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(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 orig_field_index,
132 int field_offset,
133 TosState field_type,
134 bool is_final,
135 bool is_volatile) {
136 set_f1(field_holder());
137 set_f2(field_offset);
138 // The field index is used by jvm/ti and is the index into fields() array
139 // in holder instanceKlass. This is scaled by instanceKlass::next_offset.
140 assert((orig_field_index % instanceKlass::next_offset) == 0, "wierd index");
141 const int field_index = orig_field_index / instanceKlass::next_offset;
142 assert(field_index <= field_index_mask,
143 "field index does not fit in low flag bits");
144 set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) |
145 (field_index & field_index_mask));
146 set_bytecode_1(get_code);
147 set_bytecode_2(put_code);
148 NOT_PRODUCT(verify(tty));
149 }
150
151 int ConstantPoolCacheEntry::field_index() const {
152 return (_flags & field_index_mask) * instanceKlass::next_offset;
153 }
154
155 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
156 methodHandle method,
157 int vtable_index) {
158 assert(!is_secondary_entry(), "");
159 assert(method->interpreter_entry() != NULL, "should have been set at this point");
160 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
161 bool change_to_virtual = (invoke_code == Bytecodes::_invokeinterface);
162
163 int byte_no = -1;
164 bool needs_vfinal_flag = false;
165 switch (invoke_code) {
166 case Bytecodes::_invokevirtual:
167 case Bytecodes::_invokeinterface: {
168 if (method->can_be_statically_bound()) {
169 set_f2((intptr_t)method());
170 needs_vfinal_flag = true;
171 } else {
172 assert(vtable_index >= 0, "valid index");
173 set_f2(vtable_index);
174 }
175 byte_no = 2;
176 break;
177 }
178
179 case Bytecodes::_invokedynamic: // similar to _invokevirtual
180 if (TraceInvokeDynamic) {
181 tty->print_cr("InvokeDynamic set_method%s method="PTR_FORMAT" index=%d",
182 (is_secondary_entry() ? " secondary" : ""),
183 (intptr_t)method(), vtable_index);
184 method->print();
185 this->print(tty, 0);
186 }
187 assert(method->can_be_statically_bound(), "must be a MH invoker method");
188 assert(AllowTransitionalJSR292 || _f2 >= constantPoolOopDesc::CPCACHE_INDEX_TAG, "BSM index initialized");
189 // SystemDictionary::find_method_handle_invoke only caches
190 // methods which signature classes are on the boot classpath,
191 // otherwise the newly created method is returned. To avoid
192 // races in that case we store the first one coming in into the
193 // cp-cache atomically if it's still unset.
194 set_f1_if_null_atomic(method());
195 needs_vfinal_flag = false; // _f2 is not an oop
196 assert(!is_vfinal(), "f2 not an oop");
197 byte_no = 1; // coordinate this with bytecode_number & is_resolved
198 break;
199
200 case Bytecodes::_invokespecial:
201 // Preserve the value of the vfinal flag on invokevirtual bytecode
202 // which may be shared with this constant pool cache entry.
203 needs_vfinal_flag = is_resolved(Bytecodes::_invokevirtual) && is_vfinal();
204 // fall through
205 case Bytecodes::_invokestatic:
206 set_f1(method());
207 byte_no = 1;
208 break;
209 default:
210 ShouldNotReachHere();
211 break;
212 }
213
214 set_flags(as_flags(as_TosState(method->result_type()),
215 method->is_final_method(),
216 needs_vfinal_flag,
217 false,
218 change_to_virtual,
219 true)|
220 method()->size_of_parameters());
221
222 // Note: byte_no also appears in TemplateTable::resolve.
223 if (byte_no == 1) {
224 set_bytecode_1(invoke_code);
225 } else if (byte_no == 2) {
226 if (change_to_virtual) {
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 set_bytecode_2(Bytecodes::_invokevirtual);
243 } else {
244 set_bytecode_2(invoke_code);
245 }
246 } else {
247 ShouldNotReachHere();
248 }
249 NOT_PRODUCT(verify(tty));
250 }
251
252
253 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
254 assert(!is_secondary_entry(), "");
255 klassOop interf = method->method_holder();
256 assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");
257 set_f1(interf);
258 set_f2(index);
259 set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());
260 set_bytecode_1(Bytecodes::_invokeinterface);
261 }
262
263
264 void ConstantPoolCacheEntry::initialize_bootstrap_method_index_in_cache(int bsm_cache_index) {
265 assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
266 assert(_f2 == 0, "initialize once");
267 assert(bsm_cache_index == (int)(u2)bsm_cache_index, "oob");
268 set_f2(bsm_cache_index + constantPoolOopDesc::CPCACHE_INDEX_TAG);
269 }
270
271 int ConstantPoolCacheEntry::bootstrap_method_index_in_cache() {
272 assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
273 intptr_t bsm_cache_index = (intptr_t) _f2 - constantPoolOopDesc::CPCACHE_INDEX_TAG;
274 assert(bsm_cache_index == (intptr_t)(u2)bsm_cache_index, "oob");
275 return (int) bsm_cache_index;
276 }
277
278 void ConstantPoolCacheEntry::set_dynamic_call(Handle call_site,
279 methodHandle signature_invoker) {
280 assert(is_secondary_entry(), "");
281 int param_size = signature_invoker->size_of_parameters();
282 assert(param_size >= 1, "method argument size must include MH.this");
283 param_size -= 1; // do not count MH.this; it is not stacked for invokedynamic
284 if (Atomic::cmpxchg_ptr(call_site(), &_f1, NULL) == NULL) {
285 // racing threads might be trying to install their own favorites
286 set_f1(call_site());
287 }
288 bool is_final = true;
289 assert(signature_invoker->is_final_method(), "is_final");
290 set_flags(as_flags(as_TosState(signature_invoker->result_type()), is_final, false, false, false, true) | param_size);
291 // do not do set_bytecode on a secondary CP cache entry
292 //set_bytecode_1(Bytecodes::_invokedynamic);
293 }
294
295
296 class LocalOopClosure: public OopClosure {
297 private:
298 void (*_f)(oop*);
299
300 public:
301 LocalOopClosure(void f(oop*)) { _f = f; }
302 virtual void do_oop(oop* o) { _f(o); }
303 virtual void do_oop(narrowOop *o) { ShouldNotReachHere(); }
304 };
305
306
307 void ConstantPoolCacheEntry::oops_do(void f(oop*)) {
308 LocalOopClosure blk(f);
309 oop_iterate(&blk);
310 }
311
312
313 void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {
314 assert(in_words(size()) == 4, "check code below - may need adjustment");
315 // field[1] is always oop or NULL
316 blk->do_oop((oop*)&_f1);
317 if (is_vfinal()) {
318 blk->do_oop((oop*)&_f2);
319 }
320 }
321
322
323 void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {
324 assert(in_words(size()) == 4, "check code below - may need adjustment");
325 // field[1] is always oop or NULL
326 if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);
327 if (is_vfinal()) {
328 if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);
329 }
330 }
331
332
333 void ConstantPoolCacheEntry::follow_contents() {
334 assert(in_words(size()) == 4, "check code below - may need adjustment");
335 // field[1] is always oop or NULL
336 MarkSweep::mark_and_push((oop*)&_f1);
337 if (is_vfinal()) {
338 MarkSweep::mark_and_push((oop*)&_f2);
339 }
340 }
341
342 #ifndef SERIALGC
343 void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {
344 assert(in_words(size()) == 4, "check code below - may need adjustment");
345 // field[1] is always oop or NULL
346 PSParallelCompact::mark_and_push(cm, (oop*)&_f1);
347 if (is_vfinal()) {
348 PSParallelCompact::mark_and_push(cm, (oop*)&_f2);
349 }
350 }
351 #endif // SERIALGC
352
353 void ConstantPoolCacheEntry::adjust_pointers() {
354 assert(in_words(size()) == 4, "check code below - may need adjustment");
355 // field[1] is always oop or NULL
356 MarkSweep::adjust_pointer((oop*)&_f1);
357 if (is_vfinal()) {
358 MarkSweep::adjust_pointer((oop*)&_f2);
359 }
360 }
361
362 #ifndef SERIALGC
363 void ConstantPoolCacheEntry::update_pointers() {
364 assert(in_words(size()) == 4, "check code below - may need adjustment");
365 // field[1] is always oop or NULL
366 PSParallelCompact::adjust_pointer((oop*)&_f1);
367 if (is_vfinal()) {
368 PSParallelCompact::adjust_pointer((oop*)&_f2);
369 }
370 }
371 #endif // SERIALGC
372
373 // RedefineClasses() API support:
374 // If this constantPoolCacheEntry refers to old_method then update it
375 // to refer to new_method.
376 bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,
377 methodOop new_method, bool * trace_name_printed) {
378
379 if (is_vfinal()) {
380 // virtual and final so f2() contains method ptr instead of vtable index
381 if (f2() == (intptr_t)old_method) {
382 // match old_method so need an update
383 _f2 = (intptr_t)new_method;
384 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
385 if (!(*trace_name_printed)) {
386 // RC_TRACE_MESG macro has an embedded ResourceMark
387 RC_TRACE_MESG(("adjust: name=%s",
388 Klass::cast(old_method->method_holder())->external_name()));
389 *trace_name_printed = true;
390 }
391 // RC_TRACE macro has an embedded ResourceMark
392 RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
393 new_method->name()->as_C_string(),
394 new_method->signature()->as_C_string()));
395 }
396
397 return true;
398 }
399
400 // f1() is not used with virtual entries so bail out
401 return false;
402 }
403
404 if ((oop)_f1 == NULL) {
405 // NULL f1() means this is a virtual entry so bail out
406 // We are assuming that the vtable index does not need change.
407 return false;
408 }
409
410 if ((oop)_f1 == old_method) {
411 _f1 = new_method;
412 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
413 if (!(*trace_name_printed)) {
414 // RC_TRACE_MESG macro has an embedded ResourceMark
415 RC_TRACE_MESG(("adjust: name=%s",
416 Klass::cast(old_method->method_holder())->external_name()));
417 *trace_name_printed = true;
418 }
419 // RC_TRACE macro has an embedded ResourceMark
420 RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
421 new_method->name()->as_C_string(),
422 new_method->signature()->as_C_string()));
423 }
424
425 return true;
426 }
427
428 return false;
429 }
430
431 bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {
432 if (!is_method_entry()) {
433 // not a method entry so not interesting by default
434 return false;
435 }
436
437 methodOop m = NULL;
438 if (is_vfinal()) {
439 // virtual and final so _f2 contains method ptr instead of vtable index
440 m = (methodOop)_f2;
441 } else if ((oop)_f1 == NULL) {
442 // NULL _f1 means this is a virtual entry so also not interesting
443 return false;
444 } else {
445 if (!((oop)_f1)->is_method()) {
446 // _f1 can also contain a klassOop for an interface
447 return false;
448 }
449 m = (methodOop)_f1;
450 }
451
452 assert(m != NULL && m->is_method(), "sanity check");
453 if (m == NULL || !m->is_method() || m->method_holder() != k) {
454 // robustness for above sanity checks or method is not in
455 // the interesting class
456 return false;
457 }
458
459 // the method is in the interesting class so the entry is interesting
460 return true;
461 }
462
463 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
464 // print separator
465 if (index == 0) tty->print_cr(" -------------");
466 // print entry
467 tty->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this);
468 if (is_secondary_entry())
469 tty->print_cr("[%5d|secondary]", main_entry_index());
470 else
471 tty->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());
472 tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)(oop)_f1);
473 tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2);
474 tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags);
475 tty->print_cr(" -------------");
476 }
477
478 void ConstantPoolCacheEntry::verify(outputStream* st) const {
479 // not implemented yet
480 }
481
482 // Implementation of ConstantPoolCache
483
484 void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {
485 assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");
486 for (int i = 0; i < length(); i++) {
487 ConstantPoolCacheEntry* e = entry_at(i);
488 int original_index = inverse_index_map[i];
489 if ((original_index & Rewriter::_secondary_entry_tag) != 0) {
490 int main_index = (original_index - Rewriter::_secondary_entry_tag);
491 assert(!entry_at(main_index)->is_secondary_entry(), "valid main index");
492 e->initialize_secondary_entry(main_index);
493 } else {
494 e->initialize_entry(original_index);
495 }
496 assert(entry_at(i) == e, "sanity");
497 }
498 }
499
500 // RedefineClasses() API support:
501 // If any entry of this constantPoolCache points to any of
502 // old_methods, replace it with the corresponding new_method.
503 void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
504 int methods_length, bool * trace_name_printed) {
505
506 if (methods_length == 0) {
507 // nothing to do if there are no methods
508 return;
509 }
510
511 // get shorthand for the interesting class
512 klassOop old_holder = old_methods[0]->method_holder();
513
514 for (int i = 0; i < length(); i++) {
515 if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
516 // skip uninteresting methods
517 continue;
518 }
519
520 // The constantPoolCache contains entries for several different
521 // things, but we only care about methods. In fact, we only care
522 // about methods in the same class as the one that contains the
523 // old_methods. At this point, we have an interesting entry.
524
525 for (int j = 0; j < methods_length; j++) {
526 methodOop old_method = old_methods[j];
527 methodOop new_method = new_methods[j];
528
529 if (entry_at(i)->adjust_method_entry(old_method, new_method,
530 trace_name_printed)) {
531 // current old_method matched this entry and we updated it so
532 // break out and get to the next interesting entry if there one
533 break;
534 }
535 }
536 }
537 }