1 /*
2 * Copyright (c) 1998, 2018, 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/resolutionErrors.hpp"
27 #include "interpreter/bytecodeStream.hpp"
28 #include "interpreter/bytecodes.hpp"
29 #include "interpreter/interpreter.hpp"
30 #include "interpreter/linkResolver.hpp"
31 #include "interpreter/rewriter.hpp"
32 #include "logging/log.hpp"
33 #include "memory/metadataFactory.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/access.inline.hpp"
38 #include "oops/constantPool.inline.hpp"
39 #include "oops/cpCache.inline.hpp"
40 #include "oops/objArrayOop.inline.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "prims/methodHandles.hpp"
43 #include "runtime/atomic.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/orderAccess.inline.hpp"
46 #include "utilities/macros.hpp"
47
48 // Implementation of ConstantPoolCacheEntry
49
50 void ConstantPoolCacheEntry::initialize_entry(int index) {
51 assert(0 < index && index < 0x10000, "sanity check");
52 _indices = index;
53 _f1 = NULL;
54 _f2 = _flags = 0;
55 assert(constant_pool_index() == index, "");
56 }
57
58 void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) {
59 assert((_indices & (~cp_index_mask)) == 0, "sanity");
60 assert(_f1 == NULL, "sanity");
61 assert(_flags == 0, "sanity");
62 if (!f2_used) {
63 assert(_f2 == 0, "sanity");
64 }
65 }
66
67 void ConstantPoolCacheEntry::reinitialize(bool f2_used) {
68 _indices &= cp_index_mask;
69 _f1 = NULL;
70 _flags = 0;
71 if (!f2_used) {
72 _f2 = 0;
73 }
74 }
75
76 int ConstantPoolCacheEntry::make_flags(TosState state,
77 int option_bits,
78 int field_index_or_method_params) {
79 assert(state < number_of_states, "Invalid state in make_flags");
80 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
81 // Preserve existing flag bit values
82 // The low bits are a field offset, or else the method parameter size.
83 #ifdef ASSERT
84 TosState old_state = flag_state();
85 assert(old_state == (TosState)0 || old_state == state,
86 "inconsistent cpCache flags state");
87 #endif
88 return (_flags | f) ;
89 }
90
91 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
92 #ifdef ASSERT
93 // Read once.
94 volatile Bytecodes::Code c = bytecode_1();
95 assert(c == 0 || c == code || code == 0, "update must be consistent");
96 #endif
97 // Need to flush pending stores here before bytecode is written.
98 OrderAccess::release_store(&_indices, _indices | ((u_char)code << bytecode_1_shift));
99 }
100
101 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
102 #ifdef ASSERT
103 // Read once.
104 volatile Bytecodes::Code c = bytecode_2();
105 assert(c == 0 || c == code || code == 0, "update must be consistent");
106 #endif
107 // Need to flush pending stores here before bytecode is written.
108 OrderAccess::release_store(&_indices, _indices | ((u_char)code << bytecode_2_shift));
109 }
110
111 // Sets f1, ordering with previous writes.
112 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
113 assert(f1 != NULL, "");
114 OrderAccess::release_store(&_f1, f1);
115 }
116
117 void ConstantPoolCacheEntry::set_indy_resolution_failed() {
118 OrderAccess::release_store(&_flags, _flags | (1 << indy_resolution_failed_shift));
119 }
120
121 // Note that concurrent update of both bytecodes can leave one of them
122 // reset to zero. This is harmless; the interpreter will simply re-resolve
123 // the damaged entry. More seriously, the memory synchronization is needed
124 // to flush other fields (f1, f2) completely to memory before the bytecodes
125 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
126 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
127 Bytecodes::Code put_code,
128 Klass* field_holder,
129 int field_index,
130 int field_offset,
131 TosState field_type,
132 bool is_final,
133 bool is_volatile,
134 Klass* root_klass) {
135 set_f1(field_holder);
136 set_f2(field_offset);
137 assert((field_index & field_index_mask) == field_index,
138 "field index does not fit in low flag bits");
139 set_field_flags(field_type,
140 ((is_volatile ? 1 : 0) << is_volatile_shift) |
141 ((is_final ? 1 : 0) << is_final_shift),
142 field_index);
143 set_bytecode_1(get_code);
144 set_bytecode_2(put_code);
145 NOT_PRODUCT(verify(tty));
146 }
147
148 void ConstantPoolCacheEntry::set_parameter_size(int value) {
149 // This routine is called only in corner cases where the CPCE is not yet initialized.
150 // See AbstractInterpreter::deopt_continue_after_entry.
151 assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
152 "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
153 // Setting the parameter size by itself is only safe if the
154 // current value of _flags is 0, otherwise another thread may have
155 // updated it and we don't want to overwrite that value. Don't
156 // bother trying to update it once it's nonzero but always make
157 // sure that the final parameter size agrees with what was passed.
158 if (_flags == 0) {
159 intx newflags = (value & parameter_size_mask);
160 Atomic::cmpxchg(newflags, &_flags, (intx)0);
161 }
162 guarantee(parameter_size() == value,
163 "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
164 }
165
166 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code,
167 const methodHandle& method,
168 int vtable_index,
169 bool sender_is_interface) {
170 bool is_vtable_call = (vtable_index >= 0); // FIXME: split this method on this boolean
171 assert(method->interpreter_entry() != NULL, "should have been set at this point");
172 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
173
174 int byte_no = -1;
175 bool change_to_virtual = false;
176
177 switch (invoke_code) {
178 case Bytecodes::_invokeinterface:
179 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
180 // instruction somehow links to a non-interface method (in Object).
181 // In that case, the method has no itable index and must be invoked as a virtual.
182 // Set a flag to keep track of this corner case.
183 assert(method->is_public(), "Calling non-public method in Object with invokeinterface");
184 change_to_virtual = true;
185
186 // ...and fall through as if we were handling invokevirtual:
187 case Bytecodes::_invokevirtual:
188 {
189 if (!is_vtable_call) {
190 assert(method->can_be_statically_bound(), "");
191 // set_f2_as_vfinal_method checks if is_vfinal flag is true.
192 set_method_flags(as_TosState(method->result_type()),
193 ( 1 << is_vfinal_shift) |
194 ((method->is_final_method() ? 1 : 0) << is_final_shift) |
195 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
196 method()->size_of_parameters());
197 set_f2_as_vfinal_method(method());
198 } else {
199 assert(!method->can_be_statically_bound(), "");
200 assert(vtable_index >= 0, "valid index");
201 assert(!method->is_final_method(), "sanity");
202 set_method_flags(as_TosState(method->result_type()),
203 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
204 method()->size_of_parameters());
205 set_f2(vtable_index);
206 }
207 byte_no = 2;
208 break;
209 }
210
211 case Bytecodes::_invokespecial:
212 case Bytecodes::_invokestatic:
213 assert(!is_vtable_call, "");
214 // Note: Read and preserve the value of the is_vfinal flag on any
215 // invokevirtual bytecode shared with this constant pool cache entry.
216 // It is cheap and safe to consult is_vfinal() at all times.
217 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
218 set_method_flags(as_TosState(method->result_type()),
219 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) |
220 ((method->is_final_method() ? 1 : 0) << is_final_shift),
221 method()->size_of_parameters());
222 set_f1(method());
223 byte_no = 1;
224 break;
225 default:
226 ShouldNotReachHere();
227 break;
228 }
229
230 // Note: byte_no also appears in TemplateTable::resolve.
231 if (byte_no == 1) {
232 assert(invoke_code != Bytecodes::_invokevirtual &&
233 invoke_code != Bytecodes::_invokeinterface, "");
234 // Don't mark invokespecial to method as resolved if sender is an interface. The receiver
235 // has to be checked that it is a subclass of the current class every time this bytecode
236 // is executed.
237 if (invoke_code != Bytecodes::_invokespecial || !sender_is_interface ||
238 method->name() == vmSymbols::object_initializer_name()) {
239 set_bytecode_1(invoke_code);
240 }
241 } else if (byte_no == 2) {
242 if (change_to_virtual) {
243 assert(invoke_code == Bytecodes::_invokeinterface, "");
244 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
245 //
246 // Workaround for the case where we encounter an invokeinterface, but we
247 // should really have an _invokevirtual since the resolved method is a
248 // virtual method in java.lang.Object. This is a corner case in the spec
249 // but is presumably legal. javac does not generate this code.
250 //
251 // We do not set bytecode_1() to _invokeinterface, because that is the
252 // bytecode # used by the interpreter to see if it is resolved. In this
253 // case, the method gets reresolved with caller for each interface call
254 // because the actual selected method may not be public.
255 //
256 // We set bytecode_2() to _invokevirtual.
257 // See also interpreterRuntime.cpp. (8/25/2000)
258 } else {
259 assert(invoke_code == Bytecodes::_invokevirtual, "");
260 }
261 // set up for invokevirtual, even if linking for invokeinterface also:
262 set_bytecode_2(Bytecodes::_invokevirtual);
263 } else {
264 ShouldNotReachHere();
265 }
266 NOT_PRODUCT(verify(tty));
267 }
268
269 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method,
270 bool sender_is_interface) {
271 int index = Method::nonvirtual_vtable_index;
272 // index < 0; FIXME: inline and customize set_direct_or_vtable_call
273 set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);
274 }
275
276 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
277 // either the method is a miranda or its holder should accept the given index
278 assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
279 // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
280 set_direct_or_vtable_call(invoke_code, method, index, false);
281 }
282
283 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code,
284 Klass* referenced_klass,
285 const methodHandle& method, int index) {
286 assert(method->method_holder()->verify_itable_index(index), "");
287 assert(invoke_code == Bytecodes::_invokeinterface, "");
288 InstanceKlass* interf = method->method_holder();
289 assert(interf->is_interface(), "must be an interface");
290 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
291 set_f1(referenced_klass);
292 set_f2((intx)method());
293 set_method_flags(as_TosState(method->result_type()),
294 0, // no option bits
295 method()->size_of_parameters());
296 set_bytecode_1(Bytecodes::_invokeinterface);
297 }
298
299
300 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {
301 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
302 }
303
304 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {
305 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
306 }
307
308 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,
309 Bytecodes::Code invoke_code,
310 const CallInfo &call_info) {
311 // NOTE: This CPCE can be the subject of data races.
312 // There are three words to update: flags, refs[f2], f1 (in that order).
313 // Writers must store all other values before f1.
314 // Readers must test f1 first for non-null before reading other fields.
315 // Competing writers must acquire exclusive access via a lock.
316 // A losing writer waits on the lock until the winner writes f1 and leaves
317 // the lock, so that when the losing writer returns, he can use the linked
318 // cache entry.
319
320 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
321 // Use the resolved_references() lock for this cpCache entry.
322 // resolved_references are created for all classes with Invokedynamic, MethodHandle
323 // or MethodType constant pool cache entries.
324 assert(resolved_references() != NULL,
325 "a resolved_references array should have been created for this class");
326 ObjectLocker ol(resolved_references, Thread::current());
327 if (!is_f1_null()) {
328 return;
329 }
330
331 if (indy_resolution_failed()) {
332 // Before we got here, another thread got a LinkageError exception during
333 // resolution. Ignore our success and throw their exception.
334 ConstantPoolCache* cpCache = cpool->cache();
335 int index = -1;
336 for (int i = 0; i < cpCache->length(); i++) {
337 if (cpCache->entry_at(i) == this) {
338 index = i;
339 break;
340 }
341 }
342 guarantee(index >= 0, "Didn't find cpCache entry!");
343 int encoded_index = ResolutionErrorTable::encode_cpcache_index(
344 ConstantPool::encode_invokedynamic_index(index));
345 Thread* THREAD = Thread::current();
346 ConstantPool::throw_resolution_error(cpool, encoded_index, THREAD);
347 return;
348 }
349
350 const methodHandle adapter = call_info.resolved_method();
351 const Handle appendix = call_info.resolved_appendix();
352 const Handle method_type = call_info.resolved_method_type();
353 const bool has_appendix = appendix.not_null();
354 const bool has_method_type = method_type.not_null();
355
356 // Write the flags.
357 set_method_flags(as_TosState(adapter->result_type()),
358 ((has_appendix ? 1 : 0) << has_appendix_shift ) |
359 ((has_method_type ? 1 : 0) << has_method_type_shift) |
360 ( 1 << is_final_shift ),
361 adapter->size_of_parameters());
362
363 if (TraceInvokeDynamic) {
364 ttyLocker ttyl;
365 tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ",
366 invoke_code,
367 p2i(appendix()), (has_appendix ? "" : " (unused)"),
368 p2i(method_type()), (has_method_type ? "" : " (unused)"),
369 p2i(adapter()));
370 adapter->print();
371 if (has_appendix) appendix()->print();
372 }
373
374 // Method handle invokes and invokedynamic sites use both cp cache words.
375 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
376 // In the general case, this could be the call site's MethodType,
377 // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
378 // f1 contains the adapter method which manages the actual call.
379 // In the general case, this is a compiled LambdaForm.
380 // (The Java code is free to optimize these calls by binding other
381 // sorts of methods and appendices to call sites.)
382 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
383 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
384 // Even with the appendix, the method will never take more than 255 parameter slots.
385 //
386 // This means that given a call site like (List)mh.invoke("foo"),
387 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
388 // not '(Ljava/lang/String;)Ljava/util/List;'.
389 // The fact that String and List are involved is encoded in the MethodType in refs[f2].
390 // This allows us to create fewer Methods, while keeping type safety.
391 //
392
393 // Store appendix, if any.
394 if (has_appendix) {
395 const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
396 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
397 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
398 resolved_references->obj_at_put(appendix_index, appendix());
399 }
400
401 // Store MethodType, if any.
402 if (has_method_type) {
403 const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
404 assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
405 assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
406 resolved_references->obj_at_put(method_type_index, method_type());
407 }
408
409 release_set_f1(adapter()); // This must be the last one to set (see NOTE above)!
410
411 // The interpreter assembly code does not check byte_2,
412 // but it is used by is_resolved, method_if_resolved, etc.
413 set_bytecode_1(invoke_code);
414 NOT_PRODUCT(verify(tty));
415 if (TraceInvokeDynamic) {
416 ttyLocker ttyl;
417 this->print(tty, 0);
418 }
419 }
420
421 bool ConstantPoolCacheEntry::save_and_throw_indy_exc(
422 const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS) {
423
424 assert(HAS_PENDING_EXCEPTION, "No exception got thrown!");
425 assert(PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass()),
426 "No LinkageError exception");
427
428 // Use the resolved_references() lock for this cpCache entry.
429 // resolved_references are created for all classes with Invokedynamic, MethodHandle
430 // or MethodType constant pool cache entries.
431 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
432 assert(resolved_references() != NULL,
433 "a resolved_references array should have been created for this class");
434 ObjectLocker ol(resolved_references, THREAD);
435
436 // if f1 is not null or the indy_resolution_failed flag is set then another
437 // thread either succeeded in resolving the method or got a LinkageError
438 // exception, before this thread was able to record its failure. So, clear
439 // this thread's exception and return false so caller can use the earlier
440 // thread's result.
441 if (!is_f1_null() || indy_resolution_failed()) {
442 CLEAR_PENDING_EXCEPTION;
443 return false;
444 }
445
446 Symbol* error = PENDING_EXCEPTION->klass()->name();
447 Symbol* message = java_lang_Throwable::detail_message(PENDING_EXCEPTION);
448 assert(message != NULL, "Missing detail message");
449
450 SystemDictionary::add_resolution_error(cpool, index, error, message);
451 set_indy_resolution_failed();
452 return true;
453 }
454
455 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {
456 // Decode the action of set_method and set_interface_call
457 Bytecodes::Code invoke_code = bytecode_1();
458 if (invoke_code != (Bytecodes::Code)0) {
459 Metadata* f1 = f1_ord();
460 if (f1 != NULL) {
461 switch (invoke_code) {
462 case Bytecodes::_invokeinterface:
463 assert(f1->is_klass(), "");
464 return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
465 case Bytecodes::_invokestatic:
466 case Bytecodes::_invokespecial:
467 assert(!has_appendix(), "");
468 case Bytecodes::_invokehandle:
469 case Bytecodes::_invokedynamic:
470 assert(f1->is_method(), "");
471 return (Method*)f1;
472 default:
473 break;
474 }
475 }
476 }
477 invoke_code = bytecode_2();
478 if (invoke_code != (Bytecodes::Code)0) {
479 switch (invoke_code) {
480 case Bytecodes::_invokevirtual:
481 if (is_vfinal()) {
482 // invokevirtual
483 Method* m = f2_as_vfinal_method();
484 assert(m->is_method(), "");
485 return m;
486 } else {
487 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
488 if (cpool->tag_at(holder_index).is_klass()) {
489 Klass* klass = cpool->resolved_klass_at(holder_index);
490 return klass->method_at_vtable(f2_as_index());
491 }
492 }
493 break;
494 default:
495 break;
496 }
497 }
498 return NULL;
499 }
500
501
502 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {
503 if (!has_appendix())
504 return NULL;
505 const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
506 objArrayOop resolved_references = cpool->resolved_references();
507 return resolved_references->obj_at(ref_index);
508 }
509
510
511 oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) {
512 if (!has_method_type())
513 return NULL;
514 const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
515 objArrayOop resolved_references = cpool->resolved_references();
516 return resolved_references->obj_at(ref_index);
517 }
518
519
520 #if INCLUDE_JVMTI
521
522 void log_adjust(const char* entry_type, Method* old_method, Method* new_method, bool* trace_name_printed) {
523 if (log_is_enabled(Info, redefine, class, update)) {
524 ResourceMark rm;
525 if (!(*trace_name_printed)) {
526 log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
527 *trace_name_printed = true;
528 }
529 log_debug(redefine, class, update, constantpool)
530 ("cpc %s entry update: %s(%s)", entry_type, new_method->name()->as_C_string(), new_method->signature()->as_C_string());
531 }
532 }
533
534 // RedefineClasses() API support:
535 // If this ConstantPoolCacheEntry refers to old_method then update it
536 // to refer to new_method.
537 void ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
538 Method* new_method, bool * trace_name_printed) {
539
540 if (is_vfinal()) {
541 // virtual and final so _f2 contains method ptr instead of vtable index
542 if (f2_as_vfinal_method() == old_method) {
543 // match old_method so need an update
544 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
545 _f2 = (intptr_t)new_method;
546 log_adjust("vfinal", old_method, new_method, trace_name_printed);
547 }
548 return;
549 }
550
551 assert (_f1 != NULL, "should not call with uninteresting entry");
552
553 if (!(_f1->is_method())) {
554 // _f1 is a Klass* for an interface, _f2 is the method
555 if (f2_as_interface_method() == old_method) {
556 _f2 = (intptr_t)new_method;
557 log_adjust("interface", old_method, new_method, trace_name_printed);
558 }
559 } else if (_f1 == old_method) {
560 _f1 = new_method;
561 log_adjust("special, static or dynamic", old_method, new_method, trace_name_printed);
562 }
563 }
564
565 // a constant pool cache entry should never contain old or obsolete methods
566 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
567 Method* m = get_interesting_method_entry(NULL);
568 // return false if m refers to a non-deleted old or obsolete method
569 if (m != NULL) {
570 assert(m->is_valid() && m->is_method(), "m is a valid method");
571 return !m->is_old() && !m->is_obsolete(); // old is always set for old and obsolete
572 } else {
573 return true;
574 }
575 }
576
577 Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) {
578 if (!is_method_entry()) {
579 // not a method entry so not interesting by default
580 return NULL;
581 }
582 Method* m = NULL;
583 if (is_vfinal()) {
584 // virtual and final so _f2 contains method ptr instead of vtable index
585 m = f2_as_vfinal_method();
586 } else if (is_f1_null()) {
587 // NULL _f1 means this is a virtual entry so also not interesting
588 return NULL;
589 } else {
590 if (!(_f1->is_method())) {
591 // _f1 is a Klass* for an interface
592 m = f2_as_interface_method();
593 } else {
594 m = f1_as_method();
595 }
596 }
597 assert(m != NULL && m->is_method(), "sanity check");
598 if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
599 // robustness for above sanity checks or method is not in
600 // the interesting class
601 return NULL;
602 }
603 // the method is in the interesting class so the entry is interesting
604 return m;
605 }
606 #endif // INCLUDE_JVMTI
607
608 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
609 // print separator
610 if (index == 0) st->print_cr(" -------------");
611 // print entry
612 st->print("%3d (" PTR_FORMAT ") ", index, (intptr_t)this);
613 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
614 constant_pool_index());
615 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f1);
616 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f2);
617 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_flags);
618 st->print_cr(" -------------");
619 }
620
621 void ConstantPoolCacheEntry::verify(outputStream* st) const {
622 // not implemented yet
623 }
624
625 // Implementation of ConstantPoolCache
626
627 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
628 const intStack& index_map,
629 const intStack& invokedynamic_index_map,
630 const intStack& invokedynamic_map, TRAPS) {
631
632 const int length = index_map.length() + invokedynamic_index_map.length();
633 int size = ConstantPoolCache::size(length);
634
635 return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD)
636 ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
637 }
638
639 void ConstantPoolCache::initialize(const intArray& inverse_index_map,
640 const intArray& invokedynamic_inverse_index_map,
641 const intArray& invokedynamic_references_map) {
642 for (int i = 0; i < inverse_index_map.length(); i++) {
643 ConstantPoolCacheEntry* e = entry_at(i);
644 int original_index = inverse_index_map.at(i);
645 e->initialize_entry(original_index);
646 assert(entry_at(i) == e, "sanity");
647 }
648
649 // Append invokedynamic entries at the end
650 int invokedynamic_offset = inverse_index_map.length();
651 for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
652 int offset = i + invokedynamic_offset;
653 ConstantPoolCacheEntry* e = entry_at(offset);
654 int original_index = invokedynamic_inverse_index_map.at(i);
655 e->initialize_entry(original_index);
656 assert(entry_at(offset) == e, "sanity");
657 }
658
659 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
660 const int cpci = invokedynamic_references_map.at(ref);
661 if (cpci >= 0) {
662 #ifdef ASSERT
663 // invokedynamic and invokehandle have more entries; check if they
664 // all point to the same constant pool cache entry.
665 for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
666 const int cpci_next = invokedynamic_references_map.at(ref + entry);
667 assert(cpci == cpci_next, "%d == %d", cpci, cpci_next);
668 }
669 #endif
670 entry_at(cpci)->initialize_resolved_reference_index(ref);
671 ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1; // skip extra entries
672 }
673 }
674 }
675
676 void ConstantPoolCache::verify_just_initialized() {
677 DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true));
678 }
679
680 void ConstantPoolCache::remove_unshareable_info() {
681 walk_entries_for_initialization(/*check_only = */ false);
682 }
683
684 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) {
685 assert(DumpSharedSpaces, "sanity");
686 // When dumping the archive, we want to clean up the ConstantPoolCache
687 // to remove any effect of linking due to the execution of Java code --
688 // each ConstantPoolCacheEntry will have the same contents as if
689 // ConstantPoolCache::initialize has just returned:
690 //
691 // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries.
692 // - We keep the "f2" field for entries used by invokedynamic and invokehandle
693 // - All other bits in the entries are cleared to zero.
694 ResourceMark rm;
695
696 InstanceKlass* ik = constant_pool()->pool_holder();
697 bool* f2_used = NEW_RESOURCE_ARRAY(bool, length());
698 memset(f2_used, 0, sizeof(bool) * length());
699
700 // Find all the slots that we need to preserve f2
701 for (int i = 0; i < ik->methods()->length(); i++) {
702 Method* m = ik->methods()->at(i);
703 RawBytecodeStream bcs(m);
704 while (!bcs.is_last_bytecode()) {
705 Bytecodes::Code opcode = bcs.raw_next();
706 switch (opcode) {
707 case Bytecodes::_invokedynamic: {
708 int index = Bytes::get_native_u4(bcs.bcp() + 1);
709 int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index);
710 f2_used[cp_cache_index] = 1;
711 }
712 break;
713 case Bytecodes::_invokehandle: {
714 int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1);
715 f2_used[cp_cache_index] = 1;
716 }
717 break;
718 default:
719 break;
720 }
721 }
722 }
723
724 if (check_only) {
725 DEBUG_ONLY(
726 for (int i=0; i<length(); i++) {
727 entry_at(i)->verify_just_initialized(f2_used[i]);
728 })
729 } else {
730 for (int i=0; i<length(); i++) {
731 entry_at(i)->reinitialize(f2_used[i]);
732 }
733 }
734 }
735
736 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) {
737 assert(!is_shared(), "shared caches are not deallocated");
738 data->remove_handle(_resolved_references);
739 set_resolved_references(NULL);
740 MetadataFactory::free_array<u2>(data, _reference_map);
741 set_reference_map(NULL);
742 }
743
744 #if INCLUDE_CDS_JAVA_HEAP
745 oop ConstantPoolCache::archived_references() {
746 // Loading an archive root forces the oop to become strongly reachable.
747 // For example, if it is loaded during concurrent marking in a SATB
748 // collector, it will be enqueued to the SATB queue, effectively
749 // shading the previously white object gray.
750 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_references);
751 }
752
753 void ConstantPoolCache::set_archived_references(oop o) {
754 assert(DumpSharedSpaces, "called only during runtime");
755 RootAccess<IN_ARCHIVE_ROOT>::oop_store(&_archived_references, o);
756 }
757 #endif
758
759 #if INCLUDE_JVMTI
760 // RedefineClasses() API support:
761 // If any entry of this ConstantPoolCache points to any of
762 // old_methods, replace it with the corresponding new_method.
763 void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
764 for (int i = 0; i < length(); i++) {
765 ConstantPoolCacheEntry* entry = entry_at(i);
766 Method* old_method = entry->get_interesting_method_entry(holder);
767 if (old_method == NULL || !old_method->is_old()) {
768 continue; // skip uninteresting entries
769 }
770 if (old_method->is_deleted()) {
771 // clean up entries with deleted methods
772 entry->initialize_entry(entry->constant_pool_index());
773 continue;
774 }
775 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
776
777 assert(new_method != NULL, "method_with_idnum() should not be NULL");
778 assert(old_method != new_method, "sanity check");
779
780 entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);
781 }
782 }
783
784 // the constant pool cache should never contain old or obsolete methods
785 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
786 for (int i = 1; i < length(); i++) {
787 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL &&
788 !entry_at(i)->check_no_old_or_obsolete_entries()) {
789 return false;
790 }
791 }
792 return true;
793 }
794
795 void ConstantPoolCache::dump_cache() {
796 for (int i = 1; i < length(); i++) {
797 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) {
798 entry_at(i)->print(tty, i);
799 }
800 }
801 }
802 #endif // INCLUDE_JVMTI
803
804 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) {
805 log_trace(cds)("Iter(ConstantPoolCache): %p", this);
806 it->push(&_constant_pool);
807 it->push(&_reference_map);
808 }
809
810 // Printing
811
812 void ConstantPoolCache::print_on(outputStream* st) const {
813 assert(is_constantPoolCache(), "obj must be constant pool cache");
814 st->print_cr("%s", internal_name());
815 // print constant pool cache entries
816 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
817 }
818
819 void ConstantPoolCache::print_value_on(outputStream* st) const {
820 assert(is_constantPoolCache(), "obj must be constant pool cache");
821 st->print("cache [%d]", length());
822 print_address_on(st);
823 st->print(" for ");
824 constant_pool()->print_value_on(st);
825 }
826
827
828 // Verification
829
830 void ConstantPoolCache::verify_on(outputStream* st) {
831 guarantee(is_constantPoolCache(), "obj must be constant pool cache");
832 // print constant pool cache entries
833 for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
834 }