1 /*
2 * Copyright (c) 1998, 2013, 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 "gc_implementation/shared/markSweep.inline.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "interpreter/rewriter.hpp"
29 #include "memory/universe.inline.hpp"
30 #include "oops/cpCacheOop.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "prims/jvmtiRedefineClassesTrace.hpp"
34 #include "prims/methodHandles.hpp"
35 #include "runtime/handles.inline.hpp"
36
37
38 // Implememtation of ConstantPoolCacheEntry
39
40 void ConstantPoolCacheEntry::initialize_entry(int index) {
41 assert(0 < index && index < 0x10000, "sanity check");
42 _indices = index;
43 assert(constant_pool_index() == index, "");
44 }
45
46 void ConstantPoolCacheEntry::initialize_secondary_entry(int main_index) {
47 assert(0 <= main_index && main_index < 0x10000, "sanity check");
48 _indices = (main_index << main_cp_index_bits);
49 assert(main_entry_index() == main_index, "");
50 }
51
52 int ConstantPoolCacheEntry::make_flags(TosState state,
53 int option_bits,
54 int field_index_or_method_params) {
55 assert(state < number_of_states, "Invalid state in make_flags");
56 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
57 // Preserve existing flag bit values
58 // The low bits are a field offset, or else the method parameter size.
59 #ifdef ASSERT
60 TosState old_state = flag_state();
61 assert(old_state == (TosState)0 || old_state == state,
62 "inconsistent cpCache flags state");
63 #endif
64 return (_flags | f) ;
65 }
66
67 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
68 assert(!is_secondary_entry(), "must not overwrite main_entry_index");
69 #ifdef ASSERT
70 // Read once.
71 volatile Bytecodes::Code c = bytecode_1();
72 assert(c == 0 || c == code || code == 0, "update must be consistent");
73 #endif
74 // Need to flush pending stores here before bytecode is written.
75 OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));
76 }
77
78 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
79 assert(!is_secondary_entry(), "must not overwrite main_entry_index");
80 #ifdef ASSERT
81 // Read once.
82 volatile Bytecodes::Code c = bytecode_2();
83 assert(c == 0 || c == code || code == 0, "update must be consistent");
84 #endif
85 // Need to flush pending stores here before bytecode is written.
86 OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));
87 }
88
89 // Sets f1, ordering with previous writes.
90 void ConstantPoolCacheEntry::release_set_f1(oop f1) {
91 // Use barriers as in oop_store
92 assert(f1 != NULL, "");
93 oop* f1_addr = (oop*) &_f1;
94 update_barrier_set_pre(f1_addr, f1);
95 OrderAccess::release_store_ptr((intptr_t*)f1_addr, f1);
96 update_barrier_set((void*) f1_addr, f1);
97 }
98
99 // Sets flags, but only if the value was previously zero.
100 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
101 intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
102 return (result == 0);
103 }
104
105 #ifdef ASSERT
106 // It is possible to have two different dummy methodOops created
107 // when the resolve code for invoke interface executes concurrently
108 // Hence the assertion below is weakened a bit for the invokeinterface
109 // case.
110 bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) {
111 return (cur_f1 == f1 || ((methodOop)cur_f1)->name() ==
112 ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() ==
113 ((methodOop)f1)->signature());
114 }
115 #endif
116
117 // Note that concurrent update of both bytecodes can leave one of them
118 // reset to zero. This is harmless; the interpreter will simply re-resolve
119 // the damaged entry. More seriously, the memory synchronization is needed
120 // to flush other fields (f1, f2) completely to memory before the bytecodes
121 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
122 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
123 Bytecodes::Code put_code,
124 KlassHandle field_holder,
125 int field_index,
126 int field_offset,
127 TosState field_type,
128 bool is_final,
129 bool is_volatile) {
130 set_f1(field_holder()->java_mirror());
131 set_f2(field_offset);
132 assert((field_index & field_index_mask) == field_index,
133 "field index does not fit in low flag bits");
134 set_field_flags(field_type,
135 ((is_volatile ? 1 : 0) << is_volatile_shift) |
136 ((is_final ? 1 : 0) << is_final_shift),
137 field_index);
138 set_bytecode_1(get_code);
139 set_bytecode_2(put_code);
140 NOT_PRODUCT(verify(tty));
141 }
142
143 void ConstantPoolCacheEntry::set_parameter_size(int value) {
144 // This routine is called only in corner cases where the CPCE is not yet initialized.
145 // See AbstractInterpreter::deopt_continue_after_entry.
146 assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
147 err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
148 // Setting the parameter size by itself is only safe if the
149 // current value of _flags is 0, otherwise another thread may have
150 // updated it and we don't want to overwrite that value. Don't
151 // bother trying to update it once it's nonzero but always make
152 // sure that the final parameter size agrees with what was passed.
153 if (_flags == 0) {
154 Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
155 }
156 guarantee(parameter_size() == value,
157 err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
158 }
159
160 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
161 methodHandle method,
162 int vtable_index) {
163 assert(!is_secondary_entry(), "");
164 assert(method->interpreter_entry() != NULL, "should have been set at this point");
165 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
166
167 int byte_no = -1;
168 bool change_to_virtual = false;
169
170 switch (invoke_code) {
171 case Bytecodes::_invokeinterface:
172 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
173 // instruction somehow links to a non-interface method (in Object).
174 // In that case, the method has no itable index and must be invoked as a virtual.
175 // Set a flag to keep track of this corner case.
176 change_to_virtual = true;
177
178 // ...and fall through as if we were handling invokevirtual:
179 case Bytecodes::_invokevirtual:
180 {
181 if (method->can_be_statically_bound()) {
182 // set_f2_as_vfinal_method checks if is_vfinal flag is true.
183 set_method_flags(as_TosState(method->result_type()),
184 ( 1 << is_vfinal_shift) |
185 ((method->is_final_method() ? 1 : 0) << is_final_shift) |
186 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
187 method()->size_of_parameters());
188 set_f2_as_vfinal_method(method());
189 } else {
190 assert(vtable_index >= 0, "valid index");
191 assert(!method->is_final_method(), "sanity");
192 set_method_flags(as_TosState(method->result_type()),
193 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
194 method()->size_of_parameters());
195 set_f2(vtable_index);
196 }
197 byte_no = 2;
198 break;
199 }
200
201 case Bytecodes::_invokespecial:
202 case Bytecodes::_invokestatic:
203 // Note: Read and preserve the value of the is_vfinal flag on any
204 // invokevirtual bytecode shared with this constant pool cache entry.
205 // It is cheap and safe to consult is_vfinal() at all times.
206 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
207 set_method_flags(as_TosState(method->result_type()),
208 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) |
209 ((method->is_final_method() ? 1 : 0) << is_final_shift),
210 method()->size_of_parameters());
211 set_f1(method());
212 byte_no = 1;
213 break;
214 default:
215 ShouldNotReachHere();
216 break;
217 }
218
219 // Note: byte_no also appears in TemplateTable::resolve.
220 if (byte_no == 1) {
221 assert(invoke_code != Bytecodes::_invokevirtual &&
222 invoke_code != Bytecodes::_invokeinterface, "");
223 set_bytecode_1(invoke_code);
224 } else if (byte_no == 2) {
225 if (change_to_virtual) {
226 assert(invoke_code == Bytecodes::_invokeinterface, "");
227 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
228 //
229 // Workaround for the case where we encounter an invokeinterface, but we
230 // should really have an _invokevirtual since the resolved method is a
231 // virtual method in java.lang.Object. This is a corner case in the spec
232 // but is presumably legal. javac does not generate this code.
233 //
234 // We set bytecode_1() to _invokeinterface, because that is the
235 // bytecode # used by the interpreter to see if it is resolved.
236 // We set bytecode_2() to _invokevirtual.
237 // See also interpreterRuntime.cpp. (8/25/2000)
238 // Only set resolved for the invokeinterface case if method is public.
239 // Otherwise, the method needs to be reresolved with caller for each
240 // interface call.
241 if (method->is_public()) set_bytecode_1(invoke_code);
242 } else {
243 assert(invoke_code == Bytecodes::_invokevirtual, "");
244 }
245 // set up for invokevirtual, even if linking for invokeinterface also:
246 set_bytecode_2(Bytecodes::_invokevirtual);
247 } else {
248 ShouldNotReachHere();
249 }
250 NOT_PRODUCT(verify(tty));
251 }
252
253
254 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
255 assert(!is_secondary_entry(), "");
256 klassOop interf = method->method_holder();
257 assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");
258 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
259 set_f1(interf);
260 set_f2(index);
261 set_method_flags(as_TosState(method->result_type()),
262 0, // no option bits
263 method()->size_of_parameters());
264 set_bytecode_1(Bytecodes::_invokeinterface);
265 }
266
267
268 void ConstantPoolCacheEntry::set_method_handle(constantPoolHandle cpool,
269 methodHandle adapter,
270 Handle appendix, Handle method_type) {
271 assert(!is_secondary_entry(), "");
272 set_method_handle_common(cpool, Bytecodes::_invokehandle, adapter, appendix, method_type);
273 }
274
275 void ConstantPoolCacheEntry::set_dynamic_call(constantPoolHandle cpool,
276 methodHandle adapter,
277 Handle appendix, Handle method_type) {
278 assert(is_secondary_entry(), "");
279 set_method_handle_common(cpool, Bytecodes::_invokedynamic, adapter, appendix, method_type);
280 }
281
282 void ConstantPoolCacheEntry::set_method_handle_common(constantPoolHandle cpool,
283 Bytecodes::Code invoke_code,
284 methodHandle adapter,
285 Handle appendix, Handle method_type) {
286 // NOTE: This CPCE can be the subject of data races.
287 // There are three words to update: flags, f2, f1 (in that order).
288 // Writers must store all other values before f1.
289 // Readers must test f1 first for non-null before reading other fields.
290 // Competing writers must acquire exclusive access via a lock.
291 // A losing writer waits on the lock until the winner writes f1 and leaves
292 // the lock, so that when the losing writer returns, he can use the linked
293 // cache entry.
294
295 Thread* THREAD = Thread::current();
296 ObjectLocker ol(cpool, THREAD);
297 if (!is_f1_null()) {
298 return;
299 }
300
301 const bool has_appendix = appendix.not_null();
302 const bool has_method_type = method_type.not_null();
303
304 if (!has_appendix) {
305 // The extra argument is not used, but we need a non-null value to signify linkage state.
306 // Set it to something benign that will never leak memory.
307 appendix = Universe::void_mirror();
308 }
309
310 // Write the flags.
311 set_method_flags(as_TosState(adapter->result_type()),
312 ((has_appendix ? 1 : 0) << has_appendix_shift) |
313 ((has_method_type ? 1 : 0) << has_method_type_shift) |
314 ( 1 << is_vfinal_shift) |
315 ( 1 << is_final_shift),
316 adapter->size_of_parameters());
317
318 if (TraceInvokeDynamic) {
319 tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method_type="PTR_FORMAT"%s method="PTR_FORMAT" ",
320 invoke_code,
321 (intptr_t)appendix(), (has_appendix ? "" : " (unused)"),
322 (intptr_t)method_type(), (has_method_type ? "" : " (unused)"),
323 (intptr_t)adapter());
324 adapter->print();
325 if (has_appendix) appendix()->print();
326 }
327
328 // Method handle invokes and invokedynamic sites use both cp cache words.
329 // f1, if not null, contains a value passed as a trailing argument to the adapter.
330 // In the general case, this could be the call site's MethodType,
331 // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
332 // f2 contains the adapter method which manages the actual call.
333 // In the general case, this is a compiled LambdaForm.
334 // (The Java code is free to optimize these calls by binding other
335 // sorts of methods and appendices to call sites.)
336 // JVM-level linking is via f2, as if for invokevfinal, and signatures are erased.
337 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
338 // In principle this means that the method (with appendix) could take up to 256 parameter slots.
339 //
340 // This means that given a call site like (List)mh.invoke("foo"),
341 // the f2 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
342 // not '(Ljava/lang/String;)Ljava/util/List;'.
343 // The fact that String and List are involved is encoded in the MethodType in f1.
344 // This allows us to create fewer method oops, while keeping type safety.
345 //
346
347 set_f2_as_vfinal_method(adapter());
348
349 // Store MethodType, if any.
350 if (has_method_type) {
351 ConstantPoolCacheEntry* e2 = cpool->cache()->find_secondary_entry_for(this);
352
353 // Write the flags.
354 e2->set_method_flags(as_TosState(adapter->result_type()),
355 ((has_method_type ? 1 : 0) << has_method_type_shift) |
356 ( 1 << is_vfinal_shift) |
357 ( 1 << is_final_shift),
358 adapter->size_of_parameters());
359 e2->release_set_f1(method_type());
360 }
361
362 assert(appendix.not_null(), "needed for linkage state");
363 release_set_f1(appendix()); // This must be the last one to set (see NOTE above)!
364
365 if (!is_secondary_entry()) {
366 // The interpreter assembly code does not check byte_2,
367 // but it is used by is_resolved, method_if_resolved, etc.
368 set_bytecode_2(invoke_code);
369 }
370
371 NOT_PRODUCT(verify(tty));
372 if (TraceInvokeDynamic) {
373 this->print(tty, 0);
374 }
375 }
376
377 methodOop ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {
378 if (is_secondary_entry()) {
379 if (!is_f1_null())
380 return f2_as_vfinal_method();
381 return NULL;
382 }
383 // Decode the action of set_method and set_interface_call
384 Bytecodes::Code invoke_code = bytecode_1();
385 if (invoke_code != (Bytecodes::Code)0) {
386 oop f1 = _f1;
387 if (f1 != NULL) {
388 switch (invoke_code) {
389 case Bytecodes::_invokeinterface:
390 assert(f1->is_klass(), "");
391 return klassItable::method_for_itable_index(klassOop(f1), f2_as_index());
392 case Bytecodes::_invokestatic:
393 case Bytecodes::_invokespecial:
394 assert(!has_appendix(), "");
395 assert(f1->is_method(), "");
396 return methodOop(f1);
397 }
398 }
399 }
400 invoke_code = bytecode_2();
401 if (invoke_code != (Bytecodes::Code)0) {
402 switch (invoke_code) {
403 case Bytecodes::_invokevirtual:
404 if (is_vfinal()) {
405 // invokevirtual
406 methodOop m = f2_as_vfinal_method();
407 assert(m->is_method(), "");
408 return m;
409 } else {
410 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
411 if (cpool->tag_at(holder_index).is_klass()) {
412 klassOop klass = cpool->resolved_klass_at(holder_index);
413 if (!Klass::cast(klass)->oop_is_instance())
414 klass = SystemDictionary::Object_klass();
415 return instanceKlass::cast(klass)->method_at_vtable(f2_as_index());
416 }
417 }
418 break;
419 case Bytecodes::_invokehandle:
420 case Bytecodes::_invokedynamic:
421 return f2_as_vfinal_method();
422 }
423 }
424 return NULL;
425 }
426
427
428 oop ConstantPoolCacheEntry::appendix_if_resolved(constantPoolHandle cpool) {
429 if (is_f1_null() || !has_appendix())
430 return NULL;
431 return f1_appendix();
432 }
433
434
435 oop ConstantPoolCacheEntry::method_type_if_resolved(constantPoolHandle cpool) {
436 if (is_f1_null() || !has_method_type())
437 return NULL;
438 return f1_as_instance();
439 }
440
441
442 class LocalOopClosure: public OopClosure {
443 private:
444 void (*_f)(oop*);
445
446 public:
447 LocalOopClosure(void f(oop*)) { _f = f; }
448 virtual void do_oop(oop* o) { _f(o); }
449 virtual void do_oop(narrowOop *o) { ShouldNotReachHere(); }
450 };
451
452
453 void ConstantPoolCacheEntry::oops_do(void f(oop*)) {
454 LocalOopClosure blk(f);
455 oop_iterate(&blk);
456 }
457
458
459 void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {
460 assert(in_words(size()) == 4, "check code below - may need adjustment");
461 // field[1] is always oop or NULL
462 blk->do_oop((oop*)&_f1);
463 if (is_vfinal()) {
464 blk->do_oop((oop*)&_f2);
465 }
466 }
467
468
469 void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {
470 assert(in_words(size()) == 4, "check code below - may need adjustment");
471 // field[1] is always oop or NULL
472 if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);
473 if (is_vfinal()) {
474 if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);
475 }
476 }
477
478
479 void ConstantPoolCacheEntry::follow_contents() {
480 assert(in_words(size()) == 4, "check code below - may need adjustment");
481 // field[1] is always oop or NULL
482 MarkSweep::mark_and_push((oop*)&_f1);
483 if (is_vfinal()) {
484 MarkSweep::mark_and_push((oop*)&_f2);
485 }
486 }
487
488 #ifndef SERIALGC
489 void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {
490 assert(in_words(size()) == 4, "check code below - may need adjustment");
491 // field[1] is always oop or NULL
492 PSParallelCompact::mark_and_push(cm, (oop*)&_f1);
493 if (is_vfinal()) {
494 PSParallelCompact::mark_and_push(cm, (oop*)&_f2);
495 }
496 }
497 #endif // SERIALGC
498
499 void ConstantPoolCacheEntry::adjust_pointers() {
500 assert(in_words(size()) == 4, "check code below - may need adjustment");
501 // field[1] is always oop or NULL
502 MarkSweep::adjust_pointer((oop*)&_f1);
503 if (is_vfinal()) {
504 MarkSweep::adjust_pointer((oop*)&_f2);
505 }
506 }
507
508 #ifndef SERIALGC
509 void ConstantPoolCacheEntry::update_pointers() {
510 assert(in_words(size()) == 4, "check code below - may need adjustment");
511 // field[1] is always oop or NULL
512 PSParallelCompact::adjust_pointer((oop*)&_f1);
513 if (is_vfinal()) {
514 PSParallelCompact::adjust_pointer((oop*)&_f2);
515 }
516 }
517 #endif // SERIALGC
518
519 // RedefineClasses() API support:
520 // If this constantPoolCacheEntry refers to old_method then update it
521 // to refer to new_method.
522 bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,
523 methodOop new_method, bool * trace_name_printed) {
524
525 if (is_vfinal()) {
526 // virtual and final so _f2 contains method ptr instead of vtable index
527 if (f2_as_vfinal_method() == old_method) {
528 // match old_method so need an update
529 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
530 _f2 = (intptr_t)new_method;
531 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
532 if (!(*trace_name_printed)) {
533 // RC_TRACE_MESG macro has an embedded ResourceMark
534 RC_TRACE_MESG(("adjust: name=%s",
535 Klass::cast(old_method->method_holder())->external_name()));
536 *trace_name_printed = true;
537 }
538 // RC_TRACE macro has an embedded ResourceMark
539 RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
540 new_method->name()->as_C_string(),
541 new_method->signature()->as_C_string()));
542 }
543
544 return true;
545 }
546
547 // f1() is not used with virtual entries so bail out
548 return false;
549 }
550
551 if ((oop)_f1 == NULL) {
552 // NULL f1() means this is a virtual entry so bail out
553 // We are assuming that the vtable index does not need change.
554 return false;
555 }
556
557 if ((oop)_f1 == old_method) {
558 _f1 = new_method;
559 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
560 if (!(*trace_name_printed)) {
561 // RC_TRACE_MESG macro has an embedded ResourceMark
562 RC_TRACE_MESG(("adjust: name=%s",
563 Klass::cast(old_method->method_holder())->external_name()));
564 *trace_name_printed = true;
565 }
566 // RC_TRACE macro has an embedded ResourceMark
567 RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
568 new_method->name()->as_C_string(),
569 new_method->signature()->as_C_string()));
570 }
571
572 return true;
573 }
574
575 return false;
576 }
577
578 // a constant pool cache entry should never contain old or obsolete methods
579 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
580 if (is_vfinal()) {
581 // virtual and final so _f2 contains method ptr instead of vtable index
582 methodOop m = (methodOop)_f2;
583 // Return false if _f2 refers to an old or an obsolete method.
584 // _f2 == NULL || !m->is_method() are just as unexpected here.
585 return (m != NULL && m->is_method() && !m->is_old() && !m->is_obsolete());
586 } else if ((oop)_f1 == NULL || !((oop)_f1)->is_method()) {
587 // _f1 == NULL || !_f1->is_method() are OK here
588 return true;
589 }
590
591 methodOop m = (methodOop)_f1;
592 // return false if _f1 refers to an old or an obsolete method
593 return (!m->is_old() && !m->is_obsolete());
594 }
595
596 bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {
597 if (!is_method_entry()) {
598 // not a method entry so not interesting by default
599 return false;
600 }
601
602 methodOop m = NULL;
603 if (is_vfinal()) {
604 // virtual and final so _f2 contains method ptr instead of vtable index
605 m = f2_as_vfinal_method();
606 } else if (is_f1_null()) {
607 // NULL _f1 means this is a virtual entry so also not interesting
608 return false;
609 } else {
610 oop f1 = _f1; // _f1 is volatile
611 if (!f1->is_method()) {
612 // _f1 can also contain a klassOop for an interface
613 return false;
614 }
615 m = f1_as_method();
616 }
617
618 // Secondary entry can have vfinal flag and a NULL _f2, giving m==NULL here:
619 assert(is_secondary_entry() || (m != NULL && m->is_method()), "sanity check");
620
621 if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
622 // robustness for above sanity checks or method is not in
623 // the interesting class
624 return false;
625 }
626
627 // the method is in the interesting class so the entry is interesting
628 return true;
629 }
630
631 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
632 // print separator
633 if (index == 0) st->print_cr(" -------------");
634 // print entry
635 st->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this);
636 if (is_secondary_entry())
637 st->print_cr("[%5d|secondary]", main_entry_index());
638 else
639 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());
640 st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)(oop)_f1);
641 st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2);
642 st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags);
643 st->print_cr(" -------------");
644 }
645
646 void ConstantPoolCacheEntry::verify(outputStream* st) const {
647 // not implemented yet
648 }
649
650 // Implementation of ConstantPoolCache
651
652 void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {
653 assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");
654 for (int i = 0; i < length(); i++) {
655 ConstantPoolCacheEntry* e = entry_at(i);
656 int original_index = inverse_index_map[i];
657 if ((original_index & Rewriter::_secondary_entry_tag) != 0) {
658 int main_index = (original_index - Rewriter::_secondary_entry_tag);
659 assert(!entry_at(main_index)->is_secondary_entry(), "valid main index");
660 e->initialize_secondary_entry(main_index);
661 } else {
662 e->initialize_entry(original_index);
663 }
664 assert(entry_at(i) == e, "sanity");
665 }
666 }
667
668 // RedefineClasses() API support:
669 // If any entry of this constantPoolCache points to any of
670 // old_methods, replace it with the corresponding new_method.
671 void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
672 int methods_length, bool * trace_name_printed) {
673
674 if (methods_length == 0) {
675 // nothing to do if there are no methods
676 return;
677 }
678
679 // get shorthand for the interesting class
680 klassOop old_holder = old_methods[0]->method_holder();
681
682 for (int i = 0; i < length(); i++) {
683 if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
684 // skip uninteresting methods
685 continue;
686 }
687
688 // The constantPoolCache contains entries for several different
689 // things, but we only care about methods. In fact, we only care
690 // about methods in the same class as the one that contains the
691 // old_methods. At this point, we have an interesting entry.
692
693 for (int j = 0; j < methods_length; j++) {
694 methodOop old_method = old_methods[j];
695 methodOop new_method = new_methods[j];
696
697 if (entry_at(i)->adjust_method_entry(old_method, new_method,
698 trace_name_printed)) {
699 // current old_method matched this entry and we updated it so
700 // break out and get to the next interesting entry if there one
701 break;
702 }
703 }
704 }
705 }
706
707 // the constant pool cache should never contain old or obsolete methods
708 bool constantPoolCacheOopDesc::check_no_old_or_obsolete_entries() {
709 for (int i = 1; i < length(); i++) {
710 if (entry_at(i)->is_interesting_method_entry(NULL) &&
711 !entry_at(i)->check_no_old_or_obsolete_entries()) {
712 return false;
713 }
714 }
715 return true;
716 }
717
718 void constantPoolCacheOopDesc::dump_cache() {
719 for (int i = 1; i < length(); i++) {
720 if (entry_at(i)->is_interesting_method_entry(NULL)) {
721 entry_at(i)->print(tty, i);
722 }
723 }
724 }