681 // There is nothing useful this routine can do from within the Compile thread.
1682 // Hopefully, the signature contains only well-known classes.
1683 // We could scan for this and return true/false, but the caller won't care.
1684 return false;
1685 }
1686 bool sig_is_loaded = true;
1687 Handle class_loader(THREAD, m->method_holder()->class_loader());
1688 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1689 ResourceMark rm(THREAD);
1690 Symbol* signature = m->signature();
1691 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1692 if (ss.is_object()) {
1693 Symbol* sym = ss.as_symbol();
1694 Symbol* name = sym;
1695 Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1696 protection_domain, THREAD);
1697 // We are loading classes eagerly. If a ClassNotFoundException or
1698 // a LinkageError was generated, be sure to ignore it.
1699 if (HAS_PENDING_EXCEPTION) {
1700 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1701 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1702 CLEAR_PENDING_EXCEPTION;
1703 } else {
1704 return false;
1705 }
1706 }
1707 if( klass == NULL) { sig_is_loaded = false; }
1708 }
1709 }
1710 return sig_is_loaded;
1711 }
1712
1713 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1714 Handle class_loader(THREAD, m->method_holder()->class_loader());
1715 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1716 ResourceMark rm(THREAD);
1717 Symbol* signature = m->signature();
1718 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1719 if (ss.type() == T_OBJECT) {
1720 Symbol* name = ss.as_symbol_or_null();
1721 if (name == NULL) return true;
1722 Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1723 if (klass == NULL) return true;
1724 }
1725 }
1726 return false;
1727 }
1728
1729 // Exposed so field engineers can debug VM
1730 void Method::print_short_name(outputStream* st) {
1731 ResourceMark rm;
1732 #ifdef PRODUCT
1733 st->print(" %s::", method_holder()->external_name());
1734 #else
1735 st->print(" %s::", method_holder()->internal_name());
1736 #endif
1737 name()->print_symbol_on(st);
1738 if (WizardMode) signature()->print_symbol_on(st);
1739 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1740 MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1741 }
1742
1743 // Comparer for sorting an object array containing
1744 // Method*s.
1745 static int method_comparator(Method* a, Method* b) {
1746 return a->name()->fast_compare(b->name());
1747 }
1748
1749 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1750 // default_methods also uses this without the ordering for fast find_method
1751 void Method::sort_methods(Array<Method*>* methods, bool set_idnums) {
1752 int length = methods->length();
1753 if (length > 1) {
1754 {
1755 NoSafepointVerifier nsv;
1756 QuickSort::sort(methods->data(), length, method_comparator, /*idempotent=*/false);
1757 }
1758 // Reset method ordering
1759 if (set_idnums) {
1760 for (int i = 0; i < length; i++) {
1761 Method* m = methods->at(i);
1762 m->set_method_idnum(i);
1763 m->set_orig_method_idnum(i);
1764 }
1765 }
1766 }
1767 }
1768
1769 //-----------------------------------------------------------------------------------
1770 // Non-product code unless JVM/TI needs it
1771
1772 #if !defined(PRODUCT) || INCLUDE_JVMTI
1773 class SignatureTypePrinter : public SignatureTypeNames {
1774 private:
1775 outputStream* _st;
1776 bool _use_separator;
1777
1778 void type_name(const char* name) {
1779 if (_use_separator) _st->print(", ");
1780 _st->print("%s", name);
1781 _use_separator = true;
1782 }
1783
1784 public:
1785 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1786 _st = st;
1787 _use_separator = false;
1788 }
1789
1790 void print_parameters() { _use_separator = false; iterate_parameters(); }
1791 void print_returntype() { _use_separator = false; iterate_returntype(); }
1792 };
1793
1794
1795 void Method::print_name(outputStream* st) {
1796 Thread *thread = Thread::current();
1797 ResourceMark rm(thread);
1798 st->print("%s ", is_static() ? "static" : "virtual");
1799 if (WizardMode) {
1800 st->print("%s.", method_holder()->internal_name());
1801 name()->print_symbol_on(st);
1802 signature()->print_symbol_on(st);
1803 } else {
1804 SignatureTypePrinter sig(signature(), st);
1805 sig.print_returntype();
1806 st->print(" %s.", method_holder()->internal_name());
1807 name()->print_symbol_on(st);
1808 st->print("(");
1809 sig.print_parameters();
1810 st->print(")");
1811 }
1812 }
1813 #endif // !PRODUCT || INCLUDE_JVMTI
1814
1815
1816 void Method::print_codes_on(outputStream* st) const {
1817 print_codes_on(0, code_size(), st);
1818 }
1819
1820 void Method::print_codes_on(int from, int to, outputStream* st) const {
1821 Thread *thread = Thread::current();
1822 ResourceMark rm(thread);
1823 methodHandle mh (thread, (Method*)this);
1824 BytecodeStream s(mh);
1825 s.set_interval(from, to);
1826 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1827 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1828 }
1829
1830 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1831 _bci = 0;
1832 _line = 0;
1833 };
1834
1835 bool CompressedLineNumberReadStream::read_pair() {
1836 jubyte next = read_byte();
1837 // Check for terminator
1838 if (next == 0) return false;
1839 if (next == 0xFF) {
1840 // Escape character, regular compression used
1841 _bci += read_signed_int();
1842 _line += read_signed_int();
1843 } else {
1844 // Single byte compression used
1845 _bci += next >> 3;
1846 _line += next & 0x7;
1847 }
1848 return true;
1849 }
1850
1851 #if INCLUDE_JVMTI
1852
1853 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1854 BreakpointInfo* bp = method_holder()->breakpoints();
1855 for (; bp != NULL; bp = bp->next()) {
1856 if (bp->match(this, bci)) {
1857 return bp->orig_bytecode();
1858 }
1859 }
1860 {
1861 ResourceMark rm;
1862 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1863 }
1864 return Bytecodes::_shouldnotreachhere;
1865 }
1866
1867 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1868 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1869 BreakpointInfo* bp = method_holder()->breakpoints();
1870 for (; bp != NULL; bp = bp->next()) {
1871 if (bp->match(this, bci)) {
1872 bp->set_orig_bytecode(code);
1873 // and continue, in case there is more than one
1874 }
1875 }
1876 }
1877
1878 void Method::set_breakpoint(int bci) {
1879 InstanceKlass* ik = method_holder();
1880 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1881 bp->set_next(ik->breakpoints());
1882 ik->set_breakpoints(bp);
1883 // do this last:
1884 bp->set(this);
1885 }
1886
1887 static void clear_matches(Method* m, int bci) {
1888 InstanceKlass* ik = m->method_holder();
1889 BreakpointInfo* prev_bp = NULL;
1890 BreakpointInfo* next_bp;
1891 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1892 next_bp = bp->next();
1893 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1894 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1895 // do this first:
1896 bp->clear(m);
1897 // unhook it
1898 if (prev_bp != NULL)
1899 prev_bp->set_next(next_bp);
1900 else
1901 ik->set_breakpoints(next_bp);
1902 delete bp;
1903 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1904 // at same location. So we have multiple matching (method_index and bci)
1905 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1906 // breakpoint for clear_breakpoint request and keep all other method versions
1907 // BreakpointInfo for future clear_breakpoint request.
1908 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1909 // which is being called when class is unloaded. We delete all the Breakpoint
1910 // information for all versions of method. We may not correctly restore the original
1911 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1912 // so these methods won't be used anymore.
1913 if (bci >= 0) {
1914 break;
1915 }
1916 } else {
1917 // This one is a keeper.
1918 prev_bp = bp;
1919 }
1920 }
1921 }
1922
1923 void Method::clear_breakpoint(int bci) {
1924 assert(bci >= 0, "");
1925 clear_matches(this, bci);
1926 }
1927
1928 void Method::clear_all_breakpoints() {
1929 clear_matches(this, -1);
1930 }
1931
1932 #endif // INCLUDE_JVMTI
1933
1934 int Method::invocation_count() {
1935 MethodCounters *mcs = method_counters();
1936 if (TieredCompilation) {
1937 MethodData* const mdo = method_data();
1938 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1939 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1940 return InvocationCounter::count_limit;
1941 } else {
1942 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1943 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1944 }
1945 } else {
1946 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1947 }
1948 }
1949
1950 int Method::backedge_count() {
1951 MethodCounters *mcs = method_counters();
1952 if (TieredCompilation) {
1953 MethodData* const mdo = method_data();
1954 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1955 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1956 return InvocationCounter::count_limit;
1957 } else {
1958 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1959 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1960 }
1961 } else {
1962 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1963 }
1964 }
1965
1966 int Method::highest_comp_level() const {
1967 const MethodCounters* mcs = method_counters();
1968 if (mcs != NULL) {
1969 return mcs->highest_comp_level();
1970 } else {
1971 return CompLevel_none;
1972 }
1973 }
1974
1975 int Method::highest_osr_comp_level() const {
1976 const MethodCounters* mcs = method_counters();
1977 if (mcs != NULL) {
1978 return mcs->highest_osr_comp_level();
1979 } else {
1980 return CompLevel_none;
1981 }
1982 }
1983
1984 void Method::set_highest_comp_level(int level) {
1985 MethodCounters* mcs = method_counters();
1986 if (mcs != NULL) {
1987 mcs->set_highest_comp_level(level);
1988 }
1989 }
1990
1991 void Method::set_highest_osr_comp_level(int level) {
1992 MethodCounters* mcs = method_counters();
1993 if (mcs != NULL) {
1994 mcs->set_highest_osr_comp_level(level);
1995 }
1996 }
1997
1998 #if INCLUDE_JVMTI
1999
2000 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
2001 _bci = bci;
2002 _name_index = m->name_index();
2003 _signature_index = m->signature_index();
2004 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
2005 if (_orig_bytecode == Bytecodes::_breakpoint)
2006 _orig_bytecode = m->orig_bytecode_at(_bci);
2007 _next = NULL;
2008 }
2009
2010 void BreakpointInfo::set(Method* method) {
2011 #ifdef ASSERT
2012 {
2013 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2014 if (code == Bytecodes::_breakpoint)
2015 code = method->orig_bytecode_at(_bci);
2016 assert(orig_bytecode() == code, "original bytecode must be the same");
2017 }
2018 #endif
2019 Thread *thread = Thread::current();
2020 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2021 method->incr_number_of_breakpoints(thread);
2022 {
2023 // Deoptimize all dependents on this method
2024 HandleMark hm(thread);
2025 methodHandle mh(thread, method);
2026 CodeCache::flush_dependents_on_method(mh);
2027 }
2028 }
2029
2030 void BreakpointInfo::clear(Method* method) {
2031 *method->bcp_from(_bci) = orig_bytecode();
2032 assert(method->number_of_breakpoints() > 0, "must not go negative");
2033 method->decr_number_of_breakpoints(Thread::current());
2034 }
2035
2036 #endif // INCLUDE_JVMTI
2037
2038 // jmethodID handling
2039
2040 // This is a block allocating object, sort of like JNIHandleBlock, only a
2041 // lot simpler.
2042 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2043 // never get rid of it.
2044
2045 static const int min_block_size = 8;
2046
2047 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2048 friend class JNIMethodBlock;
2049 Method** _methods;
2050 int _number_of_methods;
2051 int _top;
2052 JNIMethodBlockNode* _next;
2053
2054 public:
2055
2056 JNIMethodBlockNode(int num_methods = min_block_size);
2057
2058 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2059
2060 void ensure_methods(int num_addl_methods) {
2061 if (_top < _number_of_methods) {
2062 num_addl_methods -= _number_of_methods - _top;
2063 if (num_addl_methods <= 0) {
2064 return;
2065 }
2066 }
2067 if (_next == NULL) {
2068 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2069 } else {
2070 _next->ensure_methods(num_addl_methods);
2071 }
2072 }
2073 };
2074
2075 class JNIMethodBlock : public CHeapObj<mtClass> {
2076 JNIMethodBlockNode _head;
2077 JNIMethodBlockNode *_last_free;
2078 public:
2079 static Method* const _free_method;
2080
2081 JNIMethodBlock(int initial_capacity = min_block_size)
2082 : _head(initial_capacity), _last_free(&_head) {}
2083
2084 void ensure_methods(int num_addl_methods) {
2085 _last_free->ensure_methods(num_addl_methods);
2086 }
2087
2088 Method** add_method(Method* m) {
2089 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2090 if (b->_top < b->_number_of_methods) {
2091 // top points to the next free entry.
2092 int i = b->_top;
2093 b->_methods[i] = m;
2094 b->_top++;
2095 _last_free = b;
2096 return &(b->_methods[i]);
2097 } else if (b->_top == b->_number_of_methods) {
2098 // if the next free entry ran off the block see if there's a free entry
2099 for (int i = 0; i < b->_number_of_methods; i++) {
2100 if (b->_methods[i] == _free_method) {
2101 b->_methods[i] = m;
2102 _last_free = b;
2103 return &(b->_methods[i]);
2104 }
2105 }
2106 // Only check each block once for frees. They're very unlikely.
2107 // Increment top past the end of the block.
2108 b->_top++;
2109 }
2110 // need to allocate a next block.
2111 if (b->_next == NULL) {
2112 b->_next = _last_free = new JNIMethodBlockNode();
2113 }
2114 }
2115 guarantee(false, "Should always allocate a free block");
2116 return NULL;
2117 }
2118
2119 bool contains(Method** m) {
2120 if (m == NULL) return false;
2121 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2122 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2123 // This is a bit of extra checking, for two reasons. One is
2124 // that contains() deals with pointers that are passed in by
2125 // JNI code, so making sure that the pointer is aligned
2126 // correctly is valuable. The other is that <= and > are
2127 // technically not defined on pointers, so the if guard can
2128 // pass spuriously; no modern compiler is likely to make that
2129 // a problem, though (and if one did, the guard could also
2130 // fail spuriously, which would be bad).
2131 ptrdiff_t idx = m - b->_methods;
2132 if (b->_methods + idx == m) {
2133 return true;
2134 }
2135 }
2136 }
2137 return false; // not found
2138 }
2139
2140 // Doesn't really destroy it, just marks it as free so it can be reused.
2141 void destroy_method(Method** m) {
2142 #ifdef ASSERT
2143 assert(contains(m), "should be a methodID");
2144 #endif // ASSERT
2145 *m = _free_method;
2146 }
2147
2148 // During class unloading the methods are cleared, which is different
2149 // than freed.
2150 void clear_all_methods() {
2151 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2152 for (int i = 0; i< b->_number_of_methods; i++) {
2153 b->_methods[i] = NULL;
2154 }
2155 }
2156 }
2157 #ifndef PRODUCT
2158 int count_methods() {
2159 // count all allocated methods
2160 int count = 0;
2161 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2162 for (int i = 0; i< b->_number_of_methods; i++) {
2163 if (b->_methods[i] != _free_method) count++;
2164 }
2165 }
2166 return count;
2167 }
2168 #endif // PRODUCT
2169 };
2170
2171 // Something that can't be mistaken for an address or a markWord
2172 Method* const JNIMethodBlock::_free_method = (Method*)55;
2173
2174 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2175 _number_of_methods = MAX2(num_methods, min_block_size);
2176 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2177 for (int i = 0; i < _number_of_methods; i++) {
2178 _methods[i] = JNIMethodBlock::_free_method;
2179 }
2180 }
2181
2182 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2183 ClassLoaderData* cld = loader_data;
2184 if (!SafepointSynchronize::is_at_safepoint()) {
2185 // Have to add jmethod_ids() to class loader data thread-safely.
2186 // Also have to add the method to the list safely, which the cld lock
2187 // protects as well.
2188 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2189 if (cld->jmethod_ids() == NULL) {
2190 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2191 } else {
2192 cld->jmethod_ids()->ensure_methods(capacity);
2193 }
2194 } else {
2195 // At safepoint, we are single threaded and can set this.
2196 if (cld->jmethod_ids() == NULL) {
2197 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2198 } else {
2199 cld->jmethod_ids()->ensure_methods(capacity);
2200 }
2201 }
2202 }
2203
2204 // Add a method id to the jmethod_ids
2205 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2206 ClassLoaderData* cld = loader_data;
2207
2208 if (!SafepointSynchronize::is_at_safepoint()) {
2209 // Have to add jmethod_ids() to class loader data thread-safely.
2210 // Also have to add the method to the list safely, which the cld lock
2211 // protects as well.
2212 MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2213 if (cld->jmethod_ids() == NULL) {
2214 cld->set_jmethod_ids(new JNIMethodBlock());
2215 }
2216 // jmethodID is a pointer to Method*
2217 return (jmethodID)cld->jmethod_ids()->add_method(m);
2218 } else {
2219 // At safepoint, we are single threaded and can set this.
2220 if (cld->jmethod_ids() == NULL) {
2221 cld->set_jmethod_ids(new JNIMethodBlock());
2222 }
2223 // jmethodID is a pointer to Method*
2224 return (jmethodID)cld->jmethod_ids()->add_method(m);
2225 }
2226 }
2227
2228 // Mark a jmethodID as free. This is called when there is a data race in
2229 // InstanceKlass while creating the jmethodID cache.
2230 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2231 ClassLoaderData* cld = loader_data;
2232 Method** ptr = (Method**)m;
2233 assert(cld->jmethod_ids() != NULL, "should have method handles");
2234 cld->jmethod_ids()->destroy_method(ptr);
2235 }
2236
2237 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2238 // Can't assert the method_holder is the same because the new method has the
2239 // scratch method holder.
2240 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2241 == new_method->method_holder()->class_loader() ||
2242 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2243 "changing to a different class loader");
2244 // Just change the method in place, jmethodID pointer doesn't change.
2245 *((Method**)jmid) = new_method;
2246 }
2247
2248 bool Method::is_method_id(jmethodID mid) {
2249 Method* m = resolve_jmethod_id(mid);
2250 assert(m != NULL, "should be called with non-null method");
2251 InstanceKlass* ik = m->method_holder();
2252 ClassLoaderData* cld = ik->class_loader_data();
2253 if (cld->jmethod_ids() == NULL) return false;
2254 return (cld->jmethod_ids()->contains((Method**)mid));
2255 }
2256
2257 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2258 if (mid == NULL) return NULL;
2259 Method* o = resolve_jmethod_id(mid);
2260 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2261 return NULL;
2262 }
2263 return o;
2264 };
2265
2266 void Method::set_on_stack(const bool value) {
2267 // Set both the method itself and its constant pool. The constant pool
2268 // on stack means some method referring to it is also on the stack.
2269 constants()->set_on_stack(value);
2270
2271 bool already_set = on_stack();
2272 _access_flags.set_on_stack(value);
2273 if (value && !already_set) {
2274 MetadataOnStackMark::record(this);
2275 }
2276 assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2277 "emcp methods cannot run after emcp bit is cleared");
2278 }
2279
2280 // Called when the class loader is unloaded to make all methods weak.
2281 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2282 loader_data->jmethod_ids()->clear_all_methods();
2283 }
2284
2285 bool Method::has_method_vptr(const void* ptr) {
2286 Method m;
2287 // This assumes that the vtbl pointer is the first word of a C++ object.
2288 return dereference_vptr(&m) == dereference_vptr(ptr);
2289 }
2290
2291 // Check that this pointer is valid by checking that the vtbl pointer matches
2292 bool Method::is_valid_method(const Method* m) {
2293 if (m == NULL) {
2294 return false;
2295 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2296 // Quick sanity check on pointer.
2297 return false;
2298 } else if (m->is_shared()) {
2299 return MetaspaceShared::is_valid_shared_method(m);
2300 } else if (Metaspace::contains_non_shared(m)) {
2301 return has_method_vptr((const void*)m);
2302 } else {
2303 return false;
2304 }
2305 }
2306
2307 #ifndef PRODUCT
2308 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2309 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2310 }
2311 #endif // PRODUCT
2312
2313
2314 // Printing
2315
2316 #ifndef PRODUCT
2317
2318 void Method::print_on(outputStream* st) const {
2319 ResourceMark rm;
2320 assert(is_method(), "must be method");
2321 st->print_cr("%s", internal_name());
2322 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2323 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2324 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2325 constants()->print_value_on(st); st->cr();
2326 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2327 st->print (" - name: "); name()->print_value_on(st); st->cr();
2328 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2329 st->print_cr(" - max stack: %d", max_stack());
2330 st->print_cr(" - max locals: %d", max_locals());
2331 st->print_cr(" - size of params: %d", size_of_parameters());
2332 st->print_cr(" - method size: %d", method_size());
2333 if (intrinsic_id() != vmIntrinsics::_none)
2334 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2335 if (highest_comp_level() != CompLevel_none)
2336 st->print_cr(" - highest level: %d", highest_comp_level());
2337 st->print_cr(" - vtable index: %d", _vtable_index);
2338 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2339 st->print( " - adapters: ");
2340 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2341 if (a == NULL)
2342 st->print_cr(INTPTR_FORMAT, p2i(a));
2343 else
2344 a->print_adapter_on(st);
2345 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2346 st->print_cr(" - code size: %d", code_size());
2347 if (code_size() != 0) {
2348 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2349 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2350 }
2351 if (method_data() != NULL) {
2352 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2353 }
2354 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2355 if (checked_exceptions_length() > 0) {
2356 CheckedExceptionElement* table = checked_exceptions_start();
2357 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2358 if (Verbose) {
2359 for (int i = 0; i < checked_exceptions_length(); i++) {
2360 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2361 }
2362 }
2363 }
2364 if (has_linenumber_table()) {
2365 u_char* table = compressed_linenumber_table();
2366 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2367 if (Verbose) {
2368 CompressedLineNumberReadStream stream(table);
2369 while (stream.read_pair()) {
2370 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2371 }
2372 }
2373 }
2374 st->print_cr(" - localvar length: %d", localvariable_table_length());
2375 if (localvariable_table_length() > 0) {
2376 LocalVariableTableElement* table = localvariable_table_start();
2377 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2378 if (Verbose) {
2379 for (int i = 0; i < localvariable_table_length(); i++) {
2380 int bci = table[i].start_bci;
2381 int len = table[i].length;
2382 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2383 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2384 int slot = table[i].slot;
2385 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2386 }
2387 }
2388 }
2389 if (code() != NULL) {
2390 st->print (" - compiled code: ");
2391 code()->print_value_on(st);
2392 }
2393 if (is_native()) {
2394 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2395 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2396 }
2397 }
2398
2399 void Method::print_linkage_flags(outputStream* st) {
2400 access_flags().print_on(st);
2401 if (is_default_method()) {
2402 st->print("default ");
2403 }
2404 if (is_overpass()) {
2405 st->print("overpass ");
2406 }
2407 }
2408 #endif //PRODUCT
2409
2410 void Method::print_value_on(outputStream* st) const {
2411 assert(is_method(), "must be method");
2412 st->print("%s", internal_name());
2413 print_address_on(st);
2414 st->print(" ");
2415 name()->print_value_on(st);
2416 st->print(" ");
2417 signature()->print_value_on(st);
2418 st->print(" in ");
2419 method_holder()->print_value_on(st);
2420 if (WizardMode) st->print("#%d", _vtable_index);
2421 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2422 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2423 }
2424
2425 #if INCLUDE_SERVICES
2426 // Size Statistics
2427 void Method::collect_statistics(KlassSizeStats *sz) const {
2428 int mysize = sz->count(this);
2429 sz->_method_bytes += mysize;
2430 sz->_method_all_bytes += mysize;
2431 sz->_rw_bytes += mysize;
2432
2433 if (constMethod()) {
2434 constMethod()->collect_statistics(sz);
2435 }
2436 if (method_data()) {
2437 method_data()->collect_statistics(sz);
2438 }
2439 }
2440 #endif // INCLUDE_SERVICES
2441
2442 // LogTouchedMethods and PrintTouchedMethods
2443
2444 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2445 // the Method may be garbage collected. Let's roll our own hash table.
2446 class TouchedMethodRecord : CHeapObj<mtTracing> {
2447 public:
2448 // It's OK to store Symbols here because they will NOT be GC'ed if
2449 // LogTouchedMethods is enabled.
2450 TouchedMethodRecord* _next;
2451 Symbol* _class_name;
2452 Symbol* _method_name;
2453 Symbol* _method_signature;
2454 };
2455
2456 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2457 static TouchedMethodRecord** _touched_method_table = NULL;
2458
2459 void Method::log_touched(TRAPS) {
2460
2461 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2462 Symbol* my_class = klass_name();
2463 Symbol* my_name = name();
2464 Symbol* my_sig = signature();
2465
2466 unsigned int hash = my_class->identity_hash() +
2467 my_name->identity_hash() +
2468 my_sig->identity_hash();
2469 juint index = juint(hash) % table_size;
2470
2471 MutexLocker ml(TouchedMethodLog_lock, THREAD);
2472 if (_touched_method_table == NULL) {
2473 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2474 mtTracing, CURRENT_PC);
2475 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2476 }
2477
2478 TouchedMethodRecord* ptr = _touched_method_table[index];
2479 while (ptr) {
2480 if (ptr->_class_name == my_class &&
2481 ptr->_method_name == my_name &&
2482 ptr->_method_signature == my_sig) {
2483 return;
2484 }
2485 if (ptr->_next == NULL) break;
2486 ptr = ptr->_next;
2487 }
2488 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2489 my_class->increment_refcount();
2490 my_name->increment_refcount();
2491 my_sig->increment_refcount();
2492 nptr->_class_name = my_class;
2493 nptr->_method_name = my_name;
2494 nptr->_method_signature = my_sig;
2495 nptr->_next = NULL;
2496
2497 if (ptr == NULL) {
2498 // first
2499 _touched_method_table[index] = nptr;
2500 } else {
2501 ptr->_next = nptr;
2502 }
2503 }
2504
2505 void Method::print_touched_methods(outputStream* out) {
2506 MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2507 out->print_cr("# Method::print_touched_methods version 1");
2508 if (_touched_method_table) {
2509 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2510 TouchedMethodRecord* ptr = _touched_method_table[i];
2511 while(ptr) {
2512 ptr->_class_name->print_symbol_on(out); out->print(".");
2513 ptr->_method_name->print_symbol_on(out); out->print(":");
2514 ptr->_method_signature->print_symbol_on(out); out->cr();
2515 ptr = ptr->_next;
2516 }
2517 }
2518 }
2519 }
2520
2521 // Verification
2522
2523 void Method::verify_on(outputStream* st) {
2524 guarantee(is_method(), "object must be method");
2525 guarantee(constants()->is_constantPool(), "should be constant pool");
2526 MethodData* md = method_data();
2527 guarantee(md == NULL ||
2528 md->is_methodData(), "should be method data");
2529 }