1 /*
2 * Copyright (c) 1998, 2021, 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 "cds/heapShared.hpp"
27 #include "classfile/resolutionErrors.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "interpreter/bytecodeStream.hpp"
31 #include "interpreter/bytecodes.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/linkResolver.hpp"
34 #include "interpreter/rewriter.hpp"
35 #include "logging/log.hpp"
36 #include "logging/logStream.hpp"
37 #include "memory/metadataFactory.hpp"
38 #include "memory/metaspaceClosure.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "oops/access.inline.hpp"
41 #include "oops/compressedOops.hpp"
42 #include "oops/constantPool.inline.hpp"
43 #include "oops/cpCache.inline.hpp"
44 #include "oops/objArrayOop.inline.hpp"
45 #include "oops/oop.inline.hpp"
46 #include "prims/methodHandles.hpp"
47 #include "runtime/arguments.hpp"
48 #include "runtime/atomic.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "runtime/vm_version.hpp"
51 #include "utilities/macros.hpp"
52
53 // Implementation of ConstantPoolCacheEntry
54
55 void ConstantPoolCacheEntry::initialize_entry(int index) {
56 assert(0 < index && index < 0x10000, "sanity check");
57 _indices = index;
58 _f1 = NULL;
59 _f2 = _flags = 0;
60 assert(constant_pool_index() == index, "");
61 }
62
63 void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) {
64 assert((_indices & (~cp_index_mask)) == 0, "sanity");
65 assert(_f1 == NULL, "sanity");
66 assert(_flags == 0, "sanity");
67 if (!f2_used) {
68 assert(_f2 == 0, "sanity");
69 }
70 }
71
72 void ConstantPoolCacheEntry::reinitialize(bool f2_used) {
73 _indices &= cp_index_mask;
74 _f1 = NULL;
75 _flags = 0;
76 if (!f2_used) {
77 _f2 = 0;
78 }
79 }
80
81 int ConstantPoolCacheEntry::make_flags(TosState state,
82 int option_bits,
83 int field_index_or_method_params) {
84 assert(state < number_of_states, "Invalid state in make_flags");
85 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
86 // Preserve existing flag bit values
87 // The low bits are a field offset, or else the method parameter size.
88 #ifdef ASSERT
89 TosState old_state = flag_state();
90 assert(old_state == (TosState)0 || old_state == state,
91 "inconsistent cpCache flags state");
92 #endif
93 return (_flags | f) ;
94 }
95
96 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
97 #ifdef ASSERT
98 // Read once.
99 volatile Bytecodes::Code c = bytecode_1();
100 assert(c == 0 || c == code || code == 0, "update must be consistent");
101 #endif
102 // Need to flush pending stores here before bytecode is written.
103 Atomic::release_store(&_indices, _indices | ((u_char)code << bytecode_1_shift));
104 }
105
106 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
107 #ifdef ASSERT
108 // Read once.
109 volatile Bytecodes::Code c = bytecode_2();
110 assert(c == 0 || c == code || code == 0, "update must be consistent");
111 #endif
112 // Need to flush pending stores here before bytecode is written.
113 Atomic::release_store(&_indices, _indices | ((u_char)code << bytecode_2_shift));
114 }
115
116 // Sets f1, ordering with previous writes.
117 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
118 assert(f1 != NULL, "");
119 Atomic::release_store(&_f1, f1);
120 }
121
122 void ConstantPoolCacheEntry::set_indy_resolution_failed() {
123 Atomic::release_store(&_flags, _flags | (1 << indy_resolution_failed_shift));
124 }
125
126 // Note that concurrent update of both bytecodes can leave one of them
127 // reset to zero. This is harmless; the interpreter will simply re-resolve
128 // the damaged entry. More seriously, the memory synchronization is needed
129 // to flush other fields (f1, f2) completely to memory before the bytecodes
130 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
131 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
132 Bytecodes::Code put_code,
133 Klass* field_holder,
134 int field_index,
135 int field_offset,
136 TosState field_type,
137 bool is_final,
138 bool is_volatile,
139 bool is_inlined,
140 bool is_null_free_inline_type) {
141 set_f1(field_holder);
142 set_f2(field_offset);
143 assert((field_index & field_index_mask) == field_index,
144 "field index does not fit in low flag bits");
145 assert(!is_inlined || is_null_free_inline_type, "Sanity check");
146 set_field_flags(field_type,
147 ((is_volatile ? 1 : 0) << is_volatile_shift) |
148 ((is_final ? 1 : 0) << is_final_shift) |
149 ((is_inlined ? 1 : 0) << is_inlined_shift) |
150 ((is_null_free_inline_type ? 1 : 0) << is_null_free_inline_type_shift),
151 field_index);
152 set_bytecode_1(get_code);
153 set_bytecode_2(put_code);
154 NOT_PRODUCT(verify(tty));
155 }
156
157 void ConstantPoolCacheEntry::set_parameter_size(int value) {
158 // This routine is called only in corner cases where the CPCE is not yet initialized.
159 // See AbstractInterpreter::deopt_continue_after_entry.
160 assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
161 "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
162 // Setting the parameter size by itself is only safe if the
163 // current value of _flags is 0, otherwise another thread may have
164 // updated it and we don't want to overwrite that value. Don't
165 // bother trying to update it once it's nonzero but always make
166 // sure that the final parameter size agrees with what was passed.
167 if (_flags == 0) {
168 intx newflags = (value & parameter_size_mask);
169 Atomic::cmpxchg(&_flags, (intx)0, newflags);
170 }
171 guarantee(parameter_size() == value,
172 "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
173 }
174
175 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code,
176 const methodHandle& method,
177 int vtable_index,
178 bool sender_is_interface) {
179 bool is_vtable_call = (vtable_index >= 0); // FIXME: split this method on this boolean
180 assert(method->interpreter_entry() != NULL, "should have been set at this point");
181 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
182
183 int byte_no = -1;
184 bool change_to_virtual = false;
185 InstanceKlass* holder = NULL; // have to declare this outside the switch
186 switch (invoke_code) {
187 case Bytecodes::_invokeinterface:
188 holder = method->method_holder();
189 // check for private interface method invocations
190 if (vtable_index == Method::nonvirtual_vtable_index && holder->is_interface() ) {
191 assert(method->is_private(), "unexpected non-private method");
192 assert(method->can_be_statically_bound(), "unexpected non-statically-bound method");
193 // set_f2_as_vfinal_method checks if is_vfinal flag is true.
194 set_method_flags(as_TosState(method->result_type()),
195 ( 1 << is_vfinal_shift) |
196 ((method->is_final_method() ? 1 : 0) << is_final_shift),
197 method()->size_of_parameters());
198 set_f2_as_vfinal_method(method());
199 byte_no = 2;
200 set_f1(holder); // interface klass*
201 break;
202 }
203 else {
204 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
205 // instruction links to a non-interface method (in Object). This can happen when
206 // an interface redeclares an Object method (like CharSequence declaring toString())
207 // or when invokeinterface is used explicitly.
208 // In that case, the method has no itable index and must be invoked as a virtual.
209 // Set a flag to keep track of this corner case.
210 assert(holder->is_interface() || holder == vmClasses::Object_klass(), "unexpected holder class");
211 assert(method->is_public(), "Calling non-public method in Object with invokeinterface");
212 change_to_virtual = true;
213
214 // ...and fall through as if we were handling invokevirtual:
215 }
216 case Bytecodes::_invokevirtual:
217 {
218 if (!is_vtable_call) {
219 assert(method->can_be_statically_bound(), "");
220 // set_f2_as_vfinal_method checks if is_vfinal flag is true.
221 set_method_flags(as_TosState(method->result_type()),
222 ( 1 << is_vfinal_shift) |
223 ((method->is_final_method() ? 1 : 0) << is_final_shift) |
224 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
225 method()->size_of_parameters());
226 set_f2_as_vfinal_method(method());
227 } else {
228 assert(!method->can_be_statically_bound(), "");
229 assert(vtable_index >= 0, "valid index");
230 assert(!method->is_final_method(), "sanity");
231 set_method_flags(as_TosState(method->result_type()),
232 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
233 method()->size_of_parameters());
234 set_f2(vtable_index);
235 }
236 byte_no = 2;
237 break;
238 }
239
240 case Bytecodes::_invokespecial:
241 case Bytecodes::_invokestatic:
242 assert(!is_vtable_call, "");
243 // Note: Read and preserve the value of the is_vfinal flag on any
244 // invokevirtual bytecode shared with this constant pool cache entry.
245 // It is cheap and safe to consult is_vfinal() at all times.
246 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
247 set_method_flags(as_TosState(method->result_type()),
248 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) |
249 ((method->is_final_method() ? 1 : 0) << is_final_shift),
250 method()->size_of_parameters());
251 set_f1(method());
252 byte_no = 1;
253 break;
254 default:
255 ShouldNotReachHere();
256 break;
257 }
258
259 // Note: byte_no also appears in TemplateTable::resolve.
260 if (byte_no == 1) {
261 assert(invoke_code != Bytecodes::_invokevirtual &&
262 invoke_code != Bytecodes::_invokeinterface, "");
263 bool do_resolve = true;
264 // Don't mark invokespecial to method as resolved if sender is an interface. The receiver
265 // has to be checked that it is a subclass of the current class every time this bytecode
266 // is executed.
267 if (invoke_code == Bytecodes::_invokespecial && sender_is_interface &&
268 method->name() != vmSymbols::object_initializer_name()) {
269 do_resolve = false;
270 }
271 if (invoke_code == Bytecodes::_invokestatic) {
272 assert(method->method_holder()->is_initialized() ||
273 method->method_holder()->is_reentrant_initialization(Thread::current()),
274 "invalid class initialization state for invoke_static");
275
276 if (!VM_Version::supports_fast_class_init_checks() && method->needs_clinit_barrier()) {
277 // Don't mark invokestatic to method as resolved if the holder class has not yet completed
278 // initialization. An invokestatic must only proceed if the class is initialized, but if
279 // we resolve it before then that class initialization check is skipped.
280 //
281 // When fast class initialization checks are supported (VM_Version::supports_fast_class_init_checks() == true),
282 // template interpreter supports fast class initialization check for
283 // invokestatic which doesn't require call site re-resolution to
284 // enforce class initialization barrier.
285 do_resolve = false;
286 }
287 }
288 if (do_resolve) {
289 set_bytecode_1(invoke_code);
290 }
291 } else if (byte_no == 2) {
292 if (change_to_virtual) {
293 assert(invoke_code == Bytecodes::_invokeinterface, "");
294 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
295 //
296 // Workaround for the case where we encounter an invokeinterface, but we
297 // should really have an _invokevirtual since the resolved method is a
298 // virtual method in java.lang.Object. This is a corner case in the spec
299 // but is presumably legal. javac does not generate this code.
300 //
301 // We do not set bytecode_1() to _invokeinterface, because that is the
302 // bytecode # used by the interpreter to see if it is resolved. In this
303 // case, the method gets reresolved with caller for each interface call
304 // because the actual selected method may not be public.
305 //
306 // We set bytecode_2() to _invokevirtual.
307 // See also interpreterRuntime.cpp. (8/25/2000)
308 invoke_code = Bytecodes::_invokevirtual;
309 } else {
310 assert(invoke_code == Bytecodes::_invokevirtual ||
311 (invoke_code == Bytecodes::_invokeinterface &&
312 ((method->is_private() ||
313 (method->is_final() && method->method_holder() == vmClasses::Object_klass())))),
314 "unexpected invocation mode");
315 if (invoke_code == Bytecodes::_invokeinterface &&
316 (method->is_private() || method->is_final())) {
317 // We set bytecode_1() to _invokeinterface, because that is the
318 // bytecode # used by the interpreter to see if it is resolved.
319 // We set bytecode_2() to _invokevirtual.
320 set_bytecode_1(invoke_code);
321 }
322 }
323 // set up for invokevirtual, even if linking for invokeinterface also:
324 set_bytecode_2(invoke_code);
325 } else {
326 ShouldNotReachHere();
327 }
328 NOT_PRODUCT(verify(tty));
329 }
330
331 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method,
332 bool sender_is_interface) {
333 int index = Method::nonvirtual_vtable_index;
334 // index < 0; FIXME: inline and customize set_direct_or_vtable_call
335 set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);
336 }
337
338 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
339 // either the method is a miranda or its holder should accept the given index
340 assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
341 // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
342 set_direct_or_vtable_call(invoke_code, method, index, false);
343 }
344
345 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code,
346 Klass* referenced_klass,
347 const methodHandle& method, int index) {
348 assert(method->method_holder()->verify_itable_index(index), "");
349 assert(invoke_code == Bytecodes::_invokeinterface, "");
350 InstanceKlass* interf = method->method_holder();
351 assert(interf->is_interface(), "must be an interface");
352 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
353 set_f1(referenced_klass);
354 set_f2((intx)method());
355 set_method_flags(as_TosState(method->result_type()),
356 0, // no option bits
357 method()->size_of_parameters());
358 set_bytecode_1(Bytecodes::_invokeinterface);
359 }
360
361
362 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {
363 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
364 }
365
366 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {
367 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
368 }
369
370 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,
371 Bytecodes::Code invoke_code,
372 const CallInfo &call_info) {
373 // NOTE: This CPCE can be the subject of data races.
374 // There are three words to update: flags, refs[f2], f1 (in that order).
375 // Writers must store all other values before f1.
376 // Readers must test f1 first for non-null before reading other fields.
377 // Competing writers must acquire exclusive access via a lock.
378 // A losing writer waits on the lock until the winner writes f1 and leaves
379 // the lock, so that when the losing writer returns, he can use the linked
380 // cache entry.
381
382 JavaThread* current = JavaThread::current();
383 objArrayHandle resolved_references(current, cpool->resolved_references());
384 // Use the resolved_references() lock for this cpCache entry.
385 // resolved_references are created for all classes with Invokedynamic, MethodHandle
386 // or MethodType constant pool cache entries.
387 assert(resolved_references() != NULL,
388 "a resolved_references array should have been created for this class");
389 ObjectLocker ol(resolved_references, current);
390 if (!is_f1_null()) {
391 return;
392 }
393
394 if (indy_resolution_failed()) {
395 // Before we got here, another thread got a LinkageError exception during
396 // resolution. Ignore our success and throw their exception.
397 ConstantPoolCache* cpCache = cpool->cache();
398 int index = -1;
399 for (int i = 0; i < cpCache->length(); i++) {
400 if (cpCache->entry_at(i) == this) {
401 index = i;
402 break;
403 }
404 }
405 guarantee(index >= 0, "Didn't find cpCache entry!");
406 int encoded_index = ResolutionErrorTable::encode_cpcache_index(
407 ConstantPool::encode_invokedynamic_index(index));
408 JavaThread* THREAD = JavaThread::current(); // For exception macros.
409 ConstantPool::throw_resolution_error(cpool, encoded_index, THREAD);
410 return;
411 }
412
413 Method* adapter = call_info.resolved_method();
414 const Handle appendix = call_info.resolved_appendix();
415 const bool has_appendix = appendix.not_null();
416
417 // Write the flags.
418 // MHs and indy are always sig-poly and have a local signature.
419 set_method_flags(as_TosState(adapter->result_type()),
420 ((has_appendix ? 1 : 0) << has_appendix_shift ) |
421 ( 1 << has_local_signature_shift ) |
422 ( 1 << is_final_shift ),
423 adapter->size_of_parameters());
424
425 LogStream* log_stream = NULL;
426 LogStreamHandle(Debug, methodhandles, indy) lsh_indy;
427 if (lsh_indy.is_enabled()) {
428 ResourceMark rm;
429 log_stream = &lsh_indy;
430 log_stream->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method=" PTR_FORMAT " (local signature) ",
431 invoke_code,
432 p2i(appendix()),
433 (has_appendix ? "" : " (unused)"),
434 p2i(adapter));
435 adapter->print_on(log_stream);
436 if (has_appendix) appendix()->print_on(log_stream);
437 }
438
439 // Method handle invokes and invokedynamic sites use both cp cache words.
440 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
441 // In the general case, this could be the call site's MethodType,
442 // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
443 // f1 contains the adapter method which manages the actual call.
444 // In the general case, this is a compiled LambdaForm.
445 // (The Java code is free to optimize these calls by binding other
446 // sorts of methods and appendices to call sites.)
447 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
448 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
449 // Even with the appendix, the method will never take more than 255 parameter slots.
450 //
451 // This means that given a call site like (List)mh.invoke("foo"),
452 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
453 // not '(Ljava/lang/String;)Ljava/util/List;'.
454 // The fact that String and List are involved is encoded in the MethodType in refs[f2].
455 // This allows us to create fewer Methods, while keeping type safety.
456 //
457
458 // Store appendix, if any.
459 if (has_appendix) {
460 const int appendix_index = f2_as_index();
461 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
462 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
463 resolved_references->obj_at_put(appendix_index, appendix());
464 }
465
466 release_set_f1(adapter); // This must be the last one to set (see NOTE above)!
467
468 // The interpreter assembly code does not check byte_2,
469 // but it is used by is_resolved, method_if_resolved, etc.
470 set_bytecode_1(invoke_code);
471 NOT_PRODUCT(verify(tty));
472
473 if (log_stream != NULL) {
474 this->print(log_stream, 0);
475 }
476
477 assert(has_appendix == this->has_appendix(), "proper storage of appendix flag");
478 assert(this->has_local_signature(), "proper storage of signature flag");
479 }
480
481 bool ConstantPoolCacheEntry::save_and_throw_indy_exc(
482 const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS) {
483
484 assert(HAS_PENDING_EXCEPTION, "No exception got thrown!");
485 assert(PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass()),
486 "No LinkageError exception");
487
488 // Use the resolved_references() lock for this cpCache entry.
489 // resolved_references are created for all classes with Invokedynamic, MethodHandle
490 // or MethodType constant pool cache entries.
491 JavaThread* current = THREAD;
492 objArrayHandle resolved_references(current, cpool->resolved_references());
493 assert(resolved_references() != NULL,
494 "a resolved_references array should have been created for this class");
495 ObjectLocker ol(resolved_references, current);
496
497 // if f1 is not null or the indy_resolution_failed flag is set then another
498 // thread either succeeded in resolving the method or got a LinkageError
499 // exception, before this thread was able to record its failure. So, clear
500 // this thread's exception and return false so caller can use the earlier
501 // thread's result.
502 if (!is_f1_null() || indy_resolution_failed()) {
503 CLEAR_PENDING_EXCEPTION;
504 return false;
505 }
506
507 Symbol* error = PENDING_EXCEPTION->klass()->name();
508 Symbol* message = java_lang_Throwable::detail_message(PENDING_EXCEPTION);
509
510 SystemDictionary::add_resolution_error(cpool, index, error, message);
511 set_indy_resolution_failed();
512 return true;
513 }
514
515 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {
516 // Decode the action of set_method and set_interface_call
517 Bytecodes::Code invoke_code = bytecode_1();
518 if (invoke_code != (Bytecodes::Code)0) {
519 Metadata* f1 = f1_ord();
520 if (f1 != NULL) {
521 switch (invoke_code) {
522 case Bytecodes::_invokeinterface:
523 assert(f1->is_klass(), "");
524 return f2_as_interface_method();
525 case Bytecodes::_invokestatic:
526 case Bytecodes::_invokespecial:
527 assert(!has_appendix(), "");
528 case Bytecodes::_invokehandle:
529 case Bytecodes::_invokedynamic:
530 assert(f1->is_method(), "");
531 return (Method*)f1;
532 default:
533 break;
534 }
535 }
536 }
537 invoke_code = bytecode_2();
538 if (invoke_code != (Bytecodes::Code)0) {
539 switch (invoke_code) {
540 case Bytecodes::_invokevirtual:
541 if (is_vfinal()) {
542 // invokevirtual
543 Method* m = f2_as_vfinal_method();
544 assert(m->is_method(), "");
545 return m;
546 } else {
547 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
548 if (cpool->tag_at(holder_index).is_klass()) {
549 Klass* klass = cpool->resolved_klass_at(holder_index);
550 return klass->method_at_vtable(f2_as_index());
551 }
552 }
553 break;
554 default:
555 break;
556 }
557 }
558 return NULL;
559 }
560
561
562 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {
563 if (!has_appendix())
564 return NULL;
565 const int ref_index = f2_as_index();
566 objArrayOop resolved_references = cpool->resolved_references();
567 return resolved_references->obj_at(ref_index);
568 }
569
570
571 #if INCLUDE_JVMTI
572
573 void log_adjust(const char* entry_type, Method* old_method, Method* new_method, bool* trace_name_printed) {
574 ResourceMark rm;
575
576 if (!(*trace_name_printed)) {
577 log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
578 *trace_name_printed = true;
579 }
580 log_trace(redefine, class, update, constantpool)
581 ("cpc %s entry update: %s", entry_type, new_method->external_name());
582 }
583
584 // RedefineClasses() API support:
585 // If this ConstantPoolCacheEntry refers to old_method then update it
586 // to refer to new_method.
587 void ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
588 Method* new_method, bool * trace_name_printed) {
589
590 if (is_vfinal()) {
591 // virtual and final so _f2 contains method ptr instead of vtable index
592 if (f2_as_vfinal_method() == old_method) {
593 // match old_method so need an update
594 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
595 _f2 = (intptr_t)new_method;
596 log_adjust("vfinal", old_method, new_method, trace_name_printed);
597 }
598 return;
599 }
600
601 assert (_f1 != NULL, "should not call with uninteresting entry");
602
603 if (!(_f1->is_method())) {
604 // _f1 is a Klass* for an interface, _f2 is the method
605 if (f2_as_interface_method() == old_method) {
606 _f2 = (intptr_t)new_method;
607 log_adjust("interface", old_method, new_method, trace_name_printed);
608 }
609 } else if (_f1 == old_method) {
610 _f1 = new_method;
611 log_adjust("special, static or dynamic", old_method, new_method, trace_name_printed);
612 }
613 }
614
615 // a constant pool cache entry should never contain old or obsolete methods
616 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
617 Method* m = get_interesting_method_entry();
618 // return false if m refers to a non-deleted old or obsolete method
619 if (m != NULL) {
620 assert(m->is_valid() && m->is_method(), "m is a valid method");
621 return !m->is_old() && !m->is_obsolete(); // old is always set for old and obsolete
622 } else {
623 return true;
624 }
625 }
626
627 Method* ConstantPoolCacheEntry::get_interesting_method_entry() {
628 if (!is_method_entry()) {
629 // not a method entry so not interesting by default
630 return NULL;
631 }
632 Method* m = NULL;
633 if (is_vfinal()) {
634 // virtual and final so _f2 contains method ptr instead of vtable index
635 m = f2_as_vfinal_method();
636 } else if (is_f1_null()) {
637 // NULL _f1 means this is a virtual entry so also not interesting
638 return NULL;
639 } else {
640 if (!(_f1->is_method())) {
641 // _f1 is a Klass* for an interface
642 m = f2_as_interface_method();
643 } else {
644 m = f1_as_method();
645 }
646 }
647 assert(m != NULL && m->is_method(), "sanity check");
648 if (m == NULL || !m->is_method()) {
649 return NULL;
650 }
651 return m;
652 }
653 #endif // INCLUDE_JVMTI
654
655 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
656 // print separator
657 if (index == 0) st->print_cr(" -------------");
658 // print entry
659 st->print("%3d (" PTR_FORMAT ") ", index, (intptr_t)this);
660 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
661 constant_pool_index());
662 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f1);
663 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f2);
664 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_flags);
665 st->print_cr(" -------------");
666 }
667
668 void ConstantPoolCacheEntry::verify(outputStream* st) const {
669 // not implemented yet
670 }
671
672 // Implementation of ConstantPoolCache
673
674 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
675 const intStack& index_map,
676 const intStack& invokedynamic_index_map,
677 const intStack& invokedynamic_map, TRAPS) {
678
679 const int length = index_map.length() + invokedynamic_index_map.length();
680 int size = ConstantPoolCache::size(length);
681
682 return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD)
683 ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
684 }
685
686 void ConstantPoolCache::initialize(const intArray& inverse_index_map,
687 const intArray& invokedynamic_inverse_index_map,
688 const intArray& invokedynamic_references_map) {
689 for (int i = 0; i < inverse_index_map.length(); i++) {
690 ConstantPoolCacheEntry* e = entry_at(i);
691 int original_index = inverse_index_map.at(i);
692 e->initialize_entry(original_index);
693 assert(entry_at(i) == e, "sanity");
694 }
695
696 // Append invokedynamic entries at the end
697 int invokedynamic_offset = inverse_index_map.length();
698 for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
699 int offset = i + invokedynamic_offset;
700 ConstantPoolCacheEntry* e = entry_at(offset);
701 int original_index = invokedynamic_inverse_index_map.at(i);
702 e->initialize_entry(original_index);
703 assert(entry_at(offset) == e, "sanity");
704 }
705
706 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
707 const int cpci = invokedynamic_references_map.at(ref);
708 if (cpci >= 0) {
709 entry_at(cpci)->initialize_resolved_reference_index(ref);
710 }
711 }
712 }
713
714 void ConstantPoolCache::verify_just_initialized() {
715 DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true));
716 }
717
718 void ConstantPoolCache::remove_unshareable_info() {
719 walk_entries_for_initialization(/*check_only = */ false);
720 }
721
722 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) {
723 Arguments::assert_is_dumping_archive();
724 // When dumping the archive, we want to clean up the ConstantPoolCache
725 // to remove any effect of linking due to the execution of Java code --
726 // each ConstantPoolCacheEntry will have the same contents as if
727 // ConstantPoolCache::initialize has just returned:
728 //
729 // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries.
730 // - We keep the "f2" field for entries used by invokedynamic and invokehandle
731 // - All other bits in the entries are cleared to zero.
732 ResourceMark rm;
733
734 InstanceKlass* ik = constant_pool()->pool_holder();
735 bool* f2_used = NEW_RESOURCE_ARRAY(bool, length());
736 memset(f2_used, 0, sizeof(bool) * length());
737
738 Thread* current = Thread::current();
739
740 // Find all the slots that we need to preserve f2
741 for (int i = 0; i < ik->methods()->length(); i++) {
742 Method* m = ik->methods()->at(i);
743 RawBytecodeStream bcs(methodHandle(current, m));
744 while (!bcs.is_last_bytecode()) {
745 Bytecodes::Code opcode = bcs.raw_next();
746 switch (opcode) {
747 case Bytecodes::_invokedynamic: {
748 int index = Bytes::get_native_u4(bcs.bcp() + 1);
749 int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index);
750 f2_used[cp_cache_index] = 1;
751 }
752 break;
753 case Bytecodes::_invokehandle: {
754 int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1);
755 f2_used[cp_cache_index] = 1;
756 }
757 break;
758 default:
759 break;
760 }
761 }
762 }
763
764 if (check_only) {
765 DEBUG_ONLY(
766 for (int i=0; i<length(); i++) {
767 entry_at(i)->verify_just_initialized(f2_used[i]);
768 })
769 } else {
770 for (int i=0; i<length(); i++) {
771 entry_at(i)->reinitialize(f2_used[i]);
772 }
773 }
774 }
775
776 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) {
777 assert(!is_shared(), "shared caches are not deallocated");
778 data->remove_handle(_resolved_references);
779 set_resolved_references(OopHandle());
780 MetadataFactory::free_array<u2>(data, _reference_map);
781 set_reference_map(NULL);
782 }
783
784 #if INCLUDE_CDS_JAVA_HEAP
785 oop ConstantPoolCache::archived_references() {
786 if (_archived_references_index < 0) {
787 return NULL;
788 }
789 return HeapShared::get_root(_archived_references_index);
790 }
791
792 void ConstantPoolCache::clear_archived_references() {
793 if (_archived_references_index >= 0) {
794 HeapShared::clear_root(_archived_references_index);
795 _archived_references_index = -1;
796 }
797 }
798
799 void ConstantPoolCache::set_archived_references(oop o) {
800 assert(DumpSharedSpaces, "called only during runtime");
801 _archived_references_index = HeapShared::append_root(o);
802 }
803 #endif
804
805 #if INCLUDE_JVMTI
806 // RedefineClasses() API support:
807 // If any entry of this ConstantPoolCache points to any of
808 // old_methods, replace it with the corresponding new_method.
809 void ConstantPoolCache::adjust_method_entries(bool * trace_name_printed) {
810 for (int i = 0; i < length(); i++) {
811 ConstantPoolCacheEntry* entry = entry_at(i);
812 Method* old_method = entry->get_interesting_method_entry();
813 if (old_method == NULL || !old_method->is_old()) {
814 continue; // skip uninteresting entries
815 }
816 if (old_method->is_deleted()) {
817 // clean up entries with deleted methods
818 entry->initialize_entry(entry->constant_pool_index());
819 continue;
820 }
821 Method* new_method = old_method->get_new_method();
822 entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);
823 }
824 }
825
826 // the constant pool cache should never contain old or obsolete methods
827 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
828 ResourceMark rm;
829 for (int i = 1; i < length(); i++) {
830 Method* m = entry_at(i)->get_interesting_method_entry();
831 if (m != NULL && !entry_at(i)->check_no_old_or_obsolete_entries()) {
832 log_trace(redefine, class, update, constantpool)
833 ("cpcache check found old method entry: class: %s, old: %d, obsolete: %d, method: %s",
834 constant_pool()->pool_holder()->external_name(), m->is_old(), m->is_obsolete(), m->external_name());
835 return false;
836 }
837 }
838 return true;
839 }
840
841 void ConstantPoolCache::dump_cache() {
842 for (int i = 1; i < length(); i++) {
843 if (entry_at(i)->get_interesting_method_entry() != NULL) {
844 entry_at(i)->print(tty, i);
845 }
846 }
847 }
848 #endif // INCLUDE_JVMTI
849
850 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) {
851 log_trace(cds)("Iter(ConstantPoolCache): %p", this);
852 it->push(&_constant_pool);
853 it->push(&_reference_map);
854 }
855
856 // Printing
857
858 void ConstantPoolCache::print_on(outputStream* st) const {
859 st->print_cr("%s", internal_name());
860 // print constant pool cache entries
861 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
862 }
863
864 void ConstantPoolCache::print_value_on(outputStream* st) const {
865 st->print("cache [%d]", length());
866 print_address_on(st);
867 st->print(" for ");
868 constant_pool()->print_value_on(st);
869 }
870
871
872 // Verification
873
874 void ConstantPoolCache::verify_on(outputStream* st) {
875 // print constant pool cache entries
876 for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
877 }