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 if (vtable_index == Method::nonvirtual_vtable_index) {
180 // Should be a private interface method invocation
181 assert(method->is_private(), "unexpected non-private method");
182 assert(method->can_be_statically_bound(), "unexpected non-statically-bound method");
183 // set_f2_as_vfinal_method checks if is_vfinal flag is true.
184 set_method_flags(as_TosState(method->result_type()),
185 ( 1 << is_vfinal_shift) |
186 ((method->is_final_method() ? 1 : 0) << is_final_shift),
187 method()->size_of_parameters());
188 set_f2_as_vfinal_method(method());
189 byte_no = 2;
190 set_f1(method->method_holder()); // interface klass*
191 break;
192 }
193 else {
194 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
195 // instruction somehow links to a non-interface method (in Object).
196 // In that case, the method has no itable index and must be invoked as a virtual.
197 // Set a flag to keep track of this corner case.
198 assert(method->is_public(), "Calling non-public method in Object with invokeinterface");
199 change_to_virtual = true;
200
201 // ...and fall through as if we were handling invokevirtual:
202 }
203 case Bytecodes::_invokevirtual:
204 {
205 if (!is_vtable_call) {
206 assert(method->can_be_statically_bound(), "");
207 // set_f2_as_vfinal_method checks if is_vfinal flag is true.
208 set_method_flags(as_TosState(method->result_type()),
209 ( 1 << is_vfinal_shift) |
210 ((method->is_final_method() ? 1 : 0) << is_final_shift) |
211 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
212 method()->size_of_parameters());
213 set_f2_as_vfinal_method(method());
214 } else {
215 assert(!method->can_be_statically_bound(), "");
216 assert(vtable_index >= 0, "valid index");
217 assert(!method->is_final_method(), "sanity");
218 set_method_flags(as_TosState(method->result_type()),
219 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
220 method()->size_of_parameters());
221 set_f2(vtable_index);
222 }
223 byte_no = 2;
224 break;
225 }
226
227 case Bytecodes::_invokespecial:
228 case Bytecodes::_invokestatic:
229 assert(!is_vtable_call, "");
230 // Note: Read and preserve the value of the is_vfinal flag on any
231 // invokevirtual bytecode shared with this constant pool cache entry.
232 // It is cheap and safe to consult is_vfinal() at all times.
233 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
234 set_method_flags(as_TosState(method->result_type()),
235 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) |
236 ((method->is_final_method() ? 1 : 0) << is_final_shift),
237 method()->size_of_parameters());
238 set_f1(method());
239 byte_no = 1;
240 break;
241 default:
242 ShouldNotReachHere();
243 break;
244 }
245
246 // Note: byte_no also appears in TemplateTable::resolve.
247 if (byte_no == 1) {
248 assert(invoke_code != Bytecodes::_invokevirtual &&
249 invoke_code != Bytecodes::_invokeinterface, "");
250 // Don't mark invokespecial to method as resolved if sender is an interface. The receiver
251 // has to be checked that it is a subclass of the current class every time this bytecode
252 // is executed.
253 if (invoke_code != Bytecodes::_invokespecial || !sender_is_interface ||
254 method->name() == vmSymbols::object_initializer_name()) {
255 set_bytecode_1(invoke_code);
256 }
257 } else if (byte_no == 2) {
258 if (change_to_virtual) {
259 assert(invoke_code == Bytecodes::_invokeinterface, "");
260 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
261 //
262 // Workaround for the case where we encounter an invokeinterface, but we
263 // should really have an _invokevirtual since the resolved method is a
264 // virtual method in java.lang.Object. This is a corner case in the spec
265 // but is presumably legal. javac does not generate this code.
266 //
267 // We do not set bytecode_1() to _invokeinterface, because that is the
268 // bytecode # used by the interpreter to see if it is resolved. In this
269 // case, the method gets reresolved with caller for each interface call
270 // because the actual selected method may not be public.
271 //
272 // We set bytecode_2() to _invokevirtual.
273 // See also interpreterRuntime.cpp. (8/25/2000)
274 } else {
275 assert(invoke_code == Bytecodes::_invokevirtual ||
276 (method->is_private() && invoke_code == Bytecodes::_invokeinterface), "");
277 if (method->is_private() && invoke_code == Bytecodes::_invokeinterface) {
278 // We set bytecode_1() to _invokeinterface, because that is the
279 // bytecode # used by the interpreter to see if it is resolved.
280 // We set bytecode_2() to _invokevirtual.
281 set_bytecode_1(invoke_code);
282 }
283 }
284 // set up for invokevirtual, even if linking for invokeinterface also:
285 set_bytecode_2(Bytecodes::_invokevirtual);
286 } else {
287 ShouldNotReachHere();
288 }
289 NOT_PRODUCT(verify(tty));
290 }
291
292 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method,
293 bool sender_is_interface) {
294 int index = Method::nonvirtual_vtable_index;
295 // index < 0; FIXME: inline and customize set_direct_or_vtable_call
296 set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);
297 }
298
299 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
300 // either the method is a miranda or its holder should accept the given index
301 assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
302 // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
303 set_direct_or_vtable_call(invoke_code, method, index, false);
304 }
305
306 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code,
307 Klass* referenced_klass,
308 const methodHandle& method, int index) {
309 assert(method->method_holder()->verify_itable_index(index), "");
310 assert(invoke_code == Bytecodes::_invokeinterface, "");
311 InstanceKlass* interf = method->method_holder();
312 assert(interf->is_interface(), "must be an interface");
313 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
314 set_f1(referenced_klass);
315 set_f2((intx)method());
316 set_method_flags(as_TosState(method->result_type()),
317 0, // no option bits
318 method()->size_of_parameters());
319 set_bytecode_1(Bytecodes::_invokeinterface);
320 }
321
322
323 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {
324 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
325 }
326
327 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {
328 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
329 }
330
331 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,
332 Bytecodes::Code invoke_code,
333 const CallInfo &call_info) {
334 // NOTE: This CPCE can be the subject of data races.
335 // There are three words to update: flags, refs[f2], f1 (in that order).
336 // Writers must store all other values before f1.
337 // Readers must test f1 first for non-null before reading other fields.
338 // Competing writers must acquire exclusive access via a lock.
339 // A losing writer waits on the lock until the winner writes f1 and leaves
340 // the lock, so that when the losing writer returns, he can use the linked
341 // cache entry.
342
343 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
344 // Use the resolved_references() lock for this cpCache entry.
345 // resolved_references are created for all classes with Invokedynamic, MethodHandle
346 // or MethodType constant pool cache entries.
347 assert(resolved_references() != NULL,
348 "a resolved_references array should have been created for this class");
349 ObjectLocker ol(resolved_references, Thread::current());
350 if (!is_f1_null()) {
351 return;
352 }
353
354 if (indy_resolution_failed()) {
355 // Before we got here, another thread got a LinkageError exception during
356 // resolution. Ignore our success and throw their exception.
357 ConstantPoolCache* cpCache = cpool->cache();
358 int index = -1;
359 for (int i = 0; i < cpCache->length(); i++) {
360 if (cpCache->entry_at(i) == this) {
361 index = i;
362 break;
363 }
364 }
365 guarantee(index >= 0, "Didn't find cpCache entry!");
366 int encoded_index = ResolutionErrorTable::encode_cpcache_index(
367 ConstantPool::encode_invokedynamic_index(index));
368 Thread* THREAD = Thread::current();
369 ConstantPool::throw_resolution_error(cpool, encoded_index, THREAD);
370 return;
371 }
372
373 const methodHandle adapter = call_info.resolved_method();
374 const Handle appendix = call_info.resolved_appendix();
375 const Handle method_type = call_info.resolved_method_type();
376 const bool has_appendix = appendix.not_null();
377 const bool has_method_type = method_type.not_null();
378
379 // Write the flags.
380 set_method_flags(as_TosState(adapter->result_type()),
381 ((has_appendix ? 1 : 0) << has_appendix_shift ) |
382 ((has_method_type ? 1 : 0) << has_method_type_shift) |
383 ( 1 << is_final_shift ),
384 adapter->size_of_parameters());
385
386 if (TraceInvokeDynamic) {
387 ttyLocker ttyl;
388 tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ",
389 invoke_code,
390 p2i(appendix()), (has_appendix ? "" : " (unused)"),
391 p2i(method_type()), (has_method_type ? "" : " (unused)"),
392 p2i(adapter()));
393 adapter->print();
394 if (has_appendix) appendix()->print();
395 }
396
397 // Method handle invokes and invokedynamic sites use both cp cache words.
398 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
399 // In the general case, this could be the call site's MethodType,
400 // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
401 // f1 contains the adapter method which manages the actual call.
402 // In the general case, this is a compiled LambdaForm.
403 // (The Java code is free to optimize these calls by binding other
404 // sorts of methods and appendices to call sites.)
405 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
406 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
407 // Even with the appendix, the method will never take more than 255 parameter slots.
408 //
409 // This means that given a call site like (List)mh.invoke("foo"),
410 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
411 // not '(Ljava/lang/String;)Ljava/util/List;'.
412 // The fact that String and List are involved is encoded in the MethodType in refs[f2].
413 // This allows us to create fewer Methods, while keeping type safety.
414 //
415
416 // Store appendix, if any.
417 if (has_appendix) {
418 const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
419 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
420 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
421 resolved_references->obj_at_put(appendix_index, appendix());
422 }
423
424 // Store MethodType, if any.
425 if (has_method_type) {
426 const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
427 assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
428 assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
429 resolved_references->obj_at_put(method_type_index, method_type());
430 }
431
432 release_set_f1(adapter()); // This must be the last one to set (see NOTE above)!
433
434 // The interpreter assembly code does not check byte_2,
435 // but it is used by is_resolved, method_if_resolved, etc.
436 set_bytecode_1(invoke_code);
437 NOT_PRODUCT(verify(tty));
438 if (TraceInvokeDynamic) {
439 ttyLocker ttyl;
440 this->print(tty, 0);
441 }
442 }
443
444 bool ConstantPoolCacheEntry::save_and_throw_indy_exc(
445 const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS) {
446
447 assert(HAS_PENDING_EXCEPTION, "No exception got thrown!");
448 assert(PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass()),
449 "No LinkageError exception");
450
451 // Use the resolved_references() lock for this cpCache entry.
452 // resolved_references are created for all classes with Invokedynamic, MethodHandle
453 // or MethodType constant pool cache entries.
454 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
455 assert(resolved_references() != NULL,
456 "a resolved_references array should have been created for this class");
457 ObjectLocker ol(resolved_references, THREAD);
458
459 // if f1 is not null or the indy_resolution_failed flag is set then another
460 // thread either succeeded in resolving the method or got a LinkageError
461 // exception, before this thread was able to record its failure. So, clear
462 // this thread's exception and return false so caller can use the earlier
463 // thread's result.
464 if (!is_f1_null() || indy_resolution_failed()) {
465 CLEAR_PENDING_EXCEPTION;
466 return false;
467 }
468
469 Symbol* error = PENDING_EXCEPTION->klass()->name();
470 Symbol* message = java_lang_Throwable::detail_message(PENDING_EXCEPTION);
471 assert(message != NULL, "Missing detail message");
472
473 SystemDictionary::add_resolution_error(cpool, index, error, message);
474 set_indy_resolution_failed();
475 return true;
476 }
477
478 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {
479 // Decode the action of set_method and set_interface_call
480 Bytecodes::Code invoke_code = bytecode_1();
481 if (invoke_code != (Bytecodes::Code)0) {
482 Metadata* f1 = f1_ord();
483 if (f1 != NULL) {
484 switch (invoke_code) {
485 case Bytecodes::_invokeinterface:
486 assert(f1->is_klass(), "");
487 return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
488 case Bytecodes::_invokestatic:
489 case Bytecodes::_invokespecial:
490 assert(!has_appendix(), "");
491 case Bytecodes::_invokehandle:
492 case Bytecodes::_invokedynamic:
493 assert(f1->is_method(), "");
494 return (Method*)f1;
495 default:
496 break;
497 }
498 }
499 }
500 invoke_code = bytecode_2();
501 if (invoke_code != (Bytecodes::Code)0) {
502 switch (invoke_code) {
503 case Bytecodes::_invokevirtual:
504 if (is_vfinal()) {
505 // invokevirtual
506 Method* m = f2_as_vfinal_method();
507 assert(m->is_method(), "");
508 return m;
509 } else {
510 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
511 if (cpool->tag_at(holder_index).is_klass()) {
512 Klass* klass = cpool->resolved_klass_at(holder_index);
513 return klass->method_at_vtable(f2_as_index());
514 }
515 }
516 break;
517 default:
518 break;
519 }
520 }
521 return NULL;
522 }
523
524
525 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {
526 if (!has_appendix())
527 return NULL;
528 const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
529 objArrayOop resolved_references = cpool->resolved_references();
530 return resolved_references->obj_at(ref_index);
531 }
532
533
534 oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) {
535 if (!has_method_type())
536 return NULL;
537 const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
538 objArrayOop resolved_references = cpool->resolved_references();
539 return resolved_references->obj_at(ref_index);
540 }
541
542
543 #if INCLUDE_JVMTI
544
545 void log_adjust(const char* entry_type, Method* old_method, Method* new_method, bool* trace_name_printed) {
546 if (log_is_enabled(Info, redefine, class, update)) {
547 ResourceMark rm;
548 if (!(*trace_name_printed)) {
549 log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
550 *trace_name_printed = true;
551 }
552 log_debug(redefine, class, update, constantpool)
553 ("cpc %s entry update: %s(%s)", entry_type, new_method->name()->as_C_string(), new_method->signature()->as_C_string());
554 }
555 }
556
557 // RedefineClasses() API support:
558 // If this ConstantPoolCacheEntry refers to old_method then update it
559 // to refer to new_method.
560 void ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
561 Method* new_method, bool * trace_name_printed) {
562
563 if (is_vfinal()) {
564 // virtual and final so _f2 contains method ptr instead of vtable index
565 if (f2_as_vfinal_method() == old_method) {
566 // match old_method so need an update
567 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
568 _f2 = (intptr_t)new_method;
569 log_adjust("vfinal", old_method, new_method, trace_name_printed);
570 }
571 return;
572 }
573
574 assert (_f1 != NULL, "should not call with uninteresting entry");
575
576 if (!(_f1->is_method())) {
577 // _f1 is a Klass* for an interface, _f2 is the method
578 if (f2_as_interface_method() == old_method) {
579 _f2 = (intptr_t)new_method;
580 log_adjust("interface", old_method, new_method, trace_name_printed);
581 }
582 } else if (_f1 == old_method) {
583 _f1 = new_method;
584 log_adjust("special, static or dynamic", old_method, new_method, trace_name_printed);
585 }
586 }
587
588 // a constant pool cache entry should never contain old or obsolete methods
589 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
590 Method* m = get_interesting_method_entry(NULL);
591 // return false if m refers to a non-deleted old or obsolete method
592 if (m != NULL) {
593 assert(m->is_valid() && m->is_method(), "m is a valid method");
594 return !m->is_old() && !m->is_obsolete(); // old is always set for old and obsolete
595 } else {
596 return true;
597 }
598 }
599
600 Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) {
601 if (!is_method_entry()) {
602 // not a method entry so not interesting by default
603 return NULL;
604 }
605 Method* m = NULL;
606 if (is_vfinal()) {
607 // virtual and final so _f2 contains method ptr instead of vtable index
608 m = f2_as_vfinal_method();
609 } else if (is_f1_null()) {
610 // NULL _f1 means this is a virtual entry so also not interesting
611 return NULL;
612 } else {
613 if (!(_f1->is_method())) {
614 // _f1 is a Klass* for an interface
615 m = f2_as_interface_method();
616 } else {
617 m = f1_as_method();
618 }
619 }
620 assert(m != NULL && m->is_method(), "sanity check");
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 NULL;
625 }
626 // the method is in the interesting class so the entry is interesting
627 return m;
628 }
629 #endif // INCLUDE_JVMTI
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 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
637 constant_pool_index());
638 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f1);
639 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f2);
640 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_flags);
641 st->print_cr(" -------------");
642 }
643
644 void ConstantPoolCacheEntry::verify(outputStream* st) const {
645 // not implemented yet
646 }
647
648 // Implementation of ConstantPoolCache
649
650 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
651 const intStack& index_map,
652 const intStack& invokedynamic_index_map,
653 const intStack& invokedynamic_map, TRAPS) {
654
655 const int length = index_map.length() + invokedynamic_index_map.length();
656 int size = ConstantPoolCache::size(length);
657
658 return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD)
659 ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
660 }
661
662 void ConstantPoolCache::initialize(const intArray& inverse_index_map,
663 const intArray& invokedynamic_inverse_index_map,
664 const intArray& invokedynamic_references_map) {
665 for (int i = 0; i < inverse_index_map.length(); i++) {
666 ConstantPoolCacheEntry* e = entry_at(i);
667 int original_index = inverse_index_map.at(i);
668 e->initialize_entry(original_index);
669 assert(entry_at(i) == e, "sanity");
670 }
671
672 // Append invokedynamic entries at the end
673 int invokedynamic_offset = inverse_index_map.length();
674 for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
675 int offset = i + invokedynamic_offset;
676 ConstantPoolCacheEntry* e = entry_at(offset);
677 int original_index = invokedynamic_inverse_index_map.at(i);
678 e->initialize_entry(original_index);
679 assert(entry_at(offset) == e, "sanity");
680 }
681
682 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
683 const int cpci = invokedynamic_references_map.at(ref);
684 if (cpci >= 0) {
685 #ifdef ASSERT
686 // invokedynamic and invokehandle have more entries; check if they
687 // all point to the same constant pool cache entry.
688 for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
689 const int cpci_next = invokedynamic_references_map.at(ref + entry);
690 assert(cpci == cpci_next, "%d == %d", cpci, cpci_next);
691 }
692 #endif
693 entry_at(cpci)->initialize_resolved_reference_index(ref);
694 ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1; // skip extra entries
695 }
696 }
697 }
698
699 void ConstantPoolCache::verify_just_initialized() {
700 DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true));
701 }
702
703 void ConstantPoolCache::remove_unshareable_info() {
704 walk_entries_for_initialization(/*check_only = */ false);
705 }
706
707 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) {
708 assert(DumpSharedSpaces, "sanity");
709 // When dumping the archive, we want to clean up the ConstantPoolCache
710 // to remove any effect of linking due to the execution of Java code --
711 // each ConstantPoolCacheEntry will have the same contents as if
712 // ConstantPoolCache::initialize has just returned:
713 //
714 // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries.
715 // - We keep the "f2" field for entries used by invokedynamic and invokehandle
716 // - All other bits in the entries are cleared to zero.
717 ResourceMark rm;
718
719 InstanceKlass* ik = constant_pool()->pool_holder();
720 bool* f2_used = NEW_RESOURCE_ARRAY(bool, length());
721 memset(f2_used, 0, sizeof(bool) * length());
722
723 // Find all the slots that we need to preserve f2
724 for (int i = 0; i < ik->methods()->length(); i++) {
725 Method* m = ik->methods()->at(i);
726 RawBytecodeStream bcs(m);
727 while (!bcs.is_last_bytecode()) {
728 Bytecodes::Code opcode = bcs.raw_next();
729 switch (opcode) {
730 case Bytecodes::_invokedynamic: {
731 int index = Bytes::get_native_u4(bcs.bcp() + 1);
732 int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index);
733 f2_used[cp_cache_index] = 1;
734 }
735 break;
736 case Bytecodes::_invokehandle: {
737 int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1);
738 f2_used[cp_cache_index] = 1;
739 }
740 break;
741 default:
742 break;
743 }
744 }
745 }
746
747 if (check_only) {
748 DEBUG_ONLY(
749 for (int i=0; i<length(); i++) {
750 entry_at(i)->verify_just_initialized(f2_used[i]);
751 })
752 } else {
753 for (int i=0; i<length(); i++) {
754 entry_at(i)->reinitialize(f2_used[i]);
755 }
756 }
757 }
758
759 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) {
760 assert(!is_shared(), "shared caches are not deallocated");
761 data->remove_handle(_resolved_references);
762 set_resolved_references(NULL);
763 MetadataFactory::free_array<u2>(data, _reference_map);
764 set_reference_map(NULL);
765 }
766
767 #if INCLUDE_CDS_JAVA_HEAP
768 oop ConstantPoolCache::archived_references() {
769 // Loading an archive root forces the oop to become strongly reachable.
770 // For example, if it is loaded during concurrent marking in a SATB
771 // collector, it will be enqueued to the SATB queue, effectively
772 // shading the previously white object gray.
773 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_references);
774 }
775
776 void ConstantPoolCache::set_archived_references(oop o) {
777 assert(DumpSharedSpaces, "called only during runtime");
778 RootAccess<IN_ARCHIVE_ROOT>::oop_store(&_archived_references, o);
779 }
780 #endif
781
782 #if INCLUDE_JVMTI
783 // RedefineClasses() API support:
784 // If any entry of this ConstantPoolCache points to any of
785 // old_methods, replace it with the corresponding new_method.
786 void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
787 for (int i = 0; i < length(); i++) {
788 ConstantPoolCacheEntry* entry = entry_at(i);
789 Method* old_method = entry->get_interesting_method_entry(holder);
790 if (old_method == NULL || !old_method->is_old()) {
791 continue; // skip uninteresting entries
792 }
793 if (old_method->is_deleted()) {
794 // clean up entries with deleted methods
795 entry->initialize_entry(entry->constant_pool_index());
796 continue;
797 }
798 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
799
800 assert(new_method != NULL, "method_with_idnum() should not be NULL");
801 assert(old_method != new_method, "sanity check");
802
803 entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);
804 }
805 }
806
807 // the constant pool cache should never contain old or obsolete methods
808 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
809 for (int i = 1; i < length(); i++) {
810 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL &&
811 !entry_at(i)->check_no_old_or_obsolete_entries()) {
812 return false;
813 }
814 }
815 return true;
816 }
817
818 void ConstantPoolCache::dump_cache() {
819 for (int i = 1; i < length(); i++) {
820 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) {
821 entry_at(i)->print(tty, i);
822 }
823 }
824 }
825 #endif // INCLUDE_JVMTI
826
827 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) {
828 log_trace(cds)("Iter(ConstantPoolCache): %p", this);
829 it->push(&_constant_pool);
830 it->push(&_reference_map);
831 }
832
833 // Printing
834
835 void ConstantPoolCache::print_on(outputStream* st) const {
836 assert(is_constantPoolCache(), "obj must be constant pool cache");
837 st->print_cr("%s", internal_name());
838 // print constant pool cache entries
839 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
840 }
841
842 void ConstantPoolCache::print_value_on(outputStream* st) const {
843 assert(is_constantPoolCache(), "obj must be constant pool cache");
844 st->print("cache [%d]", length());
845 print_address_on(st);
846 st->print(" for ");
847 constant_pool()->print_value_on(st);
848 }
849
850
851 // Verification
852
853 void ConstantPoolCache::verify_on(outputStream* st) {
854 guarantee(is_constantPoolCache(), "obj must be constant pool cache");
855 // print constant pool cache entries
856 for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
857 }