Thu, 08 Oct 2015 09:37:51 +0200
8075805: Crash while trying to release CompiledICHolder
Summary: Removed nmethod transition to zombie outside of sweeper. Added cleaning of ICs of unloaded nmethods.
Reviewed-by: kvn, iveresov
1 /*
2 * Copyright (c) 2003, 2015, 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 */
25 #include "precompiled.hpp"
26 #include "classfile/metadataOnStackMark.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "code/codeCache.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "interpreter/oopMapCache.hpp"
32 #include "interpreter/rewriter.hpp"
33 #include "memory/gcLocker.hpp"
34 #include "memory/metadataFactory.hpp"
35 #include "memory/metaspaceShared.hpp"
36 #include "memory/universe.inline.hpp"
37 #include "oops/fieldStreams.hpp"
38 #include "oops/klassVtable.hpp"
39 #include "prims/jvmtiImpl.hpp"
40 #include "prims/jvmtiRedefineClasses.hpp"
41 #include "prims/methodComparator.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/relocator.hpp"
44 #include "utilities/bitMap.inline.hpp"
46 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
48 Array<Method*>* VM_RedefineClasses::_old_methods = NULL;
49 Array<Method*>* VM_RedefineClasses::_new_methods = NULL;
50 Method** VM_RedefineClasses::_matching_old_methods = NULL;
51 Method** VM_RedefineClasses::_matching_new_methods = NULL;
52 Method** VM_RedefineClasses::_deleted_methods = NULL;
53 Method** VM_RedefineClasses::_added_methods = NULL;
54 int VM_RedefineClasses::_matching_methods_length = 0;
55 int VM_RedefineClasses::_deleted_methods_length = 0;
56 int VM_RedefineClasses::_added_methods_length = 0;
57 Klass* VM_RedefineClasses::_the_class_oop = NULL;
60 VM_RedefineClasses::VM_RedefineClasses(jint class_count,
61 const jvmtiClassDefinition *class_defs,
62 JvmtiClassLoadKind class_load_kind) {
63 _class_count = class_count;
64 _class_defs = class_defs;
65 _class_load_kind = class_load_kind;
66 _res = JVMTI_ERROR_NONE;
67 }
69 bool VM_RedefineClasses::doit_prologue() {
70 if (_class_count == 0) {
71 _res = JVMTI_ERROR_NONE;
72 return false;
73 }
74 if (_class_defs == NULL) {
75 _res = JVMTI_ERROR_NULL_POINTER;
76 return false;
77 }
78 for (int i = 0; i < _class_count; i++) {
79 if (_class_defs[i].klass == NULL) {
80 _res = JVMTI_ERROR_INVALID_CLASS;
81 return false;
82 }
83 if (_class_defs[i].class_byte_count == 0) {
84 _res = JVMTI_ERROR_INVALID_CLASS_FORMAT;
85 return false;
86 }
87 if (_class_defs[i].class_bytes == NULL) {
88 _res = JVMTI_ERROR_NULL_POINTER;
89 return false;
90 }
91 }
93 // Start timer after all the sanity checks; not quite accurate, but
94 // better than adding a bunch of stop() calls.
95 RC_TIMER_START(_timer_vm_op_prologue);
97 // We first load new class versions in the prologue, because somewhere down the
98 // call chain it is required that the current thread is a Java thread.
99 _res = load_new_class_versions(Thread::current());
100 if (_res != JVMTI_ERROR_NONE) {
101 // free any successfully created classes, since none are redefined
102 for (int i = 0; i < _class_count; i++) {
103 if (_scratch_classes[i] != NULL) {
104 ClassLoaderData* cld = _scratch_classes[i]->class_loader_data();
105 // Free the memory for this class at class unloading time. Not before
106 // because CMS might think this is still live.
107 cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]);
108 }
109 }
110 // Free os::malloc allocated memory in load_new_class_version.
111 os::free(_scratch_classes);
112 RC_TIMER_STOP(_timer_vm_op_prologue);
113 return false;
114 }
116 RC_TIMER_STOP(_timer_vm_op_prologue);
117 return true;
118 }
120 void VM_RedefineClasses::doit() {
121 Thread *thread = Thread::current();
123 if (UseSharedSpaces) {
124 // Sharing is enabled so we remap the shared readonly space to
125 // shared readwrite, private just in case we need to redefine
126 // a shared class. We do the remap during the doit() phase of
127 // the safepoint to be safer.
128 if (!MetaspaceShared::remap_shared_readonly_as_readwrite()) {
129 RC_TRACE_WITH_THREAD(0x00000001, thread,
130 ("failed to remap shared readonly space to readwrite, private"));
131 _res = JVMTI_ERROR_INTERNAL;
132 return;
133 }
134 }
136 // Mark methods seen on stack and everywhere else so old methods are not
137 // cleaned up if they're on the stack.
138 MetadataOnStackMark md_on_stack(true);
139 HandleMark hm(thread); // make sure any handles created are deleted
140 // before the stack walk again.
142 for (int i = 0; i < _class_count; i++) {
143 redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread);
144 ClassLoaderData* cld = _scratch_classes[i]->class_loader_data();
145 // Free the memory for this class at class unloading time. Not before
146 // because CMS might think this is still live.
147 cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]);
148 _scratch_classes[i] = NULL;
149 }
151 // Disable any dependent concurrent compilations
152 SystemDictionary::notice_modification();
154 // Set flag indicating that some invariants are no longer true.
155 // See jvmtiExport.hpp for detailed explanation.
156 JvmtiExport::set_has_redefined_a_class();
158 // check_class() is optionally called for product bits, but is
159 // always called for non-product bits.
160 #ifdef PRODUCT
161 if (RC_TRACE_ENABLED(0x00004000)) {
162 #endif
163 RC_TRACE_WITH_THREAD(0x00004000, thread, ("calling check_class"));
164 CheckClass check_class(thread);
165 ClassLoaderDataGraph::classes_do(&check_class);
166 #ifdef PRODUCT
167 }
168 #endif
169 }
171 void VM_RedefineClasses::doit_epilogue() {
172 // Free os::malloc allocated memory.
173 os::free(_scratch_classes);
175 if (RC_TRACE_ENABLED(0x00000004)) {
176 // Used to have separate timers for "doit" and "all", but the timer
177 // overhead skewed the measurements.
178 jlong doit_time = _timer_rsc_phase1.milliseconds() +
179 _timer_rsc_phase2.milliseconds();
180 jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time;
182 RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT
183 " prologue=" UINT64_FORMAT " doit=" UINT64_FORMAT, all_time,
184 _timer_vm_op_prologue.milliseconds(), doit_time));
185 RC_TRACE(0x00000004,
186 ("redefine_single_class: phase1=" UINT64_FORMAT " phase2=" UINT64_FORMAT,
187 _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds()));
188 }
189 }
191 bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) {
192 // classes for primitives cannot be redefined
193 if (java_lang_Class::is_primitive(klass_mirror)) {
194 return false;
195 }
196 Klass* the_class_oop = java_lang_Class::as_Klass(klass_mirror);
197 // classes for arrays cannot be redefined
198 if (the_class_oop == NULL || !the_class_oop->oop_is_instance()) {
199 return false;
200 }
201 return true;
202 }
204 // Append the current entry at scratch_i in scratch_cp to *merge_cp_p
205 // where the end of *merge_cp_p is specified by *merge_cp_length_p. For
206 // direct CP entries, there is just the current entry to append. For
207 // indirect and double-indirect CP entries, there are zero or more
208 // referenced CP entries along with the current entry to append.
209 // Indirect and double-indirect CP entries are handled by recursive
210 // calls to append_entry() as needed. The referenced CP entries are
211 // always appended to *merge_cp_p before the referee CP entry. These
212 // referenced CP entries may already exist in *merge_cp_p in which case
213 // there is nothing extra to append and only the current entry is
214 // appended.
215 void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp,
216 int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p,
217 TRAPS) {
219 // append is different depending on entry tag type
220 switch (scratch_cp->tag_at(scratch_i).value()) {
222 // The old verifier is implemented outside the VM. It loads classes,
223 // but does not resolve constant pool entries directly so we never
224 // see Class entries here with the old verifier. Similarly the old
225 // verifier does not like Class entries in the input constant pool.
226 // The split-verifier is implemented in the VM so it can optionally
227 // and directly resolve constant pool entries to load classes. The
228 // split-verifier can accept either Class entries or UnresolvedClass
229 // entries in the input constant pool. We revert the appended copy
230 // back to UnresolvedClass so that either verifier will be happy
231 // with the constant pool entry.
232 case JVM_CONSTANT_Class:
233 {
234 // revert the copy to JVM_CONSTANT_UnresolvedClass
235 (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p,
236 scratch_cp->klass_name_at(scratch_i));
238 if (scratch_i != *merge_cp_length_p) {
239 // The new entry in *merge_cp_p is at a different index than
240 // the new entry in scratch_cp so we need to map the index values.
241 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
242 }
243 (*merge_cp_length_p)++;
244 } break;
246 // these are direct CP entries so they can be directly appended,
247 // but double and long take two constant pool entries
248 case JVM_CONSTANT_Double: // fall through
249 case JVM_CONSTANT_Long:
250 {
251 ConstantPool::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p,
252 THREAD);
254 if (scratch_i != *merge_cp_length_p) {
255 // The new entry in *merge_cp_p is at a different index than
256 // the new entry in scratch_cp so we need to map the index values.
257 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
258 }
259 (*merge_cp_length_p) += 2;
260 } break;
262 // these are direct CP entries so they can be directly appended
263 case JVM_CONSTANT_Float: // fall through
264 case JVM_CONSTANT_Integer: // fall through
265 case JVM_CONSTANT_Utf8: // fall through
267 // This was an indirect CP entry, but it has been changed into
268 // Symbol*s so this entry can be directly appended.
269 case JVM_CONSTANT_String: // fall through
271 // These were indirect CP entries, but they have been changed into
272 // Symbol*s so these entries can be directly appended.
273 case JVM_CONSTANT_UnresolvedClass: // fall through
274 {
275 ConstantPool::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p,
276 THREAD);
278 if (scratch_i != *merge_cp_length_p) {
279 // The new entry in *merge_cp_p is at a different index than
280 // the new entry in scratch_cp so we need to map the index values.
281 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
282 }
283 (*merge_cp_length_p)++;
284 } break;
286 // this is an indirect CP entry so it needs special handling
287 case JVM_CONSTANT_NameAndType:
288 {
289 int name_ref_i = scratch_cp->name_ref_index_at(scratch_i);
290 int new_name_ref_i = find_or_append_indirect_entry(scratch_cp, name_ref_i, merge_cp_p,
291 merge_cp_length_p, THREAD);
293 int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i);
294 int new_signature_ref_i = find_or_append_indirect_entry(scratch_cp, signature_ref_i,
295 merge_cp_p, merge_cp_length_p,
296 THREAD);
298 // If the referenced entries already exist in *merge_cp_p, then
299 // both new_name_ref_i and new_signature_ref_i will both be 0.
300 // In that case, all we are appending is the current entry.
301 if (new_name_ref_i != name_ref_i) {
302 RC_TRACE(0x00080000,
303 ("NameAndType entry@%d name_ref_index change: %d to %d",
304 *merge_cp_length_p, name_ref_i, new_name_ref_i));
305 }
306 if (new_signature_ref_i != signature_ref_i) {
307 RC_TRACE(0x00080000,
308 ("NameAndType entry@%d signature_ref_index change: %d to %d",
309 *merge_cp_length_p, signature_ref_i, new_signature_ref_i));
310 }
312 (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p,
313 new_name_ref_i, new_signature_ref_i);
314 if (scratch_i != *merge_cp_length_p) {
315 // The new entry in *merge_cp_p is at a different index than
316 // the new entry in scratch_cp so we need to map the index values.
317 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
318 }
319 (*merge_cp_length_p)++;
320 } break;
322 // this is a double-indirect CP entry so it needs special handling
323 case JVM_CONSTANT_Fieldref: // fall through
324 case JVM_CONSTANT_InterfaceMethodref: // fall through
325 case JVM_CONSTANT_Methodref:
326 {
327 int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i);
328 int new_klass_ref_i = find_or_append_indirect_entry(scratch_cp, klass_ref_i,
329 merge_cp_p, merge_cp_length_p, THREAD);
331 int name_and_type_ref_i = scratch_cp->uncached_name_and_type_ref_index_at(scratch_i);
332 int new_name_and_type_ref_i = find_or_append_indirect_entry(scratch_cp, name_and_type_ref_i,
333 merge_cp_p, merge_cp_length_p, THREAD);
335 const char *entry_name;
336 switch (scratch_cp->tag_at(scratch_i).value()) {
337 case JVM_CONSTANT_Fieldref:
338 entry_name = "Fieldref";
339 (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i,
340 new_name_and_type_ref_i);
341 break;
342 case JVM_CONSTANT_InterfaceMethodref:
343 entry_name = "IFMethodref";
344 (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p,
345 new_klass_ref_i, new_name_and_type_ref_i);
346 break;
347 case JVM_CONSTANT_Methodref:
348 entry_name = "Methodref";
349 (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i,
350 new_name_and_type_ref_i);
351 break;
352 default:
353 guarantee(false, "bad switch");
354 break;
355 }
357 if (klass_ref_i != new_klass_ref_i) {
358 RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d",
359 entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i));
360 }
361 if (name_and_type_ref_i != new_name_and_type_ref_i) {
362 RC_TRACE(0x00080000,
363 ("%s entry@%d name_and_type_index changed: %d to %d",
364 entry_name, *merge_cp_length_p, name_and_type_ref_i,
365 new_name_and_type_ref_i));
366 }
368 if (scratch_i != *merge_cp_length_p) {
369 // The new entry in *merge_cp_p is at a different index than
370 // the new entry in scratch_cp so we need to map the index values.
371 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
372 }
373 (*merge_cp_length_p)++;
374 } break;
376 // this is an indirect CP entry so it needs special handling
377 case JVM_CONSTANT_MethodType:
378 {
379 int ref_i = scratch_cp->method_type_index_at(scratch_i);
380 int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
381 merge_cp_length_p, THREAD);
382 if (new_ref_i != ref_i) {
383 RC_TRACE(0x00080000,
384 ("MethodType entry@%d ref_index change: %d to %d",
385 *merge_cp_length_p, ref_i, new_ref_i));
386 }
387 (*merge_cp_p)->method_type_index_at_put(*merge_cp_length_p, new_ref_i);
388 if (scratch_i != *merge_cp_length_p) {
389 // The new entry in *merge_cp_p is at a different index than
390 // the new entry in scratch_cp so we need to map the index values.
391 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
392 }
393 (*merge_cp_length_p)++;
394 } break;
396 // this is an indirect CP entry so it needs special handling
397 case JVM_CONSTANT_MethodHandle:
398 {
399 int ref_kind = scratch_cp->method_handle_ref_kind_at(scratch_i);
400 int ref_i = scratch_cp->method_handle_index_at(scratch_i);
401 int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
402 merge_cp_length_p, THREAD);
403 if (new_ref_i != ref_i) {
404 RC_TRACE(0x00080000,
405 ("MethodHandle entry@%d ref_index change: %d to %d",
406 *merge_cp_length_p, ref_i, new_ref_i));
407 }
408 (*merge_cp_p)->method_handle_index_at_put(*merge_cp_length_p, ref_kind, new_ref_i);
409 if (scratch_i != *merge_cp_length_p) {
410 // The new entry in *merge_cp_p is at a different index than
411 // the new entry in scratch_cp so we need to map the index values.
412 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
413 }
414 (*merge_cp_length_p)++;
415 } break;
417 // this is an indirect CP entry so it needs special handling
418 case JVM_CONSTANT_InvokeDynamic:
419 {
420 // Index of the bootstrap specifier in the operands array
421 int old_bs_i = scratch_cp->invoke_dynamic_bootstrap_specifier_index(scratch_i);
422 int new_bs_i = find_or_append_operand(scratch_cp, old_bs_i, merge_cp_p,
423 merge_cp_length_p, THREAD);
424 // The bootstrap method NameAndType_info index
425 int old_ref_i = scratch_cp->invoke_dynamic_name_and_type_ref_index_at(scratch_i);
426 int new_ref_i = find_or_append_indirect_entry(scratch_cp, old_ref_i, merge_cp_p,
427 merge_cp_length_p, THREAD);
428 if (new_bs_i != old_bs_i) {
429 RC_TRACE(0x00080000,
430 ("InvokeDynamic entry@%d bootstrap_method_attr_index change: %d to %d",
431 *merge_cp_length_p, old_bs_i, new_bs_i));
432 }
433 if (new_ref_i != old_ref_i) {
434 RC_TRACE(0x00080000,
435 ("InvokeDynamic entry@%d name_and_type_index change: %d to %d",
436 *merge_cp_length_p, old_ref_i, new_ref_i));
437 }
439 (*merge_cp_p)->invoke_dynamic_at_put(*merge_cp_length_p, new_bs_i, new_ref_i);
440 if (scratch_i != *merge_cp_length_p) {
441 // The new entry in *merge_cp_p is at a different index than
442 // the new entry in scratch_cp so we need to map the index values.
443 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
444 }
445 (*merge_cp_length_p)++;
446 } break;
448 // At this stage, Class or UnresolvedClass could be here, but not
449 // ClassIndex
450 case JVM_CONSTANT_ClassIndex: // fall through
452 // Invalid is used as the tag for the second constant pool entry
453 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
454 // not be seen by itself.
455 case JVM_CONSTANT_Invalid: // fall through
457 // At this stage, String could be here, but not StringIndex
458 case JVM_CONSTANT_StringIndex: // fall through
460 // At this stage JVM_CONSTANT_UnresolvedClassInError should not be
461 // here
462 case JVM_CONSTANT_UnresolvedClassInError: // fall through
464 default:
465 {
466 // leave a breadcrumb
467 jbyte bad_value = scratch_cp->tag_at(scratch_i).value();
468 ShouldNotReachHere();
469 } break;
470 } // end switch tag value
471 } // end append_entry()
474 int VM_RedefineClasses::find_or_append_indirect_entry(constantPoolHandle scratch_cp,
475 int ref_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
477 int new_ref_i = ref_i;
478 bool match = (ref_i < *merge_cp_length_p) &&
479 scratch_cp->compare_entry_to(ref_i, *merge_cp_p, ref_i, THREAD);
481 if (!match) {
482 // forward reference in *merge_cp_p or not a direct match
483 int found_i = scratch_cp->find_matching_entry(ref_i, *merge_cp_p, THREAD);
484 if (found_i != 0) {
485 guarantee(found_i != ref_i, "compare_entry_to() and find_matching_entry() do not agree");
486 // Found a matching entry somewhere else in *merge_cp_p so just need a mapping entry.
487 new_ref_i = found_i;
488 map_index(scratch_cp, ref_i, found_i);
489 } else {
490 // no match found so we have to append this entry to *merge_cp_p
491 append_entry(scratch_cp, ref_i, merge_cp_p, merge_cp_length_p, THREAD);
492 // The above call to append_entry() can only append one entry
493 // so the post call query of *merge_cp_length_p is only for
494 // the sake of consistency.
495 new_ref_i = *merge_cp_length_p - 1;
496 }
497 }
499 return new_ref_i;
500 } // end find_or_append_indirect_entry()
503 // Append a bootstrap specifier into the merge_cp operands that is semantically equal
504 // to the scratch_cp operands bootstrap specifier passed by the old_bs_i index.
505 // Recursively append new merge_cp entries referenced by the new bootstrap specifier.
506 void VM_RedefineClasses::append_operand(constantPoolHandle scratch_cp, int old_bs_i,
507 constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
509 int old_ref_i = scratch_cp->operand_bootstrap_method_ref_index_at(old_bs_i);
510 int new_ref_i = find_or_append_indirect_entry(scratch_cp, old_ref_i, merge_cp_p,
511 merge_cp_length_p, THREAD);
512 if (new_ref_i != old_ref_i) {
513 RC_TRACE(0x00080000,
514 ("operands entry@%d bootstrap method ref_index change: %d to %d",
515 _operands_cur_length, old_ref_i, new_ref_i));
516 }
518 Array<u2>* merge_ops = (*merge_cp_p)->operands();
519 int new_bs_i = _operands_cur_length;
520 // We have _operands_cur_length == 0 when the merge_cp operands is empty yet.
521 // However, the operand_offset_at(0) was set in the extend_operands() call.
522 int new_base = (new_bs_i == 0) ? (*merge_cp_p)->operand_offset_at(0)
523 : (*merge_cp_p)->operand_next_offset_at(new_bs_i - 1);
524 int argc = scratch_cp->operand_argument_count_at(old_bs_i);
526 ConstantPool::operand_offset_at_put(merge_ops, _operands_cur_length, new_base);
527 merge_ops->at_put(new_base++, new_ref_i);
528 merge_ops->at_put(new_base++, argc);
530 for (int i = 0; i < argc; i++) {
531 int old_arg_ref_i = scratch_cp->operand_argument_index_at(old_bs_i, i);
532 int new_arg_ref_i = find_or_append_indirect_entry(scratch_cp, old_arg_ref_i, merge_cp_p,
533 merge_cp_length_p, THREAD);
534 merge_ops->at_put(new_base++, new_arg_ref_i);
535 if (new_arg_ref_i != old_arg_ref_i) {
536 RC_TRACE(0x00080000,
537 ("operands entry@%d bootstrap method argument ref_index change: %d to %d",
538 _operands_cur_length, old_arg_ref_i, new_arg_ref_i));
539 }
540 }
541 if (old_bs_i != _operands_cur_length) {
542 // The bootstrap specifier in *merge_cp_p is at a different index than
543 // that in scratch_cp so we need to map the index values.
544 map_operand_index(old_bs_i, new_bs_i);
545 }
546 _operands_cur_length++;
547 } // end append_operand()
550 int VM_RedefineClasses::find_or_append_operand(constantPoolHandle scratch_cp,
551 int old_bs_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
553 int new_bs_i = old_bs_i; // bootstrap specifier index
554 bool match = (old_bs_i < _operands_cur_length) &&
555 scratch_cp->compare_operand_to(old_bs_i, *merge_cp_p, old_bs_i, THREAD);
557 if (!match) {
558 // forward reference in *merge_cp_p or not a direct match
559 int found_i = scratch_cp->find_matching_operand(old_bs_i, *merge_cp_p,
560 _operands_cur_length, THREAD);
561 if (found_i != -1) {
562 guarantee(found_i != old_bs_i, "compare_operand_to() and find_matching_operand() disagree");
563 // found a matching operand somewhere else in *merge_cp_p so just need a mapping
564 new_bs_i = found_i;
565 map_operand_index(old_bs_i, found_i);
566 } else {
567 // no match found so we have to append this bootstrap specifier to *merge_cp_p
568 append_operand(scratch_cp, old_bs_i, merge_cp_p, merge_cp_length_p, THREAD);
569 new_bs_i = _operands_cur_length - 1;
570 }
571 }
572 return new_bs_i;
573 } // end find_or_append_operand()
576 void VM_RedefineClasses::finalize_operands_merge(constantPoolHandle merge_cp, TRAPS) {
577 if (merge_cp->operands() == NULL) {
578 return;
579 }
580 // Shrink the merge_cp operands
581 merge_cp->shrink_operands(_operands_cur_length, CHECK);
583 if (RC_TRACE_ENABLED(0x00040000)) {
584 // don't want to loop unless we are tracing
585 int count = 0;
586 for (int i = 1; i < _operands_index_map_p->length(); i++) {
587 int value = _operands_index_map_p->at(i);
588 if (value != -1) {
589 RC_TRACE_WITH_THREAD(0x00040000, THREAD,
590 ("operands_index_map[%d]: old=%d new=%d", count, i, value));
591 count++;
592 }
593 }
594 }
595 // Clean-up
596 _operands_index_map_p = NULL;
597 _operands_cur_length = 0;
598 _operands_index_map_count = 0;
599 } // end finalize_operands_merge()
602 jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
603 instanceKlassHandle the_class,
604 instanceKlassHandle scratch_class) {
605 int i;
607 // Check superclasses, or rather their names, since superclasses themselves can be
608 // requested to replace.
609 // Check for NULL superclass first since this might be java.lang.Object
610 if (the_class->super() != scratch_class->super() &&
611 (the_class->super() == NULL || scratch_class->super() == NULL ||
612 the_class->super()->name() !=
613 scratch_class->super()->name())) {
614 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
615 }
617 // Check if the number, names and order of directly implemented interfaces are the same.
618 // I think in principle we should just check if the sets of names of directly implemented
619 // interfaces are the same, i.e. the order of declaration (which, however, if changed in the
620 // .java file, also changes in .class file) should not matter. However, comparing sets is
621 // technically a bit more difficult, and, more importantly, I am not sure at present that the
622 // order of interfaces does not matter on the implementation level, i.e. that the VM does not
623 // rely on it somewhere.
624 Array<Klass*>* k_interfaces = the_class->local_interfaces();
625 Array<Klass*>* k_new_interfaces = scratch_class->local_interfaces();
626 int n_intfs = k_interfaces->length();
627 if (n_intfs != k_new_interfaces->length()) {
628 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
629 }
630 for (i = 0; i < n_intfs; i++) {
631 if (k_interfaces->at(i)->name() !=
632 k_new_interfaces->at(i)->name()) {
633 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
634 }
635 }
637 // Check whether class is in the error init state.
638 if (the_class->is_in_error_state()) {
639 // TBD #5057930: special error code is needed in 1.6
640 return JVMTI_ERROR_INVALID_CLASS;
641 }
643 // Check whether class modifiers are the same.
644 jushort old_flags = (jushort) the_class->access_flags().get_flags();
645 jushort new_flags = (jushort) scratch_class->access_flags().get_flags();
646 if (old_flags != new_flags) {
647 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED;
648 }
650 // Check if the number, names, types and order of fields declared in these classes
651 // are the same.
652 JavaFieldStream old_fs(the_class);
653 JavaFieldStream new_fs(scratch_class);
654 for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) {
655 // access
656 old_flags = old_fs.access_flags().as_short();
657 new_flags = new_fs.access_flags().as_short();
658 if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) {
659 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
660 }
661 // offset
662 if (old_fs.offset() != new_fs.offset()) {
663 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
664 }
665 // name and signature
666 Symbol* name_sym1 = the_class->constants()->symbol_at(old_fs.name_index());
667 Symbol* sig_sym1 = the_class->constants()->symbol_at(old_fs.signature_index());
668 Symbol* name_sym2 = scratch_class->constants()->symbol_at(new_fs.name_index());
669 Symbol* sig_sym2 = scratch_class->constants()->symbol_at(new_fs.signature_index());
670 if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
671 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
672 }
673 }
675 // If both streams aren't done then we have a differing number of
676 // fields.
677 if (!old_fs.done() || !new_fs.done()) {
678 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
679 }
681 // Do a parallel walk through the old and new methods. Detect
682 // cases where they match (exist in both), have been added in
683 // the new methods, or have been deleted (exist only in the
684 // old methods). The class file parser places methods in order
685 // by method name, but does not order overloaded methods by
686 // signature. In order to determine what fate befell the methods,
687 // this code places the overloaded new methods that have matching
688 // old methods in the same order as the old methods and places
689 // new overloaded methods at the end of overloaded methods of
690 // that name. The code for this order normalization is adapted
691 // from the algorithm used in InstanceKlass::find_method().
692 // Since we are swapping out of order entries as we find them,
693 // we only have to search forward through the overloaded methods.
694 // Methods which are added and have the same name as an existing
695 // method (but different signature) will be put at the end of
696 // the methods with that name, and the name mismatch code will
697 // handle them.
698 Array<Method*>* k_old_methods(the_class->methods());
699 Array<Method*>* k_new_methods(scratch_class->methods());
700 int n_old_methods = k_old_methods->length();
701 int n_new_methods = k_new_methods->length();
702 Thread* thread = Thread::current();
704 int ni = 0;
705 int oi = 0;
706 while (true) {
707 Method* k_old_method;
708 Method* k_new_method;
709 enum { matched, added, deleted, undetermined } method_was = undetermined;
711 if (oi >= n_old_methods) {
712 if (ni >= n_new_methods) {
713 break; // we've looked at everything, done
714 }
715 // New method at the end
716 k_new_method = k_new_methods->at(ni);
717 method_was = added;
718 } else if (ni >= n_new_methods) {
719 // Old method, at the end, is deleted
720 k_old_method = k_old_methods->at(oi);
721 method_was = deleted;
722 } else {
723 // There are more methods in both the old and new lists
724 k_old_method = k_old_methods->at(oi);
725 k_new_method = k_new_methods->at(ni);
726 if (k_old_method->name() != k_new_method->name()) {
727 // Methods are sorted by method name, so a mismatch means added
728 // or deleted
729 if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) {
730 method_was = added;
731 } else {
732 method_was = deleted;
733 }
734 } else if (k_old_method->signature() == k_new_method->signature()) {
735 // Both the name and signature match
736 method_was = matched;
737 } else {
738 // The name matches, but the signature doesn't, which means we have to
739 // search forward through the new overloaded methods.
740 int nj; // outside the loop for post-loop check
741 for (nj = ni + 1; nj < n_new_methods; nj++) {
742 Method* m = k_new_methods->at(nj);
743 if (k_old_method->name() != m->name()) {
744 // reached another method name so no more overloaded methods
745 method_was = deleted;
746 break;
747 }
748 if (k_old_method->signature() == m->signature()) {
749 // found a match so swap the methods
750 k_new_methods->at_put(ni, m);
751 k_new_methods->at_put(nj, k_new_method);
752 k_new_method = m;
753 method_was = matched;
754 break;
755 }
756 }
758 if (nj >= n_new_methods) {
759 // reached the end without a match; so method was deleted
760 method_was = deleted;
761 }
762 }
763 }
765 switch (method_was) {
766 case matched:
767 // methods match, be sure modifiers do too
768 old_flags = (jushort) k_old_method->access_flags().get_flags();
769 new_flags = (jushort) k_new_method->access_flags().get_flags();
770 if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) {
771 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED;
772 }
773 {
774 u2 new_num = k_new_method->method_idnum();
775 u2 old_num = k_old_method->method_idnum();
776 if (new_num != old_num) {
777 Method* idnum_owner = scratch_class->method_with_idnum(old_num);
778 if (idnum_owner != NULL) {
779 // There is already a method assigned this idnum -- switch them
780 // Take current and original idnum from the new_method
781 idnum_owner->set_method_idnum(new_num);
782 idnum_owner->set_orig_method_idnum(k_new_method->orig_method_idnum());
783 }
784 // Take current and original idnum from the old_method
785 k_new_method->set_method_idnum(old_num);
786 k_new_method->set_orig_method_idnum(k_old_method->orig_method_idnum());
787 if (thread->has_pending_exception()) {
788 return JVMTI_ERROR_OUT_OF_MEMORY;
789 }
790 }
791 }
792 RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]",
793 k_new_method->name_and_sig_as_C_string(), ni,
794 k_old_method->name_and_sig_as_C_string(), oi));
795 // advance to next pair of methods
796 ++oi;
797 ++ni;
798 break;
799 case added:
800 // method added, see if it is OK
801 new_flags = (jushort) k_new_method->access_flags().get_flags();
802 if ((new_flags & JVM_ACC_PRIVATE) == 0
803 // hack: private should be treated as final, but alas
804 || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
805 ) {
806 // new methods must be private
807 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
808 }
809 {
810 u2 num = the_class->next_method_idnum();
811 if (num == ConstMethod::UNSET_IDNUM) {
812 // cannot add any more methods
813 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
814 }
815 u2 new_num = k_new_method->method_idnum();
816 Method* idnum_owner = scratch_class->method_with_idnum(num);
817 if (idnum_owner != NULL) {
818 // There is already a method assigned this idnum -- switch them
819 // Take current and original idnum from the new_method
820 idnum_owner->set_method_idnum(new_num);
821 idnum_owner->set_orig_method_idnum(k_new_method->orig_method_idnum());
822 }
823 k_new_method->set_method_idnum(num);
824 k_new_method->set_orig_method_idnum(num);
825 if (thread->has_pending_exception()) {
826 return JVMTI_ERROR_OUT_OF_MEMORY;
827 }
828 }
829 RC_TRACE(0x00008000, ("Method added: new: %s [%d]",
830 k_new_method->name_and_sig_as_C_string(), ni));
831 ++ni; // advance to next new method
832 break;
833 case deleted:
834 // method deleted, see if it is OK
835 old_flags = (jushort) k_old_method->access_flags().get_flags();
836 if ((old_flags & JVM_ACC_PRIVATE) == 0
837 // hack: private should be treated as final, but alas
838 || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
839 ) {
840 // deleted methods must be private
841 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
842 }
843 RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]",
844 k_old_method->name_and_sig_as_C_string(), oi));
845 ++oi; // advance to next old method
846 break;
847 default:
848 ShouldNotReachHere();
849 }
850 }
852 return JVMTI_ERROR_NONE;
853 }
856 // Find new constant pool index value for old constant pool index value
857 // by seaching the index map. Returns zero (0) if there is no mapped
858 // value for the old constant pool index.
859 int VM_RedefineClasses::find_new_index(int old_index) {
860 if (_index_map_count == 0) {
861 // map is empty so nothing can be found
862 return 0;
863 }
865 if (old_index < 1 || old_index >= _index_map_p->length()) {
866 // The old_index is out of range so it is not mapped. This should
867 // not happen in regular constant pool merging use, but it can
868 // happen if a corrupt annotation is processed.
869 return 0;
870 }
872 int value = _index_map_p->at(old_index);
873 if (value == -1) {
874 // the old_index is not mapped
875 return 0;
876 }
878 return value;
879 } // end find_new_index()
882 // Find new bootstrap specifier index value for old bootstrap specifier index
883 // value by seaching the index map. Returns unused index (-1) if there is
884 // no mapped value for the old bootstrap specifier index.
885 int VM_RedefineClasses::find_new_operand_index(int old_index) {
886 if (_operands_index_map_count == 0) {
887 // map is empty so nothing can be found
888 return -1;
889 }
891 if (old_index == -1 || old_index >= _operands_index_map_p->length()) {
892 // The old_index is out of range so it is not mapped.
893 // This should not happen in regular constant pool merging use.
894 return -1;
895 }
897 int value = _operands_index_map_p->at(old_index);
898 if (value == -1) {
899 // the old_index is not mapped
900 return -1;
901 }
903 return value;
904 } // end find_new_operand_index()
907 // Returns true if the current mismatch is due to a resolved/unresolved
908 // class pair. Otherwise, returns false.
909 bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1,
910 int index1, constantPoolHandle cp2, int index2) {
912 jbyte t1 = cp1->tag_at(index1).value();
913 if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) {
914 return false; // wrong entry type; not our special case
915 }
917 jbyte t2 = cp2->tag_at(index2).value();
918 if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) {
919 return false; // wrong entry type; not our special case
920 }
922 if (t1 == t2) {
923 return false; // not a mismatch; not our special case
924 }
926 char *s1 = cp1->klass_name_at(index1)->as_C_string();
927 char *s2 = cp2->klass_name_at(index2)->as_C_string();
928 if (strcmp(s1, s2) != 0) {
929 return false; // strings don't match; not our special case
930 }
932 return true; // made it through the gauntlet; this is our special case
933 } // end is_unresolved_class_mismatch()
936 jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) {
938 // For consistency allocate memory using os::malloc wrapper.
939 _scratch_classes = (Klass**)
940 os::malloc(sizeof(Klass*) * _class_count, mtClass);
941 if (_scratch_classes == NULL) {
942 return JVMTI_ERROR_OUT_OF_MEMORY;
943 }
944 // Zero initialize the _scratch_classes array.
945 for (int i = 0; i < _class_count; i++) {
946 _scratch_classes[i] = NULL;
947 }
949 ResourceMark rm(THREAD);
951 JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current());
952 // state can only be NULL if the current thread is exiting which
953 // should not happen since we're trying to do a RedefineClasses
954 guarantee(state != NULL, "exiting thread calling load_new_class_versions");
955 for (int i = 0; i < _class_count; i++) {
956 // Create HandleMark so that any handles created while loading new class
957 // versions are deleted. Constant pools are deallocated while merging
958 // constant pools
959 HandleMark hm(THREAD);
961 oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass);
962 // classes for primitives cannot be redefined
963 if (!is_modifiable_class(mirror)) {
964 return JVMTI_ERROR_UNMODIFIABLE_CLASS;
965 }
966 Klass* the_class_oop = java_lang_Class::as_Klass(mirror);
967 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
968 Symbol* the_class_sym = the_class->name();
970 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
971 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
972 ("loading name=%s kind=%d (avail_mem=" UINT64_FORMAT "K)",
973 the_class->external_name(), _class_load_kind,
974 os::available_memory() >> 10));
976 ClassFileStream st((u1*) _class_defs[i].class_bytes,
977 _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__");
979 // Parse the stream.
980 Handle the_class_loader(THREAD, the_class->class_loader());
981 Handle protection_domain(THREAD, the_class->protection_domain());
982 // Set redefined class handle in JvmtiThreadState class.
983 // This redefined class is sent to agent event handler for class file
984 // load hook event.
985 state->set_class_being_redefined(&the_class, _class_load_kind);
987 Klass* k = SystemDictionary::parse_stream(the_class_sym,
988 the_class_loader,
989 protection_domain,
990 &st,
991 THREAD);
992 // Clear class_being_redefined just to be sure.
993 state->clear_class_being_redefined();
995 // TODO: if this is retransform, and nothing changed we can skip it
997 instanceKlassHandle scratch_class (THREAD, k);
999 // Need to clean up allocated InstanceKlass if there's an error so assign
1000 // the result here. Caller deallocates all the scratch classes in case of
1001 // an error.
1002 _scratch_classes[i] = k;
1004 if (HAS_PENDING_EXCEPTION) {
1005 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1006 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1007 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'",
1008 ex_name->as_C_string()));
1009 CLEAR_PENDING_EXCEPTION;
1011 if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) {
1012 return JVMTI_ERROR_UNSUPPORTED_VERSION;
1013 } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) {
1014 return JVMTI_ERROR_INVALID_CLASS_FORMAT;
1015 } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) {
1016 return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
1017 } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) {
1018 // The message will be "XXX (wrong name: YYY)"
1019 return JVMTI_ERROR_NAMES_DONT_MATCH;
1020 } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1021 return JVMTI_ERROR_OUT_OF_MEMORY;
1022 } else { // Just in case more exceptions can be thrown..
1023 return JVMTI_ERROR_FAILS_VERIFICATION;
1024 }
1025 }
1027 // Ensure class is linked before redefine
1028 if (!the_class->is_linked()) {
1029 the_class->link_class(THREAD);
1030 if (HAS_PENDING_EXCEPTION) {
1031 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1032 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1033 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'",
1034 ex_name->as_C_string()));
1035 CLEAR_PENDING_EXCEPTION;
1036 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1037 return JVMTI_ERROR_OUT_OF_MEMORY;
1038 } else {
1039 return JVMTI_ERROR_INTERNAL;
1040 }
1041 }
1042 }
1044 // Do the validity checks in compare_and_normalize_class_versions()
1045 // before verifying the byte codes. By doing these checks first, we
1046 // limit the number of functions that require redirection from
1047 // the_class to scratch_class. In particular, we don't have to
1048 // modify JNI GetSuperclass() and thus won't change its performance.
1049 jvmtiError res = compare_and_normalize_class_versions(the_class,
1050 scratch_class);
1051 if (res != JVMTI_ERROR_NONE) {
1052 return res;
1053 }
1055 // verify what the caller passed us
1056 {
1057 // The bug 6214132 caused the verification to fail.
1058 // Information about the_class and scratch_class is temporarily
1059 // recorded into jvmtiThreadState. This data is used to redirect
1060 // the_class to scratch_class in the JVM_* functions called by the
1061 // verifier. Please, refer to jvmtiThreadState.hpp for the detailed
1062 // description.
1063 RedefineVerifyMark rvm(&the_class, &scratch_class, state);
1064 Verifier::verify(
1065 scratch_class, Verifier::ThrowException, true, THREAD);
1066 }
1068 if (HAS_PENDING_EXCEPTION) {
1069 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1070 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1071 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1072 ("verify_byte_codes exception: '%s'", ex_name->as_C_string()));
1073 CLEAR_PENDING_EXCEPTION;
1074 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1075 return JVMTI_ERROR_OUT_OF_MEMORY;
1076 } else {
1077 // tell the caller the bytecodes are bad
1078 return JVMTI_ERROR_FAILS_VERIFICATION;
1079 }
1080 }
1082 res = merge_cp_and_rewrite(the_class, scratch_class, THREAD);
1083 if (HAS_PENDING_EXCEPTION) {
1084 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1085 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1086 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1087 ("merge_cp_and_rewrite exception: '%s'", ex_name->as_C_string()));
1088 CLEAR_PENDING_EXCEPTION;
1089 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1090 return JVMTI_ERROR_OUT_OF_MEMORY;
1091 } else {
1092 return JVMTI_ERROR_INTERNAL;
1093 }
1094 }
1096 if (VerifyMergedCPBytecodes) {
1097 // verify what we have done during constant pool merging
1098 {
1099 RedefineVerifyMark rvm(&the_class, &scratch_class, state);
1100 Verifier::verify(scratch_class, Verifier::ThrowException, true, THREAD);
1101 }
1103 if (HAS_PENDING_EXCEPTION) {
1104 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1105 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1106 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1107 ("verify_byte_codes post merge-CP exception: '%s'",
1108 ex_name->as_C_string()));
1109 CLEAR_PENDING_EXCEPTION;
1110 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1111 return JVMTI_ERROR_OUT_OF_MEMORY;
1112 } else {
1113 // tell the caller that constant pool merging screwed up
1114 return JVMTI_ERROR_INTERNAL;
1115 }
1116 }
1117 }
1119 Rewriter::rewrite(scratch_class, THREAD);
1120 if (!HAS_PENDING_EXCEPTION) {
1121 scratch_class->link_methods(THREAD);
1122 }
1123 if (HAS_PENDING_EXCEPTION) {
1124 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1125 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1126 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1127 ("Rewriter::rewrite or link_methods exception: '%s'", ex_name->as_C_string()));
1128 CLEAR_PENDING_EXCEPTION;
1129 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1130 return JVMTI_ERROR_OUT_OF_MEMORY;
1131 } else {
1132 return JVMTI_ERROR_INTERNAL;
1133 }
1134 }
1136 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1137 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
1138 ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)",
1139 the_class->external_name(), os::available_memory() >> 10));
1140 }
1142 return JVMTI_ERROR_NONE;
1143 }
1146 // Map old_index to new_index as needed. scratch_cp is only needed
1147 // for RC_TRACE() calls.
1148 void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp,
1149 int old_index, int new_index) {
1150 if (find_new_index(old_index) != 0) {
1151 // old_index is already mapped
1152 return;
1153 }
1155 if (old_index == new_index) {
1156 // no mapping is needed
1157 return;
1158 }
1160 _index_map_p->at_put(old_index, new_index);
1161 _index_map_count++;
1163 RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d",
1164 scratch_cp->tag_at(old_index).value(), old_index, new_index));
1165 } // end map_index()
1168 // Map old_index to new_index as needed.
1169 void VM_RedefineClasses::map_operand_index(int old_index, int new_index) {
1170 if (find_new_operand_index(old_index) != -1) {
1171 // old_index is already mapped
1172 return;
1173 }
1175 if (old_index == new_index) {
1176 // no mapping is needed
1177 return;
1178 }
1180 _operands_index_map_p->at_put(old_index, new_index);
1181 _operands_index_map_count++;
1183 RC_TRACE(0x00040000, ("mapped bootstrap specifier at index %d to %d", old_index, new_index));
1184 } // end map_index()
1187 // Merge old_cp and scratch_cp and return the results of the merge via
1188 // merge_cp_p. The number of entries in *merge_cp_p is returned via
1189 // merge_cp_length_p. The entries in old_cp occupy the same locations
1190 // in *merge_cp_p. Also creates a map of indices from entries in
1191 // scratch_cp to the corresponding entry in *merge_cp_p. Index map
1192 // entries are only created for entries in scratch_cp that occupy a
1193 // different location in *merged_cp_p.
1194 bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp,
1195 constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p,
1196 int *merge_cp_length_p, TRAPS) {
1198 if (merge_cp_p == NULL) {
1199 assert(false, "caller must provide scratch constantPool");
1200 return false; // robustness
1201 }
1202 if (merge_cp_length_p == NULL) {
1203 assert(false, "caller must provide scratch CP length");
1204 return false; // robustness
1205 }
1206 // Worst case we need old_cp->length() + scratch_cp()->length(),
1207 // but the caller might be smart so make sure we have at least
1208 // the minimum.
1209 if ((*merge_cp_p)->length() < old_cp->length()) {
1210 assert(false, "merge area too small");
1211 return false; // robustness
1212 }
1214 RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1215 ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(),
1216 scratch_cp->length()));
1218 {
1219 // Pass 0:
1220 // The old_cp is copied to *merge_cp_p; this means that any code
1221 // using old_cp does not have to change. This work looks like a
1222 // perfect fit for ConstantPool*::copy_cp_to(), but we need to
1223 // handle one special case:
1224 // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass
1225 // This will make verification happy.
1227 int old_i; // index into old_cp
1229 // index zero (0) is not used in constantPools
1230 for (old_i = 1; old_i < old_cp->length(); old_i++) {
1231 // leave debugging crumb
1232 jbyte old_tag = old_cp->tag_at(old_i).value();
1233 switch (old_tag) {
1234 case JVM_CONSTANT_Class:
1235 case JVM_CONSTANT_UnresolvedClass:
1236 // revert the copy to JVM_CONSTANT_UnresolvedClass
1237 // May be resolving while calling this so do the same for
1238 // JVM_CONSTANT_UnresolvedClass (klass_name_at() deals with transition)
1239 (*merge_cp_p)->unresolved_klass_at_put(old_i,
1240 old_cp->klass_name_at(old_i));
1241 break;
1243 case JVM_CONSTANT_Double:
1244 case JVM_CONSTANT_Long:
1245 // just copy the entry to *merge_cp_p, but double and long take
1246 // two constant pool entries
1247 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
1248 old_i++;
1249 break;
1251 default:
1252 // just copy the entry to *merge_cp_p
1253 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
1254 break;
1255 }
1256 } // end for each old_cp entry
1258 ConstantPool::copy_operands(old_cp, *merge_cp_p, CHECK_0);
1259 (*merge_cp_p)->extend_operands(scratch_cp, CHECK_0);
1261 // We don't need to sanity check that *merge_cp_length_p is within
1262 // *merge_cp_p bounds since we have the minimum on-entry check above.
1263 (*merge_cp_length_p) = old_i;
1264 }
1266 // merge_cp_len should be the same as old_cp->length() at this point
1267 // so this trace message is really a "warm-and-breathing" message.
1268 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1269 ("after pass 0: merge_cp_len=%d", *merge_cp_length_p));
1271 int scratch_i; // index into scratch_cp
1272 {
1273 // Pass 1a:
1274 // Compare scratch_cp entries to the old_cp entries that we have
1275 // already copied to *merge_cp_p. In this pass, we are eliminating
1276 // exact duplicates (matching entry at same index) so we only
1277 // compare entries in the common indice range.
1278 int increment = 1;
1279 int pass1a_length = MIN2(old_cp->length(), scratch_cp->length());
1280 for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) {
1281 switch (scratch_cp->tag_at(scratch_i).value()) {
1282 case JVM_CONSTANT_Double:
1283 case JVM_CONSTANT_Long:
1284 // double and long take two constant pool entries
1285 increment = 2;
1286 break;
1288 default:
1289 increment = 1;
1290 break;
1291 }
1293 bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p,
1294 scratch_i, CHECK_0);
1295 if (match) {
1296 // found a match at the same index so nothing more to do
1297 continue;
1298 } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i,
1299 *merge_cp_p, scratch_i)) {
1300 // The mismatch in compare_entry_to() above is because of a
1301 // resolved versus unresolved class entry at the same index
1302 // with the same string value. Since Pass 0 reverted any
1303 // class entries to unresolved class entries in *merge_cp_p,
1304 // we go with the unresolved class entry.
1305 continue;
1306 }
1308 int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p,
1309 CHECK_0);
1310 if (found_i != 0) {
1311 guarantee(found_i != scratch_i,
1312 "compare_entry_to() and find_matching_entry() do not agree");
1314 // Found a matching entry somewhere else in *merge_cp_p so
1315 // just need a mapping entry.
1316 map_index(scratch_cp, scratch_i, found_i);
1317 continue;
1318 }
1320 // The find_matching_entry() call above could fail to find a match
1321 // due to a resolved versus unresolved class or string entry situation
1322 // like we solved above with the is_unresolved_*_mismatch() calls.
1323 // However, we would have to call is_unresolved_*_mismatch() over
1324 // all of *merge_cp_p (potentially) and that doesn't seem to be
1325 // worth the time.
1327 // No match found so we have to append this entry and any unique
1328 // referenced entries to *merge_cp_p.
1329 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1330 CHECK_0);
1331 }
1332 }
1334 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1335 ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1336 *merge_cp_length_p, scratch_i, _index_map_count));
1338 if (scratch_i < scratch_cp->length()) {
1339 // Pass 1b:
1340 // old_cp is smaller than scratch_cp so there are entries in
1341 // scratch_cp that we have not yet processed. We take care of
1342 // those now.
1343 int increment = 1;
1344 for (; scratch_i < scratch_cp->length(); scratch_i += increment) {
1345 switch (scratch_cp->tag_at(scratch_i).value()) {
1346 case JVM_CONSTANT_Double:
1347 case JVM_CONSTANT_Long:
1348 // double and long take two constant pool entries
1349 increment = 2;
1350 break;
1352 default:
1353 increment = 1;
1354 break;
1355 }
1357 int found_i =
1358 scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0);
1359 if (found_i != 0) {
1360 // Found a matching entry somewhere else in *merge_cp_p so
1361 // just need a mapping entry.
1362 map_index(scratch_cp, scratch_i, found_i);
1363 continue;
1364 }
1366 // No match found so we have to append this entry and any unique
1367 // referenced entries to *merge_cp_p.
1368 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1369 CHECK_0);
1370 }
1372 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1373 ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1374 *merge_cp_length_p, scratch_i, _index_map_count));
1375 }
1376 finalize_operands_merge(*merge_cp_p, THREAD);
1378 return true;
1379 } // end merge_constant_pools()
1382 // Scoped object to clean up the constant pool(s) created for merging
1383 class MergeCPCleaner {
1384 ClassLoaderData* _loader_data;
1385 ConstantPool* _cp;
1386 ConstantPool* _scratch_cp;
1387 public:
1388 MergeCPCleaner(ClassLoaderData* loader_data, ConstantPool* merge_cp) :
1389 _loader_data(loader_data), _cp(merge_cp), _scratch_cp(NULL) {}
1390 ~MergeCPCleaner() {
1391 _loader_data->add_to_deallocate_list(_cp);
1392 if (_scratch_cp != NULL) {
1393 _loader_data->add_to_deallocate_list(_scratch_cp);
1394 }
1395 }
1396 void add_scratch_cp(ConstantPool* scratch_cp) { _scratch_cp = scratch_cp; }
1397 };
1399 // Merge constant pools between the_class and scratch_class and
1400 // potentially rewrite bytecodes in scratch_class to use the merged
1401 // constant pool.
1402 jvmtiError VM_RedefineClasses::merge_cp_and_rewrite(
1403 instanceKlassHandle the_class, instanceKlassHandle scratch_class,
1404 TRAPS) {
1405 // worst case merged constant pool length is old and new combined
1406 int merge_cp_length = the_class->constants()->length()
1407 + scratch_class->constants()->length();
1409 // Constant pools are not easily reused so we allocate a new one
1410 // each time.
1411 // merge_cp is created unsafe for concurrent GC processing. It
1412 // should be marked safe before discarding it. Even though
1413 // garbage, if it crosses a card boundary, it may be scanned
1414 // in order to find the start of the first complete object on the card.
1415 ClassLoaderData* loader_data = the_class->class_loader_data();
1416 ConstantPool* merge_cp_oop =
1417 ConstantPool::allocate(loader_data,
1418 merge_cp_length,
1419 CHECK_(JVMTI_ERROR_OUT_OF_MEMORY));
1420 MergeCPCleaner cp_cleaner(loader_data, merge_cp_oop);
1422 HandleMark hm(THREAD); // make sure handles are cleared before
1423 // MergeCPCleaner clears out merge_cp_oop
1424 constantPoolHandle merge_cp(THREAD, merge_cp_oop);
1426 // Get constants() from the old class because it could have been rewritten
1427 // while we were at a safepoint allocating a new constant pool.
1428 constantPoolHandle old_cp(THREAD, the_class->constants());
1429 constantPoolHandle scratch_cp(THREAD, scratch_class->constants());
1431 // If the length changed, the class was redefined out from under us. Return
1432 // an error.
1433 if (merge_cp_length != the_class->constants()->length()
1434 + scratch_class->constants()->length()) {
1435 return JVMTI_ERROR_INTERNAL;
1436 }
1438 // Update the version number of the constant pool
1439 merge_cp->increment_and_save_version(old_cp->version());
1441 ResourceMark rm(THREAD);
1442 _index_map_count = 0;
1443 _index_map_p = new intArray(scratch_cp->length(), -1);
1445 _operands_cur_length = ConstantPool::operand_array_length(old_cp->operands());
1446 _operands_index_map_count = 0;
1447 _operands_index_map_p = new intArray(
1448 ConstantPool::operand_array_length(scratch_cp->operands()), -1);
1450 // reference to the cp holder is needed for copy_operands()
1451 merge_cp->set_pool_holder(scratch_class());
1452 bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp,
1453 &merge_cp_length, THREAD);
1454 merge_cp->set_pool_holder(NULL);
1456 if (!result) {
1457 // The merge can fail due to memory allocation failure or due
1458 // to robustness checks.
1459 return JVMTI_ERROR_INTERNAL;
1460 }
1462 RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1463 ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count));
1465 if (_index_map_count == 0) {
1466 // there is nothing to map between the new and merged constant pools
1468 if (old_cp->length() == scratch_cp->length()) {
1469 // The old and new constant pools are the same length and the
1470 // index map is empty. This means that the three constant pools
1471 // are equivalent (but not the same). Unfortunately, the new
1472 // constant pool has not gone through link resolution nor have
1473 // the new class bytecodes gone through constant pool cache
1474 // rewriting so we can't use the old constant pool with the new
1475 // class.
1477 // toss the merged constant pool at return
1478 } else if (old_cp->length() < scratch_cp->length()) {
1479 // The old constant pool has fewer entries than the new constant
1480 // pool and the index map is empty. This means the new constant
1481 // pool is a superset of the old constant pool. However, the old
1482 // class bytecodes have already gone through constant pool cache
1483 // rewriting so we can't use the new constant pool with the old
1484 // class.
1486 // toss the merged constant pool at return
1487 } else {
1488 // The old constant pool has more entries than the new constant
1489 // pool and the index map is empty. This means that both the old
1490 // and merged constant pools are supersets of the new constant
1491 // pool.
1493 // Replace the new constant pool with a shrunken copy of the
1494 // merged constant pool
1495 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length,
1496 CHECK_(JVMTI_ERROR_OUT_OF_MEMORY));
1497 // The new constant pool replaces scratch_cp so have cleaner clean it up.
1498 // It can't be cleaned up while there are handles to it.
1499 cp_cleaner.add_scratch_cp(scratch_cp());
1500 }
1501 } else {
1502 if (RC_TRACE_ENABLED(0x00040000)) {
1503 // don't want to loop unless we are tracing
1504 int count = 0;
1505 for (int i = 1; i < _index_map_p->length(); i++) {
1506 int value = _index_map_p->at(i);
1508 if (value != -1) {
1509 RC_TRACE_WITH_THREAD(0x00040000, THREAD,
1510 ("index_map[%d]: old=%d new=%d", count, i, value));
1511 count++;
1512 }
1513 }
1514 }
1516 // We have entries mapped between the new and merged constant pools
1517 // so we have to rewrite some constant pool references.
1518 if (!rewrite_cp_refs(scratch_class, THREAD)) {
1519 return JVMTI_ERROR_INTERNAL;
1520 }
1522 // Replace the new constant pool with a shrunken copy of the
1523 // merged constant pool so now the rewritten bytecodes have
1524 // valid references; the previous new constant pool will get
1525 // GCed.
1526 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length,
1527 CHECK_(JVMTI_ERROR_OUT_OF_MEMORY));
1528 // The new constant pool replaces scratch_cp so have cleaner clean it up.
1529 // It can't be cleaned up while there are handles to it.
1530 cp_cleaner.add_scratch_cp(scratch_cp());
1531 }
1533 return JVMTI_ERROR_NONE;
1534 } // end merge_cp_and_rewrite()
1537 // Rewrite constant pool references in klass scratch_class.
1538 bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
1539 TRAPS) {
1541 // rewrite constant pool references in the methods:
1542 if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) {
1543 // propagate failure back to caller
1544 return false;
1545 }
1547 // rewrite constant pool references in the class_annotations:
1548 if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) {
1549 // propagate failure back to caller
1550 return false;
1551 }
1553 // rewrite constant pool references in the fields_annotations:
1554 if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) {
1555 // propagate failure back to caller
1556 return false;
1557 }
1559 // rewrite constant pool references in the methods_annotations:
1560 if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) {
1561 // propagate failure back to caller
1562 return false;
1563 }
1565 // rewrite constant pool references in the methods_parameter_annotations:
1566 if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class,
1567 THREAD)) {
1568 // propagate failure back to caller
1569 return false;
1570 }
1572 // rewrite constant pool references in the methods_default_annotations:
1573 if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class,
1574 THREAD)) {
1575 // propagate failure back to caller
1576 return false;
1577 }
1579 // rewrite constant pool references in the class_type_annotations:
1580 if (!rewrite_cp_refs_in_class_type_annotations(scratch_class, THREAD)) {
1581 // propagate failure back to caller
1582 return false;
1583 }
1585 // rewrite constant pool references in the fields_type_annotations:
1586 if (!rewrite_cp_refs_in_fields_type_annotations(scratch_class, THREAD)) {
1587 // propagate failure back to caller
1588 return false;
1589 }
1591 // rewrite constant pool references in the methods_type_annotations:
1592 if (!rewrite_cp_refs_in_methods_type_annotations(scratch_class, THREAD)) {
1593 // propagate failure back to caller
1594 return false;
1595 }
1597 // There can be type annotations in the Code part of a method_info attribute.
1598 // These annotations are not accessible, even by reflection.
1599 // Currently they are not even parsed by the ClassFileParser.
1600 // If runtime access is added they will also need to be rewritten.
1602 // rewrite source file name index:
1603 u2 source_file_name_idx = scratch_class->source_file_name_index();
1604 if (source_file_name_idx != 0) {
1605 u2 new_source_file_name_idx = find_new_index(source_file_name_idx);
1606 if (new_source_file_name_idx != 0) {
1607 scratch_class->set_source_file_name_index(new_source_file_name_idx);
1608 }
1609 }
1611 // rewrite class generic signature index:
1612 u2 generic_signature_index = scratch_class->generic_signature_index();
1613 if (generic_signature_index != 0) {
1614 u2 new_generic_signature_index = find_new_index(generic_signature_index);
1615 if (new_generic_signature_index != 0) {
1616 scratch_class->set_generic_signature_index(new_generic_signature_index);
1617 }
1618 }
1620 return true;
1621 } // end rewrite_cp_refs()
1623 // Rewrite constant pool references in the methods.
1624 bool VM_RedefineClasses::rewrite_cp_refs_in_methods(
1625 instanceKlassHandle scratch_class, TRAPS) {
1627 Array<Method*>* methods = scratch_class->methods();
1629 if (methods == NULL || methods->length() == 0) {
1630 // no methods so nothing to do
1631 return true;
1632 }
1634 // rewrite constant pool references in the methods:
1635 for (int i = methods->length() - 1; i >= 0; i--) {
1636 methodHandle method(THREAD, methods->at(i));
1637 methodHandle new_method;
1638 rewrite_cp_refs_in_method(method, &new_method, THREAD);
1639 if (!new_method.is_null()) {
1640 // the method has been replaced so save the new method version
1641 // even in the case of an exception. original method is on the
1642 // deallocation list.
1643 methods->at_put(i, new_method());
1644 }
1645 if (HAS_PENDING_EXCEPTION) {
1646 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1647 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1648 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1649 ("rewrite_cp_refs_in_method exception: '%s'", ex_name->as_C_string()));
1650 // Need to clear pending exception here as the super caller sets
1651 // the JVMTI_ERROR_INTERNAL if the returned value is false.
1652 CLEAR_PENDING_EXCEPTION;
1653 return false;
1654 }
1655 }
1657 return true;
1658 }
1661 // Rewrite constant pool references in the specific method. This code
1662 // was adapted from Rewriter::rewrite_method().
1663 void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method,
1664 methodHandle *new_method_p, TRAPS) {
1666 *new_method_p = methodHandle(); // default is no new method
1668 // We cache a pointer to the bytecodes here in code_base. If GC
1669 // moves the Method*, then the bytecodes will also move which
1670 // will likely cause a crash. We create a No_Safepoint_Verifier
1671 // object to detect whether we pass a possible safepoint in this
1672 // code block.
1673 No_Safepoint_Verifier nsv;
1675 // Bytecodes and their length
1676 address code_base = method->code_base();
1677 int code_length = method->code_size();
1679 int bc_length;
1680 for (int bci = 0; bci < code_length; bci += bc_length) {
1681 address bcp = code_base + bci;
1682 Bytecodes::Code c = (Bytecodes::Code)(*bcp);
1684 bc_length = Bytecodes::length_for(c);
1685 if (bc_length == 0) {
1686 // More complicated bytecodes report a length of zero so
1687 // we have to try again a slightly different way.
1688 bc_length = Bytecodes::length_at(method(), bcp);
1689 }
1691 assert(bc_length != 0, "impossible bytecode length");
1693 switch (c) {
1694 case Bytecodes::_ldc:
1695 {
1696 int cp_index = *(bcp + 1);
1697 int new_index = find_new_index(cp_index);
1699 if (StressLdcRewrite && new_index == 0) {
1700 // If we are stressing ldc -> ldc_w rewriting, then we
1701 // always need a new_index value.
1702 new_index = cp_index;
1703 }
1704 if (new_index != 0) {
1705 // the original index is mapped so we have more work to do
1706 if (!StressLdcRewrite && new_index <= max_jubyte) {
1707 // The new value can still use ldc instead of ldc_w
1708 // unless we are trying to stress ldc -> ldc_w rewriting
1709 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1710 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1711 bcp, cp_index, new_index));
1712 *(bcp + 1) = new_index;
1713 } else {
1714 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1715 ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d",
1716 Bytecodes::name(c), bcp, cp_index, new_index));
1717 // the new value needs ldc_w instead of ldc
1718 u_char inst_buffer[4]; // max instruction size is 4 bytes
1719 bcp = (address)inst_buffer;
1720 // construct new instruction sequence
1721 *bcp = Bytecodes::_ldc_w;
1722 bcp++;
1723 // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w.
1724 // See comment below for difference between put_Java_u2()
1725 // and put_native_u2().
1726 Bytes::put_Java_u2(bcp, new_index);
1728 Relocator rc(method, NULL /* no RelocatorListener needed */);
1729 methodHandle m;
1730 {
1731 Pause_No_Safepoint_Verifier pnsv(&nsv);
1733 // ldc is 2 bytes and ldc_w is 3 bytes
1734 m = rc.insert_space_at(bci, 3, inst_buffer, CHECK);
1735 }
1737 // return the new method so that the caller can update
1738 // the containing class
1739 *new_method_p = method = m;
1740 // switch our bytecode processing loop from the old method
1741 // to the new method
1742 code_base = method->code_base();
1743 code_length = method->code_size();
1744 bcp = code_base + bci;
1745 c = (Bytecodes::Code)(*bcp);
1746 bc_length = Bytecodes::length_for(c);
1747 assert(bc_length != 0, "sanity check");
1748 } // end we need ldc_w instead of ldc
1749 } // end if there is a mapped index
1750 } break;
1752 // these bytecodes have a two-byte constant pool index
1753 case Bytecodes::_anewarray : // fall through
1754 case Bytecodes::_checkcast : // fall through
1755 case Bytecodes::_getfield : // fall through
1756 case Bytecodes::_getstatic : // fall through
1757 case Bytecodes::_instanceof : // fall through
1758 case Bytecodes::_invokedynamic : // fall through
1759 case Bytecodes::_invokeinterface: // fall through
1760 case Bytecodes::_invokespecial : // fall through
1761 case Bytecodes::_invokestatic : // fall through
1762 case Bytecodes::_invokevirtual : // fall through
1763 case Bytecodes::_ldc_w : // fall through
1764 case Bytecodes::_ldc2_w : // fall through
1765 case Bytecodes::_multianewarray : // fall through
1766 case Bytecodes::_new : // fall through
1767 case Bytecodes::_putfield : // fall through
1768 case Bytecodes::_putstatic :
1769 {
1770 address p = bcp + 1;
1771 int cp_index = Bytes::get_Java_u2(p);
1772 int new_index = find_new_index(cp_index);
1773 if (new_index != 0) {
1774 // the original index is mapped so update w/ new value
1775 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1776 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1777 bcp, cp_index, new_index));
1778 // Rewriter::rewrite_method() uses put_native_u2() in this
1779 // situation because it is reusing the constant pool index
1780 // location for a native index into the ConstantPoolCache.
1781 // Since we are updating the constant pool index prior to
1782 // verification and ConstantPoolCache initialization, we
1783 // need to keep the new index in Java byte order.
1784 Bytes::put_Java_u2(p, new_index);
1785 }
1786 } break;
1787 }
1788 } // end for each bytecode
1790 // We also need to rewrite the parameter name indexes, if there is
1791 // method parameter data present
1792 if(method->has_method_parameters()) {
1793 const int len = method->method_parameters_length();
1794 MethodParametersElement* elem = method->method_parameters_start();
1796 for (int i = 0; i < len; i++) {
1797 const u2 cp_index = elem[i].name_cp_index;
1798 const u2 new_cp_index = find_new_index(cp_index);
1799 if (new_cp_index != 0) {
1800 elem[i].name_cp_index = new_cp_index;
1801 }
1802 }
1803 }
1804 } // end rewrite_cp_refs_in_method()
1807 // Rewrite constant pool references in the class_annotations field.
1808 bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations(
1809 instanceKlassHandle scratch_class, TRAPS) {
1811 AnnotationArray* class_annotations = scratch_class->class_annotations();
1812 if (class_annotations == NULL || class_annotations->length() == 0) {
1813 // no class_annotations so nothing to do
1814 return true;
1815 }
1817 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1818 ("class_annotations length=%d", class_annotations->length()));
1820 int byte_i = 0; // byte index into class_annotations
1821 return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i,
1822 THREAD);
1823 }
1826 // Rewrite constant pool references in an annotations typeArray. This
1827 // "structure" is adapted from the RuntimeVisibleAnnotations_attribute
1828 // that is described in section 4.8.15 of the 2nd-edition of the VM spec:
1829 //
1830 // annotations_typeArray {
1831 // u2 num_annotations;
1832 // annotation annotations[num_annotations];
1833 // }
1834 //
1835 bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray(
1836 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1838 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1839 // not enough room for num_annotations field
1840 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1841 ("length() is too small for num_annotations field"));
1842 return false;
1843 }
1845 u2 num_annotations = Bytes::get_Java_u2((address)
1846 annotations_typeArray->adr_at(byte_i_ref));
1847 byte_i_ref += 2;
1849 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1850 ("num_annotations=%d", num_annotations));
1852 int calc_num_annotations = 0;
1853 for (; calc_num_annotations < num_annotations; calc_num_annotations++) {
1854 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1855 byte_i_ref, THREAD)) {
1856 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1857 ("bad annotation_struct at %d", calc_num_annotations));
1858 // propagate failure back to caller
1859 return false;
1860 }
1861 }
1862 assert(num_annotations == calc_num_annotations, "sanity check");
1864 return true;
1865 } // end rewrite_cp_refs_in_annotations_typeArray()
1868 // Rewrite constant pool references in the annotation struct portion of
1869 // an annotations_typeArray. This "structure" is from section 4.8.15 of
1870 // the 2nd-edition of the VM spec:
1871 //
1872 // struct annotation {
1873 // u2 type_index;
1874 // u2 num_element_value_pairs;
1875 // {
1876 // u2 element_name_index;
1877 // element_value value;
1878 // } element_value_pairs[num_element_value_pairs];
1879 // }
1880 //
1881 bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct(
1882 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1883 if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) {
1884 // not enough room for smallest annotation_struct
1885 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1886 ("length() is too small for annotation_struct"));
1887 return false;
1888 }
1890 u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray,
1891 byte_i_ref, "mapped old type_index=%d", THREAD);
1893 u2 num_element_value_pairs = Bytes::get_Java_u2((address)
1894 annotations_typeArray->adr_at(byte_i_ref));
1895 byte_i_ref += 2;
1897 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1898 ("type_index=%d num_element_value_pairs=%d", type_index,
1899 num_element_value_pairs));
1901 int calc_num_element_value_pairs = 0;
1902 for (; calc_num_element_value_pairs < num_element_value_pairs;
1903 calc_num_element_value_pairs++) {
1904 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1905 // not enough room for another element_name_index, let alone
1906 // the rest of another component
1907 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1908 ("length() is too small for element_name_index"));
1909 return false;
1910 }
1912 u2 element_name_index = rewrite_cp_ref_in_annotation_data(
1913 annotations_typeArray, byte_i_ref,
1914 "mapped old element_name_index=%d", THREAD);
1916 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1917 ("element_name_index=%d", element_name_index));
1919 if (!rewrite_cp_refs_in_element_value(annotations_typeArray,
1920 byte_i_ref, THREAD)) {
1921 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1922 ("bad element_value at %d", calc_num_element_value_pairs));
1923 // propagate failure back to caller
1924 return false;
1925 }
1926 } // end for each component
1927 assert(num_element_value_pairs == calc_num_element_value_pairs,
1928 "sanity check");
1930 return true;
1931 } // end rewrite_cp_refs_in_annotation_struct()
1934 // Rewrite a constant pool reference at the current position in
1935 // annotations_typeArray if needed. Returns the original constant
1936 // pool reference if a rewrite was not needed or the new constant
1937 // pool reference if a rewrite was needed.
1938 PRAGMA_DIAG_PUSH
1939 PRAGMA_FORMAT_NONLITERAL_IGNORED
1940 u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data(
1941 AnnotationArray* annotations_typeArray, int &byte_i_ref,
1942 const char * trace_mesg, TRAPS) {
1944 address cp_index_addr = (address)
1945 annotations_typeArray->adr_at(byte_i_ref);
1946 u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr);
1947 u2 new_cp_index = find_new_index(old_cp_index);
1948 if (new_cp_index != 0) {
1949 RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index));
1950 Bytes::put_Java_u2(cp_index_addr, new_cp_index);
1951 old_cp_index = new_cp_index;
1952 }
1953 byte_i_ref += 2;
1954 return old_cp_index;
1955 }
1956 PRAGMA_DIAG_POP
1959 // Rewrite constant pool references in the element_value portion of an
1960 // annotations_typeArray. This "structure" is from section 4.8.15.1 of
1961 // the 2nd-edition of the VM spec:
1962 //
1963 // struct element_value {
1964 // u1 tag;
1965 // union {
1966 // u2 const_value_index;
1967 // {
1968 // u2 type_name_index;
1969 // u2 const_name_index;
1970 // } enum_const_value;
1971 // u2 class_info_index;
1972 // annotation annotation_value;
1973 // struct {
1974 // u2 num_values;
1975 // element_value values[num_values];
1976 // } array_value;
1977 // } value;
1978 // }
1979 //
1980 bool VM_RedefineClasses::rewrite_cp_refs_in_element_value(
1981 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1983 if ((byte_i_ref + 1) > annotations_typeArray->length()) {
1984 // not enough room for a tag let alone the rest of an element_value
1985 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1986 ("length() is too small for a tag"));
1987 return false;
1988 }
1990 u1 tag = annotations_typeArray->at(byte_i_ref);
1991 byte_i_ref++;
1992 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag));
1994 switch (tag) {
1995 // These BaseType tag values are from Table 4.2 in VM spec:
1996 case 'B': // byte
1997 case 'C': // char
1998 case 'D': // double
1999 case 'F': // float
2000 case 'I': // int
2001 case 'J': // long
2002 case 'S': // short
2003 case 'Z': // boolean
2005 // The remaining tag values are from Table 4.8 in the 2nd-edition of
2006 // the VM spec:
2007 case 's':
2008 {
2009 // For the above tag values (including the BaseType values),
2010 // value.const_value_index is right union field.
2012 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
2013 // not enough room for a const_value_index
2014 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2015 ("length() is too small for a const_value_index"));
2016 return false;
2017 }
2019 u2 const_value_index = rewrite_cp_ref_in_annotation_data(
2020 annotations_typeArray, byte_i_ref,
2021 "mapped old const_value_index=%d", THREAD);
2023 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2024 ("const_value_index=%d", const_value_index));
2025 } break;
2027 case 'e':
2028 {
2029 // for the above tag value, value.enum_const_value is right union field
2031 if ((byte_i_ref + 4) > annotations_typeArray->length()) {
2032 // not enough room for a enum_const_value
2033 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2034 ("length() is too small for a enum_const_value"));
2035 return false;
2036 }
2038 u2 type_name_index = rewrite_cp_ref_in_annotation_data(
2039 annotations_typeArray, byte_i_ref,
2040 "mapped old type_name_index=%d", THREAD);
2042 u2 const_name_index = rewrite_cp_ref_in_annotation_data(
2043 annotations_typeArray, byte_i_ref,
2044 "mapped old const_name_index=%d", THREAD);
2046 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2047 ("type_name_index=%d const_name_index=%d", type_name_index,
2048 const_name_index));
2049 } break;
2051 case 'c':
2052 {
2053 // for the above tag value, value.class_info_index is right union field
2055 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
2056 // not enough room for a class_info_index
2057 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2058 ("length() is too small for a class_info_index"));
2059 return false;
2060 }
2062 u2 class_info_index = rewrite_cp_ref_in_annotation_data(
2063 annotations_typeArray, byte_i_ref,
2064 "mapped old class_info_index=%d", THREAD);
2066 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2067 ("class_info_index=%d", class_info_index));
2068 } break;
2070 case '@':
2071 // For the above tag value, value.attr_value is the right union
2072 // field. This is a nested annotation.
2073 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
2074 byte_i_ref, THREAD)) {
2075 // propagate failure back to caller
2076 return false;
2077 }
2078 break;
2080 case '[':
2081 {
2082 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
2083 // not enough room for a num_values field
2084 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2085 ("length() is too small for a num_values field"));
2086 return false;
2087 }
2089 // For the above tag value, value.array_value is the right union
2090 // field. This is an array of nested element_value.
2091 u2 num_values = Bytes::get_Java_u2((address)
2092 annotations_typeArray->adr_at(byte_i_ref));
2093 byte_i_ref += 2;
2094 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values));
2096 int calc_num_values = 0;
2097 for (; calc_num_values < num_values; calc_num_values++) {
2098 if (!rewrite_cp_refs_in_element_value(
2099 annotations_typeArray, byte_i_ref, THREAD)) {
2100 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2101 ("bad nested element_value at %d", calc_num_values));
2102 // propagate failure back to caller
2103 return false;
2104 }
2105 }
2106 assert(num_values == calc_num_values, "sanity check");
2107 } break;
2109 default:
2110 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag));
2111 return false;
2112 } // end decode tag field
2114 return true;
2115 } // end rewrite_cp_refs_in_element_value()
2118 // Rewrite constant pool references in a fields_annotations field.
2119 bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations(
2120 instanceKlassHandle scratch_class, TRAPS) {
2122 Array<AnnotationArray*>* fields_annotations = scratch_class->fields_annotations();
2124 if (fields_annotations == NULL || fields_annotations->length() == 0) {
2125 // no fields_annotations so nothing to do
2126 return true;
2127 }
2129 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2130 ("fields_annotations length=%d", fields_annotations->length()));
2132 for (int i = 0; i < fields_annotations->length(); i++) {
2133 AnnotationArray* field_annotations = fields_annotations->at(i);
2134 if (field_annotations == NULL || field_annotations->length() == 0) {
2135 // this field does not have any annotations so skip it
2136 continue;
2137 }
2139 int byte_i = 0; // byte index into field_annotations
2140 if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i,
2141 THREAD)) {
2142 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2143 ("bad field_annotations at %d", i));
2144 // propagate failure back to caller
2145 return false;
2146 }
2147 }
2149 return true;
2150 } // end rewrite_cp_refs_in_fields_annotations()
2153 // Rewrite constant pool references in a methods_annotations field.
2154 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations(
2155 instanceKlassHandle scratch_class, TRAPS) {
2157 for (int i = 0; i < scratch_class->methods()->length(); i++) {
2158 Method* m = scratch_class->methods()->at(i);
2159 AnnotationArray* method_annotations = m->constMethod()->method_annotations();
2161 if (method_annotations == NULL || method_annotations->length() == 0) {
2162 // this method does not have any annotations so skip it
2163 continue;
2164 }
2166 int byte_i = 0; // byte index into method_annotations
2167 if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i,
2168 THREAD)) {
2169 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2170 ("bad method_annotations at %d", i));
2171 // propagate failure back to caller
2172 return false;
2173 }
2174 }
2176 return true;
2177 } // end rewrite_cp_refs_in_methods_annotations()
2180 // Rewrite constant pool references in a methods_parameter_annotations
2181 // field. This "structure" is adapted from the
2182 // RuntimeVisibleParameterAnnotations_attribute described in section
2183 // 4.8.17 of the 2nd-edition of the VM spec:
2184 //
2185 // methods_parameter_annotations_typeArray {
2186 // u1 num_parameters;
2187 // {
2188 // u2 num_annotations;
2189 // annotation annotations[num_annotations];
2190 // } parameter_annotations[num_parameters];
2191 // }
2192 //
2193 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations(
2194 instanceKlassHandle scratch_class, TRAPS) {
2196 for (int i = 0; i < scratch_class->methods()->length(); i++) {
2197 Method* m = scratch_class->methods()->at(i);
2198 AnnotationArray* method_parameter_annotations = m->constMethod()->parameter_annotations();
2199 if (method_parameter_annotations == NULL
2200 || method_parameter_annotations->length() == 0) {
2201 // this method does not have any parameter annotations so skip it
2202 continue;
2203 }
2205 if (method_parameter_annotations->length() < 1) {
2206 // not enough room for a num_parameters field
2207 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2208 ("length() is too small for a num_parameters field at %d", i));
2209 return false;
2210 }
2212 int byte_i = 0; // byte index into method_parameter_annotations
2214 u1 num_parameters = method_parameter_annotations->at(byte_i);
2215 byte_i++;
2217 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2218 ("num_parameters=%d", num_parameters));
2220 int calc_num_parameters = 0;
2221 for (; calc_num_parameters < num_parameters; calc_num_parameters++) {
2222 if (!rewrite_cp_refs_in_annotations_typeArray(
2223 method_parameter_annotations, byte_i, THREAD)) {
2224 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2225 ("bad method_parameter_annotations at %d", calc_num_parameters));
2226 // propagate failure back to caller
2227 return false;
2228 }
2229 }
2230 assert(num_parameters == calc_num_parameters, "sanity check");
2231 }
2233 return true;
2234 } // end rewrite_cp_refs_in_methods_parameter_annotations()
2237 // Rewrite constant pool references in a methods_default_annotations
2238 // field. This "structure" is adapted from the AnnotationDefault_attribute
2239 // that is described in section 4.8.19 of the 2nd-edition of the VM spec:
2240 //
2241 // methods_default_annotations_typeArray {
2242 // element_value default_value;
2243 // }
2244 //
2245 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations(
2246 instanceKlassHandle scratch_class, TRAPS) {
2248 for (int i = 0; i < scratch_class->methods()->length(); i++) {
2249 Method* m = scratch_class->methods()->at(i);
2250 AnnotationArray* method_default_annotations = m->constMethod()->default_annotations();
2251 if (method_default_annotations == NULL
2252 || method_default_annotations->length() == 0) {
2253 // this method does not have any default annotations so skip it
2254 continue;
2255 }
2257 int byte_i = 0; // byte index into method_default_annotations
2259 if (!rewrite_cp_refs_in_element_value(
2260 method_default_annotations, byte_i, THREAD)) {
2261 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2262 ("bad default element_value at %d", i));
2263 // propagate failure back to caller
2264 return false;
2265 }
2266 }
2268 return true;
2269 } // end rewrite_cp_refs_in_methods_default_annotations()
2272 // Rewrite constant pool references in a class_type_annotations field.
2273 bool VM_RedefineClasses::rewrite_cp_refs_in_class_type_annotations(
2274 instanceKlassHandle scratch_class, TRAPS) {
2276 AnnotationArray* class_type_annotations = scratch_class->class_type_annotations();
2277 if (class_type_annotations == NULL || class_type_annotations->length() == 0) {
2278 // no class_type_annotations so nothing to do
2279 return true;
2280 }
2282 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2283 ("class_type_annotations length=%d", class_type_annotations->length()));
2285 int byte_i = 0; // byte index into class_type_annotations
2286 return rewrite_cp_refs_in_type_annotations_typeArray(class_type_annotations,
2287 byte_i, "ClassFile", THREAD);
2288 } // end rewrite_cp_refs_in_class_type_annotations()
2291 // Rewrite constant pool references in a fields_type_annotations field.
2292 bool VM_RedefineClasses::rewrite_cp_refs_in_fields_type_annotations(
2293 instanceKlassHandle scratch_class, TRAPS) {
2295 Array<AnnotationArray*>* fields_type_annotations = scratch_class->fields_type_annotations();
2296 if (fields_type_annotations == NULL || fields_type_annotations->length() == 0) {
2297 // no fields_type_annotations so nothing to do
2298 return true;
2299 }
2301 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2302 ("fields_type_annotations length=%d", fields_type_annotations->length()));
2304 for (int i = 0; i < fields_type_annotations->length(); i++) {
2305 AnnotationArray* field_type_annotations = fields_type_annotations->at(i);
2306 if (field_type_annotations == NULL || field_type_annotations->length() == 0) {
2307 // this field does not have any annotations so skip it
2308 continue;
2309 }
2311 int byte_i = 0; // byte index into field_type_annotations
2312 if (!rewrite_cp_refs_in_type_annotations_typeArray(field_type_annotations,
2313 byte_i, "field_info", THREAD)) {
2314 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2315 ("bad field_type_annotations at %d", i));
2316 // propagate failure back to caller
2317 return false;
2318 }
2319 }
2321 return true;
2322 } // end rewrite_cp_refs_in_fields_type_annotations()
2325 // Rewrite constant pool references in a methods_type_annotations field.
2326 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_type_annotations(
2327 instanceKlassHandle scratch_class, TRAPS) {
2329 for (int i = 0; i < scratch_class->methods()->length(); i++) {
2330 Method* m = scratch_class->methods()->at(i);
2331 AnnotationArray* method_type_annotations = m->constMethod()->type_annotations();
2333 if (method_type_annotations == NULL || method_type_annotations->length() == 0) {
2334 // this method does not have any annotations so skip it
2335 continue;
2336 }
2338 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2339 ("methods type_annotations length=%d", method_type_annotations->length()));
2341 int byte_i = 0; // byte index into method_type_annotations
2342 if (!rewrite_cp_refs_in_type_annotations_typeArray(method_type_annotations,
2343 byte_i, "method_info", THREAD)) {
2344 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2345 ("bad method_type_annotations at %d", i));
2346 // propagate failure back to caller
2347 return false;
2348 }
2349 }
2351 return true;
2352 } // end rewrite_cp_refs_in_methods_type_annotations()
2355 // Rewrite constant pool references in a type_annotations
2356 // field. This "structure" is adapted from the
2357 // RuntimeVisibleTypeAnnotations_attribute described in
2358 // section 4.7.20 of the Java SE 8 Edition of the VM spec:
2359 //
2360 // type_annotations_typeArray {
2361 // u2 num_annotations;
2362 // type_annotation annotations[num_annotations];
2363 // }
2364 //
2365 bool VM_RedefineClasses::rewrite_cp_refs_in_type_annotations_typeArray(
2366 AnnotationArray* type_annotations_typeArray, int &byte_i_ref,
2367 const char * location_mesg, TRAPS) {
2369 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2370 // not enough room for num_annotations field
2371 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2372 ("length() is too small for num_annotations field"));
2373 return false;
2374 }
2376 u2 num_annotations = Bytes::get_Java_u2((address)
2377 type_annotations_typeArray->adr_at(byte_i_ref));
2378 byte_i_ref += 2;
2380 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2381 ("num_type_annotations=%d", num_annotations));
2383 int calc_num_annotations = 0;
2384 for (; calc_num_annotations < num_annotations; calc_num_annotations++) {
2385 if (!rewrite_cp_refs_in_type_annotation_struct(type_annotations_typeArray,
2386 byte_i_ref, location_mesg, THREAD)) {
2387 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2388 ("bad type_annotation_struct at %d", calc_num_annotations));
2389 // propagate failure back to caller
2390 return false;
2391 }
2392 }
2393 assert(num_annotations == calc_num_annotations, "sanity check");
2395 if (byte_i_ref != type_annotations_typeArray->length()) {
2396 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2397 ("read wrong amount of bytes at end of processing "
2398 "type_annotations_typeArray (%d of %d bytes were read)",
2399 byte_i_ref, type_annotations_typeArray->length()));
2400 return false;
2401 }
2403 return true;
2404 } // end rewrite_cp_refs_in_type_annotations_typeArray()
2407 // Rewrite constant pool references in a type_annotation
2408 // field. This "structure" is adapted from the
2409 // RuntimeVisibleTypeAnnotations_attribute described in
2410 // section 4.7.20 of the Java SE 8 Edition of the VM spec:
2411 //
2412 // type_annotation {
2413 // u1 target_type;
2414 // union {
2415 // type_parameter_target;
2416 // supertype_target;
2417 // type_parameter_bound_target;
2418 // empty_target;
2419 // method_formal_parameter_target;
2420 // throws_target;
2421 // localvar_target;
2422 // catch_target;
2423 // offset_target;
2424 // type_argument_target;
2425 // } target_info;
2426 // type_path target_path;
2427 // annotation anno;
2428 // }
2429 //
2430 bool VM_RedefineClasses::rewrite_cp_refs_in_type_annotation_struct(
2431 AnnotationArray* type_annotations_typeArray, int &byte_i_ref,
2432 const char * location_mesg, TRAPS) {
2434 if (!skip_type_annotation_target(type_annotations_typeArray,
2435 byte_i_ref, location_mesg, THREAD)) {
2436 return false;
2437 }
2439 if (!skip_type_annotation_type_path(type_annotations_typeArray,
2440 byte_i_ref, THREAD)) {
2441 return false;
2442 }
2444 if (!rewrite_cp_refs_in_annotation_struct(type_annotations_typeArray,
2445 byte_i_ref, THREAD)) {
2446 return false;
2447 }
2449 return true;
2450 } // end rewrite_cp_refs_in_type_annotation_struct()
2453 // Read, verify and skip over the target_type and target_info part
2454 // so that rewriting can continue in the later parts of the struct.
2455 //
2456 // u1 target_type;
2457 // union {
2458 // type_parameter_target;
2459 // supertype_target;
2460 // type_parameter_bound_target;
2461 // empty_target;
2462 // method_formal_parameter_target;
2463 // throws_target;
2464 // localvar_target;
2465 // catch_target;
2466 // offset_target;
2467 // type_argument_target;
2468 // } target_info;
2469 //
2470 bool VM_RedefineClasses::skip_type_annotation_target(
2471 AnnotationArray* type_annotations_typeArray, int &byte_i_ref,
2472 const char * location_mesg, TRAPS) {
2474 if ((byte_i_ref + 1) > type_annotations_typeArray->length()) {
2475 // not enough room for a target_type let alone the rest of a type_annotation
2476 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2477 ("length() is too small for a target_type"));
2478 return false;
2479 }
2481 u1 target_type = type_annotations_typeArray->at(byte_i_ref);
2482 byte_i_ref += 1;
2483 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("target_type=0x%.2x", target_type));
2484 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("location=%s", location_mesg));
2486 // Skip over target_info
2487 switch (target_type) {
2488 case 0x00:
2489 // kind: type parameter declaration of generic class or interface
2490 // location: ClassFile
2491 case 0x01:
2492 // kind: type parameter declaration of generic method or constructor
2493 // location: method_info
2495 {
2496 // struct:
2497 // type_parameter_target {
2498 // u1 type_parameter_index;
2499 // }
2500 //
2501 if ((byte_i_ref + 1) > type_annotations_typeArray->length()) {
2502 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2503 ("length() is too small for a type_parameter_target"));
2504 return false;
2505 }
2507 u1 type_parameter_index = type_annotations_typeArray->at(byte_i_ref);
2508 byte_i_ref += 1;
2510 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2511 ("type_parameter_target: type_parameter_index=%d",
2512 type_parameter_index));
2513 } break;
2515 case 0x10:
2516 // kind: type in extends clause of class or interface declaration
2517 // (including the direct superclass of an anonymous class declaration),
2518 // or in implements clause of interface declaration
2519 // location: ClassFile
2521 {
2522 // struct:
2523 // supertype_target {
2524 // u2 supertype_index;
2525 // }
2526 //
2527 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2528 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2529 ("length() is too small for a supertype_target"));
2530 return false;
2531 }
2533 u2 supertype_index = Bytes::get_Java_u2((address)
2534 type_annotations_typeArray->adr_at(byte_i_ref));
2535 byte_i_ref += 2;
2537 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2538 ("supertype_target: supertype_index=%d", supertype_index));
2539 } break;
2541 case 0x11:
2542 // kind: type in bound of type parameter declaration of generic class or interface
2543 // location: ClassFile
2544 case 0x12:
2545 // kind: type in bound of type parameter declaration of generic method or constructor
2546 // location: method_info
2548 {
2549 // struct:
2550 // type_parameter_bound_target {
2551 // u1 type_parameter_index;
2552 // u1 bound_index;
2553 // }
2554 //
2555 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2556 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2557 ("length() is too small for a type_parameter_bound_target"));
2558 return false;
2559 }
2561 u1 type_parameter_index = type_annotations_typeArray->at(byte_i_ref);
2562 byte_i_ref += 1;
2563 u1 bound_index = type_annotations_typeArray->at(byte_i_ref);
2564 byte_i_ref += 1;
2566 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2567 ("type_parameter_bound_target: type_parameter_index=%d, bound_index=%d",
2568 type_parameter_index, bound_index));
2569 } break;
2571 case 0x13:
2572 // kind: type in field declaration
2573 // location: field_info
2574 case 0x14:
2575 // kind: return type of method, or type of newly constructed object
2576 // location: method_info
2577 case 0x15:
2578 // kind: receiver type of method or constructor
2579 // location: method_info
2581 {
2582 // struct:
2583 // empty_target {
2584 // }
2585 //
2586 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2587 ("empty_target"));
2588 } break;
2590 case 0x16:
2591 // kind: type in formal parameter declaration of method, constructor, or lambda expression
2592 // location: method_info
2594 {
2595 // struct:
2596 // formal_parameter_target {
2597 // u1 formal_parameter_index;
2598 // }
2599 //
2600 if ((byte_i_ref + 1) > type_annotations_typeArray->length()) {
2601 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2602 ("length() is too small for a formal_parameter_target"));
2603 return false;
2604 }
2606 u1 formal_parameter_index = type_annotations_typeArray->at(byte_i_ref);
2607 byte_i_ref += 1;
2609 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2610 ("formal_parameter_target: formal_parameter_index=%d",
2611 formal_parameter_index));
2612 } break;
2614 case 0x17:
2615 // kind: type in throws clause of method or constructor
2616 // location: method_info
2618 {
2619 // struct:
2620 // throws_target {
2621 // u2 throws_type_index
2622 // }
2623 //
2624 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2625 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2626 ("length() is too small for a throws_target"));
2627 return false;
2628 }
2630 u2 throws_type_index = Bytes::get_Java_u2((address)
2631 type_annotations_typeArray->adr_at(byte_i_ref));
2632 byte_i_ref += 2;
2634 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2635 ("throws_target: throws_type_index=%d", throws_type_index));
2636 } break;
2638 case 0x40:
2639 // kind: type in local variable declaration
2640 // location: Code
2641 case 0x41:
2642 // kind: type in resource variable declaration
2643 // location: Code
2645 {
2646 // struct:
2647 // localvar_target {
2648 // u2 table_length;
2649 // struct {
2650 // u2 start_pc;
2651 // u2 length;
2652 // u2 index;
2653 // } table[table_length];
2654 // }
2655 //
2656 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2657 // not enough room for a table_length let alone the rest of a localvar_target
2658 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2659 ("length() is too small for a localvar_target table_length"));
2660 return false;
2661 }
2663 u2 table_length = Bytes::get_Java_u2((address)
2664 type_annotations_typeArray->adr_at(byte_i_ref));
2665 byte_i_ref += 2;
2667 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2668 ("localvar_target: table_length=%d", table_length));
2670 int table_struct_size = 2 + 2 + 2; // 3 u2 variables per table entry
2671 int table_size = table_length * table_struct_size;
2673 if ((byte_i_ref + table_size) > type_annotations_typeArray->length()) {
2674 // not enough room for a table
2675 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2676 ("length() is too small for a table array of length %d", table_length));
2677 return false;
2678 }
2680 // Skip over table
2681 byte_i_ref += table_size;
2682 } break;
2684 case 0x42:
2685 // kind: type in exception parameter declaration
2686 // location: Code
2688 {
2689 // struct:
2690 // catch_target {
2691 // u2 exception_table_index;
2692 // }
2693 //
2694 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2695 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2696 ("length() is too small for a catch_target"));
2697 return false;
2698 }
2700 u2 exception_table_index = Bytes::get_Java_u2((address)
2701 type_annotations_typeArray->adr_at(byte_i_ref));
2702 byte_i_ref += 2;
2704 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2705 ("catch_target: exception_table_index=%d", exception_table_index));
2706 } break;
2708 case 0x43:
2709 // kind: type in instanceof expression
2710 // location: Code
2711 case 0x44:
2712 // kind: type in new expression
2713 // location: Code
2714 case 0x45:
2715 // kind: type in method reference expression using ::new
2716 // location: Code
2717 case 0x46:
2718 // kind: type in method reference expression using ::Identifier
2719 // location: Code
2721 {
2722 // struct:
2723 // offset_target {
2724 // u2 offset;
2725 // }
2726 //
2727 if ((byte_i_ref + 2) > type_annotations_typeArray->length()) {
2728 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2729 ("length() is too small for a offset_target"));
2730 return false;
2731 }
2733 u2 offset = Bytes::get_Java_u2((address)
2734 type_annotations_typeArray->adr_at(byte_i_ref));
2735 byte_i_ref += 2;
2737 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2738 ("offset_target: offset=%d", offset));
2739 } break;
2741 case 0x47:
2742 // kind: type in cast expression
2743 // location: Code
2744 case 0x48:
2745 // kind: type argument for generic constructor in new expression or
2746 // explicit constructor invocation statement
2747 // location: Code
2748 case 0x49:
2749 // kind: type argument for generic method in method invocation expression
2750 // location: Code
2751 case 0x4A:
2752 // kind: type argument for generic constructor in method reference expression using ::new
2753 // location: Code
2754 case 0x4B:
2755 // kind: type argument for generic method in method reference expression using ::Identifier
2756 // location: Code
2758 {
2759 // struct:
2760 // type_argument_target {
2761 // u2 offset;
2762 // u1 type_argument_index;
2763 // }
2764 //
2765 if ((byte_i_ref + 3) > type_annotations_typeArray->length()) {
2766 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2767 ("length() is too small for a type_argument_target"));
2768 return false;
2769 }
2771 u2 offset = Bytes::get_Java_u2((address)
2772 type_annotations_typeArray->adr_at(byte_i_ref));
2773 byte_i_ref += 2;
2774 u1 type_argument_index = type_annotations_typeArray->at(byte_i_ref);
2775 byte_i_ref += 1;
2777 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2778 ("type_argument_target: offset=%d, type_argument_index=%d",
2779 offset, type_argument_index));
2780 } break;
2782 default:
2783 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2784 ("unknown target_type"));
2785 #ifdef ASSERT
2786 ShouldNotReachHere();
2787 #endif
2788 return false;
2789 }
2791 return true;
2792 } // end skip_type_annotation_target()
2795 // Read, verify and skip over the type_path part so that rewriting
2796 // can continue in the later parts of the struct.
2797 //
2798 // type_path {
2799 // u1 path_length;
2800 // {
2801 // u1 type_path_kind;
2802 // u1 type_argument_index;
2803 // } path[path_length];
2804 // }
2805 //
2806 bool VM_RedefineClasses::skip_type_annotation_type_path(
2807 AnnotationArray* type_annotations_typeArray, int &byte_i_ref, TRAPS) {
2809 if ((byte_i_ref + 1) > type_annotations_typeArray->length()) {
2810 // not enough room for a path_length let alone the rest of the type_path
2811 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2812 ("length() is too small for a type_path"));
2813 return false;
2814 }
2816 u1 path_length = type_annotations_typeArray->at(byte_i_ref);
2817 byte_i_ref += 1;
2819 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2820 ("type_path: path_length=%d", path_length));
2822 int calc_path_length = 0;
2823 for (; calc_path_length < path_length; calc_path_length++) {
2824 if ((byte_i_ref + 1 + 1) > type_annotations_typeArray->length()) {
2825 // not enough room for a path
2826 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2827 ("length() is too small for path entry %d of %d",
2828 calc_path_length, path_length));
2829 return false;
2830 }
2832 u1 type_path_kind = type_annotations_typeArray->at(byte_i_ref);
2833 byte_i_ref += 1;
2834 u1 type_argument_index = type_annotations_typeArray->at(byte_i_ref);
2835 byte_i_ref += 1;
2837 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2838 ("type_path: path[%d]: type_path_kind=%d, type_argument_index=%d",
2839 calc_path_length, type_path_kind, type_argument_index));
2841 if (type_path_kind > 3 || (type_path_kind != 3 && type_argument_index != 0)) {
2842 // not enough room for a path
2843 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2844 ("inconsistent type_path values"));
2845 return false;
2846 }
2847 }
2848 assert(path_length == calc_path_length, "sanity check");
2850 return true;
2851 } // end skip_type_annotation_type_path()
2854 // Rewrite constant pool references in the method's stackmap table.
2855 // These "structures" are adapted from the StackMapTable_attribute that
2856 // is described in section 4.8.4 of the 6.0 version of the VM spec
2857 // (dated 2005.10.26):
2858 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
2859 //
2860 // stack_map {
2861 // u2 number_of_entries;
2862 // stack_map_frame entries[number_of_entries];
2863 // }
2864 //
2865 void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table(
2866 methodHandle method, TRAPS) {
2868 if (!method->has_stackmap_table()) {
2869 return;
2870 }
2872 AnnotationArray* stackmap_data = method->stackmap_data();
2873 address stackmap_p = (address)stackmap_data->adr_at(0);
2874 address stackmap_end = stackmap_p + stackmap_data->length();
2876 assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries");
2877 u2 number_of_entries = Bytes::get_Java_u2(stackmap_p);
2878 stackmap_p += 2;
2880 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2881 ("number_of_entries=%u", number_of_entries));
2883 // walk through each stack_map_frame
2884 u2 calc_number_of_entries = 0;
2885 for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) {
2886 // The stack_map_frame structure is a u1 frame_type followed by
2887 // 0 or more bytes of data:
2888 //
2889 // union stack_map_frame {
2890 // same_frame;
2891 // same_locals_1_stack_item_frame;
2892 // same_locals_1_stack_item_frame_extended;
2893 // chop_frame;
2894 // same_frame_extended;
2895 // append_frame;
2896 // full_frame;
2897 // }
2899 assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type");
2900 // The Linux compiler does not like frame_type to be u1 or u2. It
2901 // issues the following warning for the first if-statement below:
2902 //
2903 // "warning: comparison is always true due to limited range of data type"
2904 //
2905 u4 frame_type = *stackmap_p;
2906 stackmap_p++;
2908 // same_frame {
2909 // u1 frame_type = SAME; /* 0-63 */
2910 // }
2911 if (frame_type >= 0 && frame_type <= 63) {
2912 // nothing more to do for same_frame
2913 }
2915 // same_locals_1_stack_item_frame {
2916 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */
2917 // verification_type_info stack[1];
2918 // }
2919 else if (frame_type >= 64 && frame_type <= 127) {
2920 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2921 calc_number_of_entries, frame_type, THREAD);
2922 }
2924 // reserved for future use
2925 else if (frame_type >= 128 && frame_type <= 246) {
2926 // nothing more to do for reserved frame_types
2927 }
2929 // same_locals_1_stack_item_frame_extended {
2930 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */
2931 // u2 offset_delta;
2932 // verification_type_info stack[1];
2933 // }
2934 else if (frame_type == 247) {
2935 stackmap_p += 2;
2936 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2937 calc_number_of_entries, frame_type, THREAD);
2938 }
2940 // chop_frame {
2941 // u1 frame_type = CHOP; /* 248-250 */
2942 // u2 offset_delta;
2943 // }
2944 else if (frame_type >= 248 && frame_type <= 250) {
2945 stackmap_p += 2;
2946 }
2948 // same_frame_extended {
2949 // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/
2950 // u2 offset_delta;
2951 // }
2952 else if (frame_type == 251) {
2953 stackmap_p += 2;
2954 }
2956 // append_frame {
2957 // u1 frame_type = APPEND; /* 252-254 */
2958 // u2 offset_delta;
2959 // verification_type_info locals[frame_type - 251];
2960 // }
2961 else if (frame_type >= 252 && frame_type <= 254) {
2962 assert(stackmap_p + 2 <= stackmap_end,
2963 "no room for offset_delta");
2964 stackmap_p += 2;
2965 u1 len = frame_type - 251;
2966 for (u1 i = 0; i < len; i++) {
2967 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2968 calc_number_of_entries, frame_type, THREAD);
2969 }
2970 }
2972 // full_frame {
2973 // u1 frame_type = FULL_FRAME; /* 255 */
2974 // u2 offset_delta;
2975 // u2 number_of_locals;
2976 // verification_type_info locals[number_of_locals];
2977 // u2 number_of_stack_items;
2978 // verification_type_info stack[number_of_stack_items];
2979 // }
2980 else if (frame_type == 255) {
2981 assert(stackmap_p + 2 + 2 <= stackmap_end,
2982 "no room for smallest full_frame");
2983 stackmap_p += 2;
2985 u2 number_of_locals = Bytes::get_Java_u2(stackmap_p);
2986 stackmap_p += 2;
2988 for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) {
2989 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2990 calc_number_of_entries, frame_type, THREAD);
2991 }
2993 // Use the largest size for the number_of_stack_items, but only get
2994 // the right number of bytes.
2995 u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p);
2996 stackmap_p += 2;
2998 for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) {
2999 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
3000 calc_number_of_entries, frame_type, THREAD);
3001 }
3002 }
3003 } // end while there is a stack_map_frame
3004 assert(number_of_entries == calc_number_of_entries, "sanity check");
3005 } // end rewrite_cp_refs_in_stack_map_table()
3008 // Rewrite constant pool references in the verification type info
3009 // portion of the method's stackmap table. These "structures" are
3010 // adapted from the StackMapTable_attribute that is described in
3011 // section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26):
3012 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
3013 //
3014 // The verification_type_info structure is a u1 tag followed by 0 or
3015 // more bytes of data:
3016 //
3017 // union verification_type_info {
3018 // Top_variable_info;
3019 // Integer_variable_info;
3020 // Float_variable_info;
3021 // Long_variable_info;
3022 // Double_variable_info;
3023 // Null_variable_info;
3024 // UninitializedThis_variable_info;
3025 // Object_variable_info;
3026 // Uninitialized_variable_info;
3027 // }
3028 //
3029 void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info(
3030 address& stackmap_p_ref, address stackmap_end, u2 frame_i,
3031 u1 frame_type, TRAPS) {
3033 assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag");
3034 u1 tag = *stackmap_p_ref;
3035 stackmap_p_ref++;
3037 switch (tag) {
3038 // Top_variable_info {
3039 // u1 tag = ITEM_Top; /* 0 */
3040 // }
3041 // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top
3042 case 0: // fall through
3044 // Integer_variable_info {
3045 // u1 tag = ITEM_Integer; /* 1 */
3046 // }
3047 case ITEM_Integer: // fall through
3049 // Float_variable_info {
3050 // u1 tag = ITEM_Float; /* 2 */
3051 // }
3052 case ITEM_Float: // fall through
3054 // Double_variable_info {
3055 // u1 tag = ITEM_Double; /* 3 */
3056 // }
3057 case ITEM_Double: // fall through
3059 // Long_variable_info {
3060 // u1 tag = ITEM_Long; /* 4 */
3061 // }
3062 case ITEM_Long: // fall through
3064 // Null_variable_info {
3065 // u1 tag = ITEM_Null; /* 5 */
3066 // }
3067 case ITEM_Null: // fall through
3069 // UninitializedThis_variable_info {
3070 // u1 tag = ITEM_UninitializedThis; /* 6 */
3071 // }
3072 case ITEM_UninitializedThis:
3073 // nothing more to do for the above tag types
3074 break;
3076 // Object_variable_info {
3077 // u1 tag = ITEM_Object; /* 7 */
3078 // u2 cpool_index;
3079 // }
3080 case ITEM_Object:
3081 {
3082 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index");
3083 u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref);
3084 u2 new_cp_index = find_new_index(cpool_index);
3085 if (new_cp_index != 0) {
3086 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
3087 ("mapped old cpool_index=%d", cpool_index));
3088 Bytes::put_Java_u2(stackmap_p_ref, new_cp_index);
3089 cpool_index = new_cp_index;
3090 }
3091 stackmap_p_ref += 2;
3093 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
3094 ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i,
3095 frame_type, cpool_index));
3096 } break;
3098 // Uninitialized_variable_info {
3099 // u1 tag = ITEM_Uninitialized; /* 8 */
3100 // u2 offset;
3101 // }
3102 case ITEM_Uninitialized:
3103 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset");
3104 stackmap_p_ref += 2;
3105 break;
3107 default:
3108 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
3109 ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag));
3110 ShouldNotReachHere();
3111 break;
3112 } // end switch (tag)
3113 } // end rewrite_cp_refs_in_verification_type_info()
3116 // Change the constant pool associated with klass scratch_class to
3117 // scratch_cp. If shrink is true, then scratch_cp_length elements
3118 // are copied from scratch_cp to a smaller constant pool and the
3119 // smaller constant pool is associated with scratch_class.
3120 void VM_RedefineClasses::set_new_constant_pool(
3121 ClassLoaderData* loader_data,
3122 instanceKlassHandle scratch_class, constantPoolHandle scratch_cp,
3123 int scratch_cp_length, TRAPS) {
3124 assert(scratch_cp->length() >= scratch_cp_length, "sanity check");
3126 // scratch_cp is a merged constant pool and has enough space for a
3127 // worst case merge situation. We want to associate the minimum
3128 // sized constant pool with the klass to save space.
3129 ConstantPool* cp = ConstantPool::allocate(loader_data, scratch_cp_length, CHECK);
3130 constantPoolHandle smaller_cp(THREAD, cp);
3132 // preserve version() value in the smaller copy
3133 int version = scratch_cp->version();
3134 assert(version != 0, "sanity check");
3135 smaller_cp->set_version(version);
3137 // attach klass to new constant pool
3138 // reference to the cp holder is needed for copy_operands()
3139 smaller_cp->set_pool_holder(scratch_class());
3141 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD);
3142 if (HAS_PENDING_EXCEPTION) {
3143 // Exception is handled in the caller
3144 loader_data->add_to_deallocate_list(smaller_cp());
3145 return;
3146 }
3147 scratch_cp = smaller_cp;
3149 // attach new constant pool to klass
3150 scratch_class->set_constants(scratch_cp());
3152 int i; // for portability
3154 // update each field in klass to use new constant pool indices as needed
3155 for (JavaFieldStream fs(scratch_class); !fs.done(); fs.next()) {
3156 jshort cur_index = fs.name_index();
3157 jshort new_index = find_new_index(cur_index);
3158 if (new_index != 0) {
3159 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3160 ("field-name_index change: %d to %d", cur_index, new_index));
3161 fs.set_name_index(new_index);
3162 }
3163 cur_index = fs.signature_index();
3164 new_index = find_new_index(cur_index);
3165 if (new_index != 0) {
3166 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3167 ("field-signature_index change: %d to %d", cur_index, new_index));
3168 fs.set_signature_index(new_index);
3169 }
3170 cur_index = fs.initval_index();
3171 new_index = find_new_index(cur_index);
3172 if (new_index != 0) {
3173 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3174 ("field-initval_index change: %d to %d", cur_index, new_index));
3175 fs.set_initval_index(new_index);
3176 }
3177 cur_index = fs.generic_signature_index();
3178 new_index = find_new_index(cur_index);
3179 if (new_index != 0) {
3180 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3181 ("field-generic_signature change: %d to %d", cur_index, new_index));
3182 fs.set_generic_signature_index(new_index);
3183 }
3184 } // end for each field
3186 // Update constant pool indices in the inner classes info to use
3187 // new constant indices as needed. The inner classes info is a
3188 // quadruple:
3189 // (inner_class_info, outer_class_info, inner_name, inner_access_flags)
3190 InnerClassesIterator iter(scratch_class);
3191 for (; !iter.done(); iter.next()) {
3192 int cur_index = iter.inner_class_info_index();
3193 if (cur_index == 0) {
3194 continue; // JVM spec. allows null inner class refs so skip it
3195 }
3196 int new_index = find_new_index(cur_index);
3197 if (new_index != 0) {
3198 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3199 ("inner_class_info change: %d to %d", cur_index, new_index));
3200 iter.set_inner_class_info_index(new_index);
3201 }
3202 cur_index = iter.outer_class_info_index();
3203 new_index = find_new_index(cur_index);
3204 if (new_index != 0) {
3205 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3206 ("outer_class_info change: %d to %d", cur_index, new_index));
3207 iter.set_outer_class_info_index(new_index);
3208 }
3209 cur_index = iter.inner_name_index();
3210 new_index = find_new_index(cur_index);
3211 if (new_index != 0) {
3212 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3213 ("inner_name change: %d to %d", cur_index, new_index));
3214 iter.set_inner_name_index(new_index);
3215 }
3216 } // end for each inner class
3218 // Attach each method in klass to the new constant pool and update
3219 // to use new constant pool indices as needed:
3220 Array<Method*>* methods = scratch_class->methods();
3221 for (i = methods->length() - 1; i >= 0; i--) {
3222 methodHandle method(THREAD, methods->at(i));
3223 method->set_constants(scratch_cp());
3225 int new_index = find_new_index(method->name_index());
3226 if (new_index != 0) {
3227 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3228 ("method-name_index change: %d to %d", method->name_index(),
3229 new_index));
3230 method->set_name_index(new_index);
3231 }
3232 new_index = find_new_index(method->signature_index());
3233 if (new_index != 0) {
3234 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3235 ("method-signature_index change: %d to %d",
3236 method->signature_index(), new_index));
3237 method->set_signature_index(new_index);
3238 }
3239 new_index = find_new_index(method->generic_signature_index());
3240 if (new_index != 0) {
3241 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3242 ("method-generic_signature_index change: %d to %d",
3243 method->generic_signature_index(), new_index));
3244 method->set_generic_signature_index(new_index);
3245 }
3247 // Update constant pool indices in the method's checked exception
3248 // table to use new constant indices as needed.
3249 int cext_length = method->checked_exceptions_length();
3250 if (cext_length > 0) {
3251 CheckedExceptionElement * cext_table =
3252 method->checked_exceptions_start();
3253 for (int j = 0; j < cext_length; j++) {
3254 int cur_index = cext_table[j].class_cp_index;
3255 int new_index = find_new_index(cur_index);
3256 if (new_index != 0) {
3257 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3258 ("cext-class_cp_index change: %d to %d", cur_index, new_index));
3259 cext_table[j].class_cp_index = (u2)new_index;
3260 }
3261 } // end for each checked exception table entry
3262 } // end if there are checked exception table entries
3264 // Update each catch type index in the method's exception table
3265 // to use new constant pool indices as needed. The exception table
3266 // holds quadruple entries of the form:
3267 // (beg_bci, end_bci, handler_bci, klass_index)
3269 ExceptionTable ex_table(method());
3270 int ext_length = ex_table.length();
3272 for (int j = 0; j < ext_length; j ++) {
3273 int cur_index = ex_table.catch_type_index(j);
3274 int new_index = find_new_index(cur_index);
3275 if (new_index != 0) {
3276 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3277 ("ext-klass_index change: %d to %d", cur_index, new_index));
3278 ex_table.set_catch_type_index(j, new_index);
3279 }
3280 } // end for each exception table entry
3282 // Update constant pool indices in the method's local variable
3283 // table to use new constant indices as needed. The local variable
3284 // table hold sextuple entries of the form:
3285 // (start_pc, length, name_index, descriptor_index, signature_index, slot)
3286 int lvt_length = method->localvariable_table_length();
3287 if (lvt_length > 0) {
3288 LocalVariableTableElement * lv_table =
3289 method->localvariable_table_start();
3290 for (int j = 0; j < lvt_length; j++) {
3291 int cur_index = lv_table[j].name_cp_index;
3292 int new_index = find_new_index(cur_index);
3293 if (new_index != 0) {
3294 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3295 ("lvt-name_cp_index change: %d to %d", cur_index, new_index));
3296 lv_table[j].name_cp_index = (u2)new_index;
3297 }
3298 cur_index = lv_table[j].descriptor_cp_index;
3299 new_index = find_new_index(cur_index);
3300 if (new_index != 0) {
3301 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3302 ("lvt-descriptor_cp_index change: %d to %d", cur_index,
3303 new_index));
3304 lv_table[j].descriptor_cp_index = (u2)new_index;
3305 }
3306 cur_index = lv_table[j].signature_cp_index;
3307 new_index = find_new_index(cur_index);
3308 if (new_index != 0) {
3309 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
3310 ("lvt-signature_cp_index change: %d to %d", cur_index, new_index));
3311 lv_table[j].signature_cp_index = (u2)new_index;
3312 }
3313 } // end for each local variable table entry
3314 } // end if there are local variable table entries
3316 rewrite_cp_refs_in_stack_map_table(method, THREAD);
3317 } // end for each method
3318 } // end set_new_constant_pool()
3321 // Unevolving classes may point to methods of the_class directly
3322 // from their constant pool caches, itables, and/or vtables. We
3323 // use the ClassLoaderDataGraph::classes_do() facility and this helper
3324 // to fix up these pointers.
3326 // Adjust cpools and vtables closure
3327 void VM_RedefineClasses::AdjustCpoolCacheAndVtable::do_klass(Klass* k) {
3329 // This is a very busy routine. We don't want too much tracing
3330 // printed out.
3331 bool trace_name_printed = false;
3332 InstanceKlass *the_class = InstanceKlass::cast(_the_class_oop);
3334 // Very noisy: only enable this call if you are trying to determine
3335 // that a specific class gets found by this routine.
3336 // RC_TRACE macro has an embedded ResourceMark
3337 // RC_TRACE_WITH_THREAD(0x00100000, THREAD,
3338 // ("adjust check: name=%s", k->external_name()));
3339 // trace_name_printed = true;
3341 // If the class being redefined is java.lang.Object, we need to fix all
3342 // array class vtables also
3343 if (k->oop_is_array() && _the_class_oop == SystemDictionary::Object_klass()) {
3344 k->vtable()->adjust_method_entries(the_class, &trace_name_printed);
3346 } else if (k->oop_is_instance()) {
3347 HandleMark hm(_thread);
3348 InstanceKlass *ik = InstanceKlass::cast(k);
3350 // HotSpot specific optimization! HotSpot does not currently
3351 // support delegation from the bootstrap class loader to a
3352 // user-defined class loader. This means that if the bootstrap
3353 // class loader is the initiating class loader, then it will also
3354 // be the defining class loader. This also means that classes
3355 // loaded by the bootstrap class loader cannot refer to classes
3356 // loaded by a user-defined class loader. Note: a user-defined
3357 // class loader can delegate to the bootstrap class loader.
3358 //
3359 // If the current class being redefined has a user-defined class
3360 // loader as its defining class loader, then we can skip all
3361 // classes loaded by the bootstrap class loader.
3362 bool is_user_defined =
3363 InstanceKlass::cast(_the_class_oop)->class_loader() != NULL;
3364 if (is_user_defined && ik->class_loader() == NULL) {
3365 return;
3366 }
3368 // Fix the vtable embedded in the_class and subclasses of the_class,
3369 // if one exists. We discard scratch_class and we don't keep an
3370 // InstanceKlass around to hold obsolete methods so we don't have
3371 // any other InstanceKlass embedded vtables to update. The vtable
3372 // holds the Method*s for virtual (but not final) methods.
3373 // Default methods, or concrete methods in interfaces are stored
3374 // in the vtable, so if an interface changes we need to check
3375 // adjust_method_entries() for every InstanceKlass, which will also
3376 // adjust the default method vtable indices.
3377 // We also need to adjust any default method entries that are
3378 // not yet in the vtable, because the vtable setup is in progress.
3379 // This must be done after we adjust the default_methods and
3380 // default_vtable_indices for methods already in the vtable.
3381 if (ik->vtable_length() > 0 && (_the_class_oop->is_interface()
3382 || ik->is_subtype_of(_the_class_oop))) {
3383 // ik->vtable() creates a wrapper object; rm cleans it up
3384 ResourceMark rm(_thread);
3386 ik->vtable()->adjust_method_entries(the_class, &trace_name_printed);
3387 ik->adjust_default_methods(the_class, &trace_name_printed);
3388 }
3390 // If the current class has an itable and we are either redefining an
3391 // interface or if the current class is a subclass of the_class, then
3392 // we potentially have to fix the itable. If we are redefining an
3393 // interface, then we have to call adjust_method_entries() for
3394 // every InstanceKlass that has an itable since there isn't a
3395 // subclass relationship between an interface and an InstanceKlass.
3396 if (ik->itable_length() > 0 && (_the_class_oop->is_interface()
3397 || ik->is_subclass_of(_the_class_oop))) {
3398 // ik->itable() creates a wrapper object; rm cleans it up
3399 ResourceMark rm(_thread);
3401 ik->itable()->adjust_method_entries(the_class, &trace_name_printed);
3402 }
3404 // The constant pools in other classes (other_cp) can refer to
3405 // methods in the_class. We have to update method information in
3406 // other_cp's cache. If other_cp has a previous version, then we
3407 // have to repeat the process for each previous version. The
3408 // constant pool cache holds the Method*s for non-virtual
3409 // methods and for virtual, final methods.
3410 //
3411 // Special case: if the current class is the_class, then new_cp
3412 // has already been attached to the_class and old_cp has already
3413 // been added as a previous version. The new_cp doesn't have any
3414 // cached references to old methods so it doesn't need to be
3415 // updated. We can simply start with the previous version(s) in
3416 // that case.
3417 constantPoolHandle other_cp;
3418 ConstantPoolCache* cp_cache;
3420 if (ik != _the_class_oop) {
3421 // this klass' constant pool cache may need adjustment
3422 other_cp = constantPoolHandle(ik->constants());
3423 cp_cache = other_cp->cache();
3424 if (cp_cache != NULL) {
3425 cp_cache->adjust_method_entries(the_class, &trace_name_printed);
3426 }
3427 }
3429 // the previous versions' constant pool caches may need adjustment
3430 PreviousVersionWalker pvw(_thread, ik);
3431 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
3432 pv_node != NULL; pv_node = pvw.next_previous_version()) {
3433 other_cp = pv_node->prev_constant_pool();
3434 cp_cache = other_cp->cache();
3435 if (cp_cache != NULL) {
3436 cp_cache->adjust_method_entries(other_cp->pool_holder(), &trace_name_printed);
3437 }
3438 }
3439 }
3440 }
3442 void VM_RedefineClasses::update_jmethod_ids() {
3443 for (int j = 0; j < _matching_methods_length; ++j) {
3444 Method* old_method = _matching_old_methods[j];
3445 jmethodID jmid = old_method->find_jmethod_id_or_null();
3446 if (jmid != NULL) {
3447 // There is a jmethodID, change it to point to the new method
3448 methodHandle new_method_h(_matching_new_methods[j]);
3449 Method::change_method_associated_with_jmethod_id(jmid, new_method_h());
3450 assert(Method::resolve_jmethod_id(jmid) == _matching_new_methods[j],
3451 "should be replaced");
3452 }
3453 }
3454 }
3456 void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
3457 BitMap *emcp_methods, int * emcp_method_count_p) {
3458 *emcp_method_count_p = 0;
3459 int obsolete_count = 0;
3460 int old_index = 0;
3461 for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
3462 Method* old_method = _matching_old_methods[j];
3463 Method* new_method = _matching_new_methods[j];
3464 Method* old_array_method;
3466 // Maintain an old_index into the _old_methods array by skipping
3467 // deleted methods
3468 while ((old_array_method = _old_methods->at(old_index)) != old_method) {
3469 ++old_index;
3470 }
3472 if (MethodComparator::methods_EMCP(old_method, new_method)) {
3473 // The EMCP definition from JSR-163 requires the bytecodes to be
3474 // the same with the exception of constant pool indices which may
3475 // differ. However, the constants referred to by those indices
3476 // must be the same.
3477 //
3478 // We use methods_EMCP() for comparison since constant pool
3479 // merging can remove duplicate constant pool entries that were
3480 // present in the old method and removed from the rewritten new
3481 // method. A faster binary comparison function would consider the
3482 // old and new methods to be different when they are actually
3483 // EMCP.
3484 //
3485 // The old and new methods are EMCP and you would think that we
3486 // could get rid of one of them here and now and save some space.
3487 // However, the concept of EMCP only considers the bytecodes and
3488 // the constant pool entries in the comparison. Other things,
3489 // e.g., the line number table (LNT) or the local variable table
3490 // (LVT) don't count in the comparison. So the new (and EMCP)
3491 // method can have a new LNT that we need so we can't just
3492 // overwrite the new method with the old method.
3493 //
3494 // When this routine is called, we have already attached the new
3495 // methods to the_class so the old methods are effectively
3496 // overwritten. However, if an old method is still executing,
3497 // then the old method cannot be collected until sometime after
3498 // the old method call has returned. So the overwriting of old
3499 // methods by new methods will save us space except for those
3500 // (hopefully few) old methods that are still executing.
3501 //
3502 // A method refers to a ConstMethod* and this presents another
3503 // possible avenue to space savings. The ConstMethod* in the
3504 // new method contains possibly new attributes (LNT, LVT, etc).
3505 // At first glance, it seems possible to save space by replacing
3506 // the ConstMethod* in the old method with the ConstMethod*
3507 // from the new method. The old and new methods would share the
3508 // same ConstMethod* and we would save the space occupied by
3509 // the old ConstMethod*. However, the ConstMethod* contains
3510 // a back reference to the containing method. Sharing the
3511 // ConstMethod* between two methods could lead to confusion in
3512 // the code that uses the back reference. This would lead to
3513 // brittle code that could be broken in non-obvious ways now or
3514 // in the future.
3515 //
3516 // Another possibility is to copy the ConstMethod* from the new
3517 // method to the old method and then overwrite the new method with
3518 // the old method. Since the ConstMethod* contains the bytecodes
3519 // for the method embedded in the oop, this option would change
3520 // the bytecodes out from under any threads executing the old
3521 // method and make the thread's bcp invalid. Since EMCP requires
3522 // that the bytecodes be the same modulo constant pool indices, it
3523 // is straight forward to compute the correct new bcp in the new
3524 // ConstMethod* from the old bcp in the old ConstMethod*. The
3525 // time consuming part would be searching all the frames in all
3526 // of the threads to find all of the calls to the old method.
3527 //
3528 // It looks like we will have to live with the limited savings
3529 // that we get from effectively overwriting the old methods
3530 // when the new methods are attached to the_class.
3532 // track which methods are EMCP for add_previous_version() call
3533 emcp_methods->set_bit(old_index);
3534 (*emcp_method_count_p)++;
3536 // An EMCP method is _not_ obsolete. An obsolete method has a
3537 // different jmethodID than the current method. An EMCP method
3538 // has the same jmethodID as the current method. Having the
3539 // same jmethodID for all EMCP versions of a method allows for
3540 // a consistent view of the EMCP methods regardless of which
3541 // EMCP method you happen to have in hand. For example, a
3542 // breakpoint set in one EMCP method will work for all EMCP
3543 // versions of the method including the current one.
3544 } else {
3545 // mark obsolete methods as such
3546 old_method->set_is_obsolete();
3547 obsolete_count++;
3549 // obsolete methods need a unique idnum so they become new entries in
3550 // the jmethodID cache in InstanceKlass
3551 assert(old_method->method_idnum() == new_method->method_idnum(), "must match");
3552 u2 num = InstanceKlass::cast(_the_class_oop)->next_method_idnum();
3553 if (num != ConstMethod::UNSET_IDNUM) {
3554 old_method->set_method_idnum(num);
3555 }
3557 // With tracing we try not to "yack" too much. The position of
3558 // this trace assumes there are fewer obsolete methods than
3559 // EMCP methods.
3560 RC_TRACE(0x00000100, ("mark %s(%s) as obsolete",
3561 old_method->name()->as_C_string(),
3562 old_method->signature()->as_C_string()));
3563 }
3564 old_method->set_is_old();
3565 }
3566 for (int i = 0; i < _deleted_methods_length; ++i) {
3567 Method* old_method = _deleted_methods[i];
3569 assert(!old_method->has_vtable_index(),
3570 "cannot delete methods with vtable entries");;
3572 // Mark all deleted methods as old, obsolete and deleted
3573 old_method->set_is_deleted();
3574 old_method->set_is_old();
3575 old_method->set_is_obsolete();
3576 ++obsolete_count;
3577 // With tracing we try not to "yack" too much. The position of
3578 // this trace assumes there are fewer obsolete methods than
3579 // EMCP methods.
3580 RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete",
3581 old_method->name()->as_C_string(),
3582 old_method->signature()->as_C_string()));
3583 }
3584 assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(),
3585 "sanity check");
3586 RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p,
3587 obsolete_count));
3588 }
3590 // This internal class transfers the native function registration from old methods
3591 // to new methods. It is designed to handle both the simple case of unchanged
3592 // native methods and the complex cases of native method prefixes being added and/or
3593 // removed.
3594 // It expects only to be used during the VM_RedefineClasses op (a safepoint).
3595 //
3596 // This class is used after the new methods have been installed in "the_class".
3597 //
3598 // So, for example, the following must be handled. Where 'm' is a method and
3599 // a number followed by an underscore is a prefix.
3600 //
3601 // Old Name New Name
3602 // Simple transfer to new method m -> m
3603 // Add prefix m -> 1_m
3604 // Remove prefix 1_m -> m
3605 // Simultaneous add of prefixes m -> 3_2_1_m
3606 // Simultaneous removal of prefixes 3_2_1_m -> m
3607 // Simultaneous add and remove 1_m -> 2_m
3608 // Same, caused by prefix removal only 3_2_1_m -> 3_2_m
3609 //
3610 class TransferNativeFunctionRegistration {
3611 private:
3612 instanceKlassHandle the_class;
3613 int prefix_count;
3614 char** prefixes;
3616 // Recursively search the binary tree of possibly prefixed method names.
3617 // Iteration could be used if all agents were well behaved. Full tree walk is
3618 // more resilent to agents not cleaning up intermediate methods.
3619 // Branch at each depth in the binary tree is:
3620 // (1) without the prefix.
3621 // (2) with the prefix.
3622 // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...)
3623 Method* search_prefix_name_space(int depth, char* name_str, size_t name_len,
3624 Symbol* signature) {
3625 TempNewSymbol name_symbol = SymbolTable::probe(name_str, (int)name_len);
3626 if (name_symbol != NULL) {
3627 Method* method = the_class()->lookup_method(name_symbol, signature);
3628 if (method != NULL) {
3629 // Even if prefixed, intermediate methods must exist.
3630 if (method->is_native()) {
3631 // Wahoo, we found a (possibly prefixed) version of the method, return it.
3632 return method;
3633 }
3634 if (depth < prefix_count) {
3635 // Try applying further prefixes (other than this one).
3636 method = search_prefix_name_space(depth+1, name_str, name_len, signature);
3637 if (method != NULL) {
3638 return method; // found
3639 }
3641 // Try adding this prefix to the method name and see if it matches
3642 // another method name.
3643 char* prefix = prefixes[depth];
3644 size_t prefix_len = strlen(prefix);
3645 size_t trial_len = name_len + prefix_len;
3646 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
3647 strcpy(trial_name_str, prefix);
3648 strcat(trial_name_str, name_str);
3649 method = search_prefix_name_space(depth+1, trial_name_str, trial_len,
3650 signature);
3651 if (method != NULL) {
3652 // If found along this branch, it was prefixed, mark as such
3653 method->set_is_prefixed_native();
3654 return method; // found
3655 }
3656 }
3657 }
3658 }
3659 return NULL; // This whole branch bore nothing
3660 }
3662 // Return the method name with old prefixes stripped away.
3663 char* method_name_without_prefixes(Method* method) {
3664 Symbol* name = method->name();
3665 char* name_str = name->as_utf8();
3667 // Old prefixing may be defunct, strip prefixes, if any.
3668 for (int i = prefix_count-1; i >= 0; i--) {
3669 char* prefix = prefixes[i];
3670 size_t prefix_len = strlen(prefix);
3671 if (strncmp(prefix, name_str, prefix_len) == 0) {
3672 name_str += prefix_len;
3673 }
3674 }
3675 return name_str;
3676 }
3678 // Strip any prefixes off the old native method, then try to find a
3679 // (possibly prefixed) new native that matches it.
3680 Method* strip_and_search_for_new_native(Method* method) {
3681 ResourceMark rm;
3682 char* name_str = method_name_without_prefixes(method);
3683 return search_prefix_name_space(0, name_str, strlen(name_str),
3684 method->signature());
3685 }
3687 public:
3689 // Construct a native method transfer processor for this class.
3690 TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
3691 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
3693 the_class = _the_class;
3694 prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
3695 }
3697 // Attempt to transfer any of the old or deleted methods that are native
3698 void transfer_registrations(Method** old_methods, int methods_length) {
3699 for (int j = 0; j < methods_length; j++) {
3700 Method* old_method = old_methods[j];
3702 if (old_method->is_native() && old_method->has_native_function()) {
3703 Method* new_method = strip_and_search_for_new_native(old_method);
3704 if (new_method != NULL) {
3705 // Actually set the native function in the new method.
3706 // Redefine does not send events (except CFLH), certainly not this
3707 // behind the scenes re-registration.
3708 new_method->set_native_function(old_method->native_function(),
3709 !Method::native_bind_event_is_interesting);
3710 }
3711 }
3712 }
3713 }
3714 };
3716 // Don't lose the association between a native method and its JNI function.
3717 void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) {
3718 TransferNativeFunctionRegistration transfer(the_class);
3719 transfer.transfer_registrations(_deleted_methods, _deleted_methods_length);
3720 transfer.transfer_registrations(_matching_old_methods, _matching_methods_length);
3721 }
3723 // Deoptimize all compiled code that depends on this class.
3724 //
3725 // If the can_redefine_classes capability is obtained in the onload
3726 // phase then the compiler has recorded all dependencies from startup.
3727 // In that case we need only deoptimize and throw away all compiled code
3728 // that depends on the class.
3729 //
3730 // If can_redefine_classes is obtained sometime after the onload
3731 // phase then the dependency information may be incomplete. In that case
3732 // the first call to RedefineClasses causes all compiled code to be
3733 // thrown away. As can_redefine_classes has been obtained then
3734 // all future compilations will record dependencies so second and
3735 // subsequent calls to RedefineClasses need only throw away code
3736 // that depends on the class.
3737 //
3738 void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
3739 assert_locked_or_safepoint(Compile_lock);
3741 // All dependencies have been recorded from startup or this is a second or
3742 // subsequent use of RedefineClasses
3743 if (JvmtiExport::all_dependencies_are_recorded()) {
3744 Universe::flush_evol_dependents_on(k_h);
3745 } else {
3746 CodeCache::mark_all_nmethods_for_deoptimization();
3748 ResourceMark rm(THREAD);
3749 DeoptimizationMarker dm;
3751 // Deoptimize all activations depending on marked nmethods
3752 Deoptimization::deoptimize_dependents();
3754 // Make the dependent methods not entrant
3755 CodeCache::make_marked_nmethods_not_entrant();
3757 // From now on we know that the dependency information is complete
3758 JvmtiExport::set_all_dependencies_are_recorded(true);
3759 }
3760 }
3762 void VM_RedefineClasses::compute_added_deleted_matching_methods() {
3763 Method* old_method;
3764 Method* new_method;
3766 _matching_old_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3767 _matching_new_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3768 _added_methods = NEW_RESOURCE_ARRAY(Method*, _new_methods->length());
3769 _deleted_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3771 _matching_methods_length = 0;
3772 _deleted_methods_length = 0;
3773 _added_methods_length = 0;
3775 int nj = 0;
3776 int oj = 0;
3777 while (true) {
3778 if (oj >= _old_methods->length()) {
3779 if (nj >= _new_methods->length()) {
3780 break; // we've looked at everything, done
3781 }
3782 // New method at the end
3783 new_method = _new_methods->at(nj);
3784 _added_methods[_added_methods_length++] = new_method;
3785 ++nj;
3786 } else if (nj >= _new_methods->length()) {
3787 // Old method, at the end, is deleted
3788 old_method = _old_methods->at(oj);
3789 _deleted_methods[_deleted_methods_length++] = old_method;
3790 ++oj;
3791 } else {
3792 old_method = _old_methods->at(oj);
3793 new_method = _new_methods->at(nj);
3794 if (old_method->name() == new_method->name()) {
3795 if (old_method->signature() == new_method->signature()) {
3796 _matching_old_methods[_matching_methods_length ] = old_method;
3797 _matching_new_methods[_matching_methods_length++] = new_method;
3798 ++nj;
3799 ++oj;
3800 } else {
3801 // added overloaded have already been moved to the end,
3802 // so this is a deleted overloaded method
3803 _deleted_methods[_deleted_methods_length++] = old_method;
3804 ++oj;
3805 }
3806 } else { // names don't match
3807 if (old_method->name()->fast_compare(new_method->name()) > 0) {
3808 // new method
3809 _added_methods[_added_methods_length++] = new_method;
3810 ++nj;
3811 } else {
3812 // deleted method
3813 _deleted_methods[_deleted_methods_length++] = old_method;
3814 ++oj;
3815 }
3816 }
3817 }
3818 }
3819 assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
3820 assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
3821 }
3824 void VM_RedefineClasses::swap_annotations(instanceKlassHandle the_class,
3825 instanceKlassHandle scratch_class) {
3826 // Swap annotation fields values
3827 Annotations* old_annotations = the_class->annotations();
3828 the_class->set_annotations(scratch_class->annotations());
3829 scratch_class->set_annotations(old_annotations);
3830 }
3833 // Install the redefinition of a class:
3834 // - house keeping (flushing breakpoints and caches, deoptimizing
3835 // dependent compiled code)
3836 // - replacing parts in the_class with parts from scratch_class
3837 // - adding a weak reference to track the obsolete but interesting
3838 // parts of the_class
3839 // - adjusting constant pool caches and vtables in other classes
3840 // that refer to methods in the_class. These adjustments use the
3841 // ClassLoaderDataGraph::classes_do() facility which only allows
3842 // a helper method to be specified. The interesting parameters
3843 // that we would like to pass to the helper method are saved in
3844 // static global fields in the VM operation.
3845 void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
3846 Klass* scratch_class_oop, TRAPS) {
3848 HandleMark hm(THREAD); // make sure handles from this call are freed
3849 RC_TIMER_START(_timer_rsc_phase1);
3851 instanceKlassHandle scratch_class(scratch_class_oop);
3853 oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass);
3854 Klass* the_class_oop = java_lang_Class::as_Klass(the_class_mirror);
3855 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
3857 // Remove all breakpoints in methods of this class
3858 JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
3859 jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop);
3861 // Deoptimize all compiled code that depends on this class
3862 flush_dependent_code(the_class, THREAD);
3864 _old_methods = the_class->methods();
3865 _new_methods = scratch_class->methods();
3866 _the_class_oop = the_class_oop;
3867 compute_added_deleted_matching_methods();
3868 update_jmethod_ids();
3870 // Attach new constant pool to the original klass. The original
3871 // klass still refers to the old constant pool (for now).
3872 scratch_class->constants()->set_pool_holder(the_class());
3874 #if 0
3875 // In theory, with constant pool merging in place we should be able
3876 // to save space by using the new, merged constant pool in place of
3877 // the old constant pool(s). By "pool(s)" I mean the constant pool in
3878 // the klass version we are replacing now and any constant pool(s) in
3879 // previous versions of klass. Nice theory, doesn't work in practice.
3880 // When this code is enabled, even simple programs throw NullPointer
3881 // exceptions. I'm guessing that this is caused by some constant pool
3882 // cache difference between the new, merged constant pool and the
3883 // constant pool that was just being used by the klass. I'm keeping
3884 // this code around to archive the idea, but the code has to remain
3885 // disabled for now.
3887 // Attach each old method to the new constant pool. This can be
3888 // done here since we are past the bytecode verification and
3889 // constant pool optimization phases.
3890 for (int i = _old_methods->length() - 1; i >= 0; i--) {
3891 Method* method = _old_methods->at(i);
3892 method->set_constants(scratch_class->constants());
3893 }
3895 {
3896 // walk all previous versions of the klass
3897 InstanceKlass *ik = (InstanceKlass *)the_class();
3898 PreviousVersionWalker pvw(ik);
3899 instanceKlassHandle ikh;
3900 do {
3901 ikh = pvw.next_previous_version();
3902 if (!ikh.is_null()) {
3903 ik = ikh();
3905 // attach previous version of klass to the new constant pool
3906 ik->set_constants(scratch_class->constants());
3908 // Attach each method in the previous version of klass to the
3909 // new constant pool
3910 Array<Method*>* prev_methods = ik->methods();
3911 for (int i = prev_methods->length() - 1; i >= 0; i--) {
3912 Method* method = prev_methods->at(i);
3913 method->set_constants(scratch_class->constants());
3914 }
3915 }
3916 } while (!ikh.is_null());
3917 }
3918 #endif
3920 // Replace methods and constantpool
3921 the_class->set_methods(_new_methods);
3922 scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods,
3923 // and to be able to undo operation easily.
3925 ConstantPool* old_constants = the_class->constants();
3926 the_class->set_constants(scratch_class->constants());
3927 scratch_class->set_constants(old_constants); // See the previous comment.
3928 #if 0
3929 // We are swapping the guts of "the new class" with the guts of "the
3930 // class". Since the old constant pool has just been attached to "the
3931 // new class", it seems logical to set the pool holder in the old
3932 // constant pool also. However, doing this will change the observable
3933 // class hierarchy for any old methods that are still executing. A
3934 // method can query the identity of its "holder" and this query uses
3935 // the method's constant pool link to find the holder. The change in
3936 // holding class from "the class" to "the new class" can confuse
3937 // things.
3938 //
3939 // Setting the old constant pool's holder will also cause
3940 // verification done during vtable initialization below to fail.
3941 // During vtable initialization, the vtable's class is verified to be
3942 // a subtype of the method's holder. The vtable's class is "the
3943 // class" and the method's holder is gotten from the constant pool
3944 // link in the method itself. For "the class"'s directly implemented
3945 // methods, the method holder is "the class" itself (as gotten from
3946 // the new constant pool). The check works fine in this case. The
3947 // check also works fine for methods inherited from super classes.
3948 //
3949 // Miranda methods are a little more complicated. A miranda method is
3950 // provided by an interface when the class implementing the interface
3951 // does not provide its own method. These interfaces are implemented
3952 // internally as an InstanceKlass. These special instanceKlasses
3953 // share the constant pool of the class that "implements" the
3954 // interface. By sharing the constant pool, the method holder of a
3955 // miranda method is the class that "implements" the interface. In a
3956 // non-redefine situation, the subtype check works fine. However, if
3957 // the old constant pool's pool holder is modified, then the check
3958 // fails because there is no class hierarchy relationship between the
3959 // vtable's class and "the new class".
3961 old_constants->set_pool_holder(scratch_class());
3962 #endif
3964 // track which methods are EMCP for add_previous_version() call below
3965 BitMap emcp_methods(_old_methods->length());
3966 int emcp_method_count = 0;
3967 emcp_methods.clear(); // clears 0..(length() - 1)
3968 check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count);
3969 transfer_old_native_function_registrations(the_class);
3971 // The class file bytes from before any retransformable agents mucked
3972 // with them was cached on the scratch class, move to the_class.
3973 // Note: we still want to do this if nothing needed caching since it
3974 // should get cleared in the_class too.
3975 if (the_class->get_cached_class_file_bytes() == 0) {
3976 // the_class doesn't have a cache yet so copy it
3977 the_class->set_cached_class_file(scratch_class->get_cached_class_file());
3978 }
3979 else if (scratch_class->get_cached_class_file_bytes() !=
3980 the_class->get_cached_class_file_bytes()) {
3981 // The same class can be present twice in the scratch classes list or there
3982 // are multiple concurrent RetransformClasses calls on different threads.
3983 // In such cases we have to deallocate scratch_class cached_class_file.
3984 os::free(scratch_class->get_cached_class_file());
3985 }
3987 // NULL out in scratch class to not delete twice. The class to be redefined
3988 // always owns these bytes.
3989 scratch_class->set_cached_class_file(NULL);
3991 // Replace inner_classes
3992 Array<u2>* old_inner_classes = the_class->inner_classes();
3993 the_class->set_inner_classes(scratch_class->inner_classes());
3994 scratch_class->set_inner_classes(old_inner_classes);
3996 // Initialize the vtable and interface table after
3997 // methods have been rewritten
3998 {
3999 ResourceMark rm(THREAD);
4000 // no exception should happen here since we explicitly
4001 // do not check loader constraints.
4002 // compare_and_normalize_class_versions has already checked:
4003 // - classloaders unchanged, signatures unchanged
4004 // - all instanceKlasses for redefined classes reused & contents updated
4005 the_class->vtable()->initialize_vtable(false, THREAD);
4006 the_class->itable()->initialize_itable(false, THREAD);
4007 assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())), "redefine exception");
4008 }
4010 // Leave arrays of jmethodIDs and itable index cache unchanged
4012 // Copy the "source file name" attribute from new class version
4013 the_class->set_source_file_name_index(
4014 scratch_class->source_file_name_index());
4016 // Copy the "source debug extension" attribute from new class version
4017 the_class->set_source_debug_extension(
4018 scratch_class->source_debug_extension(),
4019 scratch_class->source_debug_extension() == NULL ? 0 :
4020 (int)strlen(scratch_class->source_debug_extension()));
4022 // Use of javac -g could be different in the old and the new
4023 if (scratch_class->access_flags().has_localvariable_table() !=
4024 the_class->access_flags().has_localvariable_table()) {
4026 AccessFlags flags = the_class->access_flags();
4027 if (scratch_class->access_flags().has_localvariable_table()) {
4028 flags.set_has_localvariable_table();
4029 } else {
4030 flags.clear_has_localvariable_table();
4031 }
4032 the_class->set_access_flags(flags);
4033 }
4035 swap_annotations(the_class, scratch_class);
4037 // Replace minor version number of class file
4038 u2 old_minor_version = the_class->minor_version();
4039 the_class->set_minor_version(scratch_class->minor_version());
4040 scratch_class->set_minor_version(old_minor_version);
4042 // Replace major version number of class file
4043 u2 old_major_version = the_class->major_version();
4044 the_class->set_major_version(scratch_class->major_version());
4045 scratch_class->set_major_version(old_major_version);
4047 // Replace CP indexes for class and name+type of enclosing method
4048 u2 old_class_idx = the_class->enclosing_method_class_index();
4049 u2 old_method_idx = the_class->enclosing_method_method_index();
4050 the_class->set_enclosing_method_indices(
4051 scratch_class->enclosing_method_class_index(),
4052 scratch_class->enclosing_method_method_index());
4053 scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx);
4055 // keep track of previous versions of this class
4056 the_class->add_previous_version(scratch_class, &emcp_methods,
4057 emcp_method_count);
4059 RC_TIMER_STOP(_timer_rsc_phase1);
4060 RC_TIMER_START(_timer_rsc_phase2);
4062 // Adjust constantpool caches and vtables for all classes
4063 // that reference methods of the evolved class.
4064 AdjustCpoolCacheAndVtable adjust_cpool_cache_and_vtable(THREAD);
4065 ClassLoaderDataGraph::classes_do(&adjust_cpool_cache_and_vtable);
4067 // JSR-292 support
4068 MemberNameTable* mnt = the_class->member_names();
4069 if (mnt != NULL) {
4070 bool trace_name_printed = false;
4071 mnt->adjust_method_entries(the_class(), &trace_name_printed);
4072 }
4074 if (the_class->oop_map_cache() != NULL) {
4075 // Flush references to any obsolete methods from the oop map cache
4076 // so that obsolete methods are not pinned.
4077 the_class->oop_map_cache()->flush_obsolete_entries();
4078 }
4080 // increment the classRedefinedCount field in the_class and in any
4081 // direct and indirect subclasses of the_class
4082 increment_class_counter((InstanceKlass *)the_class(), THREAD);
4084 // RC_TRACE macro has an embedded ResourceMark
4085 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
4086 ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)",
4087 the_class->external_name(),
4088 java_lang_Class::classRedefinedCount(the_class_mirror),
4089 os::available_memory() >> 10));
4091 RC_TIMER_STOP(_timer_rsc_phase2);
4092 } // end redefine_single_class()
4095 // Increment the classRedefinedCount field in the specific InstanceKlass
4096 // and in all direct and indirect subclasses.
4097 void VM_RedefineClasses::increment_class_counter(InstanceKlass *ik, TRAPS) {
4098 oop class_mirror = ik->java_mirror();
4099 Klass* class_oop = java_lang_Class::as_Klass(class_mirror);
4100 int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1;
4101 java_lang_Class::set_classRedefinedCount(class_mirror, new_count);
4103 if (class_oop != _the_class_oop) {
4104 // _the_class_oop count is printed at end of redefine_single_class()
4105 RC_TRACE_WITH_THREAD(0x00000008, THREAD,
4106 ("updated count in subclass=%s to %d", ik->external_name(), new_count));
4107 }
4109 for (Klass *subk = ik->subklass(); subk != NULL;
4110 subk = subk->next_sibling()) {
4111 if (subk->oop_is_instance()) {
4112 // Only update instanceKlasses
4113 InstanceKlass *subik = (InstanceKlass*)subk;
4114 // recursively do subclasses of the current subclass
4115 increment_class_counter(subik, THREAD);
4116 }
4117 }
4118 }
4120 void VM_RedefineClasses::CheckClass::do_klass(Klass* k) {
4121 bool no_old_methods = true; // be optimistic
4123 // Both array and instance classes have vtables.
4124 // a vtable should never contain old or obsolete methods
4125 ResourceMark rm(_thread);
4126 if (k->vtable_length() > 0 &&
4127 !k->vtable()->check_no_old_or_obsolete_entries()) {
4128 if (RC_TRACE_ENABLED(0x00004000)) {
4129 RC_TRACE_WITH_THREAD(0x00004000, _thread,
4130 ("klassVtable::check_no_old_or_obsolete_entries failure"
4131 " -- OLD or OBSOLETE method found -- class: %s",
4132 k->signature_name()));
4133 k->vtable()->dump_vtable();
4134 }
4135 no_old_methods = false;
4136 }
4138 if (k->oop_is_instance()) {
4139 HandleMark hm(_thread);
4140 InstanceKlass *ik = InstanceKlass::cast(k);
4142 // an itable should never contain old or obsolete methods
4143 if (ik->itable_length() > 0 &&
4144 !ik->itable()->check_no_old_or_obsolete_entries()) {
4145 if (RC_TRACE_ENABLED(0x00004000)) {
4146 RC_TRACE_WITH_THREAD(0x00004000, _thread,
4147 ("klassItable::check_no_old_or_obsolete_entries failure"
4148 " -- OLD or OBSOLETE method found -- class: %s",
4149 ik->signature_name()));
4150 ik->itable()->dump_itable();
4151 }
4152 no_old_methods = false;
4153 }
4155 // the constant pool cache should never contain non-deleted old or obsolete methods
4156 if (ik->constants() != NULL &&
4157 ik->constants()->cache() != NULL &&
4158 !ik->constants()->cache()->check_no_old_or_obsolete_entries()) {
4159 if (RC_TRACE_ENABLED(0x00004000)) {
4160 RC_TRACE_WITH_THREAD(0x00004000, _thread,
4161 ("cp-cache::check_no_old_or_obsolete_entries failure"
4162 " -- OLD or OBSOLETE method found -- class: %s",
4163 ik->signature_name()));
4164 ik->constants()->cache()->dump_cache();
4165 }
4166 no_old_methods = false;
4167 }
4168 }
4170 // print and fail guarantee if old methods are found.
4171 if (!no_old_methods) {
4172 if (RC_TRACE_ENABLED(0x00004000)) {
4173 dump_methods();
4174 } else {
4175 tty->print_cr("INFO: use the '-XX:TraceRedefineClasses=16384' option "
4176 "to see more info about the following guarantee() failure.");
4177 }
4178 guarantee(false, "OLD and/or OBSOLETE method(s) found");
4179 }
4180 }
4183 void VM_RedefineClasses::dump_methods() {
4184 int j;
4185 RC_TRACE(0x00004000, ("_old_methods --"));
4186 for (j = 0; j < _old_methods->length(); ++j) {
4187 Method* m = _old_methods->at(j);
4188 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
4189 m->access_flags().print_on(tty);
4190 tty->print(" -- ");
4191 m->print_name(tty);
4192 tty->cr();
4193 }
4194 RC_TRACE(0x00004000, ("_new_methods --"));
4195 for (j = 0; j < _new_methods->length(); ++j) {
4196 Method* m = _new_methods->at(j);
4197 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
4198 m->access_flags().print_on(tty);
4199 tty->print(" -- ");
4200 m->print_name(tty);
4201 tty->cr();
4202 }
4203 RC_TRACE(0x00004000, ("_matching_(old/new)_methods --"));
4204 for (j = 0; j < _matching_methods_length; ++j) {
4205 Method* m = _matching_old_methods[j];
4206 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
4207 m->access_flags().print_on(tty);
4208 tty->print(" -- ");
4209 m->print_name(tty);
4210 tty->cr();
4211 m = _matching_new_methods[j];
4212 RC_TRACE_NO_CR(0x00004000, (" (%5d) ", m->vtable_index()));
4213 m->access_flags().print_on(tty);
4214 tty->cr();
4215 }
4216 RC_TRACE(0x00004000, ("_deleted_methods --"));
4217 for (j = 0; j < _deleted_methods_length; ++j) {
4218 Method* m = _deleted_methods[j];
4219 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
4220 m->access_flags().print_on(tty);
4221 tty->print(" -- ");
4222 m->print_name(tty);
4223 tty->cr();
4224 }
4225 RC_TRACE(0x00004000, ("_added_methods --"));
4226 for (j = 0; j < _added_methods_length; ++j) {
4227 Method* m = _added_methods[j];
4228 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
4229 m->access_flags().print_on(tty);
4230 tty->print(" -- ");
4231 m->print_name(tty);
4232 tty->cr();
4233 }
4234 }