1 /* 2 * Copyright (c) 2003, 2013, 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 "interpreter/oopMapCache.hpp" 30 #include "interpreter/rewriter.hpp" 31 #include "memory/gcLocker.hpp" 32 #include "memory/universe.inline.hpp" 33 #include "oops/fieldStreams.hpp" 34 #include "oops/klassVtable.hpp" 35 #include "prims/jvmtiImpl.hpp" 36 #include "prims/jvmtiRedefineClasses.hpp" 37 #include "prims/methodComparator.hpp" 38 #include "runtime/deoptimization.hpp" 39 #include "runtime/relocator.hpp" 40 #include "utilities/bitMap.inline.hpp" 41 42 43 objArrayOop VM_RedefineClasses::_old_methods = NULL; 44 objArrayOop VM_RedefineClasses::_new_methods = NULL; 45 methodOop* VM_RedefineClasses::_matching_old_methods = NULL; 46 methodOop* VM_RedefineClasses::_matching_new_methods = NULL; 47 methodOop* VM_RedefineClasses::_deleted_methods = NULL; 48 methodOop* VM_RedefineClasses::_added_methods = NULL; 49 int VM_RedefineClasses::_matching_methods_length = 0; 50 int VM_RedefineClasses::_deleted_methods_length = 0; 51 int VM_RedefineClasses::_added_methods_length = 0; 52 klassOop VM_RedefineClasses::_the_class_oop = NULL; 53 54 55 VM_RedefineClasses::VM_RedefineClasses(jint class_count, 56 const jvmtiClassDefinition *class_defs, 57 JvmtiClassLoadKind class_load_kind) { 58 _class_count = class_count; 59 _class_defs = class_defs; 60 _class_load_kind = class_load_kind; 61 _res = JVMTI_ERROR_NONE; 62 } 63 64 bool VM_RedefineClasses::doit_prologue() { 65 if (_class_count == 0) { 66 _res = JVMTI_ERROR_NONE; 67 return false; 68 } 69 if (_class_defs == NULL) { 70 _res = JVMTI_ERROR_NULL_POINTER; 71 return false; 72 } 73 for (int i = 0; i < _class_count; i++) { 74 if (_class_defs[i].klass == NULL) { 75 _res = JVMTI_ERROR_INVALID_CLASS; 76 return false; 77 } 78 if (_class_defs[i].class_byte_count == 0) { 79 _res = JVMTI_ERROR_INVALID_CLASS_FORMAT; 80 return false; 81 } 82 if (_class_defs[i].class_bytes == NULL) { 83 _res = JVMTI_ERROR_NULL_POINTER; 84 return false; 85 } 86 } 87 88 // Start timer after all the sanity checks; not quite accurate, but 89 // better than adding a bunch of stop() calls. 90 RC_TIMER_START(_timer_vm_op_prologue); 91 92 // We first load new class versions in the prologue, because somewhere down the 93 // call chain it is required that the current thread is a Java thread. 94 _res = load_new_class_versions(Thread::current()); 95 if (_res != JVMTI_ERROR_NONE) { 96 // Free os::malloc allocated memory in load_new_class_version. 97 os::free(_scratch_classes); 98 RC_TIMER_STOP(_timer_vm_op_prologue); 99 return false; 100 } 101 102 RC_TIMER_STOP(_timer_vm_op_prologue); 103 return true; 104 } 105 106 void VM_RedefineClasses::doit() { 107 Thread *thread = Thread::current(); 108 109 if (UseSharedSpaces) { 110 // Sharing is enabled so we remap the shared readonly space to 111 // shared readwrite, private just in case we need to redefine 112 // a shared class. We do the remap during the doit() phase of 113 // the safepoint to be safer. 114 if (!CompactingPermGenGen::remap_shared_readonly_as_readwrite()) { 115 RC_TRACE_WITH_THREAD(0x00000001, thread, 116 ("failed to remap shared readonly space to readwrite, private")); 117 _res = JVMTI_ERROR_INTERNAL; 118 return; 119 } 120 } 121 122 for (int i = 0; i < _class_count; i++) { 123 redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread); 124 } 125 // Disable any dependent concurrent compilations 126 SystemDictionary::notice_modification(); 127 128 // Set flag indicating that some invariants are no longer true. 129 // See jvmtiExport.hpp for detailed explanation. 130 JvmtiExport::set_has_redefined_a_class(); 131 132 // check_class() is optionally called for product bits, but is 133 // always called for non-product bits. 134 #ifdef PRODUCT 135 if (RC_TRACE_ENABLED(0x00004000)) { 136 #endif 137 RC_TRACE_WITH_THREAD(0x00004000, thread, ("calling check_class")); 138 SystemDictionary::classes_do(check_class, thread); 139 #ifdef PRODUCT 140 } 141 #endif 142 } 143 144 void VM_RedefineClasses::doit_epilogue() { 145 // Free os::malloc allocated memory. 146 // The memory allocated in redefine will be free'ed in next VM operation. 147 os::free(_scratch_classes); 148 149 if (RC_TRACE_ENABLED(0x00000004)) { 150 // Used to have separate timers for "doit" and "all", but the timer 151 // overhead skewed the measurements. 152 jlong doit_time = _timer_rsc_phase1.milliseconds() + 153 _timer_rsc_phase2.milliseconds(); 154 jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time; 155 156 RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT 157 " prologue=" UINT64_FORMAT " doit=" UINT64_FORMAT, all_time, 158 _timer_vm_op_prologue.milliseconds(), doit_time)); 159 RC_TRACE(0x00000004, 160 ("redefine_single_class: phase1=" UINT64_FORMAT " phase2=" UINT64_FORMAT, 161 _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds())); 162 } 163 } 164 165 bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) { 166 // classes for primitives cannot be redefined 167 if (java_lang_Class::is_primitive(klass_mirror)) { 168 return false; 169 } 170 klassOop the_class_oop = java_lang_Class::as_klassOop(klass_mirror); 171 // classes for arrays cannot be redefined 172 if (the_class_oop == NULL || !Klass::cast(the_class_oop)->oop_is_instance()) { 173 return false; 174 } 175 return true; 176 } 177 178 // Append the current entry at scratch_i in scratch_cp to *merge_cp_p 179 // where the end of *merge_cp_p is specified by *merge_cp_length_p. For 180 // direct CP entries, there is just the current entry to append. For 181 // indirect and double-indirect CP entries, there are zero or more 182 // referenced CP entries along with the current entry to append. 183 // Indirect and double-indirect CP entries are handled by recursive 184 // calls to append_entry() as needed. The referenced CP entries are 185 // always appended to *merge_cp_p before the referee CP entry. These 186 // referenced CP entries may already exist in *merge_cp_p in which case 187 // there is nothing extra to append and only the current entry is 188 // appended. 189 void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp, 190 int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, 191 TRAPS) { 192 193 // append is different depending on entry tag type 194 switch (scratch_cp->tag_at(scratch_i).value()) { 195 196 // The old verifier is implemented outside the VM. It loads classes, 197 // but does not resolve constant pool entries directly so we never 198 // see Class entries here with the old verifier. Similarly the old 199 // verifier does not like Class entries in the input constant pool. 200 // The split-verifier is implemented in the VM so it can optionally 201 // and directly resolve constant pool entries to load classes. The 202 // split-verifier can accept either Class entries or UnresolvedClass 203 // entries in the input constant pool. We revert the appended copy 204 // back to UnresolvedClass so that either verifier will be happy 205 // with the constant pool entry. 206 case JVM_CONSTANT_Class: 207 { 208 // revert the copy to JVM_CONSTANT_UnresolvedClass 209 (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p, 210 scratch_cp->klass_name_at(scratch_i)); 211 212 if (scratch_i != *merge_cp_length_p) { 213 // The new entry in *merge_cp_p is at a different index than 214 // the new entry in scratch_cp so we need to map the index values. 215 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 216 } 217 (*merge_cp_length_p)++; 218 } break; 219 220 // these are direct CP entries so they can be directly appended, 221 // but double and long take two constant pool entries 222 case JVM_CONSTANT_Double: // fall through 223 case JVM_CONSTANT_Long: 224 { 225 constantPoolOopDesc::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p, 226 THREAD); 227 228 if (scratch_i != *merge_cp_length_p) { 229 // The new entry in *merge_cp_p is at a different index than 230 // the new entry in scratch_cp so we need to map the index values. 231 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 232 } 233 (*merge_cp_length_p) += 2; 234 } break; 235 236 // these are direct CP entries so they can be directly appended 237 case JVM_CONSTANT_Float: // fall through 238 case JVM_CONSTANT_Integer: // fall through 239 case JVM_CONSTANT_Utf8: // fall through 240 241 // This was an indirect CP entry, but it has been changed into 242 // an interned string so this entry can be directly appended. 243 case JVM_CONSTANT_String: // fall through 244 245 // These were indirect CP entries, but they have been changed into 246 // Symbol*s so these entries can be directly appended. 247 case JVM_CONSTANT_UnresolvedClass: // fall through 248 case JVM_CONSTANT_UnresolvedString: 249 { 250 constantPoolOopDesc::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p, 251 THREAD); 252 253 if (scratch_i != *merge_cp_length_p) { 254 // The new entry in *merge_cp_p is at a different index than 255 // the new entry in scratch_cp so we need to map the index values. 256 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 257 } 258 (*merge_cp_length_p)++; 259 } break; 260 261 // this is an indirect CP entry so it needs special handling 262 case JVM_CONSTANT_NameAndType: 263 { 264 int name_ref_i = scratch_cp->name_ref_index_at(scratch_i); 265 int new_name_ref_i = 0; 266 bool match = (name_ref_i < *merge_cp_length_p) && 267 scratch_cp->compare_entry_to(name_ref_i, *merge_cp_p, name_ref_i, 268 THREAD); 269 if (!match) { 270 // forward reference in *merge_cp_p or not a direct match 271 272 int found_i = scratch_cp->find_matching_entry(name_ref_i, *merge_cp_p, 273 THREAD); 274 if (found_i != 0) { 275 guarantee(found_i != name_ref_i, 276 "compare_entry_to() and find_matching_entry() do not agree"); 277 278 // Found a matching entry somewhere else in *merge_cp_p so 279 // just need a mapping entry. 280 new_name_ref_i = found_i; 281 map_index(scratch_cp, name_ref_i, found_i); 282 } else { 283 // no match found so we have to append this entry to *merge_cp_p 284 append_entry(scratch_cp, name_ref_i, merge_cp_p, merge_cp_length_p, 285 THREAD); 286 // The above call to append_entry() can only append one entry 287 // so the post call query of *merge_cp_length_p is only for 288 // the sake of consistency. 289 new_name_ref_i = *merge_cp_length_p - 1; 290 } 291 } 292 293 int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i); 294 int new_signature_ref_i = 0; 295 match = (signature_ref_i < *merge_cp_length_p) && 296 scratch_cp->compare_entry_to(signature_ref_i, *merge_cp_p, 297 signature_ref_i, THREAD); 298 if (!match) { 299 // forward reference in *merge_cp_p or not a direct match 300 301 int found_i = scratch_cp->find_matching_entry(signature_ref_i, 302 *merge_cp_p, THREAD); 303 if (found_i != 0) { 304 guarantee(found_i != signature_ref_i, 305 "compare_entry_to() and find_matching_entry() do not agree"); 306 307 // Found a matching entry somewhere else in *merge_cp_p so 308 // just need a mapping entry. 309 new_signature_ref_i = found_i; 310 map_index(scratch_cp, signature_ref_i, found_i); 311 } else { 312 // no match found so we have to append this entry to *merge_cp_p 313 append_entry(scratch_cp, signature_ref_i, merge_cp_p, 314 merge_cp_length_p, THREAD); 315 // The above call to append_entry() can only append one entry 316 // so the post call query of *merge_cp_length_p is only for 317 // the sake of consistency. 318 new_signature_ref_i = *merge_cp_length_p - 1; 319 } 320 } 321 322 // If the referenced entries already exist in *merge_cp_p, then 323 // both new_name_ref_i and new_signature_ref_i will both be 0. 324 // In that case, all we are appending is the current entry. 325 if (new_name_ref_i == 0) { 326 new_name_ref_i = name_ref_i; 327 } else { 328 RC_TRACE(0x00080000, 329 ("NameAndType entry@%d name_ref_index change: %d to %d", 330 *merge_cp_length_p, name_ref_i, new_name_ref_i)); 331 } 332 if (new_signature_ref_i == 0) { 333 new_signature_ref_i = signature_ref_i; 334 } else { 335 RC_TRACE(0x00080000, 336 ("NameAndType entry@%d signature_ref_index change: %d to %d", 337 *merge_cp_length_p, signature_ref_i, new_signature_ref_i)); 338 } 339 340 (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p, 341 new_name_ref_i, new_signature_ref_i); 342 if (scratch_i != *merge_cp_length_p) { 343 // The new entry in *merge_cp_p is at a different index than 344 // the new entry in scratch_cp so we need to map the index values. 345 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 346 } 347 (*merge_cp_length_p)++; 348 } break; 349 350 // this is a double-indirect CP entry so it needs special handling 351 case JVM_CONSTANT_Fieldref: // fall through 352 case JVM_CONSTANT_InterfaceMethodref: // fall through 353 case JVM_CONSTANT_Methodref: 354 { 355 int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i); 356 int new_klass_ref_i = 0; 357 bool match = (klass_ref_i < *merge_cp_length_p) && 358 scratch_cp->compare_entry_to(klass_ref_i, *merge_cp_p, klass_ref_i, 359 THREAD); 360 if (!match) { 361 // forward reference in *merge_cp_p or not a direct match 362 363 int found_i = scratch_cp->find_matching_entry(klass_ref_i, *merge_cp_p, 364 THREAD); 365 if (found_i != 0) { 366 guarantee(found_i != klass_ref_i, 367 "compare_entry_to() and find_matching_entry() do not agree"); 368 369 // Found a matching entry somewhere else in *merge_cp_p so 370 // just need a mapping entry. 371 new_klass_ref_i = found_i; 372 map_index(scratch_cp, klass_ref_i, found_i); 373 } else { 374 // no match found so we have to append this entry to *merge_cp_p 375 append_entry(scratch_cp, klass_ref_i, merge_cp_p, merge_cp_length_p, 376 THREAD); 377 // The above call to append_entry() can only append one entry 378 // so the post call query of *merge_cp_length_p is only for 379 // the sake of consistency. Without the optimization where we 380 // use JVM_CONSTANT_UnresolvedClass, then up to two entries 381 // could be appended. 382 new_klass_ref_i = *merge_cp_length_p - 1; 383 } 384 } 385 386 int name_and_type_ref_i = 387 scratch_cp->uncached_name_and_type_ref_index_at(scratch_i); 388 int new_name_and_type_ref_i = 0; 389 match = (name_and_type_ref_i < *merge_cp_length_p) && 390 scratch_cp->compare_entry_to(name_and_type_ref_i, *merge_cp_p, 391 name_and_type_ref_i, THREAD); 392 if (!match) { 393 // forward reference in *merge_cp_p or not a direct match 394 395 int found_i = scratch_cp->find_matching_entry(name_and_type_ref_i, 396 *merge_cp_p, THREAD); 397 if (found_i != 0) { 398 guarantee(found_i != name_and_type_ref_i, 399 "compare_entry_to() and find_matching_entry() do not agree"); 400 401 // Found a matching entry somewhere else in *merge_cp_p so 402 // just need a mapping entry. 403 new_name_and_type_ref_i = found_i; 404 map_index(scratch_cp, name_and_type_ref_i, found_i); 405 } else { 406 // no match found so we have to append this entry to *merge_cp_p 407 append_entry(scratch_cp, name_and_type_ref_i, merge_cp_p, 408 merge_cp_length_p, THREAD); 409 // The above call to append_entry() can append more than 410 // one entry so the post call query of *merge_cp_length_p 411 // is required in order to get the right index for the 412 // JVM_CONSTANT_NameAndType entry. 413 new_name_and_type_ref_i = *merge_cp_length_p - 1; 414 } 415 } 416 417 // If the referenced entries already exist in *merge_cp_p, then 418 // both new_klass_ref_i and new_name_and_type_ref_i will both be 419 // 0. In that case, all we are appending is the current entry. 420 if (new_klass_ref_i == 0) { 421 new_klass_ref_i = klass_ref_i; 422 } 423 if (new_name_and_type_ref_i == 0) { 424 new_name_and_type_ref_i = name_and_type_ref_i; 425 } 426 427 const char *entry_name; 428 switch (scratch_cp->tag_at(scratch_i).value()) { 429 case JVM_CONSTANT_Fieldref: 430 entry_name = "Fieldref"; 431 (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i, 432 new_name_and_type_ref_i); 433 break; 434 case JVM_CONSTANT_InterfaceMethodref: 435 entry_name = "IFMethodref"; 436 (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p, 437 new_klass_ref_i, new_name_and_type_ref_i); 438 break; 439 case JVM_CONSTANT_Methodref: 440 entry_name = "Methodref"; 441 (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i, 442 new_name_and_type_ref_i); 443 break; 444 default: 445 guarantee(false, "bad switch"); 446 break; 447 } 448 449 if (klass_ref_i != new_klass_ref_i) { 450 RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d", 451 entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i)); 452 } 453 if (name_and_type_ref_i != new_name_and_type_ref_i) { 454 RC_TRACE(0x00080000, 455 ("%s entry@%d name_and_type_index changed: %d to %d", 456 entry_name, *merge_cp_length_p, name_and_type_ref_i, 457 new_name_and_type_ref_i)); 458 } 459 460 if (scratch_i != *merge_cp_length_p) { 461 // The new entry in *merge_cp_p is at a different index than 462 // the new entry in scratch_cp so we need to map the index values. 463 map_index(scratch_cp, scratch_i, *merge_cp_length_p); 464 } 465 (*merge_cp_length_p)++; 466 } break; 467 468 // At this stage, Class or UnresolvedClass could be here, but not 469 // ClassIndex 470 case JVM_CONSTANT_ClassIndex: // fall through 471 472 // Invalid is used as the tag for the second constant pool entry 473 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should 474 // not be seen by itself. 475 case JVM_CONSTANT_Invalid: // fall through 476 477 // At this stage, String or UnresolvedString could be here, but not 478 // StringIndex 479 case JVM_CONSTANT_StringIndex: // fall through 480 481 // At this stage JVM_CONSTANT_UnresolvedClassInError should not be 482 // here 483 case JVM_CONSTANT_UnresolvedClassInError: // fall through 484 485 default: 486 { 487 // leave a breadcrumb 488 jbyte bad_value = scratch_cp->tag_at(scratch_i).value(); 489 ShouldNotReachHere(); 490 } break; 491 } // end switch tag value 492 } // end append_entry() 493 494 495 void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class) { 496 typeArrayOop save; 497 498 save = scratch_class->get_method_annotations_of(i); 499 scratch_class->set_method_annotations_of(i, scratch_class->get_method_annotations_of(j)); 500 scratch_class->set_method_annotations_of(j, save); 501 502 save = scratch_class->get_method_parameter_annotations_of(i); 503 scratch_class->set_method_parameter_annotations_of(i, scratch_class->get_method_parameter_annotations_of(j)); 504 scratch_class->set_method_parameter_annotations_of(j, save); 505 506 save = scratch_class->get_method_default_annotations_of(i); 507 scratch_class->set_method_default_annotations_of(i, scratch_class->get_method_default_annotations_of(j)); 508 scratch_class->set_method_default_annotations_of(j, save); 509 } 510 511 512 jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions( 513 instanceKlassHandle the_class, 514 instanceKlassHandle scratch_class) { 515 int i; 516 517 // Check superclasses, or rather their names, since superclasses themselves can be 518 // requested to replace. 519 // Check for NULL superclass first since this might be java.lang.Object 520 if (the_class->super() != scratch_class->super() && 521 (the_class->super() == NULL || scratch_class->super() == NULL || 522 Klass::cast(the_class->super())->name() != 523 Klass::cast(scratch_class->super())->name())) { 524 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; 525 } 526 527 // Check if the number, names and order of directly implemented interfaces are the same. 528 // I think in principle we should just check if the sets of names of directly implemented 529 // interfaces are the same, i.e. the order of declaration (which, however, if changed in the 530 // .java file, also changes in .class file) should not matter. However, comparing sets is 531 // technically a bit more difficult, and, more importantly, I am not sure at present that the 532 // order of interfaces does not matter on the implementation level, i.e. that the VM does not 533 // rely on it somewhere. 534 objArrayOop k_interfaces = the_class->local_interfaces(); 535 objArrayOop k_new_interfaces = scratch_class->local_interfaces(); 536 int n_intfs = k_interfaces->length(); 537 if (n_intfs != k_new_interfaces->length()) { 538 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; 539 } 540 for (i = 0; i < n_intfs; i++) { 541 if (Klass::cast((klassOop) k_interfaces->obj_at(i))->name() != 542 Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) { 543 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; 544 } 545 } 546 547 // Check whether class is in the error init state. 548 if (the_class->is_in_error_state()) { 549 // TBD #5057930: special error code is needed in 1.6 550 return JVMTI_ERROR_INVALID_CLASS; 551 } 552 553 // Check whether class modifiers are the same. 554 jushort old_flags = (jushort) the_class->access_flags().get_flags(); 555 jushort new_flags = (jushort) scratch_class->access_flags().get_flags(); 556 if (old_flags != new_flags) { 557 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED; 558 } 559 560 // Check if the number, names, types and order of fields declared in these classes 561 // are the same. 562 JavaFieldStream old_fs(the_class); 563 JavaFieldStream new_fs(scratch_class); 564 for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) { 565 // access 566 old_flags = old_fs.access_flags().as_short(); 567 new_flags = new_fs.access_flags().as_short(); 568 if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) { 569 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 570 } 571 // offset 572 if (old_fs.offset() != new_fs.offset()) { 573 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 574 } 575 // name and signature 576 Symbol* name_sym1 = the_class->constants()->symbol_at(old_fs.name_index()); 577 Symbol* sig_sym1 = the_class->constants()->symbol_at(old_fs.signature_index()); 578 Symbol* name_sym2 = scratch_class->constants()->symbol_at(new_fs.name_index()); 579 Symbol* sig_sym2 = scratch_class->constants()->symbol_at(new_fs.signature_index()); 580 if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) { 581 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 582 } 583 } 584 585 // If both streams aren't done then we have a differing number of 586 // fields. 587 if (!old_fs.done() || !new_fs.done()) { 588 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; 589 } 590 591 // Do a parallel walk through the old and new methods. Detect 592 // cases where they match (exist in both), have been added in 593 // the new methods, or have been deleted (exist only in the 594 // old methods). The class file parser places methods in order 595 // by method name, but does not order overloaded methods by 596 // signature. In order to determine what fate befell the methods, 597 // this code places the overloaded new methods that have matching 598 // old methods in the same order as the old methods and places 599 // new overloaded methods at the end of overloaded methods of 600 // that name. The code for this order normalization is adapted 601 // from the algorithm used in instanceKlass::find_method(). 602 // Since we are swapping out of order entries as we find them, 603 // we only have to search forward through the overloaded methods. 604 // Methods which are added and have the same name as an existing 605 // method (but different signature) will be put at the end of 606 // the methods with that name, and the name mismatch code will 607 // handle them. 608 objArrayHandle k_old_methods(the_class->methods()); 609 objArrayHandle k_new_methods(scratch_class->methods()); 610 int n_old_methods = k_old_methods->length(); 611 int n_new_methods = k_new_methods->length(); 612 613 int ni = 0; 614 int oi = 0; 615 while (true) { 616 methodOop k_old_method; 617 methodOop k_new_method; 618 enum { matched, added, deleted, undetermined } method_was = undetermined; 619 620 if (oi >= n_old_methods) { 621 if (ni >= n_new_methods) { 622 break; // we've looked at everything, done 623 } 624 // New method at the end 625 k_new_method = (methodOop) k_new_methods->obj_at(ni); 626 method_was = added; 627 } else if (ni >= n_new_methods) { 628 // Old method, at the end, is deleted 629 k_old_method = (methodOop) k_old_methods->obj_at(oi); 630 method_was = deleted; 631 } else { 632 // There are more methods in both the old and new lists 633 k_old_method = (methodOop) k_old_methods->obj_at(oi); 634 k_new_method = (methodOop) k_new_methods->obj_at(ni); 635 if (k_old_method->name() != k_new_method->name()) { 636 // Methods are sorted by method name, so a mismatch means added 637 // or deleted 638 if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) { 639 method_was = added; 640 } else { 641 method_was = deleted; 642 } 643 } else if (k_old_method->signature() == k_new_method->signature()) { 644 // Both the name and signature match 645 method_was = matched; 646 } else { 647 // The name matches, but the signature doesn't, which means we have to 648 // search forward through the new overloaded methods. 649 int nj; // outside the loop for post-loop check 650 for (nj = ni + 1; nj < n_new_methods; nj++) { 651 methodOop m = (methodOop)k_new_methods->obj_at(nj); 652 if (k_old_method->name() != m->name()) { 653 // reached another method name so no more overloaded methods 654 method_was = deleted; 655 break; 656 } 657 if (k_old_method->signature() == m->signature()) { 658 // found a match so swap the methods 659 k_new_methods->obj_at_put(ni, m); 660 k_new_methods->obj_at_put(nj, k_new_method); 661 k_new_method = m; 662 method_was = matched; 663 break; 664 } 665 } 666 667 if (nj >= n_new_methods) { 668 // reached the end without a match; so method was deleted 669 method_was = deleted; 670 } 671 } 672 } 673 674 switch (method_was) { 675 case matched: 676 // methods match, be sure modifiers do too 677 old_flags = (jushort) k_old_method->access_flags().get_flags(); 678 new_flags = (jushort) k_new_method->access_flags().get_flags(); 679 if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) { 680 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED; 681 } 682 { 683 u2 new_num = k_new_method->method_idnum(); 684 u2 old_num = k_old_method->method_idnum(); 685 if (new_num != old_num) { 686 methodOop idnum_owner = scratch_class->method_with_idnum(old_num); 687 if (idnum_owner != NULL) { 688 // There is already a method assigned this idnum -- switch them 689 idnum_owner->set_method_idnum(new_num); 690 } 691 k_new_method->set_method_idnum(old_num); 692 swap_all_method_annotations(old_num, new_num, scratch_class); 693 } 694 } 695 RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]", 696 k_new_method->name_and_sig_as_C_string(), ni, 697 k_old_method->name_and_sig_as_C_string(), oi)); 698 // advance to next pair of methods 699 ++oi; 700 ++ni; 701 break; 702 case added: 703 // method added, see if it is OK 704 new_flags = (jushort) k_new_method->access_flags().get_flags(); 705 if ((new_flags & JVM_ACC_PRIVATE) == 0 706 // hack: private should be treated as final, but alas 707 || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0 708 ) { 709 // new methods must be private 710 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED; 711 } 712 { 713 u2 num = the_class->next_method_idnum(); 714 if (num == constMethodOopDesc::UNSET_IDNUM) { 715 // cannot add any more methods 716 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED; 717 } 718 u2 new_num = k_new_method->method_idnum(); 719 methodOop idnum_owner = scratch_class->method_with_idnum(num); 720 if (idnum_owner != NULL) { 721 // There is already a method assigned this idnum -- switch them 722 idnum_owner->set_method_idnum(new_num); 723 } 724 k_new_method->set_method_idnum(num); 725 swap_all_method_annotations(new_num, num, scratch_class); 726 } 727 RC_TRACE(0x00008000, ("Method added: new: %s [%d]", 728 k_new_method->name_and_sig_as_C_string(), ni)); 729 ++ni; // advance to next new method 730 break; 731 case deleted: 732 // method deleted, see if it is OK 733 old_flags = (jushort) k_old_method->access_flags().get_flags(); 734 if ((old_flags & JVM_ACC_PRIVATE) == 0 735 // hack: private should be treated as final, but alas 736 || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0 737 ) { 738 // deleted methods must be private 739 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED; 740 } 741 RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]", 742 k_old_method->name_and_sig_as_C_string(), oi)); 743 ++oi; // advance to next old method 744 break; 745 default: 746 ShouldNotReachHere(); 747 } 748 } 749 750 return JVMTI_ERROR_NONE; 751 } 752 753 754 // Find new constant pool index value for old constant pool index value 755 // by seaching the index map. Returns zero (0) if there is no mapped 756 // value for the old constant pool index. 757 int VM_RedefineClasses::find_new_index(int old_index) { 758 if (_index_map_count == 0) { 759 // map is empty so nothing can be found 760 return 0; 761 } 762 763 if (old_index < 1 || old_index >= _index_map_p->length()) { 764 // The old_index is out of range so it is not mapped. This should 765 // not happen in regular constant pool merging use, but it can 766 // happen if a corrupt annotation is processed. 767 return 0; 768 } 769 770 int value = _index_map_p->at(old_index); 771 if (value == -1) { 772 // the old_index is not mapped 773 return 0; 774 } 775 776 return value; 777 } // end find_new_index() 778 779 780 // Returns true if the current mismatch is due to a resolved/unresolved 781 // class pair. Otherwise, returns false. 782 bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1, 783 int index1, constantPoolHandle cp2, int index2) { 784 785 jbyte t1 = cp1->tag_at(index1).value(); 786 if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) { 787 return false; // wrong entry type; not our special case 788 } 789 790 jbyte t2 = cp2->tag_at(index2).value(); 791 if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) { 792 return false; // wrong entry type; not our special case 793 } 794 795 if (t1 == t2) { 796 return false; // not a mismatch; not our special case 797 } 798 799 char *s1 = cp1->klass_name_at(index1)->as_C_string(); 800 char *s2 = cp2->klass_name_at(index2)->as_C_string(); 801 if (strcmp(s1, s2) != 0) { 802 return false; // strings don't match; not our special case 803 } 804 805 return true; // made it through the gauntlet; this is our special case 806 } // end is_unresolved_class_mismatch() 807 808 809 // Returns true if the current mismatch is due to a resolved/unresolved 810 // string pair. Otherwise, returns false. 811 bool VM_RedefineClasses::is_unresolved_string_mismatch(constantPoolHandle cp1, 812 int index1, constantPoolHandle cp2, int index2) { 813 814 jbyte t1 = cp1->tag_at(index1).value(); 815 if (t1 != JVM_CONSTANT_String && t1 != JVM_CONSTANT_UnresolvedString) { 816 return false; // wrong entry type; not our special case 817 } 818 819 jbyte t2 = cp2->tag_at(index2).value(); 820 if (t2 != JVM_CONSTANT_String && t2 != JVM_CONSTANT_UnresolvedString) { 821 return false; // wrong entry type; not our special case 822 } 823 824 if (t1 == t2) { 825 return false; // not a mismatch; not our special case 826 } 827 828 char *s1 = cp1->string_at_noresolve(index1); 829 char *s2 = cp2->string_at_noresolve(index2); 830 if (strcmp(s1, s2) != 0) { 831 return false; // strings don't match; not our special case 832 } 833 834 return true; // made it through the gauntlet; this is our special case 835 } // end is_unresolved_string_mismatch() 836 837 838 jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) { 839 // For consistency allocate memory using os::malloc wrapper. 840 _scratch_classes = (instanceKlassHandle *) 841 os::malloc(sizeof(instanceKlassHandle) * _class_count, mtInternal); 842 if (_scratch_classes == NULL) { 843 return JVMTI_ERROR_OUT_OF_MEMORY; 844 } 845 846 ResourceMark rm(THREAD); 847 848 JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current()); 849 // state can only be NULL if the current thread is exiting which 850 // should not happen since we're trying to do a RedefineClasses 851 guarantee(state != NULL, "exiting thread calling load_new_class_versions"); 852 for (int i = 0; i < _class_count; i++) { 853 oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass); 854 // classes for primitives cannot be redefined 855 if (!is_modifiable_class(mirror)) { 856 return JVMTI_ERROR_UNMODIFIABLE_CLASS; 857 } 858 klassOop the_class_oop = java_lang_Class::as_klassOop(mirror); 859 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop); 860 Symbol* the_class_sym = the_class->name(); 861 862 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 863 RC_TRACE_WITH_THREAD(0x00000001, THREAD, 864 ("loading name=%s kind=%d (avail_mem=" UINT64_FORMAT "K)", 865 the_class->external_name(), _class_load_kind, 866 os::available_memory() >> 10)); 867 868 ClassFileStream st((u1*) _class_defs[i].class_bytes, 869 _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__"); 870 871 // Parse the stream. 872 Handle the_class_loader(THREAD, the_class->class_loader()); 873 Handle protection_domain(THREAD, the_class->protection_domain()); 874 // Set redefined class handle in JvmtiThreadState class. 875 // This redefined class is sent to agent event handler for class file 876 // load hook event. 877 state->set_class_being_redefined(&the_class, _class_load_kind); 878 879 klassOop k = SystemDictionary::parse_stream(the_class_sym, 880 the_class_loader, 881 protection_domain, 882 &st, 883 THREAD); 884 // Clear class_being_redefined just to be sure. 885 state->clear_class_being_redefined(); 886 887 // TODO: if this is retransform, and nothing changed we can skip it 888 889 instanceKlassHandle scratch_class (THREAD, k); 890 891 if (HAS_PENDING_EXCEPTION) { 892 Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); 893 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 894 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'", 895 ex_name->as_C_string())); 896 CLEAR_PENDING_EXCEPTION; 897 898 if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) { 899 return JVMTI_ERROR_UNSUPPORTED_VERSION; 900 } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) { 901 return JVMTI_ERROR_INVALID_CLASS_FORMAT; 902 } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) { 903 return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION; 904 } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) { 905 // The message will be "XXX (wrong name: YYY)" 906 return JVMTI_ERROR_NAMES_DONT_MATCH; 907 } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 908 return JVMTI_ERROR_OUT_OF_MEMORY; 909 } else { // Just in case more exceptions can be thrown.. 910 return JVMTI_ERROR_FAILS_VERIFICATION; 911 } 912 } 913 914 // Ensure class is linked before redefine 915 if (!the_class->is_linked()) { 916 the_class->link_class(THREAD); 917 if (HAS_PENDING_EXCEPTION) { 918 Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); 919 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 920 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'", 921 ex_name->as_C_string())); 922 CLEAR_PENDING_EXCEPTION; 923 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 924 return JVMTI_ERROR_OUT_OF_MEMORY; 925 } else { 926 return JVMTI_ERROR_INTERNAL; 927 } 928 } 929 } 930 931 // Do the validity checks in compare_and_normalize_class_versions() 932 // before verifying the byte codes. By doing these checks first, we 933 // limit the number of functions that require redirection from 934 // the_class to scratch_class. In particular, we don't have to 935 // modify JNI GetSuperclass() and thus won't change its performance. 936 jvmtiError res = compare_and_normalize_class_versions(the_class, 937 scratch_class); 938 if (res != JVMTI_ERROR_NONE) { 939 return res; 940 } 941 942 // verify what the caller passed us 943 { 944 // The bug 6214132 caused the verification to fail. 945 // Information about the_class and scratch_class is temporarily 946 // recorded into jvmtiThreadState. This data is used to redirect 947 // the_class to scratch_class in the JVM_* functions called by the 948 // verifier. Please, refer to jvmtiThreadState.hpp for the detailed 949 // description. 950 RedefineVerifyMark rvm(&the_class, &scratch_class, state); 951 Verifier::verify( 952 scratch_class, Verifier::ThrowException, true, THREAD); 953 } 954 955 if (HAS_PENDING_EXCEPTION) { 956 Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); 957 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 958 RC_TRACE_WITH_THREAD(0x00000002, THREAD, 959 ("verify_byte_codes exception: '%s'", ex_name->as_C_string())); 960 CLEAR_PENDING_EXCEPTION; 961 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 962 return JVMTI_ERROR_OUT_OF_MEMORY; 963 } else { 964 // tell the caller the bytecodes are bad 965 return JVMTI_ERROR_FAILS_VERIFICATION; 966 } 967 } 968 969 res = merge_cp_and_rewrite(the_class, scratch_class, THREAD); 970 if (res != JVMTI_ERROR_NONE) { 971 return res; 972 } 973 974 if (VerifyMergedCPBytecodes) { 975 // verify what we have done during constant pool merging 976 { 977 RedefineVerifyMark rvm(&the_class, &scratch_class, state); 978 Verifier::verify(scratch_class, Verifier::ThrowException, true, THREAD); 979 } 980 981 if (HAS_PENDING_EXCEPTION) { 982 Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); 983 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 984 RC_TRACE_WITH_THREAD(0x00000002, THREAD, 985 ("verify_byte_codes post merge-CP exception: '%s'", 986 ex_name->as_C_string())); 987 CLEAR_PENDING_EXCEPTION; 988 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 989 return JVMTI_ERROR_OUT_OF_MEMORY; 990 } else { 991 // tell the caller that constant pool merging screwed up 992 return JVMTI_ERROR_INTERNAL; 993 } 994 } 995 } 996 997 Rewriter::rewrite(scratch_class, THREAD); 998 if (!HAS_PENDING_EXCEPTION) { 999 Rewriter::relocate_and_link(scratch_class, THREAD); 1000 } 1001 if (HAS_PENDING_EXCEPTION) { 1002 Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); 1003 CLEAR_PENDING_EXCEPTION; 1004 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 1005 return JVMTI_ERROR_OUT_OF_MEMORY; 1006 } else { 1007 return JVMTI_ERROR_INTERNAL; 1008 } 1009 } 1010 1011 _scratch_classes[i] = scratch_class; 1012 1013 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark 1014 RC_TRACE_WITH_THREAD(0x00000001, THREAD, 1015 ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)", 1016 the_class->external_name(), os::available_memory() >> 10)); 1017 } 1018 1019 return JVMTI_ERROR_NONE; 1020 } 1021 1022 1023 // Map old_index to new_index as needed. scratch_cp is only needed 1024 // for RC_TRACE() calls. 1025 void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp, 1026 int old_index, int new_index) { 1027 if (find_new_index(old_index) != 0) { 1028 // old_index is already mapped 1029 return; 1030 } 1031 1032 if (old_index == new_index) { 1033 // no mapping is needed 1034 return; 1035 } 1036 1037 _index_map_p->at_put(old_index, new_index); 1038 _index_map_count++; 1039 1040 RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d", 1041 scratch_cp->tag_at(old_index).value(), old_index, new_index)); 1042 } // end map_index() 1043 1044 1045 // Merge old_cp and scratch_cp and return the results of the merge via 1046 // merge_cp_p. The number of entries in *merge_cp_p is returned via 1047 // merge_cp_length_p. The entries in old_cp occupy the same locations 1048 // in *merge_cp_p. Also creates a map of indices from entries in 1049 // scratch_cp to the corresponding entry in *merge_cp_p. Index map 1050 // entries are only created for entries in scratch_cp that occupy a 1051 // different location in *merged_cp_p. 1052 bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp, 1053 constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p, 1054 int *merge_cp_length_p, TRAPS) { 1055 1056 if (merge_cp_p == NULL) { 1057 assert(false, "caller must provide scatch constantPool"); 1058 return false; // robustness 1059 } 1060 if (merge_cp_length_p == NULL) { 1061 assert(false, "caller must provide scatch CP length"); 1062 return false; // robustness 1063 } 1064 // Worst case we need old_cp->length() + scratch_cp()->length(), 1065 // but the caller might be smart so make sure we have at least 1066 // the minimum. 1067 if ((*merge_cp_p)->length() < old_cp->length()) { 1068 assert(false, "merge area too small"); 1069 return false; // robustness 1070 } 1071 1072 RC_TRACE_WITH_THREAD(0x00010000, THREAD, 1073 ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(), 1074 scratch_cp->length())); 1075 1076 { 1077 // Pass 0: 1078 // The old_cp is copied to *merge_cp_p; this means that any code 1079 // using old_cp does not have to change. This work looks like a 1080 // perfect fit for constantPoolOop::copy_cp_to(), but we need to 1081 // handle one special case: 1082 // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass 1083 // This will make verification happy. 1084 1085 int old_i; // index into old_cp 1086 1087 // index zero (0) is not used in constantPools 1088 for (old_i = 1; old_i < old_cp->length(); old_i++) { 1089 // leave debugging crumb 1090 jbyte old_tag = old_cp->tag_at(old_i).value(); 1091 switch (old_tag) { 1092 case JVM_CONSTANT_Class: 1093 case JVM_CONSTANT_UnresolvedClass: 1094 // revert the copy to JVM_CONSTANT_UnresolvedClass 1095 // May be resolving while calling this so do the same for 1096 // JVM_CONSTANT_UnresolvedClass (klass_name_at() deals with transition) 1097 (*merge_cp_p)->unresolved_klass_at_put(old_i, 1098 old_cp->klass_name_at(old_i)); 1099 break; 1100 1101 case JVM_CONSTANT_Double: 1102 case JVM_CONSTANT_Long: 1103 // just copy the entry to *merge_cp_p, but double and long take 1104 // two constant pool entries 1105 constantPoolOopDesc::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0); 1106 old_i++; 1107 break; 1108 1109 default: 1110 // just copy the entry to *merge_cp_p 1111 constantPoolOopDesc::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0); 1112 break; 1113 } 1114 } // end for each old_cp entry 1115 1116 // We don't need to sanity check that *merge_cp_length_p is within 1117 // *merge_cp_p bounds since we have the minimum on-entry check above. 1118 (*merge_cp_length_p) = old_i; 1119 } 1120 1121 // merge_cp_len should be the same as old_cp->length() at this point 1122 // so this trace message is really a "warm-and-breathing" message. 1123 RC_TRACE_WITH_THREAD(0x00020000, THREAD, 1124 ("after pass 0: merge_cp_len=%d", *merge_cp_length_p)); 1125 1126 int scratch_i; // index into scratch_cp 1127 { 1128 // Pass 1a: 1129 // Compare scratch_cp entries to the old_cp entries that we have 1130 // already copied to *merge_cp_p. In this pass, we are eliminating 1131 // exact duplicates (matching entry at same index) so we only 1132 // compare entries in the common indice range. 1133 int increment = 1; 1134 int pass1a_length = MIN2(old_cp->length(), scratch_cp->length()); 1135 for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) { 1136 switch (scratch_cp->tag_at(scratch_i).value()) { 1137 case JVM_CONSTANT_Double: 1138 case JVM_CONSTANT_Long: 1139 // double and long take two constant pool entries 1140 increment = 2; 1141 break; 1142 1143 default: 1144 increment = 1; 1145 break; 1146 } 1147 1148 bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p, 1149 scratch_i, CHECK_0); 1150 if (match) { 1151 // found a match at the same index so nothing more to do 1152 continue; 1153 } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i, 1154 *merge_cp_p, scratch_i)) { 1155 // The mismatch in compare_entry_to() above is because of a 1156 // resolved versus unresolved class entry at the same index 1157 // with the same string value. Since Pass 0 reverted any 1158 // class entries to unresolved class entries in *merge_cp_p, 1159 // we go with the unresolved class entry. 1160 continue; 1161 } else if (is_unresolved_string_mismatch(scratch_cp, scratch_i, 1162 *merge_cp_p, scratch_i)) { 1163 // The mismatch in compare_entry_to() above is because of a 1164 // resolved versus unresolved string entry at the same index 1165 // with the same string value. We can live with whichever 1166 // happens to be at scratch_i in *merge_cp_p. 1167 continue; 1168 } 1169 1170 int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, 1171 CHECK_0); 1172 if (found_i != 0) { 1173 guarantee(found_i != scratch_i, 1174 "compare_entry_to() and find_matching_entry() do not agree"); 1175 1176 // Found a matching entry somewhere else in *merge_cp_p so 1177 // just need a mapping entry. 1178 map_index(scratch_cp, scratch_i, found_i); 1179 continue; 1180 } 1181 1182 // The find_matching_entry() call above could fail to find a match 1183 // due to a resolved versus unresolved class or string entry situation 1184 // like we solved above with the is_unresolved_*_mismatch() calls. 1185 // However, we would have to call is_unresolved_*_mismatch() over 1186 // all of *merge_cp_p (potentially) and that doesn't seem to be 1187 // worth the time. 1188 1189 // No match found so we have to append this entry and any unique 1190 // referenced entries to *merge_cp_p. 1191 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p, 1192 CHECK_0); 1193 } 1194 } 1195 1196 RC_TRACE_WITH_THREAD(0x00020000, THREAD, 1197 ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d", 1198 *merge_cp_length_p, scratch_i, _index_map_count)); 1199 1200 if (scratch_i < scratch_cp->length()) { 1201 // Pass 1b: 1202 // old_cp is smaller than scratch_cp so there are entries in 1203 // scratch_cp that we have not yet processed. We take care of 1204 // those now. 1205 int increment = 1; 1206 for (; scratch_i < scratch_cp->length(); scratch_i += increment) { 1207 switch (scratch_cp->tag_at(scratch_i).value()) { 1208 case JVM_CONSTANT_Double: 1209 case JVM_CONSTANT_Long: 1210 // double and long take two constant pool entries 1211 increment = 2; 1212 break; 1213 1214 default: 1215 increment = 1; 1216 break; 1217 } 1218 1219 int found_i = 1220 scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0); 1221 if (found_i != 0) { 1222 // Found a matching entry somewhere else in *merge_cp_p so 1223 // just need a mapping entry. 1224 map_index(scratch_cp, scratch_i, found_i); 1225 continue; 1226 } 1227 1228 // No match found so we have to append this entry and any unique 1229 // referenced entries to *merge_cp_p. 1230 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p, 1231 CHECK_0); 1232 } 1233 1234 RC_TRACE_WITH_THREAD(0x00020000, THREAD, 1235 ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d", 1236 *merge_cp_length_p, scratch_i, _index_map_count)); 1237 } 1238 1239 return true; 1240 } // end merge_constant_pools() 1241 1242 1243 // Merge constant pools between the_class and scratch_class and 1244 // potentially rewrite bytecodes in scratch_class to use the merged 1245 // constant pool. 1246 jvmtiError VM_RedefineClasses::merge_cp_and_rewrite( 1247 instanceKlassHandle the_class, instanceKlassHandle scratch_class, 1248 TRAPS) { 1249 // worst case merged constant pool length is old and new combined 1250 int merge_cp_length = the_class->constants()->length() 1251 + scratch_class->constants()->length(); 1252 1253 constantPoolHandle old_cp(THREAD, the_class->constants()); 1254 constantPoolHandle scratch_cp(THREAD, scratch_class->constants()); 1255 1256 // Constant pools are not easily reused so we allocate a new one 1257 // each time. 1258 // merge_cp is created unsafe for concurrent GC processing. It 1259 // should be marked safe before discarding it. Even though 1260 // garbage, if it crosses a card boundary, it may be scanned 1261 // in order to find the start of the first complete object on the card. 1262 constantPoolHandle merge_cp(THREAD, 1263 oopFactory::new_constantPool(merge_cp_length, 1264 oopDesc::IsUnsafeConc, 1265 THREAD)); 1266 int orig_length = old_cp->orig_length(); 1267 if (orig_length == 0) { 1268 // This old_cp is an actual original constant pool. We save 1269 // the original length in the merged constant pool so that 1270 // merge_constant_pools() can be more efficient. If a constant 1271 // pool has a non-zero orig_length() value, then that constant 1272 // pool was created by a merge operation in RedefineClasses. 1273 merge_cp->set_orig_length(old_cp->length()); 1274 } else { 1275 // This old_cp is a merged constant pool from a previous 1276 // RedefineClasses() calls so just copy the orig_length() 1277 // value. 1278 merge_cp->set_orig_length(old_cp->orig_length()); 1279 } 1280 1281 ResourceMark rm(THREAD); 1282 _index_map_count = 0; 1283 _index_map_p = new intArray(scratch_cp->length(), -1); 1284 1285 bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp, 1286 &merge_cp_length, THREAD); 1287 if (!result) { 1288 // The merge can fail due to memory allocation failure or due 1289 // to robustness checks. 1290 return JVMTI_ERROR_INTERNAL; 1291 } 1292 1293 RC_TRACE_WITH_THREAD(0x00010000, THREAD, 1294 ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count)); 1295 1296 if (_index_map_count == 0) { 1297 // there is nothing to map between the new and merged constant pools 1298 1299 if (old_cp->length() == scratch_cp->length()) { 1300 // The old and new constant pools are the same length and the 1301 // index map is empty. This means that the three constant pools 1302 // are equivalent (but not the same). Unfortunately, the new 1303 // constant pool has not gone through link resolution nor have 1304 // the new class bytecodes gone through constant pool cache 1305 // rewriting so we can't use the old constant pool with the new 1306 // class. 1307 1308 merge_cp()->set_is_conc_safe(true); 1309 merge_cp = constantPoolHandle(); // toss the merged constant pool 1310 } else if (old_cp->length() < scratch_cp->length()) { 1311 // The old constant pool has fewer entries than the new constant 1312 // pool and the index map is empty. This means the new constant 1313 // pool is a superset of the old constant pool. However, the old 1314 // class bytecodes have already gone through constant pool cache 1315 // rewriting so we can't use the new constant pool with the old 1316 // class. 1317 1318 merge_cp()->set_is_conc_safe(true); 1319 merge_cp = constantPoolHandle(); // toss the merged constant pool 1320 } else { 1321 // The old constant pool has more entries than the new constant 1322 // pool and the index map is empty. This means that both the old 1323 // and merged constant pools are supersets of the new constant 1324 // pool. 1325 1326 // Replace the new constant pool with a shrunken copy of the 1327 // merged constant pool; the previous new constant pool will 1328 // get GCed. 1329 set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true, 1330 THREAD); 1331 // drop local ref to the merged constant pool 1332 merge_cp()->set_is_conc_safe(true); 1333 merge_cp = constantPoolHandle(); 1334 } 1335 } else { 1336 if (RC_TRACE_ENABLED(0x00040000)) { 1337 // don't want to loop unless we are tracing 1338 int count = 0; 1339 for (int i = 1; i < _index_map_p->length(); i++) { 1340 int value = _index_map_p->at(i); 1341 1342 if (value != -1) { 1343 RC_TRACE_WITH_THREAD(0x00040000, THREAD, 1344 ("index_map[%d]: old=%d new=%d", count, i, value)); 1345 count++; 1346 } 1347 } 1348 } 1349 1350 // We have entries mapped between the new and merged constant pools 1351 // so we have to rewrite some constant pool references. 1352 if (!rewrite_cp_refs(scratch_class, THREAD)) { 1353 return JVMTI_ERROR_INTERNAL; 1354 } 1355 1356 // Replace the new constant pool with a shrunken copy of the 1357 // merged constant pool so now the rewritten bytecodes have 1358 // valid references; the previous new constant pool will get 1359 // GCed. 1360 set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true, 1361 THREAD); 1362 merge_cp()->set_is_conc_safe(true); 1363 } 1364 assert(old_cp()->is_conc_safe(), "Just checking"); 1365 assert(scratch_cp()->is_conc_safe(), "Just checking"); 1366 1367 return JVMTI_ERROR_NONE; 1368 } // end merge_cp_and_rewrite() 1369 1370 1371 // Rewrite constant pool references in klass scratch_class. 1372 bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class, 1373 TRAPS) { 1374 1375 // rewrite constant pool references in the methods: 1376 if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) { 1377 // propagate failure back to caller 1378 return false; 1379 } 1380 1381 // rewrite constant pool references in the class_annotations: 1382 if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) { 1383 // propagate failure back to caller 1384 return false; 1385 } 1386 1387 // rewrite constant pool references in the fields_annotations: 1388 if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) { 1389 // propagate failure back to caller 1390 return false; 1391 } 1392 1393 // rewrite constant pool references in the methods_annotations: 1394 if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) { 1395 // propagate failure back to caller 1396 return false; 1397 } 1398 1399 // rewrite constant pool references in the methods_parameter_annotations: 1400 if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class, 1401 THREAD)) { 1402 // propagate failure back to caller 1403 return false; 1404 } 1405 1406 // rewrite constant pool references in the methods_default_annotations: 1407 if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class, 1408 THREAD)) { 1409 // propagate failure back to caller 1410 return false; 1411 } 1412 1413 return true; 1414 } // end rewrite_cp_refs() 1415 1416 1417 // Rewrite constant pool references in the methods. 1418 bool VM_RedefineClasses::rewrite_cp_refs_in_methods( 1419 instanceKlassHandle scratch_class, TRAPS) { 1420 1421 objArrayHandle methods(THREAD, scratch_class->methods()); 1422 1423 if (methods.is_null() || methods->length() == 0) { 1424 // no methods so nothing to do 1425 return true; 1426 } 1427 1428 // rewrite constant pool references in the methods: 1429 for (int i = methods->length() - 1; i >= 0; i--) { 1430 methodHandle method(THREAD, (methodOop)methods->obj_at(i)); 1431 methodHandle new_method; 1432 rewrite_cp_refs_in_method(method, &new_method, CHECK_false); 1433 if (!new_method.is_null()) { 1434 // the method has been replaced so save the new method version 1435 methods->obj_at_put(i, new_method()); 1436 } 1437 } 1438 1439 return true; 1440 } 1441 1442 1443 // Rewrite constant pool references in the specific method. This code 1444 // was adapted from Rewriter::rewrite_method(). 1445 void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method, 1446 methodHandle *new_method_p, TRAPS) { 1447 1448 *new_method_p = methodHandle(); // default is no new method 1449 1450 // We cache a pointer to the bytecodes here in code_base. If GC 1451 // moves the methodOop, then the bytecodes will also move which 1452 // will likely cause a crash. We create a No_Safepoint_Verifier 1453 // object to detect whether we pass a possible safepoint in this 1454 // code block. 1455 No_Safepoint_Verifier nsv; 1456 1457 // Bytecodes and their length 1458 address code_base = method->code_base(); 1459 int code_length = method->code_size(); 1460 1461 int bc_length; 1462 for (int bci = 0; bci < code_length; bci += bc_length) { 1463 address bcp = code_base + bci; 1464 Bytecodes::Code c = (Bytecodes::Code)(*bcp); 1465 1466 bc_length = Bytecodes::length_for(c); 1467 if (bc_length == 0) { 1468 // More complicated bytecodes report a length of zero so 1469 // we have to try again a slightly different way. 1470 bc_length = Bytecodes::length_at(method(), bcp); 1471 } 1472 1473 assert(bc_length != 0, "impossible bytecode length"); 1474 1475 switch (c) { 1476 case Bytecodes::_ldc: 1477 { 1478 int cp_index = *(bcp + 1); 1479 int new_index = find_new_index(cp_index); 1480 1481 if (StressLdcRewrite && new_index == 0) { 1482 // If we are stressing ldc -> ldc_w rewriting, then we 1483 // always need a new_index value. 1484 new_index = cp_index; 1485 } 1486 if (new_index != 0) { 1487 // the original index is mapped so we have more work to do 1488 if (!StressLdcRewrite && new_index <= max_jubyte) { 1489 // The new value can still use ldc instead of ldc_w 1490 // unless we are trying to stress ldc -> ldc_w rewriting 1491 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 1492 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c), 1493 bcp, cp_index, new_index)); 1494 *(bcp + 1) = new_index; 1495 } else { 1496 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 1497 ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d", 1498 Bytecodes::name(c), bcp, cp_index, new_index)); 1499 // the new value needs ldc_w instead of ldc 1500 u_char inst_buffer[4]; // max instruction size is 4 bytes 1501 bcp = (address)inst_buffer; 1502 // construct new instruction sequence 1503 *bcp = Bytecodes::_ldc_w; 1504 bcp++; 1505 // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w. 1506 // See comment below for difference between put_Java_u2() 1507 // and put_native_u2(). 1508 Bytes::put_Java_u2(bcp, new_index); 1509 1510 Relocator rc(method, NULL /* no RelocatorListener needed */); 1511 methodHandle m; 1512 { 1513 Pause_No_Safepoint_Verifier pnsv(&nsv); 1514 1515 // ldc is 2 bytes and ldc_w is 3 bytes 1516 m = rc.insert_space_at(bci, 3, inst_buffer, THREAD); 1517 if (m.is_null() || HAS_PENDING_EXCEPTION) { 1518 guarantee(false, "insert_space_at() failed"); 1519 } 1520 } 1521 1522 // return the new method so that the caller can update 1523 // the containing class 1524 *new_method_p = method = m; 1525 // switch our bytecode processing loop from the old method 1526 // to the new method 1527 code_base = method->code_base(); 1528 code_length = method->code_size(); 1529 bcp = code_base + bci; 1530 c = (Bytecodes::Code)(*bcp); 1531 bc_length = Bytecodes::length_for(c); 1532 assert(bc_length != 0, "sanity check"); 1533 } // end we need ldc_w instead of ldc 1534 } // end if there is a mapped index 1535 } break; 1536 1537 // these bytecodes have a two-byte constant pool index 1538 case Bytecodes::_anewarray : // fall through 1539 case Bytecodes::_checkcast : // fall through 1540 case Bytecodes::_getfield : // fall through 1541 case Bytecodes::_getstatic : // fall through 1542 case Bytecodes::_instanceof : // fall through 1543 case Bytecodes::_invokeinterface: // fall through 1544 case Bytecodes::_invokespecial : // fall through 1545 case Bytecodes::_invokestatic : // fall through 1546 case Bytecodes::_invokevirtual : // fall through 1547 case Bytecodes::_ldc_w : // fall through 1548 case Bytecodes::_ldc2_w : // fall through 1549 case Bytecodes::_multianewarray : // fall through 1550 case Bytecodes::_new : // fall through 1551 case Bytecodes::_putfield : // fall through 1552 case Bytecodes::_putstatic : 1553 { 1554 address p = bcp + 1; 1555 int cp_index = Bytes::get_Java_u2(p); 1556 int new_index = find_new_index(cp_index); 1557 if (new_index != 0) { 1558 // the original index is mapped so update w/ new value 1559 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 1560 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c), 1561 bcp, cp_index, new_index)); 1562 // Rewriter::rewrite_method() uses put_native_u2() in this 1563 // situation because it is reusing the constant pool index 1564 // location for a native index into the constantPoolCache. 1565 // Since we are updating the constant pool index prior to 1566 // verification and constantPoolCache initialization, we 1567 // need to keep the new index in Java byte order. 1568 Bytes::put_Java_u2(p, new_index); 1569 } 1570 } break; 1571 } 1572 } // end for each bytecode 1573 } // end rewrite_cp_refs_in_method() 1574 1575 1576 // Rewrite constant pool references in the class_annotations field. 1577 bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations( 1578 instanceKlassHandle scratch_class, TRAPS) { 1579 1580 typeArrayHandle class_annotations(THREAD, 1581 scratch_class->class_annotations()); 1582 if (class_annotations.is_null() || class_annotations->length() == 0) { 1583 // no class_annotations so nothing to do 1584 return true; 1585 } 1586 1587 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1588 ("class_annotations length=%d", class_annotations->length())); 1589 1590 int byte_i = 0; // byte index into class_annotations 1591 return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i, 1592 THREAD); 1593 } 1594 1595 1596 // Rewrite constant pool references in an annotations typeArray. This 1597 // "structure" is adapted from the RuntimeVisibleAnnotations_attribute 1598 // that is described in section 4.8.15 of the 2nd-edition of the VM spec: 1599 // 1600 // annotations_typeArray { 1601 // u2 num_annotations; 1602 // annotation annotations[num_annotations]; 1603 // } 1604 // 1605 bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray( 1606 typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) { 1607 1608 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1609 // not enough room for num_annotations field 1610 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1611 ("length() is too small for num_annotations field")); 1612 return false; 1613 } 1614 1615 u2 num_annotations = Bytes::get_Java_u2((address) 1616 annotations_typeArray->byte_at_addr(byte_i_ref)); 1617 byte_i_ref += 2; 1618 1619 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1620 ("num_annotations=%d", num_annotations)); 1621 1622 int calc_num_annotations = 0; 1623 for (; calc_num_annotations < num_annotations; calc_num_annotations++) { 1624 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray, 1625 byte_i_ref, THREAD)) { 1626 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1627 ("bad annotation_struct at %d", calc_num_annotations)); 1628 // propagate failure back to caller 1629 return false; 1630 } 1631 } 1632 assert(num_annotations == calc_num_annotations, "sanity check"); 1633 1634 return true; 1635 } // end rewrite_cp_refs_in_annotations_typeArray() 1636 1637 1638 // Rewrite constant pool references in the annotation struct portion of 1639 // an annotations_typeArray. This "structure" is from section 4.8.15 of 1640 // the 2nd-edition of the VM spec: 1641 // 1642 // struct annotation { 1643 // u2 type_index; 1644 // u2 num_element_value_pairs; 1645 // { 1646 // u2 element_name_index; 1647 // element_value value; 1648 // } element_value_pairs[num_element_value_pairs]; 1649 // } 1650 // 1651 bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct( 1652 typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) { 1653 if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) { 1654 // not enough room for smallest annotation_struct 1655 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1656 ("length() is too small for annotation_struct")); 1657 return false; 1658 } 1659 1660 u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray, 1661 byte_i_ref, "mapped old type_index=%d", THREAD); 1662 1663 u2 num_element_value_pairs = Bytes::get_Java_u2((address) 1664 annotations_typeArray->byte_at_addr( 1665 byte_i_ref)); 1666 byte_i_ref += 2; 1667 1668 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1669 ("type_index=%d num_element_value_pairs=%d", type_index, 1670 num_element_value_pairs)); 1671 1672 int calc_num_element_value_pairs = 0; 1673 for (; calc_num_element_value_pairs < num_element_value_pairs; 1674 calc_num_element_value_pairs++) { 1675 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1676 // not enough room for another element_name_index, let alone 1677 // the rest of another component 1678 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1679 ("length() is too small for element_name_index")); 1680 return false; 1681 } 1682 1683 u2 element_name_index = rewrite_cp_ref_in_annotation_data( 1684 annotations_typeArray, byte_i_ref, 1685 "mapped old element_name_index=%d", THREAD); 1686 1687 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1688 ("element_name_index=%d", element_name_index)); 1689 1690 if (!rewrite_cp_refs_in_element_value(annotations_typeArray, 1691 byte_i_ref, THREAD)) { 1692 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1693 ("bad element_value at %d", calc_num_element_value_pairs)); 1694 // propagate failure back to caller 1695 return false; 1696 } 1697 } // end for each component 1698 assert(num_element_value_pairs == calc_num_element_value_pairs, 1699 "sanity check"); 1700 1701 return true; 1702 } // end rewrite_cp_refs_in_annotation_struct() 1703 1704 1705 // Rewrite a constant pool reference at the current position in 1706 // annotations_typeArray if needed. Returns the original constant 1707 // pool reference if a rewrite was not needed or the new constant 1708 // pool reference if a rewrite was needed. 1709 u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data( 1710 typeArrayHandle annotations_typeArray, int &byte_i_ref, 1711 const char * trace_mesg, TRAPS) { 1712 1713 address cp_index_addr = (address) 1714 annotations_typeArray->byte_at_addr(byte_i_ref); 1715 u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr); 1716 u2 new_cp_index = find_new_index(old_cp_index); 1717 if (new_cp_index != 0) { 1718 RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index)); 1719 Bytes::put_Java_u2(cp_index_addr, new_cp_index); 1720 old_cp_index = new_cp_index; 1721 } 1722 byte_i_ref += 2; 1723 return old_cp_index; 1724 } 1725 1726 1727 // Rewrite constant pool references in the element_value portion of an 1728 // annotations_typeArray. This "structure" is from section 4.8.15.1 of 1729 // the 2nd-edition of the VM spec: 1730 // 1731 // struct element_value { 1732 // u1 tag; 1733 // union { 1734 // u2 const_value_index; 1735 // { 1736 // u2 type_name_index; 1737 // u2 const_name_index; 1738 // } enum_const_value; 1739 // u2 class_info_index; 1740 // annotation annotation_value; 1741 // struct { 1742 // u2 num_values; 1743 // element_value values[num_values]; 1744 // } array_value; 1745 // } value; 1746 // } 1747 // 1748 bool VM_RedefineClasses::rewrite_cp_refs_in_element_value( 1749 typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) { 1750 1751 if ((byte_i_ref + 1) > annotations_typeArray->length()) { 1752 // not enough room for a tag let alone the rest of an element_value 1753 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1754 ("length() is too small for a tag")); 1755 return false; 1756 } 1757 1758 u1 tag = annotations_typeArray->byte_at(byte_i_ref); 1759 byte_i_ref++; 1760 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag)); 1761 1762 switch (tag) { 1763 // These BaseType tag values are from Table 4.2 in VM spec: 1764 case 'B': // byte 1765 case 'C': // char 1766 case 'D': // double 1767 case 'F': // float 1768 case 'I': // int 1769 case 'J': // long 1770 case 'S': // short 1771 case 'Z': // boolean 1772 1773 // The remaining tag values are from Table 4.8 in the 2nd-edition of 1774 // the VM spec: 1775 case 's': 1776 { 1777 // For the above tag values (including the BaseType values), 1778 // value.const_value_index is right union field. 1779 1780 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1781 // not enough room for a const_value_index 1782 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1783 ("length() is too small for a const_value_index")); 1784 return false; 1785 } 1786 1787 u2 const_value_index = rewrite_cp_ref_in_annotation_data( 1788 annotations_typeArray, byte_i_ref, 1789 "mapped old const_value_index=%d", THREAD); 1790 1791 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1792 ("const_value_index=%d", const_value_index)); 1793 } break; 1794 1795 case 'e': 1796 { 1797 // for the above tag value, value.enum_const_value is right union field 1798 1799 if ((byte_i_ref + 4) > annotations_typeArray->length()) { 1800 // not enough room for a enum_const_value 1801 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1802 ("length() is too small for a enum_const_value")); 1803 return false; 1804 } 1805 1806 u2 type_name_index = rewrite_cp_ref_in_annotation_data( 1807 annotations_typeArray, byte_i_ref, 1808 "mapped old type_name_index=%d", THREAD); 1809 1810 u2 const_name_index = rewrite_cp_ref_in_annotation_data( 1811 annotations_typeArray, byte_i_ref, 1812 "mapped old const_name_index=%d", THREAD); 1813 1814 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1815 ("type_name_index=%d const_name_index=%d", type_name_index, 1816 const_name_index)); 1817 } break; 1818 1819 case 'c': 1820 { 1821 // for the above tag value, value.class_info_index is right union field 1822 1823 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1824 // not enough room for a class_info_index 1825 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1826 ("length() is too small for a class_info_index")); 1827 return false; 1828 } 1829 1830 u2 class_info_index = rewrite_cp_ref_in_annotation_data( 1831 annotations_typeArray, byte_i_ref, 1832 "mapped old class_info_index=%d", THREAD); 1833 1834 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1835 ("class_info_index=%d", class_info_index)); 1836 } break; 1837 1838 case '@': 1839 // For the above tag value, value.attr_value is the right union 1840 // field. This is a nested annotation. 1841 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray, 1842 byte_i_ref, THREAD)) { 1843 // propagate failure back to caller 1844 return false; 1845 } 1846 break; 1847 1848 case '[': 1849 { 1850 if ((byte_i_ref + 2) > annotations_typeArray->length()) { 1851 // not enough room for a num_values field 1852 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1853 ("length() is too small for a num_values field")); 1854 return false; 1855 } 1856 1857 // For the above tag value, value.array_value is the right union 1858 // field. This is an array of nested element_value. 1859 u2 num_values = Bytes::get_Java_u2((address) 1860 annotations_typeArray->byte_at_addr(byte_i_ref)); 1861 byte_i_ref += 2; 1862 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values)); 1863 1864 int calc_num_values = 0; 1865 for (; calc_num_values < num_values; calc_num_values++) { 1866 if (!rewrite_cp_refs_in_element_value( 1867 annotations_typeArray, byte_i_ref, THREAD)) { 1868 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1869 ("bad nested element_value at %d", calc_num_values)); 1870 // propagate failure back to caller 1871 return false; 1872 } 1873 } 1874 assert(num_values == calc_num_values, "sanity check"); 1875 } break; 1876 1877 default: 1878 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag)); 1879 return false; 1880 } // end decode tag field 1881 1882 return true; 1883 } // end rewrite_cp_refs_in_element_value() 1884 1885 1886 // Rewrite constant pool references in a fields_annotations field. 1887 bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations( 1888 instanceKlassHandle scratch_class, TRAPS) { 1889 1890 objArrayHandle fields_annotations(THREAD, 1891 scratch_class->fields_annotations()); 1892 1893 if (fields_annotations.is_null() || fields_annotations->length() == 0) { 1894 // no fields_annotations so nothing to do 1895 return true; 1896 } 1897 1898 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1899 ("fields_annotations length=%d", fields_annotations->length())); 1900 1901 for (int i = 0; i < fields_annotations->length(); i++) { 1902 typeArrayHandle field_annotations(THREAD, 1903 (typeArrayOop)fields_annotations->obj_at(i)); 1904 if (field_annotations.is_null() || field_annotations->length() == 0) { 1905 // this field does not have any annotations so skip it 1906 continue; 1907 } 1908 1909 int byte_i = 0; // byte index into field_annotations 1910 if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i, 1911 THREAD)) { 1912 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1913 ("bad field_annotations at %d", i)); 1914 // propagate failure back to caller 1915 return false; 1916 } 1917 } 1918 1919 return true; 1920 } // end rewrite_cp_refs_in_fields_annotations() 1921 1922 1923 // Rewrite constant pool references in a methods_annotations field. 1924 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations( 1925 instanceKlassHandle scratch_class, TRAPS) { 1926 1927 objArrayHandle methods_annotations(THREAD, 1928 scratch_class->methods_annotations()); 1929 1930 if (methods_annotations.is_null() || methods_annotations->length() == 0) { 1931 // no methods_annotations so nothing to do 1932 return true; 1933 } 1934 1935 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1936 ("methods_annotations length=%d", methods_annotations->length())); 1937 1938 for (int i = 0; i < methods_annotations->length(); i++) { 1939 typeArrayHandle method_annotations(THREAD, 1940 (typeArrayOop)methods_annotations->obj_at(i)); 1941 if (method_annotations.is_null() || method_annotations->length() == 0) { 1942 // this method does not have any annotations so skip it 1943 continue; 1944 } 1945 1946 int byte_i = 0; // byte index into method_annotations 1947 if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i, 1948 THREAD)) { 1949 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1950 ("bad method_annotations at %d", i)); 1951 // propagate failure back to caller 1952 return false; 1953 } 1954 } 1955 1956 return true; 1957 } // end rewrite_cp_refs_in_methods_annotations() 1958 1959 1960 // Rewrite constant pool references in a methods_parameter_annotations 1961 // field. This "structure" is adapted from the 1962 // RuntimeVisibleParameterAnnotations_attribute described in section 1963 // 4.8.17 of the 2nd-edition of the VM spec: 1964 // 1965 // methods_parameter_annotations_typeArray { 1966 // u1 num_parameters; 1967 // { 1968 // u2 num_annotations; 1969 // annotation annotations[num_annotations]; 1970 // } parameter_annotations[num_parameters]; 1971 // } 1972 // 1973 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations( 1974 instanceKlassHandle scratch_class, TRAPS) { 1975 1976 objArrayHandle methods_parameter_annotations(THREAD, 1977 scratch_class->methods_parameter_annotations()); 1978 1979 if (methods_parameter_annotations.is_null() 1980 || methods_parameter_annotations->length() == 0) { 1981 // no methods_parameter_annotations so nothing to do 1982 return true; 1983 } 1984 1985 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 1986 ("methods_parameter_annotations length=%d", 1987 methods_parameter_annotations->length())); 1988 1989 for (int i = 0; i < methods_parameter_annotations->length(); i++) { 1990 typeArrayHandle method_parameter_annotations(THREAD, 1991 (typeArrayOop)methods_parameter_annotations->obj_at(i)); 1992 if (method_parameter_annotations.is_null() 1993 || method_parameter_annotations->length() == 0) { 1994 // this method does not have any parameter annotations so skip it 1995 continue; 1996 } 1997 1998 if (method_parameter_annotations->length() < 1) { 1999 // not enough room for a num_parameters field 2000 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2001 ("length() is too small for a num_parameters field at %d", i)); 2002 return false; 2003 } 2004 2005 int byte_i = 0; // byte index into method_parameter_annotations 2006 2007 u1 num_parameters = method_parameter_annotations->byte_at(byte_i); 2008 byte_i++; 2009 2010 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2011 ("num_parameters=%d", num_parameters)); 2012 2013 int calc_num_parameters = 0; 2014 for (; calc_num_parameters < num_parameters; calc_num_parameters++) { 2015 if (!rewrite_cp_refs_in_annotations_typeArray( 2016 method_parameter_annotations, byte_i, THREAD)) { 2017 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2018 ("bad method_parameter_annotations at %d", calc_num_parameters)); 2019 // propagate failure back to caller 2020 return false; 2021 } 2022 } 2023 assert(num_parameters == calc_num_parameters, "sanity check"); 2024 } 2025 2026 return true; 2027 } // end rewrite_cp_refs_in_methods_parameter_annotations() 2028 2029 2030 // Rewrite constant pool references in a methods_default_annotations 2031 // field. This "structure" is adapted from the AnnotationDefault_attribute 2032 // that is described in section 4.8.19 of the 2nd-edition of the VM spec: 2033 // 2034 // methods_default_annotations_typeArray { 2035 // element_value default_value; 2036 // } 2037 // 2038 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations( 2039 instanceKlassHandle scratch_class, TRAPS) { 2040 2041 objArrayHandle methods_default_annotations(THREAD, 2042 scratch_class->methods_default_annotations()); 2043 2044 if (methods_default_annotations.is_null() 2045 || methods_default_annotations->length() == 0) { 2046 // no methods_default_annotations so nothing to do 2047 return true; 2048 } 2049 2050 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2051 ("methods_default_annotations length=%d", 2052 methods_default_annotations->length())); 2053 2054 for (int i = 0; i < methods_default_annotations->length(); i++) { 2055 typeArrayHandle method_default_annotations(THREAD, 2056 (typeArrayOop)methods_default_annotations->obj_at(i)); 2057 if (method_default_annotations.is_null() 2058 || method_default_annotations->length() == 0) { 2059 // this method does not have any default annotations so skip it 2060 continue; 2061 } 2062 2063 int byte_i = 0; // byte index into method_default_annotations 2064 2065 if (!rewrite_cp_refs_in_element_value( 2066 method_default_annotations, byte_i, THREAD)) { 2067 RC_TRACE_WITH_THREAD(0x02000000, THREAD, 2068 ("bad default element_value at %d", i)); 2069 // propagate failure back to caller 2070 return false; 2071 } 2072 } 2073 2074 return true; 2075 } // end rewrite_cp_refs_in_methods_default_annotations() 2076 2077 2078 // Rewrite constant pool references in the method's stackmap table. 2079 // These "structures" are adapted from the StackMapTable_attribute that 2080 // is described in section 4.8.4 of the 6.0 version of the VM spec 2081 // (dated 2005.10.26): 2082 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf 2083 // 2084 // stack_map { 2085 // u2 number_of_entries; 2086 // stack_map_frame entries[number_of_entries]; 2087 // } 2088 // 2089 void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table( 2090 methodHandle method, TRAPS) { 2091 2092 if (!method->has_stackmap_table()) { 2093 return; 2094 } 2095 2096 typeArrayOop stackmap_data = method->stackmap_data(); 2097 address stackmap_p = (address)stackmap_data->byte_at_addr(0); 2098 address stackmap_end = stackmap_p + stackmap_data->length(); 2099 2100 assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries"); 2101 u2 number_of_entries = Bytes::get_Java_u2(stackmap_p); 2102 stackmap_p += 2; 2103 2104 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2105 ("number_of_entries=%u", number_of_entries)); 2106 2107 // walk through each stack_map_frame 2108 u2 calc_number_of_entries = 0; 2109 for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) { 2110 // The stack_map_frame structure is a u1 frame_type followed by 2111 // 0 or more bytes of data: 2112 // 2113 // union stack_map_frame { 2114 // same_frame; 2115 // same_locals_1_stack_item_frame; 2116 // same_locals_1_stack_item_frame_extended; 2117 // chop_frame; 2118 // same_frame_extended; 2119 // append_frame; 2120 // full_frame; 2121 // } 2122 2123 assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type"); 2124 // The Linux compiler does not like frame_type to be u1 or u2. It 2125 // issues the following warning for the first if-statement below: 2126 // 2127 // "warning: comparison is always true due to limited range of data type" 2128 // 2129 u4 frame_type = *stackmap_p; 2130 stackmap_p++; 2131 2132 // same_frame { 2133 // u1 frame_type = SAME; /* 0-63 */ 2134 // } 2135 if (frame_type >= 0 && frame_type <= 63) { 2136 // nothing more to do for same_frame 2137 } 2138 2139 // same_locals_1_stack_item_frame { 2140 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */ 2141 // verification_type_info stack[1]; 2142 // } 2143 else if (frame_type >= 64 && frame_type <= 127) { 2144 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2145 calc_number_of_entries, frame_type, THREAD); 2146 } 2147 2148 // reserved for future use 2149 else if (frame_type >= 128 && frame_type <= 246) { 2150 // nothing more to do for reserved frame_types 2151 } 2152 2153 // same_locals_1_stack_item_frame_extended { 2154 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */ 2155 // u2 offset_delta; 2156 // verification_type_info stack[1]; 2157 // } 2158 else if (frame_type == 247) { 2159 stackmap_p += 2; 2160 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2161 calc_number_of_entries, frame_type, THREAD); 2162 } 2163 2164 // chop_frame { 2165 // u1 frame_type = CHOP; /* 248-250 */ 2166 // u2 offset_delta; 2167 // } 2168 else if (frame_type >= 248 && frame_type <= 250) { 2169 stackmap_p += 2; 2170 } 2171 2172 // same_frame_extended { 2173 // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/ 2174 // u2 offset_delta; 2175 // } 2176 else if (frame_type == 251) { 2177 stackmap_p += 2; 2178 } 2179 2180 // append_frame { 2181 // u1 frame_type = APPEND; /* 252-254 */ 2182 // u2 offset_delta; 2183 // verification_type_info locals[frame_type - 251]; 2184 // } 2185 else if (frame_type >= 252 && frame_type <= 254) { 2186 assert(stackmap_p + 2 <= stackmap_end, 2187 "no room for offset_delta"); 2188 stackmap_p += 2; 2189 u1 len = frame_type - 251; 2190 for (u1 i = 0; i < len; i++) { 2191 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2192 calc_number_of_entries, frame_type, THREAD); 2193 } 2194 } 2195 2196 // full_frame { 2197 // u1 frame_type = FULL_FRAME; /* 255 */ 2198 // u2 offset_delta; 2199 // u2 number_of_locals; 2200 // verification_type_info locals[number_of_locals]; 2201 // u2 number_of_stack_items; 2202 // verification_type_info stack[number_of_stack_items]; 2203 // } 2204 else if (frame_type == 255) { 2205 assert(stackmap_p + 2 + 2 <= stackmap_end, 2206 "no room for smallest full_frame"); 2207 stackmap_p += 2; 2208 2209 u2 number_of_locals = Bytes::get_Java_u2(stackmap_p); 2210 stackmap_p += 2; 2211 2212 for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) { 2213 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2214 calc_number_of_entries, frame_type, THREAD); 2215 } 2216 2217 // Use the largest size for the number_of_stack_items, but only get 2218 // the right number of bytes. 2219 u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p); 2220 stackmap_p += 2; 2221 2222 for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) { 2223 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, 2224 calc_number_of_entries, frame_type, THREAD); 2225 } 2226 } 2227 } // end while there is a stack_map_frame 2228 assert(number_of_entries == calc_number_of_entries, "sanity check"); 2229 } // end rewrite_cp_refs_in_stack_map_table() 2230 2231 2232 // Rewrite constant pool references in the verification type info 2233 // portion of the method's stackmap table. These "structures" are 2234 // adapted from the StackMapTable_attribute that is described in 2235 // section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26): 2236 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf 2237 // 2238 // The verification_type_info structure is a u1 tag followed by 0 or 2239 // more bytes of data: 2240 // 2241 // union verification_type_info { 2242 // Top_variable_info; 2243 // Integer_variable_info; 2244 // Float_variable_info; 2245 // Long_variable_info; 2246 // Double_variable_info; 2247 // Null_variable_info; 2248 // UninitializedThis_variable_info; 2249 // Object_variable_info; 2250 // Uninitialized_variable_info; 2251 // } 2252 // 2253 void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info( 2254 address& stackmap_p_ref, address stackmap_end, u2 frame_i, 2255 u1 frame_type, TRAPS) { 2256 2257 assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag"); 2258 u1 tag = *stackmap_p_ref; 2259 stackmap_p_ref++; 2260 2261 switch (tag) { 2262 // Top_variable_info { 2263 // u1 tag = ITEM_Top; /* 0 */ 2264 // } 2265 // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top 2266 case 0: // fall through 2267 2268 // Integer_variable_info { 2269 // u1 tag = ITEM_Integer; /* 1 */ 2270 // } 2271 case ITEM_Integer: // fall through 2272 2273 // Float_variable_info { 2274 // u1 tag = ITEM_Float; /* 2 */ 2275 // } 2276 case ITEM_Float: // fall through 2277 2278 // Double_variable_info { 2279 // u1 tag = ITEM_Double; /* 3 */ 2280 // } 2281 case ITEM_Double: // fall through 2282 2283 // Long_variable_info { 2284 // u1 tag = ITEM_Long; /* 4 */ 2285 // } 2286 case ITEM_Long: // fall through 2287 2288 // Null_variable_info { 2289 // u1 tag = ITEM_Null; /* 5 */ 2290 // } 2291 case ITEM_Null: // fall through 2292 2293 // UninitializedThis_variable_info { 2294 // u1 tag = ITEM_UninitializedThis; /* 6 */ 2295 // } 2296 case ITEM_UninitializedThis: 2297 // nothing more to do for the above tag types 2298 break; 2299 2300 // Object_variable_info { 2301 // u1 tag = ITEM_Object; /* 7 */ 2302 // u2 cpool_index; 2303 // } 2304 case ITEM_Object: 2305 { 2306 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index"); 2307 u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref); 2308 u2 new_cp_index = find_new_index(cpool_index); 2309 if (new_cp_index != 0) { 2310 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2311 ("mapped old cpool_index=%d", cpool_index)); 2312 Bytes::put_Java_u2(stackmap_p_ref, new_cp_index); 2313 cpool_index = new_cp_index; 2314 } 2315 stackmap_p_ref += 2; 2316 2317 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2318 ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i, 2319 frame_type, cpool_index)); 2320 } break; 2321 2322 // Uninitialized_variable_info { 2323 // u1 tag = ITEM_Uninitialized; /* 8 */ 2324 // u2 offset; 2325 // } 2326 case ITEM_Uninitialized: 2327 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset"); 2328 stackmap_p_ref += 2; 2329 break; 2330 2331 default: 2332 RC_TRACE_WITH_THREAD(0x04000000, THREAD, 2333 ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag)); 2334 ShouldNotReachHere(); 2335 break; 2336 } // end switch (tag) 2337 } // end rewrite_cp_refs_in_verification_type_info() 2338 2339 2340 // Change the constant pool associated with klass scratch_class to 2341 // scratch_cp. If shrink is true, then scratch_cp_length elements 2342 // are copied from scratch_cp to a smaller constant pool and the 2343 // smaller constant pool is associated with scratch_class. 2344 void VM_RedefineClasses::set_new_constant_pool( 2345 instanceKlassHandle scratch_class, constantPoolHandle scratch_cp, 2346 int scratch_cp_length, bool shrink, TRAPS) { 2347 assert(!shrink || scratch_cp->length() >= scratch_cp_length, "sanity check"); 2348 2349 if (shrink) { 2350 // scratch_cp is a merged constant pool and has enough space for a 2351 // worst case merge situation. We want to associate the minimum 2352 // sized constant pool with the klass to save space. 2353 constantPoolHandle smaller_cp(THREAD, 2354 oopFactory::new_constantPool(scratch_cp_length, 2355 oopDesc::IsUnsafeConc, 2356 THREAD)); 2357 // preserve orig_length() value in the smaller copy 2358 int orig_length = scratch_cp->orig_length(); 2359 assert(orig_length != 0, "sanity check"); 2360 smaller_cp->set_orig_length(orig_length); 2361 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD); 2362 scratch_cp = smaller_cp; 2363 smaller_cp()->set_is_conc_safe(true); 2364 } 2365 2366 // attach new constant pool to klass 2367 scratch_cp->set_pool_holder(scratch_class()); 2368 2369 // attach klass to new constant pool 2370 scratch_class->set_constants(scratch_cp()); 2371 2372 int i; // for portability 2373 2374 // update each field in klass to use new constant pool indices as needed 2375 for (JavaFieldStream fs(scratch_class); !fs.done(); fs.next()) { 2376 jshort cur_index = fs.name_index(); 2377 jshort new_index = find_new_index(cur_index); 2378 if (new_index != 0) { 2379 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2380 ("field-name_index change: %d to %d", cur_index, new_index)); 2381 fs.set_name_index(new_index); 2382 } 2383 cur_index = fs.signature_index(); 2384 new_index = find_new_index(cur_index); 2385 if (new_index != 0) { 2386 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2387 ("field-signature_index change: %d to %d", cur_index, new_index)); 2388 fs.set_signature_index(new_index); 2389 } 2390 cur_index = fs.initval_index(); 2391 new_index = find_new_index(cur_index); 2392 if (new_index != 0) { 2393 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2394 ("field-initval_index change: %d to %d", cur_index, new_index)); 2395 fs.set_initval_index(new_index); 2396 } 2397 cur_index = fs.generic_signature_index(); 2398 new_index = find_new_index(cur_index); 2399 if (new_index != 0) { 2400 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2401 ("field-generic_signature change: %d to %d", cur_index, new_index)); 2402 fs.set_generic_signature_index(new_index); 2403 } 2404 } // end for each field 2405 2406 // Update constant pool indices in the inner classes info to use 2407 // new constant indices as needed. The inner classes info is a 2408 // quadruple: 2409 // (inner_class_info, outer_class_info, inner_name, inner_access_flags) 2410 InnerClassesIterator iter(scratch_class); 2411 for (; !iter.done(); iter.next()) { 2412 int cur_index = iter.inner_class_info_index(); 2413 if (cur_index == 0) { 2414 continue; // JVM spec. allows null inner class refs so skip it 2415 } 2416 int new_index = find_new_index(cur_index); 2417 if (new_index != 0) { 2418 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2419 ("inner_class_info change: %d to %d", cur_index, new_index)); 2420 iter.set_inner_class_info_index(new_index); 2421 } 2422 cur_index = iter.outer_class_info_index(); 2423 new_index = find_new_index(cur_index); 2424 if (new_index != 0) { 2425 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2426 ("outer_class_info change: %d to %d", cur_index, new_index)); 2427 iter.set_outer_class_info_index(new_index); 2428 } 2429 cur_index = iter.inner_name_index(); 2430 new_index = find_new_index(cur_index); 2431 if (new_index != 0) { 2432 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2433 ("inner_name change: %d to %d", cur_index, new_index)); 2434 iter.set_inner_name_index(new_index); 2435 } 2436 } // end for each inner class 2437 2438 // Attach each method in klass to the new constant pool and update 2439 // to use new constant pool indices as needed: 2440 objArrayHandle methods(THREAD, scratch_class->methods()); 2441 for (i = methods->length() - 1; i >= 0; i--) { 2442 methodHandle method(THREAD, (methodOop)methods->obj_at(i)); 2443 method->set_constants(scratch_cp()); 2444 2445 int new_index = find_new_index(method->name_index()); 2446 if (new_index != 0) { 2447 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2448 ("method-name_index change: %d to %d", method->name_index(), 2449 new_index)); 2450 method->set_name_index(new_index); 2451 } 2452 new_index = find_new_index(method->signature_index()); 2453 if (new_index != 0) { 2454 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2455 ("method-signature_index change: %d to %d", 2456 method->signature_index(), new_index)); 2457 method->set_signature_index(new_index); 2458 } 2459 new_index = find_new_index(method->generic_signature_index()); 2460 if (new_index != 0) { 2461 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2462 ("method-generic_signature_index change: %d to %d", 2463 method->generic_signature_index(), new_index)); 2464 method->set_generic_signature_index(new_index); 2465 } 2466 2467 // Update constant pool indices in the method's checked exception 2468 // table to use new constant indices as needed. 2469 int cext_length = method->checked_exceptions_length(); 2470 if (cext_length > 0) { 2471 CheckedExceptionElement * cext_table = 2472 method->checked_exceptions_start(); 2473 for (int j = 0; j < cext_length; j++) { 2474 int cur_index = cext_table[j].class_cp_index; 2475 int new_index = find_new_index(cur_index); 2476 if (new_index != 0) { 2477 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2478 ("cext-class_cp_index change: %d to %d", cur_index, new_index)); 2479 cext_table[j].class_cp_index = (u2)new_index; 2480 } 2481 } // end for each checked exception table entry 2482 } // end if there are checked exception table entries 2483 2484 // Update each catch type index in the method's exception table 2485 // to use new constant pool indices as needed. The exception table 2486 // holds quadruple entries of the form: 2487 // (beg_bci, end_bci, handler_bci, klass_index) 2488 2489 ExceptionTable ex_table(method()); 2490 int ext_length = ex_table.length(); 2491 2492 for (int j = 0; j < ext_length; j ++) { 2493 int cur_index = ex_table.catch_type_index(j); 2494 int new_index = find_new_index(cur_index); 2495 if (new_index != 0) { 2496 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2497 ("ext-klass_index change: %d to %d", cur_index, new_index)); 2498 ex_table.set_catch_type_index(j, new_index); 2499 } 2500 } // end for each exception table entry 2501 2502 // Update constant pool indices in the method's local variable 2503 // table to use new constant indices as needed. The local variable 2504 // table hold sextuple entries of the form: 2505 // (start_pc, length, name_index, descriptor_index, signature_index, slot) 2506 int lvt_length = method->localvariable_table_length(); 2507 if (lvt_length > 0) { 2508 LocalVariableTableElement * lv_table = 2509 method->localvariable_table_start(); 2510 for (int j = 0; j < lvt_length; j++) { 2511 int cur_index = lv_table[j].name_cp_index; 2512 int new_index = find_new_index(cur_index); 2513 if (new_index != 0) { 2514 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2515 ("lvt-name_cp_index change: %d to %d", cur_index, new_index)); 2516 lv_table[j].name_cp_index = (u2)new_index; 2517 } 2518 cur_index = lv_table[j].descriptor_cp_index; 2519 new_index = find_new_index(cur_index); 2520 if (new_index != 0) { 2521 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2522 ("lvt-descriptor_cp_index change: %d to %d", cur_index, 2523 new_index)); 2524 lv_table[j].descriptor_cp_index = (u2)new_index; 2525 } 2526 cur_index = lv_table[j].signature_cp_index; 2527 new_index = find_new_index(cur_index); 2528 if (new_index != 0) { 2529 RC_TRACE_WITH_THREAD(0x00080000, THREAD, 2530 ("lvt-signature_cp_index change: %d to %d", cur_index, new_index)); 2531 lv_table[j].signature_cp_index = (u2)new_index; 2532 } 2533 } // end for each local variable table entry 2534 } // end if there are local variable table entries 2535 2536 rewrite_cp_refs_in_stack_map_table(method, THREAD); 2537 } // end for each method 2538 assert(scratch_cp()->is_conc_safe(), "Just checking"); 2539 } // end set_new_constant_pool() 2540 2541 2542 // Unevolving classes may point to methods of the_class directly 2543 // from their constant pool caches, itables, and/or vtables. We 2544 // use the SystemDictionary::classes_do() facility and this helper 2545 // to fix up these pointers. 2546 // 2547 // Note: We currently don't support updating the vtable in 2548 // arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp. 2549 void VM_RedefineClasses::adjust_cpool_cache_and_vtable(klassOop k_oop, 2550 oop initiating_loader, TRAPS) { 2551 Klass *k = k_oop->klass_part(); 2552 if (k->oop_is_instance()) { 2553 HandleMark hm(THREAD); 2554 instanceKlass *ik = (instanceKlass *) k; 2555 2556 // HotSpot specific optimization! HotSpot does not currently 2557 // support delegation from the bootstrap class loader to a 2558 // user-defined class loader. This means that if the bootstrap 2559 // class loader is the initiating class loader, then it will also 2560 // be the defining class loader. This also means that classes 2561 // loaded by the bootstrap class loader cannot refer to classes 2562 // loaded by a user-defined class loader. Note: a user-defined 2563 // class loader can delegate to the bootstrap class loader. 2564 // 2565 // If the current class being redefined has a user-defined class 2566 // loader as its defining class loader, then we can skip all 2567 // classes loaded by the bootstrap class loader. 2568 bool is_user_defined = 2569 instanceKlass::cast(_the_class_oop)->class_loader() != NULL; 2570 if (is_user_defined && ik->class_loader() == NULL) { 2571 return; 2572 } 2573 2574 // This is a very busy routine. We don't want too much tracing 2575 // printed out. 2576 bool trace_name_printed = false; 2577 2578 // Very noisy: only enable this call if you are trying to determine 2579 // that a specific class gets found by this routine. 2580 // RC_TRACE macro has an embedded ResourceMark 2581 // RC_TRACE_WITH_THREAD(0x00100000, THREAD, 2582 // ("adjust check: name=%s", ik->external_name())); 2583 // trace_name_printed = true; 2584 2585 // Fix the vtable embedded in the_class and subclasses of the_class, 2586 // if one exists. We discard scratch_class and we don't keep an 2587 // instanceKlass around to hold obsolete methods so we don't have 2588 // any other instanceKlass embedded vtables to update. The vtable 2589 // holds the methodOops for virtual (but not final) methods. 2590 if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) { 2591 // ik->vtable() creates a wrapper object; rm cleans it up 2592 ResourceMark rm(THREAD); 2593 ik->vtable()->adjust_method_entries(_matching_old_methods, 2594 _matching_new_methods, 2595 _matching_methods_length, 2596 &trace_name_printed); 2597 } 2598 2599 // If the current class has an itable and we are either redefining an 2600 // interface or if the current class is a subclass of the_class, then 2601 // we potentially have to fix the itable. If we are redefining an 2602 // interface, then we have to call adjust_method_entries() for 2603 // every instanceKlass that has an itable since there isn't a 2604 // subclass relationship between an interface and an instanceKlass. 2605 if (ik->itable_length() > 0 && (Klass::cast(_the_class_oop)->is_interface() 2606 || ik->is_subclass_of(_the_class_oop))) { 2607 // ik->itable() creates a wrapper object; rm cleans it up 2608 ResourceMark rm(THREAD); 2609 ik->itable()->adjust_method_entries(_matching_old_methods, 2610 _matching_new_methods, 2611 _matching_methods_length, 2612 &trace_name_printed); 2613 } 2614 2615 // The constant pools in other classes (other_cp) can refer to 2616 // methods in the_class. We have to update method information in 2617 // other_cp's cache. If other_cp has a previous version, then we 2618 // have to repeat the process for each previous version. The 2619 // constant pool cache holds the methodOops for non-virtual 2620 // methods and for virtual, final methods. 2621 // 2622 // Special case: if the current class is the_class, then new_cp 2623 // has already been attached to the_class and old_cp has already 2624 // been added as a previous version. The new_cp doesn't have any 2625 // cached references to old methods so it doesn't need to be 2626 // updated. We can simply start with the previous version(s) in 2627 // that case. 2628 constantPoolHandle other_cp; 2629 constantPoolCacheOop cp_cache; 2630 2631 if (k_oop != _the_class_oop) { 2632 // this klass' constant pool cache may need adjustment 2633 other_cp = constantPoolHandle(ik->constants()); 2634 cp_cache = other_cp->cache(); 2635 if (cp_cache != NULL) { 2636 cp_cache->adjust_method_entries(_matching_old_methods, 2637 _matching_new_methods, 2638 _matching_methods_length, 2639 &trace_name_printed); 2640 } 2641 } 2642 { 2643 ResourceMark rm(THREAD); 2644 // PreviousVersionInfo objects returned via PreviousVersionWalker 2645 // contain a GrowableArray of handles. We have to clean up the 2646 // GrowableArray _after_ the PreviousVersionWalker destructor 2647 // has destroyed the handles. 2648 { 2649 // the previous versions' constant pool caches may need adjustment 2650 PreviousVersionWalker pvw(ik); 2651 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); 2652 pv_info != NULL; pv_info = pvw.next_previous_version()) { 2653 other_cp = pv_info->prev_constant_pool_handle(); 2654 cp_cache = other_cp->cache(); 2655 if (cp_cache != NULL) { 2656 cp_cache->adjust_method_entries(_matching_old_methods, 2657 _matching_new_methods, 2658 _matching_methods_length, 2659 &trace_name_printed); 2660 } 2661 } 2662 } // pvw is cleaned up 2663 } // rm is cleaned up 2664 } 2665 } 2666 2667 void VM_RedefineClasses::update_jmethod_ids() { 2668 for (int j = 0; j < _matching_methods_length; ++j) { 2669 methodOop old_method = _matching_old_methods[j]; 2670 jmethodID jmid = old_method->find_jmethod_id_or_null(); 2671 if (jmid != NULL) { 2672 // There is a jmethodID, change it to point to the new method 2673 methodHandle new_method_h(_matching_new_methods[j]); 2674 JNIHandles::change_method_associated_with_jmethod_id(jmid, new_method_h); 2675 assert(JNIHandles::resolve_jmethod_id(jmid) == _matching_new_methods[j], 2676 "should be replaced"); 2677 } 2678 } 2679 } 2680 2681 void VM_RedefineClasses::check_methods_and_mark_as_obsolete( 2682 BitMap *emcp_methods, int * emcp_method_count_p) { 2683 *emcp_method_count_p = 0; 2684 int obsolete_count = 0; 2685 int old_index = 0; 2686 for (int j = 0; j < _matching_methods_length; ++j, ++old_index) { 2687 methodOop old_method = _matching_old_methods[j]; 2688 methodOop new_method = _matching_new_methods[j]; 2689 methodOop old_array_method; 2690 2691 // Maintain an old_index into the _old_methods array by skipping 2692 // deleted methods 2693 while ((old_array_method = (methodOop) _old_methods->obj_at(old_index)) 2694 != old_method) { 2695 ++old_index; 2696 } 2697 2698 if (MethodComparator::methods_EMCP(old_method, new_method)) { 2699 // The EMCP definition from JSR-163 requires the bytecodes to be 2700 // the same with the exception of constant pool indices which may 2701 // differ. However, the constants referred to by those indices 2702 // must be the same. 2703 // 2704 // We use methods_EMCP() for comparison since constant pool 2705 // merging can remove duplicate constant pool entries that were 2706 // present in the old method and removed from the rewritten new 2707 // method. A faster binary comparison function would consider the 2708 // old and new methods to be different when they are actually 2709 // EMCP. 2710 // 2711 // The old and new methods are EMCP and you would think that we 2712 // could get rid of one of them here and now and save some space. 2713 // However, the concept of EMCP only considers the bytecodes and 2714 // the constant pool entries in the comparison. Other things, 2715 // e.g., the line number table (LNT) or the local variable table 2716 // (LVT) don't count in the comparison. So the new (and EMCP) 2717 // method can have a new LNT that we need so we can't just 2718 // overwrite the new method with the old method. 2719 // 2720 // When this routine is called, we have already attached the new 2721 // methods to the_class so the old methods are effectively 2722 // overwritten. However, if an old method is still executing, 2723 // then the old method cannot be collected until sometime after 2724 // the old method call has returned. So the overwriting of old 2725 // methods by new methods will save us space except for those 2726 // (hopefully few) old methods that are still executing. 2727 // 2728 // A method refers to a constMethodOop and this presents another 2729 // possible avenue to space savings. The constMethodOop in the 2730 // new method contains possibly new attributes (LNT, LVT, etc). 2731 // At first glance, it seems possible to save space by replacing 2732 // the constMethodOop in the old method with the constMethodOop 2733 // from the new method. The old and new methods would share the 2734 // same constMethodOop and we would save the space occupied by 2735 // the old constMethodOop. However, the constMethodOop contains 2736 // a back reference to the containing method. Sharing the 2737 // constMethodOop between two methods could lead to confusion in 2738 // the code that uses the back reference. This would lead to 2739 // brittle code that could be broken in non-obvious ways now or 2740 // in the future. 2741 // 2742 // Another possibility is to copy the constMethodOop from the new 2743 // method to the old method and then overwrite the new method with 2744 // the old method. Since the constMethodOop contains the bytecodes 2745 // for the method embedded in the oop, this option would change 2746 // the bytecodes out from under any threads executing the old 2747 // method and make the thread's bcp invalid. Since EMCP requires 2748 // that the bytecodes be the same modulo constant pool indices, it 2749 // is straight forward to compute the correct new bcp in the new 2750 // constMethodOop from the old bcp in the old constMethodOop. The 2751 // time consuming part would be searching all the frames in all 2752 // of the threads to find all of the calls to the old method. 2753 // 2754 // It looks like we will have to live with the limited savings 2755 // that we get from effectively overwriting the old methods 2756 // when the new methods are attached to the_class. 2757 2758 // track which methods are EMCP for add_previous_version() call 2759 emcp_methods->set_bit(old_index); 2760 (*emcp_method_count_p)++; 2761 2762 // An EMCP method is _not_ obsolete. An obsolete method has a 2763 // different jmethodID than the current method. An EMCP method 2764 // has the same jmethodID as the current method. Having the 2765 // same jmethodID for all EMCP versions of a method allows for 2766 // a consistent view of the EMCP methods regardless of which 2767 // EMCP method you happen to have in hand. For example, a 2768 // breakpoint set in one EMCP method will work for all EMCP 2769 // versions of the method including the current one. 2770 } else { 2771 // mark obsolete methods as such 2772 old_method->set_is_obsolete(); 2773 obsolete_count++; 2774 2775 // obsolete methods need a unique idnum 2776 u2 num = instanceKlass::cast(_the_class_oop)->next_method_idnum(); 2777 if (num != constMethodOopDesc::UNSET_IDNUM) { 2778 // u2 old_num = old_method->method_idnum(); 2779 old_method->set_method_idnum(num); 2780 // TO DO: attach obsolete annotations to obsolete method's new idnum 2781 } 2782 // With tracing we try not to "yack" too much. The position of 2783 // this trace assumes there are fewer obsolete methods than 2784 // EMCP methods. 2785 RC_TRACE(0x00000100, ("mark %s(%s) as obsolete", 2786 old_method->name()->as_C_string(), 2787 old_method->signature()->as_C_string())); 2788 } 2789 old_method->set_is_old(); 2790 } 2791 for (int i = 0; i < _deleted_methods_length; ++i) { 2792 methodOop old_method = _deleted_methods[i]; 2793 2794 assert(old_method->vtable_index() < 0, 2795 "cannot delete methods with vtable entries");; 2796 2797 // Mark all deleted methods as old and obsolete 2798 old_method->set_is_old(); 2799 old_method->set_is_obsolete(); 2800 ++obsolete_count; 2801 // With tracing we try not to "yack" too much. The position of 2802 // this trace assumes there are fewer obsolete methods than 2803 // EMCP methods. 2804 RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete", 2805 old_method->name()->as_C_string(), 2806 old_method->signature()->as_C_string())); 2807 } 2808 assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(), 2809 "sanity check"); 2810 RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p, 2811 obsolete_count)); 2812 } 2813 2814 // This internal class transfers the native function registration from old methods 2815 // to new methods. It is designed to handle both the simple case of unchanged 2816 // native methods and the complex cases of native method prefixes being added and/or 2817 // removed. 2818 // It expects only to be used during the VM_RedefineClasses op (a safepoint). 2819 // 2820 // This class is used after the new methods have been installed in "the_class". 2821 // 2822 // So, for example, the following must be handled. Where 'm' is a method and 2823 // a number followed by an underscore is a prefix. 2824 // 2825 // Old Name New Name 2826 // Simple transfer to new method m -> m 2827 // Add prefix m -> 1_m 2828 // Remove prefix 1_m -> m 2829 // Simultaneous add of prefixes m -> 3_2_1_m 2830 // Simultaneous removal of prefixes 3_2_1_m -> m 2831 // Simultaneous add and remove 1_m -> 2_m 2832 // Same, caused by prefix removal only 3_2_1_m -> 3_2_m 2833 // 2834 class TransferNativeFunctionRegistration { 2835 private: 2836 instanceKlassHandle the_class; 2837 int prefix_count; 2838 char** prefixes; 2839 2840 // Recursively search the binary tree of possibly prefixed method names. 2841 // Iteration could be used if all agents were well behaved. Full tree walk is 2842 // more resilent to agents not cleaning up intermediate methods. 2843 // Branch at each depth in the binary tree is: 2844 // (1) without the prefix. 2845 // (2) with the prefix. 2846 // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...) 2847 methodOop search_prefix_name_space(int depth, char* name_str, size_t name_len, 2848 Symbol* signature) { 2849 TempNewSymbol name_symbol = SymbolTable::probe(name_str, (int)name_len); 2850 if (name_symbol != NULL) { 2851 methodOop method = Klass::cast(the_class())->lookup_method(name_symbol, signature); 2852 if (method != NULL) { 2853 // Even if prefixed, intermediate methods must exist. 2854 if (method->is_native()) { 2855 // Wahoo, we found a (possibly prefixed) version of the method, return it. 2856 return method; 2857 } 2858 if (depth < prefix_count) { 2859 // Try applying further prefixes (other than this one). 2860 method = search_prefix_name_space(depth+1, name_str, name_len, signature); 2861 if (method != NULL) { 2862 return method; // found 2863 } 2864 2865 // Try adding this prefix to the method name and see if it matches 2866 // another method name. 2867 char* prefix = prefixes[depth]; 2868 size_t prefix_len = strlen(prefix); 2869 size_t trial_len = name_len + prefix_len; 2870 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1); 2871 strcpy(trial_name_str, prefix); 2872 strcat(trial_name_str, name_str); 2873 method = search_prefix_name_space(depth+1, trial_name_str, trial_len, 2874 signature); 2875 if (method != NULL) { 2876 // If found along this branch, it was prefixed, mark as such 2877 method->set_is_prefixed_native(); 2878 return method; // found 2879 } 2880 } 2881 } 2882 } 2883 return NULL; // This whole branch bore nothing 2884 } 2885 2886 // Return the method name with old prefixes stripped away. 2887 char* method_name_without_prefixes(methodOop method) { 2888 Symbol* name = method->name(); 2889 char* name_str = name->as_utf8(); 2890 2891 // Old prefixing may be defunct, strip prefixes, if any. 2892 for (int i = prefix_count-1; i >= 0; i--) { 2893 char* prefix = prefixes[i]; 2894 size_t prefix_len = strlen(prefix); 2895 if (strncmp(prefix, name_str, prefix_len) == 0) { 2896 name_str += prefix_len; 2897 } 2898 } 2899 return name_str; 2900 } 2901 2902 // Strip any prefixes off the old native method, then try to find a 2903 // (possibly prefixed) new native that matches it. 2904 methodOop strip_and_search_for_new_native(methodOop method) { 2905 ResourceMark rm; 2906 char* name_str = method_name_without_prefixes(method); 2907 return search_prefix_name_space(0, name_str, strlen(name_str), 2908 method->signature()); 2909 } 2910 2911 public: 2912 2913 // Construct a native method transfer processor for this class. 2914 TransferNativeFunctionRegistration(instanceKlassHandle _the_class) { 2915 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 2916 2917 the_class = _the_class; 2918 prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); 2919 } 2920 2921 // Attempt to transfer any of the old or deleted methods that are native 2922 void transfer_registrations(methodOop* old_methods, int methods_length) { 2923 for (int j = 0; j < methods_length; j++) { 2924 methodOop old_method = old_methods[j]; 2925 2926 if (old_method->is_native() && old_method->has_native_function()) { 2927 methodOop new_method = strip_and_search_for_new_native(old_method); 2928 if (new_method != NULL) { 2929 // Actually set the native function in the new method. 2930 // Redefine does not send events (except CFLH), certainly not this 2931 // behind the scenes re-registration. 2932 new_method->set_native_function(old_method->native_function(), 2933 !methodOopDesc::native_bind_event_is_interesting); 2934 } 2935 } 2936 } 2937 } 2938 }; 2939 2940 // Don't lose the association between a native method and its JNI function. 2941 void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) { 2942 TransferNativeFunctionRegistration transfer(the_class); 2943 transfer.transfer_registrations(_deleted_methods, _deleted_methods_length); 2944 transfer.transfer_registrations(_matching_old_methods, _matching_methods_length); 2945 } 2946 2947 // Deoptimize all compiled code that depends on this class. 2948 // 2949 // If the can_redefine_classes capability is obtained in the onload 2950 // phase then the compiler has recorded all dependencies from startup. 2951 // In that case we need only deoptimize and throw away all compiled code 2952 // that depends on the class. 2953 // 2954 // If can_redefine_classes is obtained sometime after the onload 2955 // phase then the dependency information may be incomplete. In that case 2956 // the first call to RedefineClasses causes all compiled code to be 2957 // thrown away. As can_redefine_classes has been obtained then 2958 // all future compilations will record dependencies so second and 2959 // subsequent calls to RedefineClasses need only throw away code 2960 // that depends on the class. 2961 // 2962 void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) { 2963 assert_locked_or_safepoint(Compile_lock); 2964 2965 // All dependencies have been recorded from startup or this is a second or 2966 // subsequent use of RedefineClasses 2967 if (JvmtiExport::all_dependencies_are_recorded()) { 2968 Universe::flush_evol_dependents_on(k_h); 2969 } else { 2970 CodeCache::mark_all_nmethods_for_deoptimization(); 2971 2972 ResourceMark rm(THREAD); 2973 DeoptimizationMarker dm; 2974 2975 // Deoptimize all activations depending on marked nmethods 2976 Deoptimization::deoptimize_dependents(); 2977 2978 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies) 2979 CodeCache::make_marked_nmethods_not_entrant(); 2980 2981 // From now on we know that the dependency information is complete 2982 JvmtiExport::set_all_dependencies_are_recorded(true); 2983 } 2984 } 2985 2986 void VM_RedefineClasses::compute_added_deleted_matching_methods() { 2987 methodOop old_method; 2988 methodOop new_method; 2989 2990 _matching_old_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length()); 2991 _matching_new_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length()); 2992 _added_methods = NEW_RESOURCE_ARRAY(methodOop, _new_methods->length()); 2993 _deleted_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length()); 2994 2995 _matching_methods_length = 0; 2996 _deleted_methods_length = 0; 2997 _added_methods_length = 0; 2998 2999 int nj = 0; 3000 int oj = 0; 3001 while (true) { 3002 if (oj >= _old_methods->length()) { 3003 if (nj >= _new_methods->length()) { 3004 break; // we've looked at everything, done 3005 } 3006 // New method at the end 3007 new_method = (methodOop) _new_methods->obj_at(nj); 3008 _added_methods[_added_methods_length++] = new_method; 3009 ++nj; 3010 } else if (nj >= _new_methods->length()) { 3011 // Old method, at the end, is deleted 3012 old_method = (methodOop) _old_methods->obj_at(oj); 3013 _deleted_methods[_deleted_methods_length++] = old_method; 3014 ++oj; 3015 } else { 3016 old_method = (methodOop) _old_methods->obj_at(oj); 3017 new_method = (methodOop) _new_methods->obj_at(nj); 3018 if (old_method->name() == new_method->name()) { 3019 if (old_method->signature() == new_method->signature()) { 3020 _matching_old_methods[_matching_methods_length ] = old_method; 3021 _matching_new_methods[_matching_methods_length++] = new_method; 3022 ++nj; 3023 ++oj; 3024 } else { 3025 // added overloaded have already been moved to the end, 3026 // so this is a deleted overloaded method 3027 _deleted_methods[_deleted_methods_length++] = old_method; 3028 ++oj; 3029 } 3030 } else { // names don't match 3031 if (old_method->name()->fast_compare(new_method->name()) > 0) { 3032 // new method 3033 _added_methods[_added_methods_length++] = new_method; 3034 ++nj; 3035 } else { 3036 // deleted method 3037 _deleted_methods[_deleted_methods_length++] = old_method; 3038 ++oj; 3039 } 3040 } 3041 } 3042 } 3043 assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity"); 3044 assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity"); 3045 } 3046 3047 3048 3049 // Install the redefinition of a class: 3050 // - house keeping (flushing breakpoints and caches, deoptimizing 3051 // dependent compiled code) 3052 // - replacing parts in the_class with parts from scratch_class 3053 // - adding a weak reference to track the obsolete but interesting 3054 // parts of the_class 3055 // - adjusting constant pool caches and vtables in other classes 3056 // that refer to methods in the_class. These adjustments use the 3057 // SystemDictionary::classes_do() facility which only allows 3058 // a helper method to be specified. The interesting parameters 3059 // that we would like to pass to the helper method are saved in 3060 // static global fields in the VM operation. 3061 void VM_RedefineClasses::redefine_single_class(jclass the_jclass, 3062 instanceKlassHandle scratch_class, TRAPS) { 3063 3064 RC_TIMER_START(_timer_rsc_phase1); 3065 3066 oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass); 3067 klassOop the_class_oop = java_lang_Class::as_klassOop(the_class_mirror); 3068 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop); 3069 3070 #ifndef JVMTI_KERNEL 3071 // Remove all breakpoints in methods of this class 3072 JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); 3073 jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop); 3074 #endif // !JVMTI_KERNEL 3075 3076 if (the_class_oop == Universe::reflect_invoke_cache()->klass()) { 3077 // We are redefining java.lang.reflect.Method. Method.invoke() is 3078 // cached and users of the cache care about each active version of 3079 // the method so we have to track this previous version. 3080 // Do this before methods get switched 3081 Universe::reflect_invoke_cache()->add_previous_version( 3082 the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum())); 3083 } 3084 3085 // Deoptimize all compiled code that depends on this class 3086 flush_dependent_code(the_class, THREAD); 3087 3088 _old_methods = the_class->methods(); 3089 _new_methods = scratch_class->methods(); 3090 _the_class_oop = the_class_oop; 3091 compute_added_deleted_matching_methods(); 3092 update_jmethod_ids(); 3093 3094 // Attach new constant pool to the original klass. The original 3095 // klass still refers to the old constant pool (for now). 3096 scratch_class->constants()->set_pool_holder(the_class()); 3097 3098 #if 0 3099 // In theory, with constant pool merging in place we should be able 3100 // to save space by using the new, merged constant pool in place of 3101 // the old constant pool(s). By "pool(s)" I mean the constant pool in 3102 // the klass version we are replacing now and any constant pool(s) in 3103 // previous versions of klass. Nice theory, doesn't work in practice. 3104 // When this code is enabled, even simple programs throw NullPointer 3105 // exceptions. I'm guessing that this is caused by some constant pool 3106 // cache difference between the new, merged constant pool and the 3107 // constant pool that was just being used by the klass. I'm keeping 3108 // this code around to archive the idea, but the code has to remain 3109 // disabled for now. 3110 3111 // Attach each old method to the new constant pool. This can be 3112 // done here since we are past the bytecode verification and 3113 // constant pool optimization phases. 3114 for (int i = _old_methods->length() - 1; i >= 0; i--) { 3115 methodOop method = (methodOop)_old_methods->obj_at(i); 3116 method->set_constants(scratch_class->constants()); 3117 } 3118 3119 { 3120 // walk all previous versions of the klass 3121 instanceKlass *ik = (instanceKlass *)the_class()->klass_part(); 3122 PreviousVersionWalker pvw(ik); 3123 instanceKlassHandle ikh; 3124 do { 3125 ikh = pvw.next_previous_version(); 3126 if (!ikh.is_null()) { 3127 ik = ikh(); 3128 3129 // attach previous version of klass to the new constant pool 3130 ik->set_constants(scratch_class->constants()); 3131 3132 // Attach each method in the previous version of klass to the 3133 // new constant pool 3134 objArrayOop prev_methods = ik->methods(); 3135 for (int i = prev_methods->length() - 1; i >= 0; i--) { 3136 methodOop method = (methodOop)prev_methods->obj_at(i); 3137 method->set_constants(scratch_class->constants()); 3138 } 3139 } 3140 } while (!ikh.is_null()); 3141 } 3142 #endif 3143 3144 // Replace methods and constantpool 3145 the_class->set_methods(_new_methods); 3146 scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods, 3147 // and to be able to undo operation easily. 3148 3149 constantPoolOop old_constants = the_class->constants(); 3150 the_class->set_constants(scratch_class->constants()); 3151 scratch_class->set_constants(old_constants); // See the previous comment. 3152 #if 0 3153 // We are swapping the guts of "the new class" with the guts of "the 3154 // class". Since the old constant pool has just been attached to "the 3155 // new class", it seems logical to set the pool holder in the old 3156 // constant pool also. However, doing this will change the observable 3157 // class hierarchy for any old methods that are still executing. A 3158 // method can query the identity of its "holder" and this query uses 3159 // the method's constant pool link to find the holder. The change in 3160 // holding class from "the class" to "the new class" can confuse 3161 // things. 3162 // 3163 // Setting the old constant pool's holder will also cause 3164 // verification done during vtable initialization below to fail. 3165 // During vtable initialization, the vtable's class is verified to be 3166 // a subtype of the method's holder. The vtable's class is "the 3167 // class" and the method's holder is gotten from the constant pool 3168 // link in the method itself. For "the class"'s directly implemented 3169 // methods, the method holder is "the class" itself (as gotten from 3170 // the new constant pool). The check works fine in this case. The 3171 // check also works fine for methods inherited from super classes. 3172 // 3173 // Miranda methods are a little more complicated. A miranda method is 3174 // provided by an interface when the class implementing the interface 3175 // does not provide its own method. These interfaces are implemented 3176 // internally as an instanceKlass. These special instanceKlasses 3177 // share the constant pool of the class that "implements" the 3178 // interface. By sharing the constant pool, the method holder of a 3179 // miranda method is the class that "implements" the interface. In a 3180 // non-redefine situation, the subtype check works fine. However, if 3181 // the old constant pool's pool holder is modified, then the check 3182 // fails because there is no class hierarchy relationship between the 3183 // vtable's class and "the new class". 3184 3185 old_constants->set_pool_holder(scratch_class()); 3186 #endif 3187 3188 // track which methods are EMCP for add_previous_version() call below 3189 BitMap emcp_methods(_old_methods->length()); 3190 int emcp_method_count = 0; 3191 emcp_methods.clear(); // clears 0..(length() - 1) 3192 check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count); 3193 transfer_old_native_function_registrations(the_class); 3194 3195 // The class file bytes from before any retransformable agents mucked 3196 // with them was cached on the scratch class, move to the_class. 3197 // Note: we still want to do this if nothing needed caching since it 3198 // should get cleared in the_class too. 3199 if (the_class->get_cached_class_file_bytes() == 0) { 3200 // the_class doesn't have a cache yet so copy it 3201 the_class->set_cached_class_file( 3202 scratch_class->get_cached_class_file_bytes(), 3203 scratch_class->get_cached_class_file_len()); 3204 } 3205 #ifndef PRODUCT 3206 else { 3207 assert(the_class->get_cached_class_file_bytes() == 3208 scratch_class->get_cached_class_file_bytes(), "cache ptrs must match"); 3209 assert(the_class->get_cached_class_file_len() == 3210 scratch_class->get_cached_class_file_len(), "cache lens must match"); 3211 } 3212 #endif 3213 3214 // Replace inner_classes 3215 typeArrayOop old_inner_classes = the_class->inner_classes(); 3216 the_class->set_inner_classes(scratch_class->inner_classes()); 3217 scratch_class->set_inner_classes(old_inner_classes); 3218 3219 // Initialize the vtable and interface table after 3220 // methods have been rewritten 3221 { 3222 ResourceMark rm(THREAD); 3223 // no exception should happen here since we explicitly 3224 // do not check loader constraints. 3225 // compare_and_normalize_class_versions has already checked: 3226 // - classloaders unchanged, signatures unchanged 3227 // - all instanceKlasses for redefined classes reused & contents updated 3228 the_class->vtable()->initialize_vtable(false, THREAD); 3229 the_class->itable()->initialize_itable(false, THREAD); 3230 assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())), "redefine exception"); 3231 } 3232 3233 // Leave arrays of jmethodIDs and itable index cache unchanged 3234 3235 // Copy the "source file name" attribute from new class version 3236 the_class->set_source_file_name(scratch_class->source_file_name()); 3237 3238 // Copy the "source debug extension" attribute from new class version 3239 the_class->set_source_debug_extension( 3240 scratch_class->source_debug_extension(), 3241 scratch_class->source_debug_extension() == NULL ? 0 : 3242 (int)strlen(scratch_class->source_debug_extension())); 3243 3244 // Use of javac -g could be different in the old and the new 3245 if (scratch_class->access_flags().has_localvariable_table() != 3246 the_class->access_flags().has_localvariable_table()) { 3247 3248 AccessFlags flags = the_class->access_flags(); 3249 if (scratch_class->access_flags().has_localvariable_table()) { 3250 flags.set_has_localvariable_table(); 3251 } else { 3252 flags.clear_has_localvariable_table(); 3253 } 3254 the_class->set_access_flags(flags); 3255 } 3256 3257 // Replace class annotation fields values 3258 typeArrayOop old_class_annotations = the_class->class_annotations(); 3259 the_class->set_class_annotations(scratch_class->class_annotations()); 3260 scratch_class->set_class_annotations(old_class_annotations); 3261 3262 // Replace fields annotation fields values 3263 objArrayOop old_fields_annotations = the_class->fields_annotations(); 3264 the_class->set_fields_annotations(scratch_class->fields_annotations()); 3265 scratch_class->set_fields_annotations(old_fields_annotations); 3266 3267 // Replace methods annotation fields values 3268 objArrayOop old_methods_annotations = the_class->methods_annotations(); 3269 the_class->set_methods_annotations(scratch_class->methods_annotations()); 3270 scratch_class->set_methods_annotations(old_methods_annotations); 3271 3272 // Replace methods parameter annotation fields values 3273 objArrayOop old_methods_parameter_annotations = 3274 the_class->methods_parameter_annotations(); 3275 the_class->set_methods_parameter_annotations( 3276 scratch_class->methods_parameter_annotations()); 3277 scratch_class->set_methods_parameter_annotations(old_methods_parameter_annotations); 3278 3279 // Replace methods default annotation fields values 3280 objArrayOop old_methods_default_annotations = 3281 the_class->methods_default_annotations(); 3282 the_class->set_methods_default_annotations( 3283 scratch_class->methods_default_annotations()); 3284 scratch_class->set_methods_default_annotations(old_methods_default_annotations); 3285 3286 // Replace minor version number of class file 3287 u2 old_minor_version = the_class->minor_version(); 3288 the_class->set_minor_version(scratch_class->minor_version()); 3289 scratch_class->set_minor_version(old_minor_version); 3290 3291 // Replace major version number of class file 3292 u2 old_major_version = the_class->major_version(); 3293 the_class->set_major_version(scratch_class->major_version()); 3294 scratch_class->set_major_version(old_major_version); 3295 3296 // Replace CP indexes for class and name+type of enclosing method 3297 u2 old_class_idx = the_class->enclosing_method_class_index(); 3298 u2 old_method_idx = the_class->enclosing_method_method_index(); 3299 the_class->set_enclosing_method_indices( 3300 scratch_class->enclosing_method_class_index(), 3301 scratch_class->enclosing_method_method_index()); 3302 scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx); 3303 3304 // keep track of previous versions of this class 3305 the_class->add_previous_version(scratch_class, &emcp_methods, 3306 emcp_method_count); 3307 3308 RC_TIMER_STOP(_timer_rsc_phase1); 3309 RC_TIMER_START(_timer_rsc_phase2); 3310 3311 // Adjust constantpool caches and vtables for all classes 3312 // that reference methods of the evolved class. 3313 SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD); 3314 3315 if (the_class->oop_map_cache() != NULL) { 3316 // Flush references to any obsolete methods from the oop map cache 3317 // so that obsolete methods are not pinned. 3318 the_class->oop_map_cache()->flush_obsolete_entries(); 3319 } 3320 3321 // increment the classRedefinedCount field in the_class and in any 3322 // direct and indirect subclasses of the_class 3323 increment_class_counter((instanceKlass *)the_class()->klass_part(), THREAD); 3324 3325 // RC_TRACE macro has an embedded ResourceMark 3326 RC_TRACE_WITH_THREAD(0x00000001, THREAD, 3327 ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)", 3328 the_class->external_name(), 3329 java_lang_Class::classRedefinedCount(the_class_mirror), 3330 os::available_memory() >> 10)); 3331 3332 RC_TIMER_STOP(_timer_rsc_phase2); 3333 } // end redefine_single_class() 3334 3335 3336 // Increment the classRedefinedCount field in the specific instanceKlass 3337 // and in all direct and indirect subclasses. 3338 void VM_RedefineClasses::increment_class_counter(instanceKlass *ik, TRAPS) { 3339 oop class_mirror = ik->java_mirror(); 3340 klassOop class_oop = java_lang_Class::as_klassOop(class_mirror); 3341 int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1; 3342 java_lang_Class::set_classRedefinedCount(class_mirror, new_count); 3343 3344 if (class_oop != _the_class_oop) { 3345 // _the_class_oop count is printed at end of redefine_single_class() 3346 RC_TRACE_WITH_THREAD(0x00000008, THREAD, 3347 ("updated count in subclass=%s to %d", ik->external_name(), new_count)); 3348 } 3349 3350 for (Klass *subk = ik->subklass(); subk != NULL; 3351 subk = subk->next_sibling()) { 3352 if (subk->oop_is_instance()) { 3353 // Only update instanceKlasses 3354 instanceKlass *subik = (instanceKlass*)subk; 3355 // recursively do subclasses of the current subclass 3356 increment_class_counter(subik, THREAD); 3357 } 3358 } 3359 } 3360 3361 void VM_RedefineClasses::check_class(klassOop k_oop, 3362 oop initiating_loader, TRAPS) { 3363 Klass *k = k_oop->klass_part(); 3364 if (k->oop_is_instance()) { 3365 HandleMark hm(THREAD); 3366 instanceKlass *ik = (instanceKlass *) k; 3367 bool no_old_methods = true; // be optimistic 3368 ResourceMark rm(THREAD); 3369 3370 // a vtable should never contain old or obsolete methods 3371 if (ik->vtable_length() > 0 && 3372 !ik->vtable()->check_no_old_or_obsolete_entries()) { 3373 if (RC_TRACE_ENABLED(0x00004000)) { 3374 RC_TRACE_WITH_THREAD(0x00004000, THREAD, 3375 ("klassVtable::check_no_old_or_obsolete_entries failure" 3376 " -- OLD or OBSOLETE method found -- class: %s", 3377 ik->signature_name())); 3378 ik->vtable()->dump_vtable(); 3379 } 3380 no_old_methods = false; 3381 } 3382 3383 // an itable should never contain old or obsolete methods 3384 if (ik->itable_length() > 0 && 3385 !ik->itable()->check_no_old_or_obsolete_entries()) { 3386 if (RC_TRACE_ENABLED(0x00004000)) { 3387 RC_TRACE_WITH_THREAD(0x00004000, THREAD, 3388 ("klassItable::check_no_old_or_obsolete_entries failure" 3389 " -- OLD or OBSOLETE method found -- class: %s", 3390 ik->signature_name())); 3391 ik->itable()->dump_itable(); 3392 } 3393 no_old_methods = false; 3394 } 3395 3396 // the constant pool cache should never contain old or obsolete methods 3397 if (ik->constants() != NULL && 3398 ik->constants()->cache() != NULL && 3399 !ik->constants()->cache()->check_no_old_or_obsolete_entries()) { 3400 if (RC_TRACE_ENABLED(0x00004000)) { 3401 RC_TRACE_WITH_THREAD(0x00004000, THREAD, 3402 ("cp-cache::check_no_old_or_obsolete_entries failure" 3403 " -- OLD or OBSOLETE method found -- class: %s", 3404 ik->signature_name())); 3405 ik->constants()->cache()->dump_cache(); 3406 } 3407 no_old_methods = false; 3408 } 3409 3410 if (!no_old_methods) { 3411 if (RC_TRACE_ENABLED(0x00004000)) { 3412 dump_methods(); 3413 } else { 3414 tty->print_cr("INFO: use the '-XX:TraceRedefineClasses=16384' option " 3415 "to see more info about the following guarantee() failure."); 3416 } 3417 guarantee(false, "OLD and/or OBSOLETE method(s) found"); 3418 } 3419 } 3420 } 3421 3422 void VM_RedefineClasses::dump_methods() { 3423 int j; 3424 RC_TRACE(0x00004000, ("_old_methods --")); 3425 for (j = 0; j < _old_methods->length(); ++j) { 3426 methodOop m = (methodOop) _old_methods->obj_at(j); 3427 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index())); 3428 m->access_flags().print_on(tty); 3429 tty->print(" -- "); 3430 m->print_name(tty); 3431 tty->cr(); 3432 } 3433 RC_TRACE(0x00004000, ("_new_methods --")); 3434 for (j = 0; j < _new_methods->length(); ++j) { 3435 methodOop m = (methodOop) _new_methods->obj_at(j); 3436 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index())); 3437 m->access_flags().print_on(tty); 3438 tty->print(" -- "); 3439 m->print_name(tty); 3440 tty->cr(); 3441 } 3442 RC_TRACE(0x00004000, ("_matching_(old/new)_methods --")); 3443 for (j = 0; j < _matching_methods_length; ++j) { 3444 methodOop m = _matching_old_methods[j]; 3445 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index())); 3446 m->access_flags().print_on(tty); 3447 tty->print(" -- "); 3448 m->print_name(tty); 3449 tty->cr(); 3450 m = _matching_new_methods[j]; 3451 RC_TRACE_NO_CR(0x00004000, (" (%5d) ", m->vtable_index())); 3452 m->access_flags().print_on(tty); 3453 tty->cr(); 3454 } 3455 RC_TRACE(0x00004000, ("_deleted_methods --")); 3456 for (j = 0; j < _deleted_methods_length; ++j) { 3457 methodOop m = _deleted_methods[j]; 3458 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index())); 3459 m->access_flags().print_on(tty); 3460 tty->print(" -- "); 3461 m->print_name(tty); 3462 tty->cr(); 3463 } 3464 RC_TRACE(0x00004000, ("_added_methods --")); 3465 for (j = 0; j < _added_methods_length; ++j) { 3466 methodOop m = _added_methods[j]; 3467 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index())); 3468 m->access_flags().print_on(tty); 3469 tty->print(" -- "); 3470 m->print_name(tty); 3471 tty->cr(); 3472 } 3473 }