1 /*
2 * Copyright (c) 1998, 2017, 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/rewriter.hpp"
31 #include "logging/log.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "memory/metaspaceClosure.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "memory/universe.inline.hpp"
36 #include "oops/access.inline.hpp"
37 #include "oops/cpCache.hpp"
38 #include "oops/objArrayOop.inline.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "prims/methodHandles.hpp"
41 #include "runtime/atomic.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/orderAccess.inline.hpp"
44 #include "utilities/macros.hpp"
45
46 // Implementation of ConstantPoolCacheEntry
47
48 void ConstantPoolCacheEntry::initialize_entry(int index) {
49 assert(0 < index && index < 0x10000, "sanity check");
50 _indices = index;
51 _f1 = NULL;
52 _f2 = _flags = 0;
53 assert(constant_pool_index() == index, "");
54 }
55
56 void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) {
57 assert((_indices & (~cp_index_mask)) == 0, "sanity");
58 assert(_f1 == NULL, "sanity");
59 assert(_flags == 0, "sanity");
60 if (!f2_used) {
61 assert(_f2 == 0, "sanity");
62 }
63 }
64
65 void ConstantPoolCacheEntry::reinitialize(bool f2_used) {
66 _indices &= cp_index_mask;
67 _f1 = NULL;
68 _flags = 0;
69 if (!f2_used) {
70 _f2 = 0;
71 }
72 }
73
74 int ConstantPoolCacheEntry::make_flags(TosState state,
75 int option_bits,
76 int field_index_or_method_params) {
77 assert(state < number_of_states, "Invalid state in make_flags");
78 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
79 // Preserve existing flag bit values
80 // The low bits are a field offset, or else the method parameter size.
81 #ifdef ASSERT
82 TosState old_state = flag_state();
83 assert(old_state == (TosState)0 || old_state == state,
84 "inconsistent cpCache flags state");
85 #endif
86 return (_flags | f) ;
87 }
88
89 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
90 #ifdef ASSERT
91 // Read once.
92 volatile Bytecodes::Code c = bytecode_1();
93 assert(c == 0 || c == code || code == 0, "update must be consistent");
94 #endif
95 // Need to flush pending stores here before bytecode is written.
96 OrderAccess::release_store(&_indices, _indices | ((u_char)code << bytecode_1_shift));
97 }
98
99 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
100 #ifdef ASSERT
101 // Read once.
102 volatile Bytecodes::Code c = bytecode_2();
103 assert(c == 0 || c == code || code == 0, "update must be consistent");
104 #endif
105 // Need to flush pending stores here before bytecode is written.
106 OrderAccess::release_store(&_indices, _indices | ((u_char)code << bytecode_2_shift));
107 }
108
109 // Sets f1, ordering with previous writes.
110 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
111 assert(f1 != NULL, "");
112 OrderAccess::release_store(&_f1, f1);
113 }
114
115 void ConstantPoolCacheEntry::set_indy_resolution_failed() {
116 OrderAccess::release_store(&_flags, _flags | (1 << indy_resolution_failed_shift));
117 }
118
119 // Note that concurrent update of both bytecodes can leave one of them
120 // reset to zero. This is harmless; the interpreter will simply re-resolve
121 // the damaged entry. More seriously, the memory synchronization is needed
122 // to flush other fields (f1, f2) completely to memory before the bytecodes
123 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
124 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
125 Bytecodes::Code put_code,
126 Klass* field_holder,
127 int field_index,
128 int field_offset,
129 TosState field_type,
130 bool is_final,
131 bool is_volatile,
132 bool is_flatten,
133 Klass* root_klass) {
134 set_f1(field_holder);
135 set_f2(field_offset);
136 assert((field_index & field_index_mask) == field_index,
137 "field index does not fit in low flag bits");
138 set_field_flags(field_type,
139 ((is_volatile ? 1 : 0) << is_volatile_shift) |
140 ((is_final ? 1 : 0) << is_final_shift) |
141 ((is_flatten ? 1 : 0) << is_flatten_field),
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 set bytecode_1() to _invokeinterface, because that is the
252 // bytecode # used by the interpreter to see if it is resolved.
253 // We set bytecode_2() to _invokevirtual.
254 // See also interpreterRuntime.cpp. (8/25/2000)
255 // Only set resolved for the invokeinterface case if method is public.
256 // Otherwise, the method needs to be reresolved with caller for each
257 // interface call.
258 if (method->is_public()) set_bytecode_1(invoke_code);
259 invoke_code = Bytecodes::_invokevirtual;
260 } else {
261 assert(invoke_code == Bytecodes::_invokevirtual, "");
262 }
263 // set up for invokevirtual, even if linking for invokeinterface also:
264 set_bytecode_2(invoke_code);
265 } else {
266 ShouldNotReachHere();
267 }
268 NOT_PRODUCT(verify(tty));
269 }
270
271 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method,
272 bool sender_is_interface) {
273 int index = Method::nonvirtual_vtable_index;
274 // index < 0; FIXME: inline and customize set_direct_or_vtable_call
275 set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);
276 }
277
278 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
279 // either the method is a miranda or its holder should accept the given index
280 assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
281 // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
282 set_direct_or_vtable_call(invoke_code, method, index, false);
283 }
284
285 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code,
286 Klass* referenced_klass,
287 const methodHandle& method, int index) {
288 assert(method->method_holder()->verify_itable_index(index), "");
289 assert(invoke_code == Bytecodes::_invokeinterface, "");
290 InstanceKlass* interf = method->method_holder();
291 assert(interf->is_interface(), "must be an interface");
292 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
293 set_f1(referenced_klass);
294 set_f2((intx)method());
295 set_method_flags(as_TosState(method->result_type()),
296 0, // no option bits
297 method()->size_of_parameters());
298 set_bytecode_1(Bytecodes::_invokeinterface);
299 }
300
301
302 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {
303 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
304 }
305
306 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {
307 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
308 }
309
310 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,
311 Bytecodes::Code invoke_code,
312 const CallInfo &call_info) {
313 // NOTE: This CPCE can be the subject of data races.
314 // There are three words to update: flags, refs[f2], f1 (in that order).
315 // Writers must store all other values before f1.
316 // Readers must test f1 first for non-null before reading other fields.
317 // Competing writers must acquire exclusive access via a lock.
318 // A losing writer waits on the lock until the winner writes f1 and leaves
319 // the lock, so that when the losing writer returns, he can use the linked
320 // cache entry.
321
322 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
323 // Use the resolved_references() lock for this cpCache entry.
324 // resolved_references are created for all classes with Invokedynamic, MethodHandle
325 // or MethodType constant pool cache entries.
326 assert(resolved_references() != NULL,
327 "a resolved_references array should have been created for this class");
328 ObjectLocker ol(resolved_references, Thread::current());
329 if (!is_f1_null()) {
330 return;
331 }
332
333 if (indy_resolution_failed()) {
334 // Before we got here, another thread got a LinkageError exception during
335 // resolution. Ignore our success and throw their exception.
336 ConstantPoolCache* cpCache = cpool->cache();
337 int index = -1;
338 for (int i = 0; i < cpCache->length(); i++) {
339 if (cpCache->entry_at(i) == this) {
340 index = i;
341 break;
342 }
343 }
344 guarantee(index >= 0, "Didn't find cpCache entry!");
345 int encoded_index = ResolutionErrorTable::encode_cpcache_index(
346 ConstantPool::encode_invokedynamic_index(index));
347 Thread* THREAD = Thread::current();
348 ConstantPool::throw_resolution_error(cpool, encoded_index, THREAD);
349 return;
350 }
351
352 const methodHandle adapter = call_info.resolved_method();
353 const Handle appendix = call_info.resolved_appendix();
354 const Handle method_type = call_info.resolved_method_type();
355 const bool has_appendix = appendix.not_null();
356 const bool has_method_type = method_type.not_null();
357
358 // Write the flags.
359 set_method_flags(as_TosState(adapter->result_type()),
360 ((has_appendix ? 1 : 0) << has_appendix_shift ) |
361 ((has_method_type ? 1 : 0) << has_method_type_shift) |
362 ( 1 << is_final_shift ),
363 adapter->size_of_parameters());
364
365 if (TraceInvokeDynamic) {
366 ttyLocker ttyl;
367 tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ",
368 invoke_code,
369 p2i(appendix()), (has_appendix ? "" : " (unused)"),
370 p2i(method_type()), (has_method_type ? "" : " (unused)"),
371 p2i(adapter()));
372 adapter->print();
373 if (has_appendix) appendix()->print();
374 }
375
376 // Method handle invokes and invokedynamic sites use both cp cache words.
377 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
378 // In the general case, this could be the call site's MethodType,
379 // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
380 // f1 contains the adapter method which manages the actual call.
381 // In the general case, this is a compiled LambdaForm.
382 // (The Java code is free to optimize these calls by binding other
383 // sorts of methods and appendices to call sites.)
384 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
385 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
386 // Even with the appendix, the method will never take more than 255 parameter slots.
387 //
388 // This means that given a call site like (List)mh.invoke("foo"),
389 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
390 // not '(Ljava/lang/String;)Ljava/util/List;'.
391 // The fact that String and List are involved is encoded in the MethodType in refs[f2].
392 // This allows us to create fewer Methods, while keeping type safety.
393 //
394
395 // Store appendix, if any.
396 if (has_appendix) {
397 const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
398 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
399 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
400 resolved_references->obj_at_put(appendix_index, appendix());
401 }
402
403 // Store MethodType, if any.
404 if (has_method_type) {
405 const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
406 assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
407 assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
408 resolved_references->obj_at_put(method_type_index, method_type());
409 }
410
411 release_set_f1(adapter()); // This must be the last one to set (see NOTE above)!
412
413 // The interpreter assembly code does not check byte_2,
414 // but it is used by is_resolved, method_if_resolved, etc.
415 set_bytecode_1(invoke_code);
416 NOT_PRODUCT(verify(tty));
417 if (TraceInvokeDynamic) {
418 ttyLocker ttyl;
419 this->print(tty, 0);
420 }
421 }
422
423 bool ConstantPoolCacheEntry::save_and_throw_indy_exc(
424 const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS) {
425
426 assert(HAS_PENDING_EXCEPTION, "No exception got thrown!");
427 assert(PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass()),
428 "No LinkageError exception");
429
430 // Use the resolved_references() lock for this cpCache entry.
431 // resolved_references are created for all classes with Invokedynamic, MethodHandle
432 // or MethodType constant pool cache entries.
433 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
434 assert(resolved_references() != NULL,
435 "a resolved_references array should have been created for this class");
436 ObjectLocker ol(resolved_references, THREAD);
437
438 // if f1 is not null or the indy_resolution_failed flag is set then another
439 // thread either succeeded in resolving the method or got a LinkageError
440 // exception, before this thread was able to record its failure. So, clear
441 // this thread's exception and return false so caller can use the earlier
442 // thread's result.
443 if (!is_f1_null() || indy_resolution_failed()) {
444 CLEAR_PENDING_EXCEPTION;
445 return false;
446 }
447
448 Symbol* error = PENDING_EXCEPTION->klass()->name();
449 Symbol* message = java_lang_Throwable::detail_message(PENDING_EXCEPTION);
450 assert(message != NULL, "Missing detail message");
451
452 SystemDictionary::add_resolution_error(cpool, index, error, message);
453 set_indy_resolution_failed();
454 return true;
455 }
456
457 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {
458 // Decode the action of set_method and set_interface_call
459 Bytecodes::Code invoke_code = bytecode_1();
460 if (invoke_code != (Bytecodes::Code)0) {
461 Metadata* f1 = f1_ord();
462 if (f1 != NULL) {
463 switch (invoke_code) {
464 case Bytecodes::_invokeinterface:
465 assert(f1->is_klass(), "");
466 return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
467 case Bytecodes::_invokestatic:
468 case Bytecodes::_invokespecial:
469 assert(!has_appendix(), "");
470 case Bytecodes::_invokehandle:
471 case Bytecodes::_invokedynamic:
472 assert(f1->is_method(), "");
473 return (Method*)f1;
474 default:
475 break;
476 }
477 }
478 }
479 invoke_code = bytecode_2();
480 if (invoke_code != (Bytecodes::Code)0) {
481 switch (invoke_code) {
482 case Bytecodes::_invokevirtual:
483 if (is_vfinal()) {
484 // invokevirtual
485 Method* m = f2_as_vfinal_method();
486 assert(m->is_method(), "");
487 return m;
488 } else {
489 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
490 if (cpool->tag_at(holder_index).is_klass()) {
491 Klass* klass = cpool->resolved_klass_at(holder_index);
492 return klass->method_at_vtable(f2_as_index());
493 }
494 }
495 break;
496 default:
497 break;
498 }
499 }
500 return NULL;
501 }
502
503
504 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {
505 if (!has_appendix())
506 return NULL;
507 const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
508 objArrayOop resolved_references = cpool->resolved_references();
509 return resolved_references->obj_at(ref_index);
510 }
511
512
513 oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) {
514 if (!has_method_type())
515 return NULL;
516 const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
517 objArrayOop resolved_references = cpool->resolved_references();
518 return resolved_references->obj_at(ref_index);
519 }
520
521
522 #if INCLUDE_JVMTI
523
524 void log_adjust(const char* entry_type, Method* old_method, Method* new_method, bool* trace_name_printed) {
525 if (log_is_enabled(Info, redefine, class, update)) {
526 ResourceMark rm;
527 if (!(*trace_name_printed)) {
528 log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
529 *trace_name_printed = true;
530 }
531 log_debug(redefine, class, update, constantpool)
532 ("cpc %s entry update: %s(%s)", entry_type, new_method->name()->as_C_string(), new_method->signature()->as_C_string());
533 }
534 }
535
536 // RedefineClasses() API support:
537 // If this ConstantPoolCacheEntry refers to old_method then update it
538 // to refer to new_method.
539 void ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
540 Method* new_method, bool * trace_name_printed) {
541
542 if (is_vfinal()) {
543 // virtual and final so _f2 contains method ptr instead of vtable index
544 if (f2_as_vfinal_method() == old_method) {
545 // match old_method so need an update
546 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
547 _f2 = (intptr_t)new_method;
548 log_adjust("vfinal", old_method, new_method, trace_name_printed);
549 }
550 return;
551 }
552
553 assert (_f1 != NULL, "should not call with uninteresting entry");
554
555 if (!(_f1->is_method())) {
556 // _f1 is a Klass* for an interface, _f2 is the method
557 if (f2_as_interface_method() == old_method) {
558 _f2 = (intptr_t)new_method;
559 log_adjust("interface", old_method, new_method, trace_name_printed);
560 }
561 } else if (_f1 == old_method) {
562 _f1 = new_method;
563 log_adjust("special, static or dynamic", old_method, new_method, trace_name_printed);
564 }
565 }
566
567 // a constant pool cache entry should never contain old or obsolete methods
568 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
569 Method* m = get_interesting_method_entry(NULL);
570 // return false if m refers to a non-deleted old or obsolete method
571 if (m != NULL) {
572 assert(m->is_valid() && m->is_method(), "m is a valid method");
573 return !m->is_old() && !m->is_obsolete(); // old is always set for old and obsolete
574 } else {
575 return true;
576 }
577 }
578
579 Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) {
580 if (!is_method_entry()) {
581 // not a method entry so not interesting by default
582 return NULL;
583 }
584 Method* m = NULL;
585 if (is_vfinal()) {
586 // virtual and final so _f2 contains method ptr instead of vtable index
587 m = f2_as_vfinal_method();
588 } else if (is_f1_null()) {
589 // NULL _f1 means this is a virtual entry so also not interesting
590 return NULL;
591 } else {
592 if (!(_f1->is_method())) {
593 // _f1 is a Klass* for an interface
594 m = f2_as_interface_method();
595 } else {
596 m = f1_as_method();
597 }
598 }
599 assert(m != NULL && m->is_method(), "sanity check");
600 if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
601 // robustness for above sanity checks or method is not in
602 // the interesting class
603 return NULL;
604 }
605 // the method is in the interesting class so the entry is interesting
606 return m;
607 }
608 #endif // INCLUDE_JVMTI
609
610 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
611 // print separator
612 if (index == 0) st->print_cr(" -------------");
613 // print entry
614 st->print("%3d (" PTR_FORMAT ") ", index, (intptr_t)this);
615 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
616 constant_pool_index());
617 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f1);
618 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f2);
619 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_flags);
620 st->print_cr(" -------------");
621 }
622
623 void ConstantPoolCacheEntry::verify(outputStream* st) const {
624 // not implemented yet
625 }
626
627 // Implementation of ConstantPoolCache
628
629 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
630 const intStack& index_map,
631 const intStack& invokedynamic_index_map,
632 const intStack& invokedynamic_map, TRAPS) {
633
634 const int length = index_map.length() + invokedynamic_index_map.length();
635 int size = ConstantPoolCache::size(length);
636
637 return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD)
638 ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
639 }
640
641 void ConstantPoolCache::initialize(const intArray& inverse_index_map,
642 const intArray& invokedynamic_inverse_index_map,
643 const intArray& invokedynamic_references_map) {
644 for (int i = 0; i < inverse_index_map.length(); i++) {
645 ConstantPoolCacheEntry* e = entry_at(i);
646 int original_index = inverse_index_map.at(i);
647 e->initialize_entry(original_index);
648 assert(entry_at(i) == e, "sanity");
649 }
650
651 // Append invokedynamic entries at the end
652 int invokedynamic_offset = inverse_index_map.length();
653 for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
654 int offset = i + invokedynamic_offset;
655 ConstantPoolCacheEntry* e = entry_at(offset);
656 int original_index = invokedynamic_inverse_index_map.at(i);
657 e->initialize_entry(original_index);
658 assert(entry_at(offset) == e, "sanity");
659 }
660
661 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
662 const int cpci = invokedynamic_references_map.at(ref);
663 if (cpci >= 0) {
664 #ifdef ASSERT
665 // invokedynamic and invokehandle have more entries; check if they
666 // all point to the same constant pool cache entry.
667 for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
668 const int cpci_next = invokedynamic_references_map.at(ref + entry);
669 assert(cpci == cpci_next, "%d == %d", cpci, cpci_next);
670 }
671 #endif
672 entry_at(cpci)->initialize_resolved_reference_index(ref);
673 ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1; // skip extra entries
674 }
675 }
676 }
677
678 void ConstantPoolCache::verify_just_initialized() {
679 DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true));
680 }
681
682 void ConstantPoolCache::remove_unshareable_info() {
683 walk_entries_for_initialization(/*check_only = */ false);
684 }
685
686 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) {
687 assert(DumpSharedSpaces, "sanity");
688 // When dumping the archive, we want to clean up the ConstantPoolCache
689 // to remove any effect of linking due to the execution of Java code --
690 // each ConstantPoolCacheEntry will have the same contents as if
691 // ConstantPoolCache::initialize has just returned:
692 //
693 // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries.
694 // - We keep the "f2" field for entries used by invokedynamic and invokehandle
695 // - All other bits in the entries are cleared to zero.
696 ResourceMark rm;
697
698 InstanceKlass* ik = constant_pool()->pool_holder();
699 bool* f2_used = NEW_RESOURCE_ARRAY(bool, length());
700 memset(f2_used, 0, sizeof(bool) * length());
701
702 // Find all the slots that we need to preserve f2
703 for (int i = 0; i < ik->methods()->length(); i++) {
704 Method* m = ik->methods()->at(i);
705 RawBytecodeStream bcs(m);
706 while (!bcs.is_last_bytecode()) {
707 Bytecodes::Code opcode = bcs.raw_next();
708 switch (opcode) {
709 case Bytecodes::_invokedynamic: {
710 int index = Bytes::get_native_u4(bcs.bcp() + 1);
711 int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index);
712 f2_used[cp_cache_index] = 1;
713 }
714 break;
715 case Bytecodes::_invokehandle: {
716 int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1);
717 f2_used[cp_cache_index] = 1;
718 }
719 break;
720 default:
721 break;
722 }
723 }
724 }
725
726 if (check_only) {
727 DEBUG_ONLY(
728 for (int i=0; i<length(); i++) {
729 entry_at(i)->verify_just_initialized(f2_used[i]);
730 })
731 } else {
732 for (int i=0; i<length(); i++) {
733 entry_at(i)->reinitialize(f2_used[i]);
734 }
735 }
736 }
737
738 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) {
739 assert(!is_shared(), "shared caches are not deallocated");
740 data->remove_handle(_resolved_references);
741 set_resolved_references(NULL);
742 MetadataFactory::free_array<u2>(data, _reference_map);
743 set_reference_map(NULL);
744 }
745
746 #if INCLUDE_CDS_JAVA_HEAP
747 oop ConstantPoolCache::archived_references() {
748 // Loading an archive root forces the oop to become strongly reachable.
749 // For example, if it is loaded during concurrent marking in a SATB
750 // collector, it will be enqueued to the SATB queue, effectively
751 // shading the previously white object gray.
752 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_references);
753 }
754
755 void ConstantPoolCache::set_archived_references(oop o) {
756 assert(DumpSharedSpaces, "called only during runtime");
757 RootAccess<IN_ARCHIVE_ROOT>::oop_store(&_archived_references, o);
758 }
759 #endif
760
761 #if INCLUDE_JVMTI
762 // RedefineClasses() API support:
763 // If any entry of this ConstantPoolCache points to any of
764 // old_methods, replace it with the corresponding new_method.
765 void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
766 for (int i = 0; i < length(); i++) {
767 ConstantPoolCacheEntry* entry = entry_at(i);
768 Method* old_method = entry->get_interesting_method_entry(holder);
769 if (old_method == NULL || !old_method->is_old()) {
770 continue; // skip uninteresting entries
771 }
772 if (old_method->is_deleted()) {
773 // clean up entries with deleted methods
774 entry->initialize_entry(entry->constant_pool_index());
775 continue;
776 }
777 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
778
779 assert(new_method != NULL, "method_with_idnum() should not be NULL");
780 assert(old_method != new_method, "sanity check");
781
782 entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);
783 }
784 }
785
786 // the constant pool cache should never contain old or obsolete methods
787 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
788 for (int i = 1; i < length(); i++) {
789 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL &&
790 !entry_at(i)->check_no_old_or_obsolete_entries()) {
791 return false;
792 }
793 }
794 return true;
795 }
796
797 void ConstantPoolCache::dump_cache() {
798 for (int i = 1; i < length(); i++) {
799 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) {
800 entry_at(i)->print(tty, i);
801 }
802 }
803 }
804 #endif // INCLUDE_JVMTI
805
806 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) {
807 log_trace(cds)("Iter(ConstantPoolCache): %p", this);
808 it->push(&_constant_pool);
809 it->push(&_reference_map);
810 }
811
812 // Printing
813
814 void ConstantPoolCache::print_on(outputStream* st) const {
815 assert(is_constantPoolCache(), "obj must be constant pool cache");
816 st->print_cr("%s", internal_name());
817 // print constant pool cache entries
818 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
819 }
820
821 void ConstantPoolCache::print_value_on(outputStream* st) const {
822 assert(is_constantPoolCache(), "obj must be constant pool cache");
823 st->print("cache [%d]", length());
824 print_address_on(st);
825 st->print(" for ");
826 constant_pool()->print_value_on(st);
827 }
828
829
830 // Verification
831
832 void ConstantPoolCache::verify_on(outputStream* st) {
833 guarantee(is_constantPoolCache(), "obj must be constant pool cache");
834 // print constant pool cache entries
835 for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
836 }