jvmtiRedefineClasses.cpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25#include "precompiled.hpp" 26#include "classfile/systemDictionary.hpp" 27#include "classfile/verifier.hpp" 28#include "code/codeCache.hpp" 29#include "compiler/compileBroker.hpp" 30#include "interpreter/oopMapCache.hpp" 31#include "interpreter/rewriter.hpp" 32#include "memory/gcLocker.hpp" 33#include "memory/metadataFactory.hpp" 34#include "memory/metaspaceShared.hpp" 35#include "memory/universe.inline.hpp" 36#include "oops/fieldStreams.hpp" 37#include "oops/klassVtable.hpp" 38#include "prims/jvmtiImpl.hpp" 39#include "prims/jvmtiRedefineClasses.hpp" 40#include "prims/methodComparator.hpp" 41#include "runtime/deoptimization.hpp" 42#include "runtime/relocator.hpp" 43#include "utilities/bitMap.inline.hpp" 44 45 46Array<Method*>* VM_RedefineClasses::_old_methods = NULL; 47Array<Method*>* VM_RedefineClasses::_new_methods = NULL; 48Method** VM_RedefineClasses::_matching_old_methods = NULL; 49Method** VM_RedefineClasses::_matching_new_methods = NULL; 50Method** VM_RedefineClasses::_deleted_methods = NULL; 51Method** VM_RedefineClasses::_added_methods = NULL; 52int VM_RedefineClasses::_matching_methods_length = 0; 53int VM_RedefineClasses::_deleted_methods_length = 0; 54int VM_RedefineClasses::_added_methods_length = 0; 55Klass* VM_RedefineClasses::_the_class_oop = NULL; 56 57 58VM_RedefineClasses::VM_RedefineClasses(jint class_count, 59 const jvmtiClassDefinition *class_defs, 60 JvmtiClassLoadKind class_load_kind) { 61 _class_count = class_count; 62 _class_defs = class_defs; 63 _class_load_kind = class_load_kind; 64 _res = JVMTI_ERROR_NONE; 65} 66 67bool VM_RedefineClasses::doit_prologue() { 68 if (_class_count == 0) { 69 _res = JVMTI_ERROR_NONE; 70 return false; 71 } 72 if (_class_defs == NULL) { 73 _res = JVMTI_ERROR_NULL_POINTER; 74 return false; 75 } 76 for (int i = 0; i < _class_count; i++) { 77 if (_class_defs[i].klass == NULL) { 78 _res = JVMTI_ERROR_INVALID_CLASS; 79 return false; 80 } 81 if (_class_defs[i].class_byte_count == 0) { 82 _res = JVMTI_ERROR_INVALID_CLASS_FORMAT; 83 return false; 84 } 85 if (_class_defs[i].class_bytes == NULL) { 86 _res = JVMTI_ERROR_NULL_POINTER; 87 return false; 88 } 89 } 90 91 // Start timer after all the sanity checks; not quite accurate, but 92 // better than adding a bunch of stop() calls. 93 RC_TIMER_START(_timer_vm_op_prologue); 94 95 // We first load new class versions in the prologue, because somewhere down the 96 // call chain it is required that the current thread is a Java thread. 97 _res = load_new_class_versions(Thread::current()); 98 if (_res != JVMTI_ERROR_NONE) { 99 // free any successfully created classes, since none are redefined 100 for (int i = 0; i < _class_count; i++) { 101 if (_scratch_classes[i] != NULL) { 102 ClassLoaderData* cld = _scratch_classes[i]->class_loader_data(); 103 // Free the memory for this class at class unloading time. Not before 104 // because CMS might think this is still live. 105 cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]); 106 } 107 } 108 // Free os::malloc allocated memory in load_new_class_version. 109 os::free(_scratch_classes); 110 RC_TIMER_STOP(_timer_vm_op_prologue); 111 return false; 112 } 113 114 RC_TIMER_STOP(_timer_vm_op_prologue); 115 return true; 116} 117 118// Keep track of marked on-stack metadata so it can be cleared. 119GrowableArray<Metadata*>* _marked_objects = NULL; 120NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;) 121 122// Walk metadata on the stack and mark it so that redefinition doesn't delete 123// it. Class unloading also walks the previous versions and might try to 124// delete it, so this class is used by class unloading also. 125MetadataOnStackMark::MetadataOnStackMark() { 126 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 127 NOT_PRODUCT(_is_active = true;) 128 if (_marked_objects == NULL) { 129 _marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true); 130 } 131 Threads::metadata_do(Metadata::mark_on_stack); 132 CodeCache::alive_nmethods_do(nmethod::mark_on_stack); 133 CompileBroker::mark_on_stack(); 134} 135 136MetadataOnStackMark::~MetadataOnStackMark() { 137 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 138 // Unmark everything that was marked. Can't do the same walk because 139 // redefine classes messes up the code cache so the set of methods 140 // might not be the same. 141 for (int i = 0; i< _marked_objects->length(); i++) { 142 _marked_objects->at(i)->set_on_stack(false); 143 } 144 _marked_objects->clear(); // reuse growable array for next time. 145 NOT_PRODUCT(_is_active = false;) 146} 147 148// Record which objects are marked so we can unmark the same objects. 149void MetadataOnStackMark::record(Metadata* m) { 150 assert(_is_active, "metadata on stack marking is active"); 151 _marked_objects->push(m); 152} 153 154 155void VM_RedefineClasses::doit() { 156 Thread *thread = Thread::current(); 157 158 if (UseSharedSpaces) { 159 // Sharing is enabled so we remap the shared readonly space to 160 // shared readwrite, private just in case we need to redefine 161 // a shared class. We do the remap during the doit() phase of 162 // the safepoint to be safer. 163 if (!MetaspaceShared::remap_shared_readonly_as_readwrite()) { 164 RC_TRACE_WITH_THREAD(0x00000001, thread, 165 ("failed to remap shared readonly space to readwrite, private")); 166 _res = JVMTI_ERROR_INTERNAL; 167 return; 168 } 169 } 170 171 // Mark methods seen on stack and everywhere else so old methods are not 172 // cleaned up if they're on the stack. 173 MetadataOnStackMark md_on_stack; 174 HandleMark hm(thread); // make sure any handles created are deleted 175 // before the stack walk again. 176 177 for (int i = 0; i < _class_count; i++) { 178 redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread); 179 ClassLoaderData* cld = _scratch_classes[i]->class_loader_data(); 180 // Free the memory for this class at class unloading time. Not before 181 // because CMS might think this is still live. 182 cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]); 183 _scratch_classes[i] = NULL; 184 } 185 186 // Disable any dependent concurrent compilations 187 SystemDictionary::notice_modification(); 188 189 // Set flag indicating that some invariants are no longer true. 190 // See jvmtiExport.hpp for detailed explanation. 191 JvmtiExport::set_has_redefined_a_class(); 192 193#ifdef ASSERT 194 SystemDictionary::classes_do(check_class, thread); 195#endif 196} 197 198void VM_RedefineClasses::doit_epilogue() { 199 // Free os::malloc allocated memory. 200 os::free(_scratch_classes); 201 202 if (RC_TRACE_ENABLED(0x00000004)) { 203 // Used to have separate timers for "doit" and "all", but the timer 204 // overhead skewed the measurements. 205 jlong doit_time = _timer_rsc_phase1.milliseconds() + 206 _timer_rsc_phase2.milliseconds(); 207 jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time; 208 209 RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT 210 " prologue=" UINT64_FORMAT " doit=" UINT64_FORMAT, all_time, 211 _timer_vm_op_prologue.milliseconds(), doit_time)); 212 RC_TRACE(0x00000004, 213 ("redefine_single_class: phase1=" UINT64_FORMAT " phase2=" UINT64_FORMAT, 214 _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds())); 215 } 216} 217 218bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) { 219 // classes for primitives cannot be redefined 220 if (java_lang_Class::is_primitive(klass_mirror)) { 221 return false; 222 } 223 Klass* the_class_oop = java_lang_Class::as_Klass(klass_mirror); 224 // classes for arrays cannot be redefined 225 if (the_class_oop == NULL || !Klass::cast(the_class_oop)->oop_is_instance()) { 226 return false; 227 } 228 return true; 229} 230 231// Append the current entry at scratch_i in scratch_cp to *merge_cp_p 232// where the end of *merge_cp_p is specified by *merge_cp_length_p. For 233// direct CP entries, there is just the current entry to append. For 234// indirect and double-indirect CP entries, there are zero or more 235// referenced CP entries along with the current entry to append. 236// Indirect and double-indirect CP entries are handled by recursive 237// calls to append_entry() as needed. The referenced CP entries are 238// always appended to *merge_cp_p before the referee CP entry. These 239// referenced CP entries may already exist in *merge_cp_p in which case 240// there is nothing extra to append and only the current entry is 241// appended. 242void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp, 243 int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, 244 TRAPS) { 245 246 // append is different depending on entry tag type 247 switch (scratch_cp->tag_at(scratch_i).value()) { 248 249 // The old verifier is implemented outside the VM. It loads classes, 250 // but does not resolve constant pool entries directly so we never 251 // see Class entries here with the old verifier. Similarly the old 252 // verifier does not like Class entries in the input constant pool. 253 // The split-verifier is implemented in the VM so it can optionally 254 // and directly resolve constant pool entries to load classes. The 255 // split-verifier can accept either Class entries or UnresolvedClass 256 // entries in the input constant pool. We revert the appended copy 257 // back to UnresolvedClass so that either verifier will be happy 258 // with the constant pool entry. 259 case JVM_CONSTANT_Class: 260 { 261 // revert the copy to JVM_CONSTANT_UnresolvedClass 262 (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p, 263 scratch_cp->klass_name_at(scratch_i)); 264 265 if (scratch_i != *merge_cp_length_p) { 266 // The new entry in *merge_cp_p is at a different index than 267 // the new entry in scratch_cp so we need to map the index values. 268 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 269 } 270 (*merge_cp_length_p)++; 271 } break; 272 273 // these are direct CP entries so they can be directly appended, 274 // but double and long take two constant pool entries 275 case JVM_CONSTANT_Double: // fall through 276 case JVM_CONSTANT_Long: 277 { 278 ConstantPool::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p, 279 THREAD); 280 281 if (scratch_i != *merge_cp_length_p) { 282 // The new entry in *merge_cp_p is at a different index than 283 // the new entry in scratch_cp so we need to map the index values. 284 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 285 } 286 (*merge_cp_length_p) += 2; 287 } break; 288 289 // these are direct CP entries so they can be directly appended 290 case JVM_CONSTANT_Float: // fall through 291 case JVM_CONSTANT_Integer: // fall through 292 case JVM_CONSTANT_Utf8: // fall through 293 294 // This was an indirect CP entry, but it has been changed into 295 // Symbol*s so this entry can be directly appended. 296 case JVM_CONSTANT_String: // fall through 297 298 // These were indirect CP entries, but they have been changed into 299 // Symbol*s so these entries can be directly appended. 300 case JVM_CONSTANT_UnresolvedClass: // fall through 301 { 302 ConstantPool::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p, 303 THREAD); 304 305 if (scratch_i != *merge_cp_length_p) { 306 // The new entry in *merge_cp_p is at a different index than 307 // the new entry in scratch_cp so we need to map the index values. 308 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 309 } 310 (*merge_cp_length_p)++; 311 } break; 312 313 // this is an indirect CP entry so it needs special handling 314 case JVM_CONSTANT_NameAndType: 315 { 316 int name_ref_i = scratch_cp->name_ref_index_at(scratch_i); 317 int new_name_ref_i = 0; 318 bool match = (name_ref_i < *merge_cp_length_p) && 319 scratch_cp->compare_entry_to(name_ref_i, *merge_cp_p, name_ref_i, 320 THREAD); 321 if (!match) { 322 // forward reference in *merge_cp_p or not a direct match 323 324 int found_i = scratch_cp->find_matching_entry(name_ref_i, *merge_cp_p, 325 THREAD); 326 if (found_i != 0) { 327 guarantee(found_i != name_ref_i, 328 "compare_entry_to() and find_matching_entry() do not agree"); 329 330 // Found a matching entry somewhere else in *merge_cp_p so 331 // just need a mapping entry. 332 new_name_ref_i = found_i; 333 map_index(scratch_cp, name_ref_i, found_i); 334 } else { 335 // no match found so we have to append this entry to *merge_cp_p 336 append_entry(scratch_cp, name_ref_i, merge_cp_p, merge_cp_length_p, 337 THREAD); 338 // The above call to append_entry() can only append one entry 339 // so the post call query of *merge_cp_length_p is only for 340 // the sake of consistency. 341 new_name_ref_i = *merge_cp_length_p - 1; 342 } 343 } 344 345 int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i); 346 int new_signature_ref_i = 0; 347 match = (signature_ref_i < *merge_cp_length_p) && 348 scratch_cp->compare_entry_to(signature_ref_i, *merge_cp_p, 349 signature_ref_i, THREAD); 350 if (!match) { 351 // forward reference in *merge_cp_p or not a direct match 352 353 int found_i = scratch_cp->find_matching_entry(signature_ref_i, 354 *merge_cp_p, THREAD); 355 if (found_i != 0) { 356 guarantee(found_i != signature_ref_i, 357 "compare_entry_to() and find_matching_entry() do not agree"); 358 359 // Found a matching entry somewhere else in *merge_cp_p so 360 // just need a mapping entry. 361 new_signature_ref_i = found_i; 362 map_index(scratch_cp, signature_ref_i, found_i); 363 } else { 364 // no match found so we have to append this entry to *merge_cp_p 365 append_entry(scratch_cp, signature_ref_i, merge_cp_p, 366 merge_cp_length_p, THREAD); 367 // The above call to append_entry() can only append one entry 368 // so the post call query of *merge_cp_length_p is only for 369 // the sake of consistency. 370 new_signature_ref_i = *merge_cp_length_p - 1; 371 } 372 } 373 374 // If the referenced entries already exist in *merge_cp_p, then 375 // both new_name_ref_i and new_signature_ref_i will both be 0. 376 // In that case, all we are appending is the current entry. 377 if (new_name_ref_i == 0) { 378 new_name_ref_i = name_ref_i; 379 } else { 380 RC_TRACE(0x00080000, 381 ("NameAndType entry@%d name_ref_index change: %d to %d", 382 *merge_cp_length_p, name_ref_i, new_name_ref_i)); 383 } 384 if (new_signature_ref_i == 0) { 385 new_signature_ref_i = signature_ref_i; 386 } else { 387 RC_TRACE(0x00080000, 388 ("NameAndType entry@%d signature_ref_index change: %d to %d", 389 *merge_cp_length_p, signature_ref_i, new_signature_ref_i)); 390 } 391 392 (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p, 393 new_name_ref_i, new_signature_ref_i); 394 if (scratch_i != *merge_cp_length_p) { 395 // The new entry in *merge_cp_p is at a different index than 396 // the new entry in scratch_cp so we need to map the index values. 397 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 398 } 399 (*merge_cp_length_p)++; 400 } break; 401 402 // this is a double-indirect CP entry so it needs special handling 403 case JVM_CONSTANT_Fieldref: // fall through 404 case JVM_CONSTANT_InterfaceMethodref: // fall through 405 case JVM_CONSTANT_Methodref: 406 { 407 int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i); 408 int new_klass_ref_i = 0; 409 bool match = (klass_ref_i < *merge_cp_length_p) && 410 scratch_cp->compare_entry_to(klass_ref_i, *merge_cp_p, klass_ref_i, 411 THREAD); 412 if (!match) { 413 // forward reference in *merge_cp_p or not a direct match 414 415 int found_i = scratch_cp->find_matching_entry(klass_ref_i, *merge_cp_p, 416 THREAD); 417 if (found_i != 0) { 418 guarantee(found_i != klass_ref_i, 419 "compare_entry_to() and find_matching_entry() do not agree"); 420 421 // Found a matching entry somewhere else in *merge_cp_p so 422 // just need a mapping entry. 423 new_klass_ref_i = found_i; 424 map_index(scratch_cp, klass_ref_i, found_i); 425 } else { 426 // no match found so we have to append this entry to *merge_cp_p 427 append_entry(scratch_cp, klass_ref_i, merge_cp_p, merge_cp_length_p, 428 THREAD); 429 // The above call to append_entry() can only append one entry 430 // so the post call query of *merge_cp_length_p is only for 431 // the sake of consistency. Without the optimization where we 432 // use JVM_CONSTANT_UnresolvedClass, then up to two entries 433 // could be appended. 434 new_klass_ref_i = *merge_cp_length_p - 1; 435 } 436 } 437 438 int name_and_type_ref_i = 439 scratch_cp->uncached_name_and_type_ref_index_at(scratch_i); 440 int new_name_and_type_ref_i = 0; 441 match = (name_and_type_ref_i < *merge_cp_length_p) && 442 scratch_cp->compare_entry_to(name_and_type_ref_i, *merge_cp_p, 443 name_and_type_ref_i, THREAD); 444 if (!match) { 445 // forward reference in *merge_cp_p or not a direct match 446 447 int found_i = scratch_cp->find_matching_entry(name_and_type_ref_i, 448 *merge_cp_p, THREAD); 449 if (found_i != 0) { 450 guarantee(found_i != name_and_type_ref_i, 451 "compare_entry_to() and find_matching_entry() do not agree"); 452 453 // Found a matching entry somewhere else in *merge_cp_p so 454 // just need a mapping entry. 455 new_name_and_type_ref_i = found_i; 456 map_index(scratch_cp, name_and_type_ref_i, found_i); 457 } else { 458 // no match found so we have to append this entry to *merge_cp_p 459 append_entry(scratch_cp, name_and_type_ref_i, merge_cp_p, 460 merge_cp_length_p, THREAD); 461 // The above call to append_entry() can append more than 462 // one entry so the post call query of *merge_cp_length_p 463 // is required in order to get the right index for the 464 // JVM_CONSTANT_NameAndType entry. 465 new_name_and_type_ref_i = *merge_cp_length_p - 1; 466 } 467 } 468 469 // If the referenced entries already exist in *merge_cp_p, then 470 // both new_klass_ref_i and new_name_and_type_ref_i will both be 471 // 0. In that case, all we are appending is the current entry. 472 if (new_klass_ref_i == 0) { 473 new_klass_ref_i = klass_ref_i; 474 } 475 if (new_name_and_type_ref_i == 0) { 476 new_name_and_type_ref_i = name_and_type_ref_i; 477 } 478 479 const char *entry_name; 480 switch (scratch_cp->tag_at(scratch_i).value()) { 481 case JVM_CONSTANT_Fieldref: 482 entry_name = "Fieldref"; 483 (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i, 484 new_name_and_type_ref_i); 485 break; 486 case JVM_CONSTANT_InterfaceMethodref: 487 entry_name = "IFMethodref"; 488 (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p, 489 new_klass_ref_i, new_name_and_type_ref_i); 490 break; 491 case JVM_CONSTANT_Methodref: 492 entry_name = "Methodref"; 493 (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i, 494 new_name_and_type_ref_i); 495 break; 496 default: 497 guarantee(false, "bad switch"); 498 break; 499 } 500 501 if (klass_ref_i != new_klass_ref_i) { 502 RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d", 503 entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i)); 504 } 505 if (name_and_type_ref_i != new_name_and_type_ref_i) { 506 RC_TRACE(0x00080000, 507 ("%s entry@%d name_and_type_index changed: %d to %d", 508 entry_name, *merge_cp_length_p, name_and_type_ref_i, 509 new_name_and_type_ref_i)); 510 } 511 512 if (scratch_i != *merge_cp_length_p) { 513 // The new entry in *merge_cp_p is at a different index than 514 // the new entry in scratch_cp so we need to map the index values. 515 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 516 } 517 (*merge_cp_length_p)++; 518 } break; 519 520 // At this stage, Class or UnresolvedClass could be here, but not 521 // ClassIndex 522 case JVM_CONSTANT_ClassIndex: // fall through 523 524 // Invalid is used as the tag for the second constant pool entry 525 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should 526 // not be seen by itself. 527 case JVM_CONSTANT_Invalid: // fall through 528 529 // At this stage, String could be here, but not StringIndex 530 case JVM_CONSTANT_StringIndex: // fall through 531 532 // At this stage JVM_CONSTANT_UnresolvedClassInError should not be 533 // here 534 case JVM_CONSTANT_UnresolvedClassInError: // fall through 535 536 default: 537 { 538 // leave a breadcrumb 539 jbyte bad_value = scratch_cp->tag_at(scratch_i).value(); 540 ShouldNotReachHere(); 541 } break; 542 } // end switch tag value 543} // end append_entry() 544 545 546void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class, TRAPS) { 547 AnnotationArray* save; 548 549 Annotations* sca = scratch_class->annotations(); 550 if (sca == NULL) return; 551 552 save = sca->get_method_annotations_of(i); 553 sca->set_method_annotations_of(scratch_class, i, sca->get_method_annotations_of(j), CHECK); 554 sca->set_method_annotations_of(scratch_class, j, save, CHECK); 555 556 save = sca->get_method_parameter_annotations_of(i); 557 sca->set_method_parameter_annotations_of(scratch_class, i, sca->get_method_parameter_annotations_of(j), CHECK); 558 sca->set_method_parameter_annotations_of(scratch_class, j, save, CHECK); 559 560 save = sca->get_method_default_annotations_of(i); 561 sca->set_method_default_annotations_of(scratch_class, i, sca->get_method_default_annotations_of(j), CHECK); 562 sca->set_method_default_annotations_of(scratch_class, j, save, CHECK); 563} 564 565 566jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions( 567 instanceKlassHandle the_class, 568 instanceKlassHandle scratch_class) { 569 int i; 570 571 // Check superclasses, or rather their names, since superclasses themselves can be 572 // requested to replace. 573 // Check for NULL superclass first since this might be java.lang.Object 574 if (the_class->super() != scratch_class->super() && 575 (the_class->super() == NULL || scratch_class->super() == NULL || 576 Klass::cast(the_class->super())->name() != 577 Klass::cast(scratch_class->super())->name())) { 578 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; 579 } 580 581 // Check if the number, names and order of directly implemented interfaces are the same. 582 // I think in principle we should just check if the sets of names of directly implemented 583 // interfaces are the same, i.e. the order of declaration (which, however, if changed in the 584 // .java file, also changes in .class file) should not matter. However, comparing sets is 585 // technically a bit more difficult, and, more importantly, I am not sure at present that the 586 // order of interfaces does not matter on the implementation level, i.e. that the VM does not 587 // rely on it somewhere. 588 Array<Klass*>* k_interfaces = the_class->local_interfaces(); 589 Array<Klass*>* k_new_interfaces = scratch_class->local_interfaces(); 590 int n_intfs = k_interfaces->length(); 591 if (n_intfs != k_new_interfaces->length()) { 592 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; 593 } 594 for (i = 0; i < n_intfs; i++) { 595 if (Klass::cast(k_interfaces->at(i))->name() != 596 Klass::cast(k_new_interfaces->at(i))->name()) { 597 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; 598 } 599 } 600 601 // Check whether class is in the error init state. 602 if (the_class->is_in_error_state()) { 603 // TBD #5057930: special error code is needed in 1.6 604 return JVMTI_ERROR_INVALID_CLASS; 605 } 606 607 // Check whether class modifiers are the same. 608 jushort old_flags = (jushort) the_class->access_flags().get_flags(); 609 jushort new_flags = (jushort) scratch_class->access_flags().get_flags(); 610 if (old_flags != new_flags) { 611 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED; 612 } 613 614 // Check if the number, names, types and order of fields declared in these classes 615 // are the same. 616 JavaFieldStream old_fs(the_class); 617 JavaFieldStream new_fs(scratch_class); 618 for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) { 619 // access 620 old_flags = old_fs.access_flags().as_short(); 621 new_flags = new_fs.access_flags().as_short(); 622 if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) { 623 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 624 } 625 // offset 626 if (old_fs.offset() != new_fs.offset()) { 627 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 628 } 629 // name and signature 630 Symbol* name_sym1 = the_class->constants()->symbol_at(old_fs.name_index()); 631 Symbol* sig_sym1 = the_class->constants()->symbol_at(old_fs.signature_index()); 632 Symbol* name_sym2 = scratch_class->constants()->symbol_at(new_fs.name_index()); 633 Symbol* sig_sym2 = scratch_class->constants()->symbol_at(new_fs.signature_index()); 634 if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) { 635 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 636 } 637 } 638 639 // If both streams aren't done then we have a differing number of 640 // fields. 641 if (!old_fs.done() || !new_fs.done()) { 642 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 643 } 644 645 // Do a parallel walk through the old and new methods. Detect 646 // cases where they match (exist in both), have been added in 647 // the new methods, or have been deleted (exist only in the 648 // old methods). The class file parser places methods in order 649 // by method name, but does not order overloaded methods by 650 // signature. In order to determine what fate befell the methods, 651 // this code places the overloaded new methods that have matching 652 // old methods in the same order as the old methods and places 653 // new overloaded methods at the end of overloaded methods of 654 // that name. The code for this order normalization is adapted 655 // from the algorithm used in InstanceKlass::find_method(). 656 // Since we are swapping out of order entries as we find them, 657 // we only have to search forward through the overloaded methods. 658 // Methods which are added and have the same name as an existing 659 // method (but different signature) will be put at the end of 660 // the methods with that name, and the name mismatch code will 661 // handle them. 662 Array<Method*>* k_old_methods(the_class->methods()); 663 Array<Method*>* k_new_methods(scratch_class->methods()); 664 int n_old_methods = k_old_methods->length(); 665 int n_new_methods = k_new_methods->length(); 666 Thread* thread = Thread::current(); 667 668 int ni = 0; 669 int oi = 0; 670 while (true) { 671 Method* k_old_method; 672 Method* k_new_method; 673 enum { matched, added, deleted, undetermined } method_was = undetermined; 674 675 if (oi >= n_old_methods) { 676 if (ni >= n_new_methods) { 677 break; // we've looked at everything, done 678 } 679 // New method at the end 680 k_new_method = k_new_methods->at(ni); 681 method_was = added; 682 } else if (ni >= n_new_methods) { 683 // Old method, at the end, is deleted 684 k_old_method = k_old_methods->at(oi); 685 method_was = deleted; 686 } else { 687 // There are more methods in both the old and new lists 688 k_old_method = k_old_methods->at(oi); 689 k_new_method = k_new_methods->at(ni); 690 if (k_old_method->name() != k_new_method->name()) { 691 // Methods are sorted by method name, so a mismatch means added 692 // or deleted 693 if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) { 694 method_was = added; 695 } else { 696 method_was = deleted; 697 } 698 } else if (k_old_method->signature() == k_new_method->signature()) { 699 // Both the name and signature match 700 method_was = matched; 701 } else { 702 // The name matches, but the signature doesn't, which means we have to 703 // search forward through the new overloaded methods. 704 int nj; // outside the loop for post-loop check 705 for (nj = ni + 1; nj < n_new_methods; nj++) { 706 Method* m = k_new_methods->at(nj); 707 if (k_old_method->name() != m->name()) { 708 // reached another method name so no more overloaded methods 709 method_was = deleted; 710 break; 711 } 712 if (k_old_method->signature() == m->signature()) { 713 // found a match so swap the methods 714 k_new_methods->at_put(ni, m); 715 k_new_methods->at_put(nj, k_new_method); 716 k_new_method = m; 717 method_was = matched; 718 break; 719 } 720 } 721 722 if (nj >= n_new_methods) { 723 // reached the end without a match; so method was deleted 724 method_was = deleted; 725 } 726 } 727 } 728 729 switch (method_was) { 730 case matched: 731 // methods match, be sure modifiers do too 732 old_flags = (jushort) k_old_method->access_flags().get_flags(); 733 new_flags = (jushort) k_new_method->access_flags().get_flags(); 734 if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) { 735 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED; 736 } 737 { 738 u2 new_num = k_new_method->method_idnum(); 739 u2 old_num = k_old_method->method_idnum(); 740 if (new_num != old_num) { 741 Method* idnum_owner = scratch_class->method_with_idnum(old_num); 742 if (idnum_owner != NULL) { 743 // There is already a method assigned this idnum -- switch them 744 idnum_owner->set_method_idnum(new_num); 745 } 746 k_new_method->set_method_idnum(old_num); 747 swap_all_method_annotations(old_num, new_num, scratch_class, thread); 748 if (thread->has_pending_exception()) { 749 return JVMTI_ERROR_OUT_OF_MEMORY; 750 } 751 } 752 } 753 RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]", 754 k_new_method->name_and_sig_as_C_string(), ni, 755 k_old_method->name_and_sig_as_C_string(), oi)); 756 // advance to next pair of methods 757 ++oi; 758 ++ni; 759 break; 760 case added: 761 // method added, see if it is OK 762 new_flags = (jushort) k_new_method->access_flags().get_flags(); 763 if ((new_flags & JVM_ACC_PRIVATE) == 0 764 // hack: private should be treated as final, but alas 765 || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0 766 ) { 767 // new methods must be private 768 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED; 769 } 770 { 771 u2 num = the_class->next_method_idnum(); 772 if (num == ConstMethod::UNSET_IDNUM) { 773 // cannot add any more methods 774 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED; 775 } 776 u2 new_num = k_new_method->method_idnum(); 777 Method* idnum_owner = scratch_class->method_with_idnum(num); 778 if (idnum_owner != NULL) { 779 // There is already a method assigned this idnum -- switch them 780 idnum_owner->set_method_idnum(new_num); 781 } 782 k_new_method->set_method_idnum(num); 783 swap_all_method_annotations(new_num, num, scratch_class, thread); 784 if (thread->has_pending_exception()) { 785 return JVMTI_ERROR_OUT_OF_MEMORY; 786 } 787 } 788 RC_TRACE(0x00008000, ("Method added: new: %s [%d]", 789 k_new_method->name_and_sig_as_C_string(), ni)); 790 ++ni; // advance to next new method 791 break; 792 case deleted: 793 // method deleted, see if it is OK 794 old_flags = (jushort) k_old_method->access_flags().get_flags(); 795 if ((old_flags & JVM_ACC_PRIVATE) == 0 796 // hack: private should be treated as final, but alas 797 || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0 798 ) { 799 // deleted methods must be private 800 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED; 801 } 802 RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]", 803 k_old_method->name_and_sig_as_C_string(), oi)); 804 ++oi; // advance to next old method 805 break; 806 default: 807 ShouldNotReachHere(); 808 } 809 } 810 811 return JVMTI_ERROR_NONE; 812} 813 814 815// Find new constant pool index value for old constant pool index value 816// by seaching the index map. Returns zero (0) if there is no mapped 817// value for the old constant pool index. 818int VM_RedefineClasses::find_new_index(int old_index) { 819 if (_index_map_count == 0) { 820 // map is empty so nothing can be found 821 return 0; 822 } 823 824 if (old_index < 1 || old_index >= _index_map_p->length()) { 825 // The old_index is out of range so it is not mapped. This should 826 // not happen in regular constant pool merging use, but it can 827 // happen if a corrupt annotation is processed. 828 return 0; 829 } 830 831 int value = _index_map_p->at(old_index); 832 if (value == -1) { 833 // the old_index is not mapped 834 return 0; 835 } 836 837 return value; 838} // end find_new_index() 839 840 841// Returns true if the current mismatch is due to a resolved/unresolved 842// class pair. Otherwise, returns false. 843bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1, 844 int index1, constantPoolHandle cp2, int index2) { 845 846 jbyte t1 = cp1->tag_at(index1).value(); 847 if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) { 848 return false; // wrong entry type; not our special case 849 } 850 851 jbyte t2 = cp2->tag_at(index2).value(); 852 if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) { 853 return false; // wrong entry type; not our special case 854 } 855 856 if (t1 == t2) { 857 return false; // not a mismatch; not our special case 858 } 859 860 char *s1 = cp1->klass_name_at(index1)->as_C_string(); 861 char *s2 = cp2->klass_name_at(index2)->as_C_string(); 862 if (strcmp(s1, s2) != 0) { 863 return false; // strings don't match; not our special case 864 } 865 866 return true; // made it through the gauntlet; this is our special case 867} // end is_unresolved_class_mismatch() 868 869 870jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) { 871 872 // For consistency allocate memory using os::malloc wrapper. 873 _scratch_classes = (Klass**) 874 os::malloc(sizeof(Klass*) * _class_count, mtClass); 875 if (_scratch_classes == NULL) { 876 return JVMTI_ERROR_OUT_OF_MEMORY; 877 } 878 // Zero initialize the _scratch_classes array. 879 for (int i = 0; i < _class_count; i++) { 880 _scratch_classes[i] = NULL; 881 } 882 883 ResourceMark rm(THREAD); 884 885 JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current()); 886 // state can only be NULL if the current thread is exiting which 887 // should not happen since we're trying to do a RedefineClasses 888 guarantee(state != NULL, "exiting thread calling load_new_class_versions"); 889 for (int i = 0; i < _class_count; i++) { 890 // Create HandleMark so that any handles created while loading new class 891 // versions are deleted. Constant pools are deallocated while merging 892 // constant pools 893 HandleMark hm(THREAD); 894 895 oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass); 896 // classes for primitives cannot be redefined 897 if (!is_modifiable_class(mirror)) { 898 return JVMTI_ERROR_UNMODIFIABLE_CLASS; 899 } 900 Klass* the_class_oop = java_lang_Class::as_Klass(mirror); 901 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop); 902 Symbol* the_class_sym = the_class->name(); 903 904 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 905 RC_TRACE_WITH_THREAD(0x00000001, THREAD, 906 ("loading name=%s kind=%d (avail_mem=" UINT64_FORMAT "K)", 907 the_class->external_name(), _class_load_kind, 908 os::available_memory() >> 10)); 909 910 ClassFileStream st((u1*) _class_defs[i].class_bytes, 911 _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__"); 912 913 // Parse the stream. 914 Handle the_class_loader(THREAD, the_class->class_loader()); 915 Handle protection_domain(THREAD, the_class->protection_domain()); 916 // Set redefined class handle in JvmtiThreadState class. 917 // This redefined class is sent to agent event handler for class file 918 // load hook event. 919 state->set_class_being_redefined(&the_class, _class_load_kind); 920 921 Klass* k = SystemDictionary::parse_stream(the_class_sym, 922 the_class_loader, 923 protection_domain, 924 &st, 925 THREAD); 926 // Clear class_being_redefined just to be sure. 927 state->clear_class_being_redefined(); 928 929 // TODO: if this is retransform, and nothing changed we can skip it 930 931 instanceKlassHandle scratch_class (THREAD, k); 932 933 // Need to clean up allocated InstanceKlass if there's an error so assign 934 // the result here. Caller deallocates all the scratch classes in case of 935 // an error. 936 _scratch_classes[i] = k; 937 938 if (HAS_PENDING_EXCEPTION) { 939 Symbol* ex_name = PENDING_EXCEPTION->klass()->name(); 940 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 941 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'", 942 ex_name->as_C_string())); 943 CLEAR_PENDING_EXCEPTION; 944 945 if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) { 946 return JVMTI_ERROR_UNSUPPORTED_VERSION; 947 } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) { 948 return JVMTI_ERROR_INVALID_CLASS_FORMAT; 949 } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) { 950 return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION; 951 } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) { 952 // The message will be "XXX (wrong name: YYY)" 953 return JVMTI_ERROR_NAMES_DONT_MATCH; 954 } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 955 return JVMTI_ERROR_OUT_OF_MEMORY; 956 } else { // Just in case more exceptions can be thrown.. 957 return JVMTI_ERROR_FAILS_VERIFICATION; 958 } 959 } 960 961 // Ensure class is linked before redefine 962 if (!the_class->is_linked()) { 963 the_class->link_class(THREAD); 964 if (HAS_PENDING_EXCEPTION) { 965 Symbol* ex_name = PENDING_EXCEPTION->klass()->name(); 966 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 967 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'", 968 ex_name->as_C_string())); 969 CLEAR_PENDING_EXCEPTION; 970 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 971 return JVMTI_ERROR_OUT_OF_MEMORY; 972 } else { 973 return JVMTI_ERROR_INTERNAL; 974 } 975 } 976 } 977 978 // Do the validity checks in compare_and_normalize_class_versions() 979 // before verifying the byte codes. By doing these checks first, we 980 // limit the number of functions that require redirection from 981 // the_class to scratch_class. In particular, we don't have to 982 // modify JNI GetSuperclass() and thus won't change its performance. 983 jvmtiError res = compare_and_normalize_class_versions(the_class, 984 scratch_class); 985 if (res != JVMTI_ERROR_NONE) { 986 return res; 987 } 988 989 // verify what the caller passed us 990 { 991 // The bug 6214132 caused the verification to fail. 992 // Information about the_class and scratch_class is temporarily 993 // recorded into jvmtiThreadState. This data is used to redirect 994 // the_class to scratch_class in the JVM_* functions called by the 995 // verifier. Please, refer to jvmtiThreadState.hpp for the detailed 996 // description. 997 RedefineVerifyMark rvm(&the_class, &scratch_class, state); 998 Verifier::verify( 999 scratch_class, Verifier::ThrowException, true, THREAD); 1000 } 1001 1002 if (HAS_PENDING_EXCEPTION) { 1003 Symbol* ex_name = PENDING_EXCEPTION->klass()->name(); 1004 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 1005 RC_TRACE_WITH_THREAD(0x00000002, THREAD, 1006 ("verify_byte_codes exception: '%s'", ex_name->as_C_string())); 1007 CLEAR_PENDING_EXCEPTION; 1008 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 1009 return JVMTI_ERROR_OUT_OF_MEMORY; 1010 } else { 1011 // tell the caller the bytecodes are bad 1012 return JVMTI_ERROR_FAILS_VERIFICATION; 1013 } 1014 } 1015 1016 res = merge_cp_and_rewrite(the_class, scratch_class, THREAD); 1017 if (res != JVMTI_ERROR_NONE) { 1018 return res; 1019 } 1020 1021 if (VerifyMergedCPBytecodes) { 1022 // verify what we have done during constant pool merging 1023 { 1024 RedefineVerifyMark rvm(&the_class, &scratch_class, state); 1025 Verifier::verify(scratch_class, Verifier::ThrowException, true, THREAD); 1026 } 1027 1028 if (HAS_PENDING_EXCEPTION) { 1029 Symbol* ex_name = PENDING_EXCEPTION->klass()->name(); 1030 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 1031 RC_TRACE_WITH_THREAD(0x00000002, THREAD, 1032 ("verify_byte_codes post merge-CP exception: '%s'", 1033 ex_name->as_C_string())); 1034 CLEAR_PENDING_EXCEPTION; 1035 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 1036 return JVMTI_ERROR_OUT_OF_MEMORY; 1037 } else { 1038 // tell the caller that constant pool merging screwed up 1039 return JVMTI_ERROR_INTERNAL; 1040 } 1041 } 1042 } 1043 1044 Rewriter::rewrite(scratch_class, THREAD); 1045 if (!HAS_PENDING_EXCEPTION) { 1046 Rewriter::relocate_and_link(scratch_class, THREAD); 1047 } 1048 if (HAS_PENDING_EXCEPTION) { 1049 Symbol* ex_name = PENDING_EXCEPTION->klass()->name(); 1050 CLEAR_PENDING_EXCEPTION; 1051 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 1052 return JVMTI_ERROR_OUT_OF_MEMORY; 1053 } else { 1054 return JVMTI_ERROR_INTERNAL; 1055 } 1056 } 1057 1058 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 1059 RC_TRACE_WITH_THREAD(0x00000001, THREAD, 1060 ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)", 1061 the_class->external_name(), os::available_memory() >> 10)); 1062 } 1063 1064 return JVMTI_ERROR_NONE; 1065} 1066 1067 1068// Map old_index to new_index as needed. scratch_cp is only needed 1069// for RC_TRACE() calls. 1070void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp, 1071 int old_index, int new_index) { 1072 if (find_new_index(old_index) != 0) { 1073 // old_index is already mapped 1074 return; 1075 } 1076 1077 if (old_index == new_index) { 1078 // no mapping is needed 1079 return; 1080 } 1081 1082 _index_map_p->at_put(old_index, new_index); 1083 _index_map_count++; 1084 1085 RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d", 1086 scratch_cp->tag_at(old_index).value(), old_index, new_index)); 1087} // end map_index() 1088 1089 1090// Merge old_cp and scratch_cp and return the results of the merge via 1091// merge_cp_p. The number of entries in *merge_cp_p is returned via 1092// merge_cp_length_p. The entries in old_cp occupy the same locations 1093// in *merge_cp_p. Also creates a map of indices from entries in 1094// scratch_cp to the corresponding entry in *merge_cp_p. Index map 1095// entries are only created for entries in scratch_cp that occupy a 1096// different location in *merged_cp_p. 1097bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp, 1098 constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p, 1099 int *merge_cp_length_p, TRAPS) { 1100 1101 if (merge_cp_p == NULL) { 1102 assert(false, "caller must provide scratch constantPool"); 1103 return false; // robustness 1104 } 1105 if (merge_cp_length_p == NULL) { 1106 assert(false, "caller must provide scratch CP length"); 1107 return false; // robustness 1108 } 1109 // Worst case we need old_cp->length() + scratch_cp()->length(), 1110 // but the caller might be smart so make sure we have at least 1111 // the minimum. 1112 if ((*merge_cp_p)->length() < old_cp->length()) { 1113 assert(false, "merge area too small"); 1114 return false; // robustness 1115 } 1116 1117 RC_TRACE_WITH_THREAD(0x00010000, THREAD, 1118 ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(), 1119 scratch_cp->length())); 1120 1121 { 1122 // Pass 0: 1123 // The old_cp is copied to *merge_cp_p; this means that any code 1124 // using old_cp does not have to change. This work looks like a 1125 // perfect fit for ConstantPool*::copy_cp_to(), but we need to 1126 // handle one special case: 1127 // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass 1128 // This will make verification happy. 1129 1130 int old_i; // index into old_cp 1131 1132 // index zero (0) is not used in constantPools 1133 for (old_i = 1; old_i < old_cp->length(); old_i++) { 1134 // leave debugging crumb 1135 jbyte old_tag = old_cp->tag_at(old_i).value(); 1136 switch (old_tag) { 1137 case JVM_CONSTANT_Class: 1138 case JVM_CONSTANT_UnresolvedClass: 1139 // revert the copy to JVM_CONSTANT_UnresolvedClass 1140 // May be resolving while calling this so do the same for 1141 // JVM_CONSTANT_UnresolvedClass (klass_name_at() deals with transition) 1142 (*merge_cp_p)->unresolved_klass_at_put(old_i, 1143 old_cp->klass_name_at(old_i)); 1144 break; 1145 1146 case JVM_CONSTANT_Double: 1147 case JVM_CONSTANT_Long: 1148 // just copy the entry to *merge_cp_p, but double and long take 1149 // two constant pool entries 1150 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0); 1151 old_i++; 1152 break; 1153 1154 default: 1155 // just copy the entry to *merge_cp_p 1156 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0); 1157 break; 1158 } 1159 } // end for each old_cp entry 1160 1161 // We don't need to sanity check that *merge_cp_length_p is within 1162 // *merge_cp_p bounds since we have the minimum on-entry check above. 1163 (*merge_cp_length_p) = old_i; 1164 } 1165 1166 // merge_cp_len should be the same as old_cp->length() at this point 1167 // so this trace message is really a "warm-and-breathing" message. 1168 RC_TRACE_WITH_THREAD(0x00020000, THREAD, 1169 ("after pass 0: merge_cp_len=%d", *merge_cp_length_p)); 1170 1171 int scratch_i; // index into scratch_cp 1172 { 1173 // Pass 1a: 1174 // Compare scratch_cp entries to the old_cp entries that we have 1175 // already copied to *merge_cp_p. In this pass, we are eliminating 1176 // exact duplicates (matching entry at same index) so we only 1177 // compare entries in the common indice range. 1178 int increment = 1; 1179 int pass1a_length = MIN2(old_cp->length(), scratch_cp->length()); 1180 for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) { 1181 switch (scratch_cp->tag_at(scratch_i).value()) { 1182 case JVM_CONSTANT_Double: 1183 case JVM_CONSTANT_Long: 1184 // double and long take two constant pool entries 1185 increment = 2; 1186 break; 1187 1188 default: 1189 increment = 1; 1190 break; 1191 } 1192 1193 bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p, 1194 scratch_i, CHECK_0); 1195 if (match) { 1196 // found a match at the same index so nothing more to do 1197 continue; 1198 } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i, 1199 *merge_cp_p, scratch_i)) { 1200 // The mismatch in compare_entry_to() above is because of a 1201 // resolved versus unresolved class entry at the same index 1202 // with the same string value. Since Pass 0 reverted any 1203 // class entries to unresolved class entries in *merge_cp_p, 1204 // we go with the unresolved class entry. 1205 continue; 1206 } 1207 1208 int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, 1209 CHECK_0); 1210 if (found_i != 0) { 1211 guarantee(found_i != scratch_i, 1212 "compare_entry_to() and find_matching_entry() do not agree"); 1213 1214 // Found a matching entry somewhere else in *merge_cp_p so 1215 // just need a mapping entry. 1216 map_index(scratch_cp, scratch_i, found_i); 1217 continue; 1218 } 1219 1220 // The find_matching_entry() call above could fail to find a match 1221 // due to a resolved versus unresolved class or string entry situation 1222 // like we solved above with the is_unresolved_*_mismatch() calls. 1223 // However, we would have to call is_unresolved_*_mismatch() over 1224 // all of *merge_cp_p (potentially) and that doesn't seem to be 1225 // worth the time. 1226 1227 // No match found so we have to append this entry and any unique 1228 // referenced entries to *merge_cp_p. 1229 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p, 1230 CHECK_0); 1231 } 1232 } 1233 1234 RC_TRACE_WITH_THREAD(0x00020000, THREAD, 1235 ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d", 1236 *merge_cp_length_p, scratch_i, _index_map_count)); 1237 1238 if (scratch_i < scratch_cp->length()) { 1239 // Pass 1b: 1240 // old_cp is smaller than scratch_cp so there are entries in 1241 // scratch_cp that we have not yet processed. We take care of 1242 // those now. 1243 int increment = 1; 1244 for (; scratch_i < scratch_cp->length(); scratch_i += increment) { 1245 switch (scratch_cp->tag_at(scratch_i).value()) { 1246 case JVM_CONSTANT_Double: 1247 case JVM_CONSTANT_Long: 1248 // double and long take two constant pool entries 1249 increment = 2; 1250 break; 1251 1252 default: 1253 increment = 1; 1254 break; 1255 } 1256 1257 int found_i = 1258 scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0); 1259 if (found_i != 0) { 1260 // Found a matching entry somewhere else in *merge_cp_p so 1261 // just need a mapping entry. 1262 map_index(scratch_cp, scratch_i, found_i); 1263 continue; 1264 } 1265 1266 // No match found so we have to append this entry and any unique 1267 // referenced entries to *merge_cp_p. 1268 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p, 1269 CHECK_0); 1270 } 1271 1272 RC_TRACE_WITH_THREAD(0x00020000, THREAD, 1273 ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d", 1274 *merge_cp_length_p, scratch_i, _index_map_count)); 1275 } 1276 1277 return true; 1278} // end merge_constant_pools() 1279 1280 1281// Scoped object to clean up the constant pool(s) created for merging 1282class MergeCPCleaner { 1283 ClassLoaderData* _loader_data; 1284 ConstantPool* _cp; 1285 ConstantPool* _scratch_cp; 1286 public: 1287 MergeCPCleaner(ClassLoaderData* loader_data, ConstantPool* merge_cp) : 1288 _loader_data(loader_data), _cp(merge_cp), _scratch_cp(NULL) {} 1289 ~MergeCPCleaner() { 1290 _loader_data->add_to_deallocate_list(_cp); 1291 if (_scratch_cp != NULL) { 1292 _loader_data->add_to_deallocate_list(_scratch_cp); 1293 } 1294 } 1295 void add_scratch_cp(ConstantPool* scratch_cp) { _scratch_cp = scratch_cp; } 1296}; 1297 1298// Merge constant pools between the_class and scratch_class and 1299// potentially rewrite bytecodes in scratch_class to use the merged 1300// constant pool. 1301jvmtiError VM_RedefineClasses::merge_cp_and_rewrite( 1302 instanceKlassHandle the_class, instanceKlassHandle scratch_class, 1303 TRAPS) { 1304 // worst case merged constant pool length is old and new combined 1305 int merge_cp_length = the_class->constants()->length() 1306 + scratch_class->constants()->length(); 1307 1308 // Constant pools are not easily reused so we allocate a new one 1309 // each time. 1310 // merge_cp is created unsafe for concurrent GC processing. It 1311 // should be marked safe before discarding it. Even though 1312 // garbage, if it crosses a card boundary, it may be scanned 1313 // in order to find the start of the first complete object on the card. 1314 ClassLoaderData* loader_data = the_class->class_loader_data(); 1315 ConstantPool* merge_cp_oop = 1316 ConstantPool::allocate(loader_data, 1317 merge_cp_length, 1318 THREAD); 1319 MergeCPCleaner cp_cleaner(loader_data, merge_cp_oop); 1320 1321 HandleMark hm(THREAD); // make sure handles are cleared before 1322 // MergeCPCleaner clears out merge_cp_oop 1323 constantPoolHandle merge_cp(THREAD, merge_cp_oop); 1324 1325 // Get constants() from the old class because it could have been rewritten 1326 // while we were at a safepoint allocating a new constant pool. 1327 constantPoolHandle old_cp(THREAD, the_class->constants()); 1328 constantPoolHandle scratch_cp(THREAD, scratch_class->constants()); 1329 1330 // If the length changed, the class was redefined out from under us. Return 1331 // an error. 1332 if (merge_cp_length != the_class->constants()->length() 1333 + scratch_class->constants()->length()) { 1334 return JVMTI_ERROR_INTERNAL; 1335 } 1336 1337 int orig_length = old_cp->orig_length(); 1338 if (orig_length == 0) { 1339 // This old_cp is an actual original constant pool. We save 1340 // the original length in the merged constant pool so that 1341 // merge_constant_pools() can be more efficient. If a constant 1342 // pool has a non-zero orig_length() value, then that constant 1343 // pool was created by a merge operation in RedefineClasses. 1344 merge_cp->set_orig_length(old_cp->length()); 1345 } else { 1346 // This old_cp is a merged constant pool from a previous 1347 // RedefineClasses() calls so just copy the orig_length() 1348 // value. 1349 merge_cp->set_orig_length(old_cp->orig_length()); 1350 } 1351 1352 ResourceMark rm(THREAD); 1353 _index_map_count = 0; 1354 _index_map_p = new intArray(scratch_cp->length(), -1); 1355 1356 bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp, 1357 &merge_cp_length, THREAD); 1358 if (!result) { 1359 // The merge can fail due to memory allocation failure or due 1360 // to robustness checks. 1361 return JVMTI_ERROR_INTERNAL; 1362 } 1363 1364 RC_TRACE_WITH_THREAD(0x00010000, THREAD, 1365 ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count)); 1366 1367 if (_index_map_count == 0) { 1368 // there is nothing to map between the new and merged constant pools 1369 1370 if (old_cp->length() == scratch_cp->length()) { 1371 // The old and new constant pools are the same length and the 1372 // index map is empty. This means that the three constant pools 1373 // are equivalent (but not the same). Unfortunately, the new 1374 // constant pool has not gone through link resolution nor have 1375 // the new class bytecodes gone through constant pool cache 1376 // rewriting so we can't use the old constant pool with the new 1377 // class. 1378 1379 // toss the merged constant pool at return 1380 } else if (old_cp->length() < scratch_cp->length()) { 1381 // The old constant pool has fewer entries than the new constant 1382 // pool and the index map is empty. This means the new constant 1383 // pool is a superset of the old constant pool. However, the old 1384 // class bytecodes have already gone through constant pool cache 1385 // rewriting so we can't use the new constant pool with the old 1386 // class. 1387 1388 // toss the merged constant pool at return 1389 } else { 1390 // The old constant pool has more entries than the new constant 1391 // pool and the index map is empty. This means that both the old 1392 // and merged constant pools are supersets of the new constant 1393 // pool. 1394 1395 // Replace the new constant pool with a shrunken copy of the 1396 // merged constant pool 1397 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length, THREAD); 1398 // The new constant pool replaces scratch_cp so have cleaner clean it up. 1399 // It can't be cleaned up while there are handles to it. 1400 cp_cleaner.add_scratch_cp(scratch_cp()); 1401 } 1402 } else { 1403 if (RC_TRACE_ENABLED(0x00040000)) { 1404 // don't want to loop unless we are tracing 1405 int count = 0; 1406 for (int i = 1; i < _index_map_p->length(); i++) { 1407 int value = _index_map_p->at(i); 1408 1409 if (value != -1) { 1410 RC_TRACE_WITH_THREAD(0x00040000, THREAD, 1411 ("index_map[%d]: old=%d new=%d", count, i, value)); 1412 count++; 1413 } 1414 } 1415 } 1416 1417 // We have entries mapped between the new and merged constant pools 1418 // so we have to rewrite some constant pool references. 1419 if (!rewrite_cp_refs(scratch_class, THREAD)) { 1420 return JVMTI_ERROR_INTERNAL; 1421 } 1422 1423 // Replace the new constant pool with a shrunken copy of the 1424 // merged constant pool so now the rewritten bytecodes have 1425 // valid references; the previous new constant pool will get 1426 // GCed. 1427 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length, THREAD); 1428 // The new constant pool replaces scratch_cp so have cleaner clean it up. 1429 // It can't be cleaned up while there are handles to it. 1430 cp_cleaner.add_scratch_cp(scratch_cp()); 1431 } 1432 1433 return JVMTI_ERROR_NONE; 1434} // end merge_cp_and_rewrite() 1435 1436 1437// Rewrite constant pool references in klass scratch_class. 1438bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class, 1439 TRAPS) { 1440 1441 // rewrite constant pool references in the methods: 1442 if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) { 1443 // propagate failure back to caller 1444 return false; 1445 } 1446 1447 // rewrite constant pool references in the class_annotations: 1448 if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) { 1449 // propagate failure back to caller 1450 return false; 1451 } 1452 1453 // rewrite constant pool references in the fields_annotations: 1454 if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) { 1455 // propagate failure back to caller 1456 return false; 1457 } 1458 1459 // rewrite constant pool references in the methods_annotations: 1460 if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) { 1461 // propagate failure back to caller 1462 return false; 1463 } 1464 1465 // rewrite constant pool references in the methods_parameter_annotations: 1466 if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class, 1467 THREAD)) { 1468 // propagate failure back to caller 1469 return false; 1470 } 1471 1472 // rewrite constant pool references in the methods_default_annotations: 1473 if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class, 1474 THREAD)) { 1475 // propagate failure back to caller 1476 return false; 1477 } 1478 1479 return true; 1480} // end rewrite_cp_refs() 1481 1482 1483// Rewrite constant pool references in the methods. 1484bool VM_RedefineClasses::rewrite_cp_refs_in_methods( 1485 instanceKlassHandle scratch_class, TRAPS) { 1486 1487 Array<Method*>* methods = scratch_class->methods(); 1488 1489 if (methods == NULL || methods->length() == 0) { 1490 // no methods so nothing to do 1491 return true; 1492 } 1493 1494 // rewrite constant pool references in the methods: 1495 for (int i = methods->length() - 1; i >= 0; i--) { 1496 methodHandle method(THREAD, methods->at(i)); 1497 methodHandle new_method; 1498 rewrite_cp_refs_in_method(method, &new_method, CHECK_false); 1499 if (!new_method.is_null()) { 1500 // the method has been replaced so save the new method version 1501 methods->at_put(i, new_method()); 1502 } 1503 } 1504 1505 return true; 1506} 1507 1508 1509// Rewrite constant pool references in the specific method. This code 1510// was adapted from Rewriter::rewrite_method(). 1511void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method, 1512 methodHandle *new_method_p, TRAPS) { 1513 1514 *new_method_p = methodHandle(); // default is no new method 1515 1516 // We cache a pointer to the bytecodes here in code_base. If GC 1517 // moves the Method*, then the bytecodes will also move which 1518 // will likely cause a crash. We create a No_Safepoint_Verifier 1519 // object to detect whether we pass a possible safepoint in this 1520 // code block. 1521 No_Safepoint_Verifier nsv; 1522 1523 // Bytecodes and their length 1524 address code_base = method->code_base(); 1525 int code_length = method->code_size(); 1526 1527 int bc_length; 1528 for (int bci = 0; bci < code_length; bci += bc_length) { 1529 address bcp = code_base + bci; 1530 Bytecodes::Code c = (Bytecodes::Code)(*bcp); 1531 1532 bc_length = Bytecodes::length_for(c); 1533 if (bc_length == 0) { 1534 // More complicated bytecodes report a length of zero so 1535 // we have to try again a slightly different way. 1536 bc_length = Bytecodes::length_at(method(), bcp); 1537 } 1538 1539 assert(bc_length != 0, "impossible bytecode length"); 1540 1541 switch (c) { 1542 case Bytecodes::_ldc: 1543 { 1544 int cp_index = *(bcp + 1); 1545 int new_index = find_new_index(cp_index); 1546 1547 if (StressLdcRewrite && new_index == 0) { 1548 // If we are stressing ldc -> ldc_w rewriting, then we 1549 // always need a new_index value. 1550 new_index = cp_index; 1551 } 1552 if (new_index != 0) { 1553 // the original index is mapped so we have more work to do 1554 if (!StressLdcRewrite && new_index <= max_jubyte) { 1555 // The new value can still use ldc instead of ldc_w 1556 // unless we are trying to stress ldc -> ldc_w rewriting 1557 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 1558 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c), 1559 bcp, cp_index, new_index)); 1560 *(bcp + 1) = new_index; 1561 } else { 1562 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 1563 ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d", 1564 Bytecodes::name(c), bcp, cp_index, new_index)); 1565 // the new value needs ldc_w instead of ldc 1566 u_char inst_buffer[4]; // max instruction size is 4 bytes 1567 bcp = (address)inst_buffer; 1568 // construct new instruction sequence 1569 *bcp = Bytecodes::_ldc_w; 1570 bcp++; 1571 // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w. 1572 // See comment below for difference between put_Java_u2() 1573 // and put_native_u2(). 1574 Bytes::put_Java_u2(bcp, new_index); 1575 1576 Relocator rc(method, NULL /* no RelocatorListener needed */); 1577 methodHandle m; 1578 { 1579 Pause_No_Safepoint_Verifier pnsv(&nsv); 1580 1581 // ldc is 2 bytes and ldc_w is 3 bytes 1582 m = rc.insert_space_at(bci, 3, inst_buffer, THREAD); 1583 if (m.is_null() || HAS_PENDING_EXCEPTION) { 1584 guarantee(false, "insert_space_at() failed"); 1585 } 1586 } 1587 1588 // return the new method so that the caller can update 1589 // the containing class 1590 *new_method_p = method = m; 1591 // switch our bytecode processing loop from the old method 1592 // to the new method 1593 code_base = method->code_base(); 1594 code_length = method->code_size(); 1595 bcp = code_base + bci; 1596 c = (Bytecodes::Code)(*bcp); 1597 bc_length = Bytecodes::length_for(c); 1598 assert(bc_length != 0, "sanity check"); 1599 } // end we need ldc_w instead of ldc 1600 } // end if there is a mapped index 1601 } break; 1602 1603 // these bytecodes have a two-byte constant pool index 1604 case Bytecodes::_anewarray : // fall through 1605 case Bytecodes::_checkcast : // fall through 1606 case Bytecodes::_getfield : // fall through 1607 case Bytecodes::_getstatic : // fall through 1608 case Bytecodes::_instanceof : // fall through 1609 case Bytecodes::_invokeinterface: // fall through 1610 case Bytecodes::_invokespecial : // fall through 1611 case Bytecodes::_invokestatic : // fall through 1612 case Bytecodes::_invokevirtual : // fall through 1613 case Bytecodes::_ldc_w : // fall through 1614 case Bytecodes::_ldc2_w : // fall through 1615 case Bytecodes::_multianewarray : // fall through 1616 case Bytecodes::_new : // fall through 1617 case Bytecodes::_putfield : // fall through 1618 case Bytecodes::_putstatic : 1619 { 1620 address p = bcp + 1; 1621 int cp_index = Bytes::get_Java_u2(p); 1622 int new_index = find_new_index(cp_index); 1623 if (new_index != 0) { 1624 // the original index is mapped so update w/ new value 1625 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 1626 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c), 1627 bcp, cp_index, new_index)); 1628 // Rewriter::rewrite_method() uses put_native_u2() in this 1629 // situation because it is reusing the constant pool index 1630 // location for a native index into the constantPoolCache. 1631 // Since we are updating the constant pool index prior to 1632 // verification and constantPoolCache initialization, we 1633 // need to keep the new index in Java byte order. 1634 Bytes::put_Java_u2(p, new_index); 1635 } 1636 } break; 1637 } 1638 } // end for each bytecode 1639} // end rewrite_cp_refs_in_method() 1640 1641 1642// Rewrite constant pool references in the class_annotations field. 1643bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations( 1644 instanceKlassHandle scratch_class, TRAPS) { 1645 1646 AnnotationArray* class_annotations = scratch_class->class_annotations(); 1647 if (class_annotations == NULL || class_annotations->length() == 0) { 1648 // no class_annotations so nothing to do 1649 return true; 1650 } 1651 1652 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1653 ("class_annotations length=%d", class_annotations->length())); 1654 1655 int byte_i = 0; // byte index into class_annotations 1656 return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i, 1657 THREAD); 1658} 1659 1660 1661// Rewrite constant pool references in an annotations typeArray. This 1662// "structure" is adapted from the RuntimeVisibleAnnotations_attribute 1663// that is described in section 4.8.15 of the 2nd-edition of the VM spec: 1664// 1665// annotations_typeArray { 1666// u2 num_annotations; 1667// annotation annotations[num_annotations]; 1668// } 1669// 1670bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray( 1671 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) { 1672 1673 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1674 // not enough room for num_annotations field 1675 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1676 ("length() is too small for num_annotations field")); 1677 return false; 1678 } 1679 1680 u2 num_annotations = Bytes::get_Java_u2((address) 1681 annotations_typeArray->adr_at(byte_i_ref)); 1682 byte_i_ref += 2; 1683 1684 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1685 ("num_annotations=%d", num_annotations)); 1686 1687 int calc_num_annotations = 0; 1688 for (; calc_num_annotations < num_annotations; calc_num_annotations++) { 1689 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray, 1690 byte_i_ref, THREAD)) { 1691 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1692 ("bad annotation_struct at %d", calc_num_annotations)); 1693 // propagate failure back to caller 1694 return false; 1695 } 1696 } 1697 assert(num_annotations == calc_num_annotations, "sanity check"); 1698 1699 return true; 1700} // end rewrite_cp_refs_in_annotations_typeArray() 1701 1702 1703// Rewrite constant pool references in the annotation struct portion of 1704// an annotations_typeArray. This "structure" is from section 4.8.15 of 1705// the 2nd-edition of the VM spec: 1706// 1707// struct annotation { 1708// u2 type_index; 1709// u2 num_element_value_pairs; 1710// { 1711// u2 element_name_index; 1712// element_value value; 1713// } element_value_pairs[num_element_value_pairs]; 1714// } 1715// 1716bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct( 1717 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) { 1718 if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) { 1719 // not enough room for smallest annotation_struct 1720 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1721 ("length() is too small for annotation_struct")); 1722 return false; 1723 } 1724 1725 u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray, 1726 byte_i_ref, "mapped old type_index=%d", THREAD); 1727 1728 u2 num_element_value_pairs = Bytes::get_Java_u2((address) 1729 annotations_typeArray->adr_at(byte_i_ref)); 1730 byte_i_ref += 2; 1731 1732 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1733 ("type_index=%d num_element_value_pairs=%d", type_index, 1734 num_element_value_pairs)); 1735 1736 int calc_num_element_value_pairs = 0; 1737 for (; calc_num_element_value_pairs < num_element_value_pairs; 1738 calc_num_element_value_pairs++) { 1739 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1740 // not enough room for another element_name_index, let alone 1741 // the rest of another component 1742 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1743 ("length() is too small for element_name_index")); 1744 return false; 1745 } 1746 1747 u2 element_name_index = rewrite_cp_ref_in_annotation_data( 1748 annotations_typeArray, byte_i_ref, 1749 "mapped old element_name_index=%d", THREAD); 1750 1751 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1752 ("element_name_index=%d", element_name_index)); 1753 1754 if (!rewrite_cp_refs_in_element_value(annotations_typeArray, 1755 byte_i_ref, THREAD)) { 1756 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1757 ("bad element_value at %d", calc_num_element_value_pairs)); 1758 // propagate failure back to caller 1759 return false; 1760 } 1761 } // end for each component 1762 assert(num_element_value_pairs == calc_num_element_value_pairs, 1763 "sanity check"); 1764 1765 return true; 1766} // end rewrite_cp_refs_in_annotation_struct() 1767 1768 1769// Rewrite a constant pool reference at the current position in 1770// annotations_typeArray if needed. Returns the original constant 1771// pool reference if a rewrite was not needed or the new constant 1772// pool reference if a rewrite was needed. 1773u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data( 1774 AnnotationArray* annotations_typeArray, int &byte_i_ref, 1775 const char * trace_mesg, TRAPS) { 1776 1777 address cp_index_addr = (address) 1778 annotations_typeArray->adr_at(byte_i_ref); 1779 u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr); 1780 u2 new_cp_index = find_new_index(old_cp_index); 1781 if (new_cp_index != 0) { 1782 RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index)); 1783 Bytes::put_Java_u2(cp_index_addr, new_cp_index); 1784 old_cp_index = new_cp_index; 1785 } 1786 byte_i_ref += 2; 1787 return old_cp_index; 1788} 1789 1790 1791// Rewrite constant pool references in the element_value portion of an 1792// annotations_typeArray. This "structure" is from section 4.8.15.1 of 1793// the 2nd-edition of the VM spec: 1794// 1795// struct element_value { 1796// u1 tag; 1797// union { 1798// u2 const_value_index; 1799// { 1800// u2 type_name_index; 1801// u2 const_name_index; 1802// } enum_const_value; 1803// u2 class_info_index; 1804// annotation annotation_value; 1805// struct { 1806// u2 num_values; 1807// element_value values[num_values]; 1808// } array_value; 1809// } value; 1810// } 1811// 1812bool VM_RedefineClasses::rewrite_cp_refs_in_element_value( 1813 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) { 1814 1815 if ((byte_i_ref + 1) > annotations_typeArray->length()) { 1816 // not enough room for a tag let alone the rest of an element_value 1817 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1818 ("length() is too small for a tag")); 1819 return false; 1820 } 1821 1822 u1 tag = annotations_typeArray->at(byte_i_ref); 1823 byte_i_ref++; 1824 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag)); 1825 1826 switch (tag) { 1827 // These BaseType tag values are from Table 4.2 in VM spec: 1828 case 'B': // byte 1829 case 'C': // char 1830 case 'D': // double 1831 case 'F': // float 1832 case 'I': // int 1833 case 'J': // long 1834 case 'S': // short 1835 case 'Z': // boolean 1836 1837 // The remaining tag values are from Table 4.8 in the 2nd-edition of 1838 // the VM spec: 1839 case 's': 1840 { 1841 // For the above tag values (including the BaseType values), 1842 // value.const_value_index is right union field. 1843 1844 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1845 // not enough room for a const_value_index 1846 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1847 ("length() is too small for a const_value_index")); 1848 return false; 1849 } 1850 1851 u2 const_value_index = rewrite_cp_ref_in_annotation_data( 1852 annotations_typeArray, byte_i_ref, 1853 "mapped old const_value_index=%d", THREAD); 1854 1855 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1856 ("const_value_index=%d", const_value_index)); 1857 } break; 1858 1859 case 'e': 1860 { 1861 // for the above tag value, value.enum_const_value is right union field 1862 1863 if ((byte_i_ref + 4) > annotations_typeArray->length()) { 1864 // not enough room for a enum_const_value 1865 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1866 ("length() is too small for a enum_const_value")); 1867 return false; 1868 } 1869 1870 u2 type_name_index = rewrite_cp_ref_in_annotation_data( 1871 annotations_typeArray, byte_i_ref, 1872 "mapped old type_name_index=%d", THREAD); 1873 1874 u2 const_name_index = rewrite_cp_ref_in_annotation_data( 1875 annotations_typeArray, byte_i_ref, 1876 "mapped old const_name_index=%d", THREAD); 1877 1878 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1879 ("type_name_index=%d const_name_index=%d", type_name_index, 1880 const_name_index)); 1881 } break; 1882 1883 case 'c': 1884 { 1885 // for the above tag value, value.class_info_index is right union field 1886 1887 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1888 // not enough room for a class_info_index 1889 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1890 ("length() is too small for a class_info_index")); 1891 return false; 1892 } 1893 1894 u2 class_info_index = rewrite_cp_ref_in_annotation_data( 1895 annotations_typeArray, byte_i_ref, 1896 "mapped old class_info_index=%d", THREAD); 1897 1898 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1899 ("class_info_index=%d", class_info_index)); 1900 } break; 1901 1902 case '@': 1903 // For the above tag value, value.attr_value is the right union 1904 // field. This is a nested annotation. 1905 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray, 1906 byte_i_ref, THREAD)) { 1907 // propagate failure back to caller 1908 return false; 1909 } 1910 break; 1911 1912 case '[': 1913 { 1914 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1915 // not enough room for a num_values field 1916 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1917 ("length() is too small for a num_values field")); 1918 return false; 1919 } 1920 1921 // For the above tag value, value.array_value is the right union 1922 // field. This is an array of nested element_value. 1923 u2 num_values = Bytes::get_Java_u2((address) 1924 annotations_typeArray->adr_at(byte_i_ref)); 1925 byte_i_ref += 2; 1926 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values)); 1927 1928 int calc_num_values = 0; 1929 for (; calc_num_values < num_values; calc_num_values++) { 1930 if (!rewrite_cp_refs_in_element_value( 1931 annotations_typeArray, byte_i_ref, THREAD)) { 1932 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1933 ("bad nested element_value at %d", calc_num_values)); 1934 // propagate failure back to caller 1935 return false; 1936 } 1937 } 1938 assert(num_values == calc_num_values, "sanity check"); 1939 } break; 1940 1941 default: 1942 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag)); 1943 return false; 1944 } // end decode tag field 1945 1946 return true; 1947} // end rewrite_cp_refs_in_element_value() 1948 1949 1950// Rewrite constant pool references in a fields_annotations field. 1951bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations( 1952 instanceKlassHandle scratch_class, TRAPS) { 1953 1954 Annotations* sca = scratch_class->annotations(); 1955 if (sca == NULL) return true; 1956 1957 Array<AnnotationArray*>* fields_annotations = sca->fields_annotations(); 1958 1959 if (fields_annotations == NULL || fields_annotations->length() == 0) { 1960 // no fields_annotations so nothing to do 1961 return true; 1962 } 1963 1964 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1965 ("fields_annotations length=%d", fields_annotations->length())); 1966 1967 for (int i = 0; i < fields_annotations->length(); i++) { 1968 AnnotationArray* field_annotations = fields_annotations->at(i); 1969 if (field_annotations == NULL || field_annotations->length() == 0) { 1970 // this field does not have any annotations so skip it 1971 continue; 1972 } 1973 1974 int byte_i = 0; // byte index into field_annotations 1975 if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i, 1976 THREAD)) { 1977 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1978 ("bad field_annotations at %d", i)); 1979 // propagate failure back to caller 1980 return false; 1981 } 1982 } 1983 1984 return true; 1985} // end rewrite_cp_refs_in_fields_annotations() 1986 1987 1988// Rewrite constant pool references in a methods_annotations field. 1989bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations( 1990 instanceKlassHandle scratch_class, TRAPS) { 1991 1992 Annotations* sca = scratch_class->annotations(); 1993 if (sca == NULL) return true; 1994 1995 Array<AnnotationArray*>* methods_annotations = sca->methods_annotations(); 1996 1997 if (methods_annotations == NULL || methods_annotations->length() == 0) { 1998 // no methods_annotations so nothing to do 1999 return true; 2000 } 2001 2002 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2003 ("methods_annotations length=%d", methods_annotations->length())); 2004 2005 for (int i = 0; i < methods_annotations->length(); i++) { 2006 AnnotationArray* method_annotations = methods_annotations->at(i); 2007 if (method_annotations == NULL || method_annotations->length() == 0) { 2008 // this method does not have any annotations so skip it 2009 continue; 2010 } 2011 2012 int byte_i = 0; // byte index into method_annotations 2013 if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i, 2014 THREAD)) { 2015 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2016 ("bad method_annotations at %d", i)); 2017 // propagate failure back to caller 2018 return false; 2019 } 2020 } 2021 2022 return true; 2023} // end rewrite_cp_refs_in_methods_annotations() 2024 2025 2026// Rewrite constant pool references in a methods_parameter_annotations 2027// field. This "structure" is adapted from the 2028// RuntimeVisibleParameterAnnotations_attribute described in section 2029// 4.8.17 of the 2nd-edition of the VM spec: 2030// 2031// methods_parameter_annotations_typeArray { 2032// u1 num_parameters; 2033// { 2034// u2 num_annotations; 2035// annotation annotations[num_annotations]; 2036// } parameter_annotations[num_parameters]; 2037// } 2038// 2039bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations( 2040 instanceKlassHandle scratch_class, TRAPS) { 2041 2042 Annotations* sca = scratch_class->annotations(); 2043 if (sca == NULL) return true; 2044 2045 Array<AnnotationArray*>* methods_parameter_annotations = 2046 sca->methods_parameter_annotations(); 2047 2048 if (methods_parameter_annotations == NULL 2049 || methods_parameter_annotations->length() == 0) { 2050 // no methods_parameter_annotations so nothing to do 2051 return true; 2052 } 2053 2054 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2055 ("methods_parameter_annotations length=%d", 2056 methods_parameter_annotations->length())); 2057 2058 for (int i = 0; i < methods_parameter_annotations->length(); i++) { 2059 AnnotationArray* method_parameter_annotations = methods_parameter_annotations->at(i); 2060 if (method_parameter_annotations == NULL 2061 || method_parameter_annotations->length() == 0) { 2062 // this method does not have any parameter annotations so skip it 2063 continue; 2064 } 2065 2066 if (method_parameter_annotations->length() < 1) { 2067 // not enough room for a num_parameters field 2068 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2069 ("length() is too small for a num_parameters field at %d", i)); 2070 return false; 2071 } 2072 2073 int byte_i = 0; // byte index into method_parameter_annotations 2074 2075 u1 num_parameters = method_parameter_annotations->at(byte_i); 2076 byte_i++; 2077 2078 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2079 ("num_parameters=%d", num_parameters)); 2080 2081 int calc_num_parameters = 0; 2082 for (; calc_num_parameters < num_parameters; calc_num_parameters++) { 2083 if (!rewrite_cp_refs_in_annotations_typeArray( 2084 method_parameter_annotations, byte_i, THREAD)) { 2085 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2086 ("bad method_parameter_annotations at %d", calc_num_parameters)); 2087 // propagate failure back to caller 2088 return false; 2089 } 2090 } 2091 assert(num_parameters == calc_num_parameters, "sanity check"); 2092 } 2093 2094 return true; 2095} // end rewrite_cp_refs_in_methods_parameter_annotations() 2096 2097 2098// Rewrite constant pool references in a methods_default_annotations 2099// field. This "structure" is adapted from the AnnotationDefault_attribute 2100// that is described in section 4.8.19 of the 2nd-edition of the VM spec: 2101// 2102// methods_default_annotations_typeArray { 2103// element_value default_value; 2104// } 2105// 2106bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations( 2107 instanceKlassHandle scratch_class, TRAPS) { 2108 2109 Annotations* sca = scratch_class->annotations(); 2110 if (sca == NULL) return true; 2111 2112 Array<AnnotationArray*>* methods_default_annotations = 2113 sca->methods_default_annotations(); 2114 2115 if (methods_default_annotations == NULL 2116 || methods_default_annotations->length() == 0) { 2117 // no methods_default_annotations so nothing to do 2118 return true; 2119 } 2120 2121 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2122 ("methods_default_annotations length=%d", 2123 methods_default_annotations->length())); 2124 2125 for (int i = 0; i < methods_default_annotations->length(); i++) { 2126 AnnotationArray* method_default_annotations = methods_default_annotations->at(i); 2127 if (method_default_annotations == NULL 2128 || method_default_annotations->length() == 0) { 2129 // this method does not have any default annotations so skip it 2130 continue; 2131 } 2132 2133 int byte_i = 0; // byte index into method_default_annotations 2134 2135 if (!rewrite_cp_refs_in_element_value( 2136 method_default_annotations, byte_i, THREAD)) { 2137 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2138 ("bad default element_value at %d", i)); 2139 // propagate failure back to caller 2140 return false; 2141 } 2142 } 2143 2144 return true; 2145} // end rewrite_cp_refs_in_methods_default_annotations() 2146 2147 2148// Rewrite constant pool references in the method's stackmap table. 2149// These "structures" are adapted from the StackMapTable_attribute that 2150// is described in section 4.8.4 of the 6.0 version of the VM spec 2151// (dated 2005.10.26): 2152// file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf 2153// 2154// stack_map { 2155// u2 number_of_entries; 2156// stack_map_frame entries[number_of_entries]; 2157// } 2158// 2159void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table( 2160 methodHandle method, TRAPS) { 2161 2162 if (!method->has_stackmap_table()) { 2163 return; 2164 } 2165 2166 AnnotationArray* stackmap_data = method->stackmap_data(); 2167 address stackmap_p = (address)stackmap_data->adr_at(0); 2168 address stackmap_end = stackmap_p + stackmap_data->length(); 2169 2170 assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries"); 2171 u2 number_of_entries = Bytes::get_Java_u2(stackmap_p); 2172 stackmap_p += 2; 2173 2174 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2175 ("number_of_entries=%u", number_of_entries)); 2176 2177 // walk through each stack_map_frame 2178 u2 calc_number_of_entries = 0; 2179 for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) { 2180 // The stack_map_frame structure is a u1 frame_type followed by 2181 // 0 or more bytes of data: 2182 // 2183 // union stack_map_frame { 2184 // same_frame; 2185 // same_locals_1_stack_item_frame; 2186 // same_locals_1_stack_item_frame_extended; 2187 // chop_frame; 2188 // same_frame_extended; 2189 // append_frame; 2190 // full_frame; 2191 // } 2192 2193 assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type"); 2194 // The Linux compiler does not like frame_type to be u1 or u2. It 2195 // issues the following warning for the first if-statement below: 2196 // 2197 // "warning: comparison is always true due to limited range of data type" 2198 // 2199 u4 frame_type = *stackmap_p; 2200 stackmap_p++; 2201 2202 // same_frame { 2203 // u1 frame_type = SAME; /* 0-63 */ 2204 // } 2205 if (frame_type >= 0 && frame_type <= 63) { 2206 // nothing more to do for same_frame 2207 } 2208 2209 // same_locals_1_stack_item_frame { 2210 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */ 2211 // verification_type_info stack[1]; 2212 // } 2213 else if (frame_type >= 64 && frame_type <= 127) { 2214 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2215 calc_number_of_entries, frame_type, THREAD); 2216 } 2217 2218 // reserved for future use 2219 else if (frame_type >= 128 && frame_type <= 246) { 2220 // nothing more to do for reserved frame_types 2221 } 2222 2223 // same_locals_1_stack_item_frame_extended { 2224 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */ 2225 // u2 offset_delta; 2226 // verification_type_info stack[1]; 2227 // } 2228 else if (frame_type == 247) { 2229 stackmap_p += 2; 2230 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2231 calc_number_of_entries, frame_type, THREAD); 2232 } 2233 2234 // chop_frame { 2235 // u1 frame_type = CHOP; /* 248-250 */ 2236 // u2 offset_delta; 2237 // } 2238 else if (frame_type >= 248 && frame_type <= 250) { 2239 stackmap_p += 2; 2240 } 2241 2242 // same_frame_extended { 2243 // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/ 2244 // u2 offset_delta; 2245 // } 2246 else if (frame_type == 251) { 2247 stackmap_p += 2; 2248 } 2249 2250 // append_frame { 2251 // u1 frame_type = APPEND; /* 252-254 */ 2252 // u2 offset_delta; 2253 // verification_type_info locals[frame_type - 251]; 2254 // } 2255 else if (frame_type >= 252 && frame_type <= 254) { 2256 assert(stackmap_p + 2 <= stackmap_end, 2257 "no room for offset_delta"); 2258 stackmap_p += 2; 2259 u1 len = frame_type - 251; 2260 for (u1 i = 0; i < len; i++) { 2261 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2262 calc_number_of_entries, frame_type, THREAD); 2263 } 2264 } 2265 2266 // full_frame { 2267 // u1 frame_type = FULL_FRAME; /* 255 */ 2268 // u2 offset_delta; 2269 // u2 number_of_locals; 2270 // verification_type_info locals[number_of_locals]; 2271 // u2 number_of_stack_items; 2272 // verification_type_info stack[number_of_stack_items]; 2273 // } 2274 else if (frame_type == 255) { 2275 assert(stackmap_p + 2 + 2 <= stackmap_end, 2276 "no room for smallest full_frame"); 2277 stackmap_p += 2; 2278 2279 u2 number_of_locals = Bytes::get_Java_u2(stackmap_p); 2280 stackmap_p += 2; 2281 2282 for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) { 2283 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2284 calc_number_of_entries, frame_type, THREAD); 2285 } 2286 2287 // Use the largest size for the number_of_stack_items, but only get 2288 // the right number of bytes. 2289 u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p); 2290 stackmap_p += 2; 2291 2292 for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) { 2293 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2294 calc_number_of_entries, frame_type, THREAD); 2295 } 2296 } 2297 } // end while there is a stack_map_frame 2298 assert(number_of_entries == calc_number_of_entries, "sanity check"); 2299} // end rewrite_cp_refs_in_stack_map_table() 2300 2301 2302// Rewrite constant pool references in the verification type info 2303// portion of the method's stackmap table. These "structures" are 2304// adapted from the StackMapTable_attribute that is described in 2305// section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26): 2306// file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf 2307// 2308// The verification_type_info structure is a u1 tag followed by 0 or 2309// more bytes of data: 2310// 2311// union verification_type_info { 2312// Top_variable_info; 2313// Integer_variable_info; 2314// Float_variable_info; 2315// Long_variable_info; 2316// Double_variable_info; 2317// Null_variable_info; 2318// UninitializedThis_variable_info; 2319// Object_variable_info; 2320// Uninitialized_variable_info; 2321// } 2322// 2323void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info( 2324 address& stackmap_p_ref, address stackmap_end, u2 frame_i, 2325 u1 frame_type, TRAPS) { 2326 2327 assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag"); 2328 u1 tag = *stackmap_p_ref; 2329 stackmap_p_ref++; 2330 2331 switch (tag) { 2332 // Top_variable_info { 2333 // u1 tag = ITEM_Top; /* 0 */ 2334 // } 2335 // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top 2336 case 0: // fall through 2337 2338 // Integer_variable_info { 2339 // u1 tag = ITEM_Integer; /* 1 */ 2340 // } 2341 case ITEM_Integer: // fall through 2342 2343 // Float_variable_info { 2344 // u1 tag = ITEM_Float; /* 2 */ 2345 // } 2346 case ITEM_Float: // fall through 2347 2348 // Double_variable_info { 2349 // u1 tag = ITEM_Double; /* 3 */ 2350 // } 2351 case ITEM_Double: // fall through 2352 2353 // Long_variable_info { 2354 // u1 tag = ITEM_Long; /* 4 */ 2355 // } 2356 case ITEM_Long: // fall through 2357 2358 // Null_variable_info { 2359 // u1 tag = ITEM_Null; /* 5 */ 2360 // } 2361 case ITEM_Null: // fall through 2362 2363 // UninitializedThis_variable_info { 2364 // u1 tag = ITEM_UninitializedThis; /* 6 */ 2365 // } 2366 case ITEM_UninitializedThis: 2367 // nothing more to do for the above tag types 2368 break; 2369 2370 // Object_variable_info { 2371 // u1 tag = ITEM_Object; /* 7 */ 2372 // u2 cpool_index; 2373 // } 2374 case ITEM_Object: 2375 { 2376 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index"); 2377 u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref); 2378 u2 new_cp_index = find_new_index(cpool_index); 2379 if (new_cp_index != 0) { 2380 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2381 ("mapped old cpool_index=%d", cpool_index)); 2382 Bytes::put_Java_u2(stackmap_p_ref, new_cp_index); 2383 cpool_index = new_cp_index; 2384 } 2385 stackmap_p_ref += 2; 2386 2387 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2388 ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i, 2389 frame_type, cpool_index)); 2390 } break; 2391 2392 // Uninitialized_variable_info { 2393 // u1 tag = ITEM_Uninitialized; /* 8 */ 2394 // u2 offset; 2395 // } 2396 case ITEM_Uninitialized: 2397 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset"); 2398 stackmap_p_ref += 2; 2399 break; 2400 2401 default: 2402 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2403 ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag)); 2404 ShouldNotReachHere(); 2405 break; 2406 } // end switch (tag) 2407} // end rewrite_cp_refs_in_verification_type_info() 2408 2409 2410// Change the constant pool associated with klass scratch_class to 2411// scratch_cp. If shrink is true, then scratch_cp_length elements 2412// are copied from scratch_cp to a smaller constant pool and the 2413// smaller constant pool is associated with scratch_class. 2414void VM_RedefineClasses::set_new_constant_pool( 2415 ClassLoaderData* loader_data, 2416 instanceKlassHandle scratch_class, constantPoolHandle scratch_cp, 2417 int scratch_cp_length, TRAPS) { 2418 assert(scratch_cp->length() >= scratch_cp_length, "sanity check"); 2419 2420 // scratch_cp is a merged constant pool and has enough space for a 2421 // worst case merge situation. We want to associate the minimum 2422 // sized constant pool with the klass to save space. 2423 constantPoolHandle smaller_cp(THREAD, 2424 ConstantPool::allocate(loader_data, scratch_cp_length, 2425 THREAD)); 2426 // preserve orig_length() value in the smaller copy 2427 int orig_length = scratch_cp->orig_length(); 2428 assert(orig_length != 0, "sanity check"); 2429 smaller_cp->set_orig_length(orig_length); 2430 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD); 2431 scratch_cp = smaller_cp; 2432 2433 // attach new constant pool to klass 2434 scratch_cp->set_pool_holder(scratch_class()); 2435 2436 // attach klass to new constant pool 2437 scratch_class->set_constants(scratch_cp()); 2438 2439 int i; // for portability 2440 2441 // update each field in klass to use new constant pool indices as needed 2442 for (JavaFieldStream fs(scratch_class); !fs.done(); fs.next()) { 2443 jshort cur_index = fs.name_index(); 2444 jshort new_index = find_new_index(cur_index); 2445 if (new_index != 0) { 2446 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2447 ("field-name_index change: %d to %d", cur_index, new_index)); 2448 fs.set_name_index(new_index); 2449 } 2450 cur_index = fs.signature_index(); 2451 new_index = find_new_index(cur_index); 2452 if (new_index != 0) { 2453 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2454 ("field-signature_index change: %d to %d", cur_index, new_index)); 2455 fs.set_signature_index(new_index); 2456 } 2457 cur_index = fs.initval_index(); 2458 new_index = find_new_index(cur_index); 2459 if (new_index != 0) { 2460 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2461 ("field-initval_index change: %d to %d", cur_index, new_index)); 2462 fs.set_initval_index(new_index); 2463 } 2464 cur_index = fs.generic_signature_index(); 2465 new_index = find_new_index(cur_index); 2466 if (new_index != 0) { 2467 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2468 ("field-generic_signature change: %d to %d", cur_index, new_index)); 2469 fs.set_generic_signature_index(new_index); 2470 } 2471 } // end for each field 2472 2473 // Update constant pool indices in the inner classes info to use 2474 // new constant indices as needed. The inner classes info is a 2475 // quadruple: 2476 // (inner_class_info, outer_class_info, inner_name, inner_access_flags) 2477 InnerClassesIterator iter(scratch_class); 2478 for (; !iter.done(); iter.next()) { 2479 int cur_index = iter.inner_class_info_index(); 2480 if (cur_index == 0) { 2481 continue; // JVM spec. allows null inner class refs so skip it 2482 } 2483 int new_index = find_new_index(cur_index); 2484 if (new_index != 0) { 2485 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2486 ("inner_class_info change: %d to %d", cur_index, new_index)); 2487 iter.set_inner_class_info_index(new_index); 2488 } 2489 cur_index = iter.outer_class_info_index(); 2490 new_index = find_new_index(cur_index); 2491 if (new_index != 0) { 2492 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2493 ("outer_class_info change: %d to %d", cur_index, new_index)); 2494 iter.set_outer_class_info_index(new_index); 2495 } 2496 cur_index = iter.inner_name_index(); 2497 new_index = find_new_index(cur_index); 2498 if (new_index != 0) { 2499 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2500 ("inner_name change: %d to %d", cur_index, new_index)); 2501 iter.set_inner_name_index(new_index); 2502 } 2503 } // end for each inner class 2504 2505 // Attach each method in klass to the new constant pool and update 2506 // to use new constant pool indices as needed: 2507 Array<Method*>* methods = scratch_class->methods(); 2508 for (i = methods->length() - 1; i >= 0; i--) { 2509 methodHandle method(THREAD, methods->at(i)); 2510 method->set_constants(scratch_cp()); 2511 2512 int new_index = find_new_index(method->name_index()); 2513 if (new_index != 0) { 2514 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2515 ("method-name_index change: %d to %d", method->name_index(), 2516 new_index)); 2517 method->set_name_index(new_index); 2518 } 2519 new_index = find_new_index(method->signature_index()); 2520 if (new_index != 0) { 2521 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2522 ("method-signature_index change: %d to %d", 2523 method->signature_index(), new_index)); 2524 method->set_signature_index(new_index); 2525 } 2526 new_index = find_new_index(method->generic_signature_index()); 2527 if (new_index != 0) { 2528 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2529 ("method-generic_signature_index change: %d to %d", 2530 method->generic_signature_index(), new_index)); 2531 method->set_generic_signature_index(new_index); 2532 } 2533 2534 // Update constant pool indices in the method's checked exception 2535 // table to use new constant indices as needed. 2536 int cext_length = method->checked_exceptions_length(); 2537 if (cext_length > 0) { 2538 CheckedExceptionElement * cext_table = 2539 method->checked_exceptions_start(); 2540 for (int j = 0; j < cext_length; j++) { 2541 int cur_index = cext_table[j].class_cp_index; 2542 int new_index = find_new_index(cur_index); 2543 if (new_index != 0) { 2544 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2545 ("cext-class_cp_index change: %d to %d", cur_index, new_index)); 2546 cext_table[j].class_cp_index = (u2)new_index; 2547 } 2548 } // end for each checked exception table entry 2549 } // end if there are checked exception table entries 2550 2551 // Update each catch type index in the method's exception table 2552 // to use new constant pool indices as needed. The exception table 2553 // holds quadruple entries of the form: 2554 // (beg_bci, end_bci, handler_bci, klass_index) 2555 2556 ExceptionTable ex_table(method()); 2557 int ext_length = ex_table.length(); 2558 2559 for (int j = 0; j < ext_length; j ++) { 2560 int cur_index = ex_table.catch_type_index(j); 2561 int new_index = find_new_index(cur_index); 2562 if (new_index != 0) { 2563 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2564 ("ext-klass_index change: %d to %d", cur_index, new_index)); 2565 ex_table.set_catch_type_index(j, new_index); 2566 } 2567 } // end for each exception table entry 2568 2569 // Update constant pool indices in the method's local variable 2570 // table to use new constant indices as needed. The local variable 2571 // table hold sextuple entries of the form: 2572 // (start_pc, length, name_index, descriptor_index, signature_index, slot) 2573 int lvt_length = method->localvariable_table_length(); 2574 if (lvt_length > 0) { 2575 LocalVariableTableElement * lv_table = 2576 method->localvariable_table_start(); 2577 for (int j = 0; j < lvt_length; j++) { 2578 int cur_index = lv_table[j].name_cp_index; 2579 int new_index = find_new_index(cur_index); 2580 if (new_index != 0) { 2581 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2582 ("lvt-name_cp_index change: %d to %d", cur_index, new_index)); 2583 lv_table[j].name_cp_index = (u2)new_index; 2584 } 2585 cur_index = lv_table[j].descriptor_cp_index; 2586 new_index = find_new_index(cur_index); 2587 if (new_index != 0) { 2588 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2589 ("lvt-descriptor_cp_index change: %d to %d", cur_index, 2590 new_index)); 2591 lv_table[j].descriptor_cp_index = (u2)new_index; 2592 } 2593 cur_index = lv_table[j].signature_cp_index; 2594 new_index = find_new_index(cur_index); 2595 if (new_index != 0) { 2596 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2597 ("lvt-signature_cp_index change: %d to %d", cur_index, new_index)); 2598 lv_table[j].signature_cp_index = (u2)new_index; 2599 } 2600 } // end for each local variable table entry 2601 } // end if there are local variable table entries 2602 2603 rewrite_cp_refs_in_stack_map_table(method, THREAD); 2604 } // end for each method 2605} // end set_new_constant_pool() 2606 2607 2608void VM_RedefineClasses::adjust_array_vtable(Klass* k_oop) { 2609 arrayKlass* ak = arrayKlass::cast(k_oop); 2610 bool trace_name_printed = false; 2611 ak->vtable()->adjust_method_entries(_matching_old_methods, 2612 _matching_new_methods, 2613 _matching_methods_length, 2614 &trace_name_printed); 2615} 2616 2617// Unevolving classes may point to methods of the_class directly 2618// from their constant pool caches, itables, and/or vtables. We 2619// use the SystemDictionary::classes_do() facility and this helper 2620// to fix up these pointers. 2621// 2622// Note: We currently don't support updating the vtable in 2623// arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp. 2624void VM_RedefineClasses::adjust_cpool_cache_and_vtable(Klass* k_oop, 2625 ClassLoaderData* initiating_loader, 2626 TRAPS) { 2627 Klass *k = k_oop; 2628 if (k->oop_is_instance()) { 2629 HandleMark hm(THREAD); 2630 InstanceKlass *ik = (InstanceKlass *) k; 2631 2632 // HotSpot specific optimization! HotSpot does not currently 2633 // support delegation from the bootstrap class loader to a 2634 // user-defined class loader. This means that if the bootstrap 2635 // class loader is the initiating class loader, then it will also 2636 // be the defining class loader. This also means that classes 2637 // loaded by the bootstrap class loader cannot refer to classes 2638 // loaded by a user-defined class loader. Note: a user-defined 2639 // class loader can delegate to the bootstrap class loader. 2640 // 2641 // If the current class being redefined has a user-defined class 2642 // loader as its defining class loader, then we can skip all 2643 // classes loaded by the bootstrap class loader. 2644 bool is_user_defined = 2645 InstanceKlass::cast(_the_class_oop)->class_loader() != NULL; 2646 if (is_user_defined && ik->class_loader() == NULL) { 2647 return; 2648 } 2649 2650 // If the class being redefined is java.lang.Object, we need to fix all 2651 // array class vtables also 2652 if (_the_class_oop == SystemDictionary::Object_klass()) { 2653 ik->array_klasses_do(adjust_array_vtable); 2654 } 2655 2656 // This is a very busy routine. We don't want too much tracing 2657 // printed out. 2658 bool trace_name_printed = false; 2659 2660 // Very noisy: only enable this call if you are trying to determine 2661 // that a specific class gets found by this routine. 2662 // RC_TRACE macro has an embedded ResourceMark 2663 // RC_TRACE_WITH_THREAD(0x00100000, THREAD, 2664 // ("adjust check: name=%s", ik->external_name())); 2665 // trace_name_printed = true; 2666 2667 // Fix the vtable embedded in the_class and subclasses of the_class, 2668 // if one exists. We discard scratch_class and we don't keep an 2669 // InstanceKlass around to hold obsolete methods so we don't have 2670 // any other InstanceKlass embedded vtables to update. The vtable 2671 // holds the Method*s for virtual (but not final) methods. 2672 if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) { 2673 // ik->vtable() creates a wrapper object; rm cleans it up 2674 ResourceMark rm(THREAD); 2675 ik->vtable()->adjust_method_entries(_matching_old_methods, 2676 _matching_new_methods, 2677 _matching_methods_length, 2678 &trace_name_printed); 2679 } 2680 2681 // If the current class has an itable and we are either redefining an 2682 // interface or if the current class is a subclass of the_class, then 2683 // we potentially have to fix the itable. If we are redefining an 2684 // interface, then we have to call adjust_method_entries() for 2685 // every InstanceKlass that has an itable since there isn't a 2686 // subclass relationship between an interface and an InstanceKlass. 2687 if (ik->itable_length() > 0 && (Klass::cast(_the_class_oop)->is_interface() 2688 || ik->is_subclass_of(_the_class_oop))) { 2689 // ik->itable() creates a wrapper object; rm cleans it up 2690 ResourceMark rm(THREAD); 2691 ik->itable()->adjust_method_entries(_matching_old_methods, 2692 _matching_new_methods, 2693 _matching_methods_length, 2694 &trace_name_printed); 2695 } 2696 2697 // The constant pools in other classes (other_cp) can refer to 2698 // methods in the_class. We have to update method information in 2699 // other_cp's cache. If other_cp has a previous version, then we 2700 // have to repeat the process for each previous version. The 2701 // constant pool cache holds the Method*s for non-virtual 2702 // methods and for virtual, final methods. 2703 // 2704 // Special case: if the current class is the_class, then new_cp 2705 // has already been attached to the_class and old_cp has already 2706 // been added as a previous version. The new_cp doesn't have any 2707 // cached references to old methods so it doesn't need to be 2708 // updated. We can simply start with the previous version(s) in 2709 // that case. 2710 constantPoolHandle other_cp; 2711 ConstantPoolCache* cp_cache; 2712 2713 if (k_oop != _the_class_oop) { 2714 // this klass' constant pool cache may need adjustment 2715 other_cp = constantPoolHandle(ik->constants()); 2716 cp_cache = other_cp->cache(); 2717 if (cp_cache != NULL) { 2718 cp_cache->adjust_method_entries(_matching_old_methods, 2719 _matching_new_methods, 2720 _matching_methods_length, 2721 &trace_name_printed); 2722 } 2723 } 2724 { 2725 ResourceMark rm(THREAD); 2726 // PreviousVersionInfo objects returned via PreviousVersionWalker 2727 // contain a GrowableArray of handles. We have to clean up the 2728 // GrowableArray _after_ the PreviousVersionWalker destructor 2729 // has destroyed the handles. 2730 { 2731 // the previous versions' constant pool caches may need adjustment 2732 PreviousVersionWalker pvw(ik); 2733 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); 2734 pv_info != NULL; pv_info = pvw.next_previous_version()) { 2735 other_cp = pv_info->prev_constant_pool_handle(); 2736 cp_cache = other_cp->cache(); 2737 if (cp_cache != NULL) { 2738 cp_cache->adjust_method_entries(_matching_old_methods, 2739 _matching_new_methods, 2740 _matching_methods_length, 2741 &trace_name_printed); 2742 } 2743 } 2744 } // pvw is cleaned up 2745 } // rm is cleaned up 2746 } 2747} 2748 2749void VM_RedefineClasses::update_jmethod_ids() { 2750 for (int j = 0; j < _matching_methods_length; ++j) { 2751 Method* old_method = _matching_old_methods[j]; 2752 jmethodID jmid = old_method->find_jmethod_id_or_null(); 2753 if (jmid != NULL) { 2754 // There is a jmethodID, change it to point to the new method 2755 methodHandle new_method_h(_matching_new_methods[j]); 2756 Method::change_method_associated_with_jmethod_id(jmid, new_method_h()); 2757 assert(Method::resolve_jmethod_id(jmid) == _matching_new_methods[j], 2758 "should be replaced"); 2759 } 2760 } 2761} 2762 2763void VM_RedefineClasses::check_methods_and_mark_as_obsolete( 2764 BitMap *emcp_methods, int * emcp_method_count_p) { 2765 *emcp_method_count_p = 0; 2766 int obsolete_count = 0; 2767 int old_index = 0; 2768 for (int j = 0; j < _matching_methods_length; ++j, ++old_index) { 2769 Method* old_method = _matching_old_methods[j]; 2770 Method* new_method = _matching_new_methods[j]; 2771 Method* old_array_method; 2772 2773 // Maintain an old_index into the _old_methods array by skipping 2774 // deleted methods 2775 while ((old_array_method = _old_methods->at(old_index)) != old_method) { 2776 ++old_index; 2777 } 2778 2779 if (MethodComparator::methods_EMCP(old_method, new_method)) { 2780 // The EMCP definition from JSR-163 requires the bytecodes to be 2781 // the same with the exception of constant pool indices which may 2782 // differ. However, the constants referred to by those indices 2783 // must be the same. 2784 // 2785 // We use methods_EMCP() for comparison since constant pool 2786 // merging can remove duplicate constant pool entries that were 2787 // present in the old method and removed from the rewritten new 2788 // method. A faster binary comparison function would consider the 2789 // old and new methods to be different when they are actually 2790 // EMCP. 2791 // 2792 // The old and new methods are EMCP and you would think that we 2793 // could get rid of one of them here and now and save some space. 2794 // However, the concept of EMCP only considers the bytecodes and 2795 // the constant pool entries in the comparison. Other things, 2796 // e.g., the line number table (LNT) or the local variable table 2797 // (LVT) don't count in the comparison. So the new (and EMCP) 2798 // method can have a new LNT that we need so we can't just 2799 // overwrite the new method with the old method. 2800 // 2801 // When this routine is called, we have already attached the new 2802 // methods to the_class so the old methods are effectively 2803 // overwritten. However, if an old method is still executing, 2804 // then the old method cannot be collected until sometime after 2805 // the old method call has returned. So the overwriting of old 2806 // methods by new methods will save us space except for those 2807 // (hopefully few) old methods that are still executing. 2808 // 2809 // A method refers to a ConstMethod* and this presents another 2810 // possible avenue to space savings. The ConstMethod* in the 2811 // new method contains possibly new attributes (LNT, LVT, etc). 2812 // At first glance, it seems possible to save space by replacing 2813 // the ConstMethod* in the old method with the ConstMethod* 2814 // from the new method. The old and new methods would share the 2815 // same ConstMethod* and we would save the space occupied by 2816 // the old ConstMethod*. However, the ConstMethod* contains 2817 // a back reference to the containing method. Sharing the 2818 // ConstMethod* between two methods could lead to confusion in 2819 // the code that uses the back reference. This would lead to 2820 // brittle code that could be broken in non-obvious ways now or 2821 // in the future. 2822 // 2823 // Another possibility is to copy the ConstMethod* from the new 2824 // method to the old method and then overwrite the new method with 2825 // the old method. Since the ConstMethod* contains the bytecodes 2826 // for the method embedded in the oop, this option would change 2827 // the bytecodes out from under any threads executing the old 2828 // method and make the thread's bcp invalid. Since EMCP requires 2829 // that the bytecodes be the same modulo constant pool indices, it 2830 // is straight forward to compute the correct new bcp in the new 2831 // ConstMethod* from the old bcp in the old ConstMethod*. The 2832 // time consuming part would be searching all the frames in all 2833 // of the threads to find all of the calls to the old method. 2834 // 2835 // It looks like we will have to live with the limited savings 2836 // that we get from effectively overwriting the old methods 2837 // when the new methods are attached to the_class. 2838 2839 // track which methods are EMCP for add_previous_version() call 2840 emcp_methods->set_bit(old_index); 2841 (*emcp_method_count_p)++; 2842 2843 // An EMCP method is _not_ obsolete. An obsolete method has a 2844 // different jmethodID than the current method. An EMCP method 2845 // has the same jmethodID as the current method. Having the 2846 // same jmethodID for all EMCP versions of a method allows for 2847 // a consistent view of the EMCP methods regardless of which 2848 // EMCP method you happen to have in hand. For example, a 2849 // breakpoint set in one EMCP method will work for all EMCP 2850 // versions of the method including the current one. 2851 } else { 2852 // mark obsolete methods as such 2853 old_method->set_is_obsolete(); 2854 obsolete_count++; 2855 2856 // obsolete methods need a unique idnum 2857 u2 num = InstanceKlass::cast(_the_class_oop)->next_method_idnum(); 2858 if (num != ConstMethod::UNSET_IDNUM) { 2859// u2 old_num = old_method->method_idnum(); 2860 old_method->set_method_idnum(num); 2861// TO DO: attach obsolete annotations to obsolete method's new idnum 2862 } 2863 // With tracing we try not to "yack" too much. The position of 2864 // this trace assumes there are fewer obsolete methods than 2865 // EMCP methods. 2866 RC_TRACE(0x00000100, ("mark %s(%s) as obsolete", 2867 old_method->name()->as_C_string(), 2868 old_method->signature()->as_C_string())); 2869 } 2870 old_method->set_is_old(); 2871 } 2872 for (int i = 0; i < _deleted_methods_length; ++i) { 2873 Method* old_method = _deleted_methods[i]; 2874 2875 assert(old_method->vtable_index() < 0, 2876 "cannot delete methods with vtable entries");; 2877 2878 // Mark all deleted methods as old and obsolete 2879 old_method->set_is_old(); 2880 old_method->set_is_obsolete(); 2881 ++obsolete_count; 2882 // With tracing we try not to "yack" too much. The position of 2883 // this trace assumes there are fewer obsolete methods than 2884 // EMCP methods. 2885 RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete", 2886 old_method->name()->as_C_string(), 2887 old_method->signature()->as_C_string())); 2888 } 2889 assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(), 2890 "sanity check"); 2891 RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p, 2892 obsolete_count)); 2893} 2894 2895// This internal class transfers the native function registration from old methods 2896// to new methods. It is designed to handle both the simple case of unchanged 2897// native methods and the complex cases of native method prefixes being added and/or 2898// removed. 2899// It expects only to be used during the VM_RedefineClasses op (a safepoint). 2900// 2901// This class is used after the new methods have been installed in "the_class". 2902// 2903// So, for example, the following must be handled. Where 'm' is a method and 2904// a number followed by an underscore is a prefix. 2905// 2906// Old Name New Name 2907// Simple transfer to new method m -> m 2908// Add prefix m -> 1_m 2909// Remove prefix 1_m -> m 2910// Simultaneous add of prefixes m -> 3_2_1_m 2911// Simultaneous removal of prefixes 3_2_1_m -> m 2912// Simultaneous add and remove 1_m -> 2_m 2913// Same, caused by prefix removal only 3_2_1_m -> 3_2_m 2914// 2915class TransferNativeFunctionRegistration { 2916 private: 2917 instanceKlassHandle the_class; 2918 int prefix_count; 2919 char** prefixes; 2920 2921 // Recursively search the binary tree of possibly prefixed method names. 2922 // Iteration could be used if all agents were well behaved. Full tree walk is 2923 // more resilent to agents not cleaning up intermediate methods. 2924 // Branch at each depth in the binary tree is: 2925 // (1) without the prefix. 2926 // (2) with the prefix. 2927 // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...) 2928 Method* search_prefix_name_space(int depth, char* name_str, size_t name_len, 2929 Symbol* signature) { 2930 TempNewSymbol name_symbol = SymbolTable::probe(name_str, (int)name_len); 2931 if (name_symbol != NULL) { 2932 Method* method = Klass::cast(the_class())->lookup_method(name_symbol, signature); 2933 if (method != NULL) { 2934 // Even if prefixed, intermediate methods must exist. 2935 if (method->is_native()) { 2936 // Wahoo, we found a (possibly prefixed) version of the method, return it. 2937 return method; 2938 } 2939 if (depth < prefix_count) { 2940 // Try applying further prefixes (other than this one). 2941 method = search_prefix_name_space(depth+1, name_str, name_len, signature); 2942 if (method != NULL) { 2943 return method; // found 2944 } 2945 2946 // Try adding this prefix to the method name and see if it matches 2947 // another method name. 2948 char* prefix = prefixes[depth]; 2949 size_t prefix_len = strlen(prefix); 2950 size_t trial_len = name_len + prefix_len; 2951 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1); 2952 strcpy(trial_name_str, prefix); 2953 strcat(trial_name_str, name_str); 2954 method = search_prefix_name_space(depth+1, trial_name_str, trial_len, 2955 signature); 2956 if (method != NULL) { 2957 // If found along this branch, it was prefixed, mark as such 2958 method->set_is_prefixed_native(); 2959 return method; // found 2960 } 2961 } 2962 } 2963 } 2964 return NULL; // This whole branch bore nothing 2965 } 2966 2967 // Return the method name with old prefixes stripped away. 2968 char* method_name_without_prefixes(Method* method) { 2969 Symbol* name = method->name(); 2970 char* name_str = name->as_utf8(); 2971 2972 // Old prefixing may be defunct, strip prefixes, if any. 2973 for (int i = prefix_count-1; i >= 0; i--) { 2974 char* prefix = prefixes[i]; 2975 size_t prefix_len = strlen(prefix); 2976 if (strncmp(prefix, name_str, prefix_len) == 0) { 2977 name_str += prefix_len; 2978 } 2979 } 2980 return name_str; 2981 } 2982 2983 // Strip any prefixes off the old native method, then try to find a 2984 // (possibly prefixed) new native that matches it. 2985 Method* strip_and_search_for_new_native(Method* method) { 2986 ResourceMark rm; 2987 char* name_str = method_name_without_prefixes(method); 2988 return search_prefix_name_space(0, name_str, strlen(name_str), 2989 method->signature()); 2990 } 2991 2992 public: 2993 2994 // Construct a native method transfer processor for this class. 2995 TransferNativeFunctionRegistration(instanceKlassHandle _the_class) { 2996 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 2997 2998 the_class = _the_class; 2999 prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); 3000 } 3001 3002 // Attempt to transfer any of the old or deleted methods that are native 3003 void transfer_registrations(Method** old_methods, int methods_length) { 3004 for (int j = 0; j < methods_length; j++) { 3005 Method* old_method = old_methods[j]; 3006 3007 if (old_method->is_native() && old_method->has_native_function()) { 3008 Method* new_method = strip_and_search_for_new_native(old_method); 3009 if (new_method != NULL) { 3010 // Actually set the native function in the new method. 3011 // Redefine does not send events (except CFLH), certainly not this 3012 // behind the scenes re-registration. 3013 new_method->set_native_function(old_method->native_function(), 3014 !Method::native_bind_event_is_interesting); 3015 } 3016 } 3017 } 3018 } 3019}; 3020 3021// Don't lose the association between a native method and its JNI function. 3022void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) { 3023 TransferNativeFunctionRegistration transfer(the_class); 3024 transfer.transfer_registrations(_deleted_methods, _deleted_methods_length); 3025 transfer.transfer_registrations(_matching_old_methods, _matching_methods_length); 3026} 3027 3028// Deoptimize all compiled code that depends on this class. 3029// 3030// If the can_redefine_classes capability is obtained in the onload 3031// phase then the compiler has recorded all dependencies from startup. 3032// In that case we need only deoptimize and throw away all compiled code 3033// that depends on the class. 3034// 3035// If can_redefine_classes is obtained sometime after the onload 3036// phase then the dependency information may be incomplete. In that case 3037// the first call to RedefineClasses causes all compiled code to be 3038// thrown away. As can_redefine_classes has been obtained then 3039// all future compilations will record dependencies so second and 3040// subsequent calls to RedefineClasses need only throw away code 3041// that depends on the class. 3042// 3043void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) { 3044 assert_locked_or_safepoint(Compile_lock); 3045 3046 // All dependencies have been recorded from startup or this is a second or 3047 // subsequent use of RedefineClasses 3048 if (JvmtiExport::all_dependencies_are_recorded()) { 3049 Universe::flush_evol_dependents_on(k_h); 3050 } else { 3051 CodeCache::mark_all_nmethods_for_deoptimization(); 3052 3053 ResourceMark rm(THREAD); 3054 DeoptimizationMarker dm; 3055 3056 // Deoptimize all activations depending on marked nmethods 3057 Deoptimization::deoptimize_dependents(); 3058 3059 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies) 3060 CodeCache::make_marked_nmethods_not_entrant(); 3061 3062 // From now on we know that the dependency information is complete 3063 JvmtiExport::set_all_dependencies_are_recorded(true); 3064 } 3065} 3066 3067void VM_RedefineClasses::compute_added_deleted_matching_methods() { 3068 Method* old_method; 3069 Method* new_method; 3070 3071 _matching_old_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length()); 3072 _matching_new_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length()); 3073 _added_methods = NEW_RESOURCE_ARRAY(Method*, _new_methods->length()); 3074 _deleted_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length()); 3075 3076 _matching_methods_length = 0; 3077 _deleted_methods_length = 0; 3078 _added_methods_length = 0; 3079 3080 int nj = 0; 3081 int oj = 0; 3082 while (true) { 3083 if (oj >= _old_methods->length()) { 3084 if (nj >= _new_methods->length()) { 3085 break; // we've looked at everything, done 3086 } 3087 // New method at the end 3088 new_method = _new_methods->at(nj); 3089 _added_methods[_added_methods_length++] = new_method; 3090 ++nj; 3091 } else if (nj >= _new_methods->length()) { 3092 // Old method, at the end, is deleted 3093 old_method = _old_methods->at(oj); 3094 _deleted_methods[_deleted_methods_length++] = old_method; 3095 ++oj; 3096 } else { 3097 old_method = _old_methods->at(oj); 3098 new_method = _new_methods->at(nj); 3099 if (old_method->name() == new_method->name()) { 3100 if (old_method->signature() == new_method->signature()) { 3101 _matching_old_methods[_matching_methods_length ] = old_method; 3102 _matching_new_methods[_matching_methods_length++] = new_method; 3103 ++nj; 3104 ++oj; 3105 } else { 3106 // added overloaded have already been moved to the end, 3107 // so this is a deleted overloaded method 3108 _deleted_methods[_deleted_methods_length++] = old_method; 3109 ++oj; 3110 } 3111 } else { // names don't match 3112 if (old_method->name()->fast_compare(new_method->name()) > 0) { 3113 // new method 3114 _added_methods[_added_methods_length++] = new_method; 3115 ++nj; 3116 } else { 3117 // deleted method 3118 _deleted_methods[_deleted_methods_length++] = old_method; 3119 ++oj; 3120 } 3121 } 3122 } 3123 } 3124 assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity"); 3125 assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity"); 3126} 3127 3128 3129 3130// Install the redefinition of a class: 3131// - house keeping (flushing breakpoints and caches, deoptimizing 3132// dependent compiled code) 3133// - replacing parts in the_class with parts from scratch_class 3134// - adding a weak reference to track the obsolete but interesting 3135// parts of the_class 3136// - adjusting constant pool caches and vtables in other classes 3137// that refer to methods in the_class. These adjustments use the 3138// SystemDictionary::classes_do() facility which only allows 3139// a helper method to be specified. The interesting parameters 3140// that we would like to pass to the helper method are saved in 3141// static global fields in the VM operation. 3142void VM_RedefineClasses::redefine_single_class(jclass the_jclass, 3143 Klass* scratch_class_oop, TRAPS) { 3144 3145 HandleMark hm(THREAD); // make sure handles from this call are freed 3146 RC_TIMER_START(_timer_rsc_phase1); 3147 3148 instanceKlassHandle scratch_class(scratch_class_oop); 3149 3150 oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass); 3151 Klass* the_class_oop = java_lang_Class::as_Klass(the_class_mirror); 3152 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop); 3153 3154#ifndef JVMTI_KERNEL 3155 // Remove all breakpoints in methods of this class 3156 JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); 3157 jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop); 3158#endif // !JVMTI_KERNEL 3159 3160 if (the_class_oop == Universe::reflect_invoke_cache()->klass()) { 3161 // We are redefining java.lang.reflect.Method. Method.invoke() is 3162 // cached and users of the cache care about each active version of 3163 // the method so we have to track this previous version. 3164 // Do this before methods get switched 3165 Universe::reflect_invoke_cache()->add_previous_version( 3166 the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum())); 3167 } 3168 3169 // Deoptimize all compiled code that depends on this class 3170 flush_dependent_code(the_class, THREAD); 3171 3172 _old_methods = the_class->methods(); 3173 _new_methods = scratch_class->methods(); 3174 _the_class_oop = the_class_oop; 3175 compute_added_deleted_matching_methods(); 3176 update_jmethod_ids(); 3177 3178 // Attach new constant pool to the original klass. The original 3179 // klass still refers to the old constant pool (for now). 3180 scratch_class->constants()->set_pool_holder(the_class()); 3181 3182#if 0 3183 // In theory, with constant pool merging in place we should be able 3184 // to save space by using the new, merged constant pool in place of 3185 // the old constant pool(s). By "pool(s)" I mean the constant pool in 3186 // the klass version we are replacing now and any constant pool(s) in 3187 // previous versions of klass. Nice theory, doesn't work in practice. 3188 // When this code is enabled, even simple programs throw NullPointer 3189 // exceptions. I'm guessing that this is caused by some constant pool 3190 // cache difference between the new, merged constant pool and the 3191 // constant pool that was just being used by the klass. I'm keeping 3192 // this code around to archive the idea, but the code has to remain 3193 // disabled for now. 3194 3195 // Attach each old method to the new constant pool. This can be 3196 // done here since we are past the bytecode verification and 3197 // constant pool optimization phases. 3198 for (int i = _old_methods->length() - 1; i >= 0; i--) { 3199 Method* method = _old_methods->at(i); 3200 method->set_constants(scratch_class->constants()); 3201 } 3202 3203 { 3204 // walk all previous versions of the klass 3205 InstanceKlass *ik = (InstanceKlass *)the_class(); 3206 PreviousVersionWalker pvw(ik); 3207 instanceKlassHandle ikh; 3208 do { 3209 ikh = pvw.next_previous_version(); 3210 if (!ikh.is_null()) { 3211 ik = ikh(); 3212 3213 // attach previous version of klass to the new constant pool 3214 ik->set_constants(scratch_class->constants()); 3215 3216 // Attach each method in the previous version of klass to the 3217 // new constant pool 3218 Array<Method*>* prev_methods = ik->methods(); 3219 for (int i = prev_methods->length() - 1; i >= 0; i--) { 3220 Method* method = prev_methods->at(i); 3221 method->set_constants(scratch_class->constants()); 3222 } 3223 } 3224 } while (!ikh.is_null()); 3225 } 3226#endif 3227 3228 // Replace methods and constantpool 3229 the_class->set_methods(_new_methods); 3230 scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods, 3231 // and to be able to undo operation easily. 3232 3233 ConstantPool* old_constants = the_class->constants(); 3234 the_class->set_constants(scratch_class->constants()); 3235 scratch_class->set_constants(old_constants); // See the previous comment. 3236#if 0 3237 // We are swapping the guts of "the new class" with the guts of "the 3238 // class". Since the old constant pool has just been attached to "the 3239 // new class", it seems logical to set the pool holder in the old 3240 // constant pool also. However, doing this will change the observable 3241 // class hierarchy for any old methods that are still executing. A 3242 // method can query the identity of its "holder" and this query uses 3243 // the method's constant pool link to find the holder. The change in 3244 // holding class from "the class" to "the new class" can confuse 3245 // things. 3246 // 3247 // Setting the old constant pool's holder will also cause 3248 // verification done during vtable initialization below to fail. 3249 // During vtable initialization, the vtable's class is verified to be 3250 // a subtype of the method's holder. The vtable's class is "the 3251 // class" and the method's holder is gotten from the constant pool 3252 // link in the method itself. For "the class"'s directly implemented 3253 // methods, the method holder is "the class" itself (as gotten from 3254 // the new constant pool). The check works fine in this case. The 3255 // check also works fine for methods inherited from super classes. 3256 // 3257 // Miranda methods are a little more complicated. A miranda method is 3258 // provided by an interface when the class implementing the interface 3259 // does not provide its own method. These interfaces are implemented 3260 // internally as an InstanceKlass. These special instanceKlasses 3261 // share the constant pool of the class that "implements" the 3262 // interface. By sharing the constant pool, the method holder of a 3263 // miranda method is the class that "implements" the interface. In a 3264 // non-redefine situation, the subtype check works fine. However, if 3265 // the old constant pool's pool holder is modified, then the check 3266 // fails because there is no class hierarchy relationship between the 3267 // vtable's class and "the new class". 3268 3269 old_constants->set_pool_holder(scratch_class()); 3270#endif 3271 3272 // track which methods are EMCP for add_previous_version() call below 3273 BitMap emcp_methods(_old_methods->length()); 3274 int emcp_method_count = 0; 3275 emcp_methods.clear(); // clears 0..(length() - 1) 3276 check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count); 3277 transfer_old_native_function_registrations(the_class); 3278 3279 // The class file bytes from before any retransformable agents mucked 3280 // with them was cached on the scratch class, move to the_class. 3281 // Note: we still want to do this if nothing needed caching since it 3282 // should get cleared in the_class too. 3283 if (the_class->get_cached_class_file_bytes() == 0) { 3284 // the_class doesn't have a cache yet so copy it 3285 the_class->set_cached_class_file( 3286 scratch_class->get_cached_class_file_bytes(), 3287 scratch_class->get_cached_class_file_len()); 3288 } 3289#ifndef PRODUCT 3290 else { 3291 assert(the_class->get_cached_class_file_bytes() == 3292 scratch_class->get_cached_class_file_bytes(), "cache ptrs must match"); 3293 assert(the_class->get_cached_class_file_len() == 3294 scratch_class->get_cached_class_file_len(), "cache lens must match"); 3295 } 3296#endif 3297 3298 // Replace inner_classes 3299 Array<u2>* old_inner_classes = the_class->inner_classes(); 3300 the_class->set_inner_classes(scratch_class->inner_classes()); 3301 scratch_class->set_inner_classes(old_inner_classes); 3302 3303 // Initialize the vtable and interface table after 3304 // methods have been rewritten 3305 { 3306 ResourceMark rm(THREAD); 3307 // no exception should happen here since we explicitly 3308 // do not check loader constraints. 3309 // compare_and_normalize_class_versions has already checked: 3310 // - classloaders unchanged, signatures unchanged 3311 // - all instanceKlasses for redefined classes reused & contents updated 3312 the_class->vtable()->initialize_vtable(false, THREAD); 3313 the_class->itable()->initialize_itable(false, THREAD); 3314 assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())), "redefine exception"); 3315 } 3316 3317 // Leave arrays of jmethodIDs and itable index cache unchanged 3318 3319 // Copy the "source file name" attribute from new class version 3320 the_class->set_source_file_name(scratch_class->source_file_name()); 3321 3322 // Copy the "source debug extension" attribute from new class version 3323 the_class->set_source_debug_extension( 3324 scratch_class->source_debug_extension(), 3325 scratch_class->source_debug_extension() == NULL ? 0 : 3326 (int)strlen(scratch_class->source_debug_extension())); 3327 3328 // Use of javac -g could be different in the old and the new 3329 if (scratch_class->access_flags().has_localvariable_table() != 3330 the_class->access_flags().has_localvariable_table()) { 3331 3332 AccessFlags flags = the_class->access_flags(); 3333 if (scratch_class->access_flags().has_localvariable_table()) { 3334 flags.set_has_localvariable_table(); 3335 } else { 3336 flags.clear_has_localvariable_table(); 3337 } 3338 the_class->set_access_flags(flags); 3339 } 3340 3341 // Replace annotation fields value 3342 Annotations* old_annotations = the_class->annotations(); 3343 the_class->set_annotations(scratch_class->annotations()); 3344 scratch_class->set_annotations(old_annotations); 3345 3346 // Replace minor version number of class file 3347 u2 old_minor_version = the_class->minor_version(); 3348 the_class->set_minor_version(scratch_class->minor_version()); 3349 scratch_class->set_minor_version(old_minor_version); 3350 3351 // Replace major version number of class file 3352 u2 old_major_version = the_class->major_version(); 3353 the_class->set_major_version(scratch_class->major_version()); 3354 scratch_class->set_major_version(old_major_version); 3355 3356 // Replace CP indexes for class and name+type of enclosing method 3357 u2 old_class_idx = the_class->enclosing_method_class_index(); 3358 u2 old_method_idx = the_class->enclosing_method_method_index(); 3359 the_class->set_enclosing_method_indices( 3360 scratch_class->enclosing_method_class_index(), 3361 scratch_class->enclosing_method_method_index()); 3362 scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx); 3363 3364 // keep track of previous versions of this class 3365 the_class->add_previous_version(scratch_class, &emcp_methods, 3366 emcp_method_count); 3367 3368 RC_TIMER_STOP(_timer_rsc_phase1); 3369 RC_TIMER_START(_timer_rsc_phase2); 3370 3371 // Adjust constantpool caches and vtables for all classes 3372 // that reference methods of the evolved class. 3373 SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD); 3374 3375 // Fix Resolution Error table also to remove old constant pools 3376 SystemDictionary::delete_resolution_error(old_constants); 3377 3378 if (the_class->oop_map_cache() != NULL) { 3379 // Flush references to any obsolete methods from the oop map cache 3380 // so that obsolete methods are not pinned. 3381 the_class->oop_map_cache()->flush_obsolete_entries(); 3382 } 3383 3384 // increment the classRedefinedCount field in the_class and in any 3385 // direct and indirect subclasses of the_class 3386 increment_class_counter((InstanceKlass *)the_class(), THREAD); 3387 3388 // RC_TRACE macro has an embedded ResourceMark 3389 RC_TRACE_WITH_THREAD(0x00000001, THREAD, 3390 ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)", 3391 the_class->external_name(), 3392 java_lang_Class::classRedefinedCount(the_class_mirror), 3393 os::available_memory() >> 10)); 3394 3395 RC_TIMER_STOP(_timer_rsc_phase2); 3396} // end redefine_single_class() 3397 3398 3399// Increment the classRedefinedCount field in the specific InstanceKlass 3400// and in all direct and indirect subclasses. 3401void VM_RedefineClasses::increment_class_counter(InstanceKlass *ik, TRAPS) { 3402 oop class_mirror = ik->java_mirror(); 3403 Klass* class_oop = java_lang_Class::as_Klass(class_mirror); 3404 int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1; 3405 java_lang_Class::set_classRedefinedCount(class_mirror, new_count); 3406 3407 if (class_oop != _the_class_oop) { 3408 // _the_class_oop count is printed at end of redefine_single_class() 3409 RC_TRACE_WITH_THREAD(0x00000008, THREAD, 3410 ("updated count in subclass=%s to %d", ik->external_name(), new_count)); 3411 } 3412 3413 for (Klass *subk = ik->subklass(); subk != NULL; 3414 subk = subk->next_sibling()) { 3415 if (subk->oop_is_instance()) { 3416 // Only update instanceKlasses 3417 InstanceKlass *subik = (InstanceKlass*)subk; 3418 // recursively do subclasses of the current subclass 3419 increment_class_counter(subik, THREAD); 3420 } 3421 } 3422} 3423 3424#ifndef PRODUCT 3425void VM_RedefineClasses::check_class(Klass* k_oop, 3426 ClassLoaderData* initiating_loader, 3427 TRAPS) { 3428 Klass *k = k_oop; 3429 if (k->oop_is_instance()) { 3430 HandleMark hm(THREAD); 3431 InstanceKlass *ik = (InstanceKlass *) k; 3432 3433 if (ik->vtable_length() > 0) { 3434 ResourceMark rm(THREAD); 3435 if (!ik->vtable()->check_no_old_entries()) { 3436 tty->print_cr("klassVtable::check_no_old_entries failure -- OLD method found -- class: %s", ik->signature_name()); 3437 ik->vtable()->dump_vtable(); 3438 assert(false, "OLD method found"); 3439 } 3440 } 3441 if (ik->itable_length() > 0) { 3442 ResourceMark rm(THREAD); 3443 if (!ik->itable()->check_no_old_entries()) { 3444 tty->print_cr("klassItable::check_no_old_entries failure -- OLD method found -- class: %s", ik->signature_name()); 3445 assert(false, "OLD method found"); 3446 } 3447 } 3448 // Check that the constant pool cache has no deleted entries. 3449 if (ik->constants() != NULL && 3450 ik->constants()->cache() != NULL && 3451 !ik->constants()->cache()->check_no_old_entries()) { 3452 tty->print_cr("klassVtable::check_no_old_entries failure -- OLD method found -- class: %s", ik->signature_name()); 3453 assert(false, "OLD method found"); 3454 } 3455 } 3456} 3457 3458void VM_RedefineClasses::dump_methods() { 3459 int j; 3460 tty->print_cr("_old_methods --"); 3461 for (j = 0; j < _old_methods->length(); ++j) { 3462 Method* m = _old_methods->at(j); 3463 tty->print("%4d (%5d) ", j, m->vtable_index()); 3464 m->access_flags().print_on(tty); 3465 tty->print(" -- "); 3466 m->print_name(tty); 3467 tty->cr(); 3468 } 3469 tty->print_cr("_new_methods --"); 3470 for (j = 0; j < _new_methods->length(); ++j) { 3471 Method* m = _new_methods->at(j); 3472 tty->print("%4d (%5d) ", j, m->vtable_index()); 3473 m->access_flags().print_on(tty); 3474 tty->print(" -- "); 3475 m->print_name(tty); 3476 tty->cr(); 3477 } 3478 tty->print_cr("_matching_(old/new)_methods --"); 3479 for (j = 0; j < _matching_methods_length; ++j) { 3480 Method* m = _matching_old_methods[j]; 3481 tty->print("%4d (%5d) ", j, m->vtable_index()); 3482 m->access_flags().print_on(tty); 3483 tty->print(" -- "); 3484 m->print_name(tty); 3485 tty->cr(); 3486 m = _matching_new_methods[j]; 3487 tty->print(" (%5d) ", m->vtable_index()); 3488 m->access_flags().print_on(tty); 3489 tty->cr(); 3490 } 3491 tty->print_cr("_deleted_methods --"); 3492 for (j = 0; j < _deleted_methods_length; ++j) { 3493 Method* m = _deleted_methods[j]; 3494 tty->print("%4d (%5d) ", j, m->vtable_index()); 3495 m->access_flags().print_on(tty); 3496 tty->print(" -- "); 3497 m->print_name(tty); 3498 tty->cr(); 3499 } 3500 tty->print_cr("_added_methods --"); 3501 for (j = 0; j < _added_methods_length; ++j) { 3502 Method* m = _added_methods[j]; 3503 tty->print("%4d (%5d) ", j, m->vtable_index()); 3504 m->access_flags().print_on(tty); 3505 tty->print(" -- "); 3506 m->print_name(tty); 3507 tty->cr(); 3508 } 3509} 3510#endif 3511