1 /*
2 * Copyright (c) 1998, 2011, 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 "runtime/handles.inline.hpp"
35
36
37 // Implememtation of ConstantPoolCacheEntry
38
39 void ConstantPoolCacheEntry::initialize_entry(int index) {
40 assert(0 < index && index < 0x10000, "sanity check");
41 _indices = index;
42 assert(constant_pool_index() == index, "");
43 }
44
45 void ConstantPoolCacheEntry::initialize_secondary_entry(int main_index) {
46 assert(0 <= main_index && main_index < 0x10000, "sanity check");
47 _indices = (main_index << 16);
48 assert(main_entry_index() == main_index, "");
49 }
50
51 int ConstantPoolCacheEntry::as_flags(TosState state, bool is_final,
52 bool is_vfinal, bool is_volatile,
53 bool is_method_interface, bool is_method) {
54 int f = state;
55
56 assert( state < number_of_states, "Invalid state in as_flags");
57
58 f <<= 1;
59 if (is_final) f |= 1;
60 f <<= 1;
61 if (is_vfinal) f |= 1;
62 f <<= 1;
63 if (is_volatile) f |= 1;
64 f <<= 1;
65 if (is_method_interface) f |= 1;
66 f <<= 1;
67 if (is_method) f |= 1;
68 f <<= ConstantPoolCacheEntry::hotSwapBit;
69 // Preserve existing flag bit values
70 #ifdef ASSERT
71 int old_state = ((_flags >> tosBits) & 0x0F);
72 assert(old_state == 0 || old_state == state,
73 "inconsistent cpCache flags state");
74 #endif
75 return (_flags | f) ;
76 }
77
78 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
79 #ifdef ASSERT
80 // Read once.
81 volatile Bytecodes::Code c = bytecode_1();
82 assert(c == 0 || c == code || code == 0, "update must be consistent");
83 #endif
84 // Need to flush pending stores here before bytecode is written.
85 OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 16));
86 }
87
88 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
89 #ifdef ASSERT
90 // Read once.
91 volatile Bytecodes::Code c = bytecode_2();
92 assert(c == 0 || c == code || code == 0, "update must be consistent");
93 #endif
94 // Need to flush pending stores here before bytecode is written.
95 OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 24));
96 }
97
98 // Atomically sets f1 if it is still NULL, otherwise it keeps the
99 // current value.
100 void ConstantPoolCacheEntry::set_f1_if_null_atomic(oop f1) {
101 // Use barriers as in oop_store
102 oop* f1_addr = (oop*) &_f1;
103 update_barrier_set_pre(f1_addr, f1);
104 void* result = Atomic::cmpxchg_ptr(f1, f1_addr, NULL);
105 bool success = (result == NULL);
106 if (success) {
107 update_barrier_set((void*) f1_addr, f1);
108 }
109 }
110
111 #ifdef ASSERT
112 // It is possible to have two different dummy methodOops created
113 // when the resolve code for invoke interface executes concurrently
114 // Hence the assertion below is weakened a bit for the invokeinterface
115 // case.
116 bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) {
117 return (cur_f1 == f1 || ((methodOop)cur_f1)->name() ==
118 ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() ==
119 ((methodOop)f1)->signature());
120 }
121 #endif
122
123 // Note that concurrent update of both bytecodes can leave one of them
124 // reset to zero. This is harmless; the interpreter will simply re-resolve
125 // the damaged entry. More seriously, the memory synchronization is needed
126 // to flush other fields (f1, f2) completely to memory before the bytecodes
127 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
128 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
129 Bytecodes::Code put_code,
130 KlassHandle field_holder,
131 int field_index,
132 int field_offset,
133 TosState field_type,
134 bool is_final,
135 bool is_volatile) {
136 set_f1(field_holder()->java_mirror());
137 set_f2(field_offset);
138 assert(field_index <= field_index_mask,
139 "field index does not fit in low flag bits");
140 set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) |
141 (field_index & field_index_mask));
142 set_bytecode_1(get_code);
143 set_bytecode_2(put_code);
144 NOT_PRODUCT(verify(tty));
145 }
146
147 int ConstantPoolCacheEntry::field_index() const {
148 return (_flags & field_index_mask);
149 }
150
151 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
152 methodHandle method,
153 int vtable_index) {
154 assert(!is_secondary_entry(), "");
155 assert(method->interpreter_entry() != NULL, "should have been set at this point");
156 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
157 bool change_to_virtual = (invoke_code == Bytecodes::_invokeinterface);
158
159 int byte_no = -1;
160 bool needs_vfinal_flag = false;
161 switch (invoke_code) {
162 case Bytecodes::_invokevirtual:
163 case Bytecodes::_invokeinterface: {
164 if (method->can_be_statically_bound()) {
165 set_f2((intptr_t)method());
166 needs_vfinal_flag = true;
167 } else {
168 assert(vtable_index >= 0, "valid index");
169 set_f2(vtable_index);
170 }
171 byte_no = 2;
172 break;
173 }
174
175 case Bytecodes::_invokedynamic: // similar to _invokevirtual
176 if (TraceInvokeDynamic) {
177 tty->print_cr("InvokeDynamic set_method%s method="PTR_FORMAT" index=%d",
178 (is_secondary_entry() ? " secondary" : ""),
179 (intptr_t)method(), vtable_index);
180 method->print();
181 this->print(tty, 0);
182 }
183 assert(method->can_be_statically_bound(), "must be a MH invoker method");
184 assert(_f2 >= constantPoolOopDesc::CPCACHE_INDEX_TAG, "BSM index initialized");
185 // SystemDictionary::find_method_handle_invoke only caches
186 // methods which signature classes are on the boot classpath,
187 // otherwise the newly created method is returned. To avoid
188 // races in that case we store the first one coming in into the
189 // cp-cache atomically if it's still unset.
190 set_f1_if_null_atomic(method());
191 needs_vfinal_flag = false; // _f2 is not an oop
192 assert(!is_vfinal(), "f2 not an oop");
193 byte_no = 1; // coordinate this with bytecode_number & is_resolved
194 break;
195
196 case Bytecodes::_invokespecial:
197 // Preserve the value of the vfinal flag on invokevirtual bytecode
198 // which may be shared with this constant pool cache entry.
199 needs_vfinal_flag = is_resolved(Bytecodes::_invokevirtual) && is_vfinal();
200 // fall through
201 case Bytecodes::_invokestatic:
202 set_f1(method());
203 byte_no = 1;
204 break;
205 default:
206 ShouldNotReachHere();
207 break;
208 }
209
210 set_flags(as_flags(as_TosState(method->result_type()),
211 method->is_final_method(),
212 needs_vfinal_flag,
213 false,
214 change_to_virtual,
215 true)|
216 method()->size_of_parameters());
217
218 // Note: byte_no also appears in TemplateTable::resolve.
219 if (byte_no == 1) {
220 set_bytecode_1(invoke_code);
221 } else if (byte_no == 2) {
222 if (change_to_virtual) {
223 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
224 //
225 // Workaround for the case where we encounter an invokeinterface, but we
226 // should really have an _invokevirtual since the resolved method is a
227 // virtual method in java.lang.Object. This is a corner case in the spec
228 // but is presumably legal. javac does not generate this code.
229 //
230 // We set bytecode_1() to _invokeinterface, because that is the
231 // bytecode # used by the interpreter to see if it is resolved.
232 // We set bytecode_2() to _invokevirtual.
233 // See also interpreterRuntime.cpp. (8/25/2000)
234 // Only set resolved for the invokeinterface case if method is public.
235 // Otherwise, the method needs to be reresolved with caller for each
236 // interface call.
237 if (method->is_public()) set_bytecode_1(invoke_code);
238 set_bytecode_2(Bytecodes::_invokevirtual);
239 } else {
240 set_bytecode_2(invoke_code);
241 }
242 } else {
243 ShouldNotReachHere();
244 }
245 NOT_PRODUCT(verify(tty));
246 }
247
248
249 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
250 assert(!is_secondary_entry(), "");
251 klassOop interf = method->method_holder();
252 assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");
253 set_f1(interf);
254 set_f2(index);
255 set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());
256 set_bytecode_1(Bytecodes::_invokeinterface);
257 }
258
259
260 void ConstantPoolCacheEntry::initialize_bootstrap_method_index_in_cache(int bsm_cache_index) {
261 assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
262 assert(_f2 == 0, "initialize once");
263 assert(bsm_cache_index == (int)(u2)bsm_cache_index, "oob");
264 set_f2(bsm_cache_index + constantPoolOopDesc::CPCACHE_INDEX_TAG);
265 }
266
267 int ConstantPoolCacheEntry::bootstrap_method_index_in_cache() {
268 assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
269 intptr_t bsm_cache_index = (intptr_t) _f2 - constantPoolOopDesc::CPCACHE_INDEX_TAG;
270 assert(bsm_cache_index == (intptr_t)(u2)bsm_cache_index, "oob");
271 return (int) bsm_cache_index;
272 }
273
274 void ConstantPoolCacheEntry::set_dynamic_call(Handle call_site, methodHandle signature_invoker) {
275 assert(is_secondary_entry(), "");
276 // NOTE: it's important that all other values are set before f1 is
277 // set since some users short circuit on f1 being set
278 // (i.e. non-null) and that may result in uninitialized values for
279 // other racing threads (e.g. flags).
280 int param_size = signature_invoker->size_of_parameters();
281 assert(param_size >= 1, "method argument size must include MH.this");
282 param_size -= 1; // do not count MH.this; it is not stacked for invokedynamic
283 bool is_final = true;
284 assert(signature_invoker->is_final_method(), "is_final");
285 int flags = as_flags(as_TosState(signature_invoker->result_type()), is_final, false, false, false, true) | param_size;
286 assert(_flags == 0 || _flags == flags, "flags should be the same");
287 set_flags(flags);
288 // do not do set_bytecode on a secondary CP cache entry
289 //set_bytecode_1(Bytecodes::_invokedynamic);
290 set_f1_if_null_atomic(call_site()); // This must be the last one to set (see NOTE above)!
291 }
292
293
294 methodOop ConstantPoolCacheEntry::get_method_if_resolved(Bytecodes::Code invoke_code, constantPoolHandle cpool) {
295 assert(invoke_code > (Bytecodes::Code)0, "bad query");
296 if (is_secondary_entry()) {
297 return cpool->cache()->entry_at(main_entry_index())->get_method_if_resolved(invoke_code, cpool);
298 }
299 // Decode the action of set_method and set_interface_call
300 if (bytecode_1() == invoke_code) {
301 oop f1 = _f1;
302 if (f1 != NULL) {
303 switch (invoke_code) {
304 case Bytecodes::_invokeinterface:
305 assert(f1->is_klass(), "");
306 return klassItable::method_for_itable_index(klassOop(f1), (int) f2());
307 case Bytecodes::_invokestatic:
308 case Bytecodes::_invokespecial:
309 assert(f1->is_method(), "");
310 return methodOop(f1);
311 }
312 }
313 }
314 if (bytecode_2() == invoke_code) {
315 switch (invoke_code) {
316 case Bytecodes::_invokevirtual:
317 if (is_vfinal()) {
318 // invokevirtual
319 methodOop m = methodOop((intptr_t) f2());
320 assert(m->is_method(), "");
321 return m;
322 } else {
323 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
324 if (cpool->tag_at(holder_index).is_klass()) {
325 klassOop klass = cpool->resolved_klass_at(holder_index);
326 if (!Klass::cast(klass)->oop_is_instance())
327 klass = SystemDictionary::Object_klass();
328 return instanceKlass::cast(klass)->method_at_vtable((int) f2());
329 }
330 }
331 }
332 }
333 return NULL;
334 }
335
336
337
338 class LocalOopClosure: public OopClosure {
339 private:
340 void (*_f)(oop*);
341
342 public:
343 LocalOopClosure(void f(oop*)) { _f = f; }
344 virtual void do_oop(oop* o) { _f(o); }
345 virtual void do_oop(narrowOop *o) { ShouldNotReachHere(); }
346 };
347
348
349 void ConstantPoolCacheEntry::oops_do(void f(oop*)) {
350 LocalOopClosure blk(f);
351 oop_iterate(&blk);
352 }
353
354
355 void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {
356 assert(in_words(size()) == 4, "check code below - may need adjustment");
357 // field[1] is always oop or NULL
358 blk->do_oop((oop*)&_f1);
359 if (is_vfinal()) {
360 blk->do_oop((oop*)&_f2);
361 }
362 }
363
364
365 void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {
366 assert(in_words(size()) == 4, "check code below - may need adjustment");
367 // field[1] is always oop or NULL
368 if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);
369 if (is_vfinal()) {
370 if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);
371 }
372 }
373
374
375 void ConstantPoolCacheEntry::follow_contents() {
376 assert(in_words(size()) == 4, "check code below - may need adjustment");
377 // field[1] is always oop or NULL
378 MarkSweep::mark_and_push((oop*)&_f1);
379 if (is_vfinal()) {
380 MarkSweep::mark_and_push((oop*)&_f2);
381 }
382 }
383
384 #ifndef SERIALGC
385 void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {
386 assert(in_words(size()) == 4, "check code below - may need adjustment");
387 // field[1] is always oop or NULL
388 PSParallelCompact::mark_and_push(cm, (oop*)&_f1);
389 if (is_vfinal()) {
390 PSParallelCompact::mark_and_push(cm, (oop*)&_f2);
391 }
392 }
393 #endif // SERIALGC
394
395 void ConstantPoolCacheEntry::adjust_pointers() {
396 assert(in_words(size()) == 4, "check code below - may need adjustment");
397 // field[1] is always oop or NULL
398 MarkSweep::adjust_pointer((oop*)&_f1);
399 if (is_vfinal()) {
400 MarkSweep::adjust_pointer((oop*)&_f2);
401 }
402 }
403
404 #ifndef SERIALGC
405 void ConstantPoolCacheEntry::update_pointers() {
406 assert(in_words(size()) == 4, "check code below - may need adjustment");
407 // field[1] is always oop or NULL
408 PSParallelCompact::adjust_pointer((oop*)&_f1);
409 if (is_vfinal()) {
410 PSParallelCompact::adjust_pointer((oop*)&_f2);
411 }
412 }
413 #endif // SERIALGC
414
415 // RedefineClasses() API support:
416 // If this constantPoolCacheEntry refers to old_method then update it
417 // to refer to new_method.
418 bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,
419 methodOop new_method, bool * trace_name_printed) {
420
421 if (is_vfinal()) {
422 // virtual and final so f2() contains method ptr instead of vtable index
423 if (f2() == (intptr_t)old_method) {
424 // match old_method so need an update
425 _f2 = (intptr_t)new_method;
426 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
427 if (!(*trace_name_printed)) {
428 // RC_TRACE_MESG macro has an embedded ResourceMark
429 RC_TRACE_MESG(("adjust: name=%s",
430 Klass::cast(old_method->method_holder())->external_name()));
431 *trace_name_printed = true;
432 }
433 // RC_TRACE macro has an embedded ResourceMark
434 RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
435 new_method->name()->as_C_string(),
436 new_method->signature()->as_C_string()));
437 }
438
439 return true;
440 }
441
442 // f1() is not used with virtual entries so bail out
443 return false;
444 }
445
446 if ((oop)_f1 == NULL) {
447 // NULL f1() means this is a virtual entry so bail out
448 // We are assuming that the vtable index does not need change.
449 return false;
450 }
451
452 if ((oop)_f1 == old_method) {
453 _f1 = new_method;
454 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
455 if (!(*trace_name_printed)) {
456 // RC_TRACE_MESG macro has an embedded ResourceMark
457 RC_TRACE_MESG(("adjust: name=%s",
458 Klass::cast(old_method->method_holder())->external_name()));
459 *trace_name_printed = true;
460 }
461 // RC_TRACE macro has an embedded ResourceMark
462 RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
463 new_method->name()->as_C_string(),
464 new_method->signature()->as_C_string()));
465 }
466
467 return true;
468 }
469
470 return false;
471 }
472
473 bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {
474 if (!is_method_entry()) {
475 // not a method entry so not interesting by default
476 return false;
477 }
478
479 methodOop m = NULL;
480 if (is_vfinal()) {
481 // virtual and final so _f2 contains method ptr instead of vtable index
482 m = (methodOop)_f2;
483 } else if ((oop)_f1 == NULL) {
484 // NULL _f1 means this is a virtual entry so also not interesting
485 return false;
486 } else {
487 if (!((oop)_f1)->is_method()) {
488 // _f1 can also contain a klassOop for an interface
489 return false;
490 }
491 m = (methodOop)_f1;
492 }
493
494 assert(m != NULL && m->is_method(), "sanity check");
495 if (m == NULL || !m->is_method() || m->method_holder() != k) {
496 // robustness for above sanity checks or method is not in
497 // the interesting class
498 return false;
499 }
500
501 // the method is in the interesting class so the entry is interesting
502 return true;
503 }
504
505 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
506 // print separator
507 if (index == 0) tty->print_cr(" -------------");
508 // print entry
509 tty->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this);
510 if (is_secondary_entry())
511 tty->print_cr("[%5d|secondary]", main_entry_index());
512 else
513 tty->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());
514 tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)(oop)_f1);
515 tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2);
516 tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags);
517 tty->print_cr(" -------------");
518 }
519
520 void ConstantPoolCacheEntry::verify(outputStream* st) const {
521 // not implemented yet
522 }
523
524 // Implementation of ConstantPoolCache
525
526 void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {
527 assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");
528 for (int i = 0; i < length(); i++) {
529 ConstantPoolCacheEntry* e = entry_at(i);
530 int original_index = inverse_index_map[i];
531 if ((original_index & Rewriter::_secondary_entry_tag) != 0) {
532 int main_index = (original_index - Rewriter::_secondary_entry_tag);
533 assert(!entry_at(main_index)->is_secondary_entry(), "valid main index");
534 e->initialize_secondary_entry(main_index);
535 } else {
536 e->initialize_entry(original_index);
537 }
538 assert(entry_at(i) == e, "sanity");
539 }
540 }
541
542 // RedefineClasses() API support:
543 // If any entry of this constantPoolCache points to any of
544 // old_methods, replace it with the corresponding new_method.
545 void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
546 int methods_length, bool * trace_name_printed) {
547
548 if (methods_length == 0) {
549 // nothing to do if there are no methods
550 return;
551 }
552
553 // get shorthand for the interesting class
554 klassOop old_holder = old_methods[0]->method_holder();
555
556 for (int i = 0; i < length(); i++) {
557 if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
558 // skip uninteresting methods
559 continue;
560 }
561
562 // The constantPoolCache contains entries for several different
563 // things, but we only care about methods. In fact, we only care
564 // about methods in the same class as the one that contains the
565 // old_methods. At this point, we have an interesting entry.
566
567 for (int j = 0; j < methods_length; j++) {
568 methodOop old_method = old_methods[j];
569 methodOop new_method = new_methods[j];
570
571 if (entry_at(i)->adjust_method_entry(old_method, new_method,
572 trace_name_printed)) {
573 // current old_method matched this entry and we updated it so
574 // break out and get to the next interesting entry if there one
575 break;
576 }
577 }
578 }
579 }