1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/prims/jvmtiRedefineClasses.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,3398 @@
1.4 +/*
1.5 + * Copyright 2003-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_jvmtiRedefineClasses.cpp.incl"
1.30 +
1.31 +
1.32 +objArrayOop VM_RedefineClasses::_old_methods = NULL;
1.33 +objArrayOop VM_RedefineClasses::_new_methods = NULL;
1.34 +methodOop* VM_RedefineClasses::_matching_old_methods = NULL;
1.35 +methodOop* VM_RedefineClasses::_matching_new_methods = NULL;
1.36 +methodOop* VM_RedefineClasses::_deleted_methods = NULL;
1.37 +methodOop* VM_RedefineClasses::_added_methods = NULL;
1.38 +int VM_RedefineClasses::_matching_methods_length = 0;
1.39 +int VM_RedefineClasses::_deleted_methods_length = 0;
1.40 +int VM_RedefineClasses::_added_methods_length = 0;
1.41 +klassOop VM_RedefineClasses::_the_class_oop = NULL;
1.42 +
1.43 +
1.44 +VM_RedefineClasses::VM_RedefineClasses(jint class_count,
1.45 + const jvmtiClassDefinition *class_defs,
1.46 + JvmtiClassLoadKind class_load_kind) {
1.47 + _class_count = class_count;
1.48 + _class_defs = class_defs;
1.49 + _class_load_kind = class_load_kind;
1.50 + _res = JVMTI_ERROR_NONE;
1.51 +}
1.52 +
1.53 +bool VM_RedefineClasses::doit_prologue() {
1.54 + if (_class_count == 0) {
1.55 + _res = JVMTI_ERROR_NONE;
1.56 + return false;
1.57 + }
1.58 + if (_class_defs == NULL) {
1.59 + _res = JVMTI_ERROR_NULL_POINTER;
1.60 + return false;
1.61 + }
1.62 + for (int i = 0; i < _class_count; i++) {
1.63 + if (_class_defs[i].klass == NULL) {
1.64 + _res = JVMTI_ERROR_INVALID_CLASS;
1.65 + return false;
1.66 + }
1.67 + if (_class_defs[i].class_byte_count == 0) {
1.68 + _res = JVMTI_ERROR_INVALID_CLASS_FORMAT;
1.69 + return false;
1.70 + }
1.71 + if (_class_defs[i].class_bytes == NULL) {
1.72 + _res = JVMTI_ERROR_NULL_POINTER;
1.73 + return false;
1.74 + }
1.75 + }
1.76 +
1.77 + // Start timer after all the sanity checks; not quite accurate, but
1.78 + // better than adding a bunch of stop() calls.
1.79 + RC_TIMER_START(_timer_vm_op_prologue);
1.80 +
1.81 + // We first load new class versions in the prologue, because somewhere down the
1.82 + // call chain it is required that the current thread is a Java thread.
1.83 + _res = load_new_class_versions(Thread::current());
1.84 + if (_res != JVMTI_ERROR_NONE) {
1.85 + // Free os::malloc allocated memory in load_new_class_version.
1.86 + os::free(_scratch_classes);
1.87 + RC_TIMER_STOP(_timer_vm_op_prologue);
1.88 + return false;
1.89 + }
1.90 +
1.91 + RC_TIMER_STOP(_timer_vm_op_prologue);
1.92 + return true;
1.93 +}
1.94 +
1.95 +void VM_RedefineClasses::doit() {
1.96 + Thread *thread = Thread::current();
1.97 +
1.98 + if (UseSharedSpaces) {
1.99 + // Sharing is enabled so we remap the shared readonly space to
1.100 + // shared readwrite, private just in case we need to redefine
1.101 + // a shared class. We do the remap during the doit() phase of
1.102 + // the safepoint to be safer.
1.103 + if (!CompactingPermGenGen::remap_shared_readonly_as_readwrite()) {
1.104 + RC_TRACE_WITH_THREAD(0x00000001, thread,
1.105 + ("failed to remap shared readonly space to readwrite, private"));
1.106 + _res = JVMTI_ERROR_INTERNAL;
1.107 + return;
1.108 + }
1.109 + }
1.110 +
1.111 + for (int i = 0; i < _class_count; i++) {
1.112 + redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread);
1.113 + }
1.114 + // Disable any dependent concurrent compilations
1.115 + SystemDictionary::notice_modification();
1.116 +
1.117 + // Set flag indicating that some invariants are no longer true.
1.118 + // See jvmtiExport.hpp for detailed explanation.
1.119 + JvmtiExport::set_has_redefined_a_class();
1.120 +
1.121 +#ifdef ASSERT
1.122 + SystemDictionary::classes_do(check_class, thread);
1.123 +#endif
1.124 +}
1.125 +
1.126 +void VM_RedefineClasses::doit_epilogue() {
1.127 + // Free os::malloc allocated memory.
1.128 + // The memory allocated in redefine will be free'ed in next VM operation.
1.129 + os::free(_scratch_classes);
1.130 +
1.131 + if (RC_TRACE_ENABLED(0x00000004)) {
1.132 + // Used to have separate timers for "doit" and "all", but the timer
1.133 + // overhead skewed the measurements.
1.134 + jlong doit_time = _timer_rsc_phase1.milliseconds() +
1.135 + _timer_rsc_phase2.milliseconds();
1.136 + jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time;
1.137 +
1.138 + RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT
1.139 + " prologue=" UINT64_FORMAT " doit=" UINT64_FORMAT, all_time,
1.140 + _timer_vm_op_prologue.milliseconds(), doit_time));
1.141 + RC_TRACE(0x00000004,
1.142 + ("redefine_single_class: phase1=" UINT64_FORMAT " phase2=" UINT64_FORMAT,
1.143 + _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds()));
1.144 + }
1.145 +}
1.146 +
1.147 +bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) {
1.148 + // classes for primitives cannot be redefined
1.149 + if (java_lang_Class::is_primitive(klass_mirror)) {
1.150 + return false;
1.151 + }
1.152 + klassOop the_class_oop = java_lang_Class::as_klassOop(klass_mirror);
1.153 + // classes for arrays cannot be redefined
1.154 + if (the_class_oop == NULL || !Klass::cast(the_class_oop)->oop_is_instance()) {
1.155 + return false;
1.156 + }
1.157 + return true;
1.158 +}
1.159 +
1.160 +// Append the current entry at scratch_i in scratch_cp to *merge_cp_p
1.161 +// where the end of *merge_cp_p is specified by *merge_cp_length_p. For
1.162 +// direct CP entries, there is just the current entry to append. For
1.163 +// indirect and double-indirect CP entries, there are zero or more
1.164 +// referenced CP entries along with the current entry to append.
1.165 +// Indirect and double-indirect CP entries are handled by recursive
1.166 +// calls to append_entry() as needed. The referenced CP entries are
1.167 +// always appended to *merge_cp_p before the referee CP entry. These
1.168 +// referenced CP entries may already exist in *merge_cp_p in which case
1.169 +// there is nothing extra to append and only the current entry is
1.170 +// appended.
1.171 +void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp,
1.172 + int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p,
1.173 + TRAPS) {
1.174 +
1.175 + // append is different depending on entry tag type
1.176 + switch (scratch_cp->tag_at(scratch_i).value()) {
1.177 +
1.178 + // The old verifier is implemented outside the VM. It loads classes,
1.179 + // but does not resolve constant pool entries directly so we never
1.180 + // see Class entries here with the old verifier. Similarly the old
1.181 + // verifier does not like Class entries in the input constant pool.
1.182 + // The split-verifier is implemented in the VM so it can optionally
1.183 + // and directly resolve constant pool entries to load classes. The
1.184 + // split-verifier can accept either Class entries or UnresolvedClass
1.185 + // entries in the input constant pool. We revert the appended copy
1.186 + // back to UnresolvedClass so that either verifier will be happy
1.187 + // with the constant pool entry.
1.188 + case JVM_CONSTANT_Class:
1.189 + {
1.190 + // revert the copy to JVM_CONSTANT_UnresolvedClass
1.191 + (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p,
1.192 + scratch_cp->klass_name_at(scratch_i));
1.193 +
1.194 + if (scratch_i != *merge_cp_length_p) {
1.195 + // The new entry in *merge_cp_p is at a different index than
1.196 + // the new entry in scratch_cp so we need to map the index values.
1.197 + map_index(scratch_cp, scratch_i, *merge_cp_length_p);
1.198 + }
1.199 + (*merge_cp_length_p)++;
1.200 + } break;
1.201 +
1.202 + // these are direct CP entries so they can be directly appended,
1.203 + // but double and long take two constant pool entries
1.204 + case JVM_CONSTANT_Double: // fall through
1.205 + case JVM_CONSTANT_Long:
1.206 + {
1.207 + scratch_cp->copy_entry_to(scratch_i, *merge_cp_p, *merge_cp_length_p,
1.208 + THREAD);
1.209 +
1.210 + if (scratch_i != *merge_cp_length_p) {
1.211 + // The new entry in *merge_cp_p is at a different index than
1.212 + // the new entry in scratch_cp so we need to map the index values.
1.213 + map_index(scratch_cp, scratch_i, *merge_cp_length_p);
1.214 + }
1.215 + (*merge_cp_length_p) += 2;
1.216 + } break;
1.217 +
1.218 + // these are direct CP entries so they can be directly appended
1.219 + case JVM_CONSTANT_Float: // fall through
1.220 + case JVM_CONSTANT_Integer: // fall through
1.221 + case JVM_CONSTANT_Utf8: // fall through
1.222 +
1.223 + // This was an indirect CP entry, but it has been changed into
1.224 + // an interned string so this entry can be directly appended.
1.225 + case JVM_CONSTANT_String: // fall through
1.226 +
1.227 + // These were indirect CP entries, but they have been changed into
1.228 + // symbolOops so these entries can be directly appended.
1.229 + case JVM_CONSTANT_UnresolvedClass: // fall through
1.230 + case JVM_CONSTANT_UnresolvedString:
1.231 + {
1.232 + scratch_cp->copy_entry_to(scratch_i, *merge_cp_p, *merge_cp_length_p,
1.233 + THREAD);
1.234 +
1.235 + if (scratch_i != *merge_cp_length_p) {
1.236 + // The new entry in *merge_cp_p is at a different index than
1.237 + // the new entry in scratch_cp so we need to map the index values.
1.238 + map_index(scratch_cp, scratch_i, *merge_cp_length_p);
1.239 + }
1.240 + (*merge_cp_length_p)++;
1.241 + } break;
1.242 +
1.243 + // this is an indirect CP entry so it needs special handling
1.244 + case JVM_CONSTANT_NameAndType:
1.245 + {
1.246 + int name_ref_i = scratch_cp->name_ref_index_at(scratch_i);
1.247 + int new_name_ref_i = 0;
1.248 + bool match = (name_ref_i < *merge_cp_length_p) &&
1.249 + scratch_cp->compare_entry_to(name_ref_i, *merge_cp_p, name_ref_i,
1.250 + THREAD);
1.251 + if (!match) {
1.252 + // forward reference in *merge_cp_p or not a direct match
1.253 +
1.254 + int found_i = scratch_cp->find_matching_entry(name_ref_i, *merge_cp_p,
1.255 + THREAD);
1.256 + if (found_i != 0) {
1.257 + guarantee(found_i != name_ref_i,
1.258 + "compare_entry_to() and find_matching_entry() do not agree");
1.259 +
1.260 + // Found a matching entry somewhere else in *merge_cp_p so
1.261 + // just need a mapping entry.
1.262 + new_name_ref_i = found_i;
1.263 + map_index(scratch_cp, name_ref_i, found_i);
1.264 + } else {
1.265 + // no match found so we have to append this entry to *merge_cp_p
1.266 + append_entry(scratch_cp, name_ref_i, merge_cp_p, merge_cp_length_p,
1.267 + THREAD);
1.268 + // The above call to append_entry() can only append one entry
1.269 + // so the post call query of *merge_cp_length_p is only for
1.270 + // the sake of consistency.
1.271 + new_name_ref_i = *merge_cp_length_p - 1;
1.272 + }
1.273 + }
1.274 +
1.275 + int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i);
1.276 + int new_signature_ref_i = 0;
1.277 + match = (signature_ref_i < *merge_cp_length_p) &&
1.278 + scratch_cp->compare_entry_to(signature_ref_i, *merge_cp_p,
1.279 + signature_ref_i, THREAD);
1.280 + if (!match) {
1.281 + // forward reference in *merge_cp_p or not a direct match
1.282 +
1.283 + int found_i = scratch_cp->find_matching_entry(signature_ref_i,
1.284 + *merge_cp_p, THREAD);
1.285 + if (found_i != 0) {
1.286 + guarantee(found_i != signature_ref_i,
1.287 + "compare_entry_to() and find_matching_entry() do not agree");
1.288 +
1.289 + // Found a matching entry somewhere else in *merge_cp_p so
1.290 + // just need a mapping entry.
1.291 + new_signature_ref_i = found_i;
1.292 + map_index(scratch_cp, signature_ref_i, found_i);
1.293 + } else {
1.294 + // no match found so we have to append this entry to *merge_cp_p
1.295 + append_entry(scratch_cp, signature_ref_i, merge_cp_p,
1.296 + merge_cp_length_p, THREAD);
1.297 + // The above call to append_entry() can only append one entry
1.298 + // so the post call query of *merge_cp_length_p is only for
1.299 + // the sake of consistency.
1.300 + new_signature_ref_i = *merge_cp_length_p - 1;
1.301 + }
1.302 + }
1.303 +
1.304 + // If the referenced entries already exist in *merge_cp_p, then
1.305 + // both new_name_ref_i and new_signature_ref_i will both be 0.
1.306 + // In that case, all we are appending is the current entry.
1.307 + if (new_name_ref_i == 0) {
1.308 + new_name_ref_i = name_ref_i;
1.309 + } else {
1.310 + RC_TRACE(0x00080000,
1.311 + ("NameAndType entry@%d name_ref_index change: %d to %d",
1.312 + *merge_cp_length_p, name_ref_i, new_name_ref_i));
1.313 + }
1.314 + if (new_signature_ref_i == 0) {
1.315 + new_signature_ref_i = signature_ref_i;
1.316 + } else {
1.317 + RC_TRACE(0x00080000,
1.318 + ("NameAndType entry@%d signature_ref_index change: %d to %d",
1.319 + *merge_cp_length_p, signature_ref_i, new_signature_ref_i));
1.320 + }
1.321 +
1.322 + (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p,
1.323 + new_name_ref_i, new_signature_ref_i);
1.324 + if (scratch_i != *merge_cp_length_p) {
1.325 + // The new entry in *merge_cp_p is at a different index than
1.326 + // the new entry in scratch_cp so we need to map the index values.
1.327 + map_index(scratch_cp, scratch_i, *merge_cp_length_p);
1.328 + }
1.329 + (*merge_cp_length_p)++;
1.330 + } break;
1.331 +
1.332 + // this is a double-indirect CP entry so it needs special handling
1.333 + case JVM_CONSTANT_Fieldref: // fall through
1.334 + case JVM_CONSTANT_InterfaceMethodref: // fall through
1.335 + case JVM_CONSTANT_Methodref:
1.336 + {
1.337 + int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i);
1.338 + int new_klass_ref_i = 0;
1.339 + bool match = (klass_ref_i < *merge_cp_length_p) &&
1.340 + scratch_cp->compare_entry_to(klass_ref_i, *merge_cp_p, klass_ref_i,
1.341 + THREAD);
1.342 + if (!match) {
1.343 + // forward reference in *merge_cp_p or not a direct match
1.344 +
1.345 + int found_i = scratch_cp->find_matching_entry(klass_ref_i, *merge_cp_p,
1.346 + THREAD);
1.347 + if (found_i != 0) {
1.348 + guarantee(found_i != klass_ref_i,
1.349 + "compare_entry_to() and find_matching_entry() do not agree");
1.350 +
1.351 + // Found a matching entry somewhere else in *merge_cp_p so
1.352 + // just need a mapping entry.
1.353 + new_klass_ref_i = found_i;
1.354 + map_index(scratch_cp, klass_ref_i, found_i);
1.355 + } else {
1.356 + // no match found so we have to append this entry to *merge_cp_p
1.357 + append_entry(scratch_cp, klass_ref_i, merge_cp_p, merge_cp_length_p,
1.358 + THREAD);
1.359 + // The above call to append_entry() can only append one entry
1.360 + // so the post call query of *merge_cp_length_p is only for
1.361 + // the sake of consistency. Without the optimization where we
1.362 + // use JVM_CONSTANT_UnresolvedClass, then up to two entries
1.363 + // could be appended.
1.364 + new_klass_ref_i = *merge_cp_length_p - 1;
1.365 + }
1.366 + }
1.367 +
1.368 + int name_and_type_ref_i =
1.369 + scratch_cp->uncached_name_and_type_ref_index_at(scratch_i);
1.370 + int new_name_and_type_ref_i = 0;
1.371 + match = (name_and_type_ref_i < *merge_cp_length_p) &&
1.372 + scratch_cp->compare_entry_to(name_and_type_ref_i, *merge_cp_p,
1.373 + name_and_type_ref_i, THREAD);
1.374 + if (!match) {
1.375 + // forward reference in *merge_cp_p or not a direct match
1.376 +
1.377 + int found_i = scratch_cp->find_matching_entry(name_and_type_ref_i,
1.378 + *merge_cp_p, THREAD);
1.379 + if (found_i != 0) {
1.380 + guarantee(found_i != name_and_type_ref_i,
1.381 + "compare_entry_to() and find_matching_entry() do not agree");
1.382 +
1.383 + // Found a matching entry somewhere else in *merge_cp_p so
1.384 + // just need a mapping entry.
1.385 + new_name_and_type_ref_i = found_i;
1.386 + map_index(scratch_cp, name_and_type_ref_i, found_i);
1.387 + } else {
1.388 + // no match found so we have to append this entry to *merge_cp_p
1.389 + append_entry(scratch_cp, name_and_type_ref_i, merge_cp_p,
1.390 + merge_cp_length_p, THREAD);
1.391 + // The above call to append_entry() can append more than
1.392 + // one entry so the post call query of *merge_cp_length_p
1.393 + // is required in order to get the right index for the
1.394 + // JVM_CONSTANT_NameAndType entry.
1.395 + new_name_and_type_ref_i = *merge_cp_length_p - 1;
1.396 + }
1.397 + }
1.398 +
1.399 + // If the referenced entries already exist in *merge_cp_p, then
1.400 + // both new_klass_ref_i and new_name_and_type_ref_i will both be
1.401 + // 0. In that case, all we are appending is the current entry.
1.402 + if (new_klass_ref_i == 0) {
1.403 + new_klass_ref_i = klass_ref_i;
1.404 + }
1.405 + if (new_name_and_type_ref_i == 0) {
1.406 + new_name_and_type_ref_i = name_and_type_ref_i;
1.407 + }
1.408 +
1.409 + const char *entry_name;
1.410 + switch (scratch_cp->tag_at(scratch_i).value()) {
1.411 + case JVM_CONSTANT_Fieldref:
1.412 + entry_name = "Fieldref";
1.413 + (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i,
1.414 + new_name_and_type_ref_i);
1.415 + break;
1.416 + case JVM_CONSTANT_InterfaceMethodref:
1.417 + entry_name = "IFMethodref";
1.418 + (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p,
1.419 + new_klass_ref_i, new_name_and_type_ref_i);
1.420 + break;
1.421 + case JVM_CONSTANT_Methodref:
1.422 + entry_name = "Methodref";
1.423 + (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i,
1.424 + new_name_and_type_ref_i);
1.425 + break;
1.426 + default:
1.427 + guarantee(false, "bad switch");
1.428 + break;
1.429 + }
1.430 +
1.431 + if (klass_ref_i != new_klass_ref_i) {
1.432 + RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d",
1.433 + entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i));
1.434 + }
1.435 + if (name_and_type_ref_i != new_name_and_type_ref_i) {
1.436 + RC_TRACE(0x00080000,
1.437 + ("%s entry@%d name_and_type_index changed: %d to %d",
1.438 + entry_name, *merge_cp_length_p, name_and_type_ref_i,
1.439 + new_name_and_type_ref_i));
1.440 + }
1.441 +
1.442 + if (scratch_i != *merge_cp_length_p) {
1.443 + // The new entry in *merge_cp_p is at a different index than
1.444 + // the new entry in scratch_cp so we need to map the index values.
1.445 + map_index(scratch_cp, scratch_i, *merge_cp_length_p);
1.446 + }
1.447 + (*merge_cp_length_p)++;
1.448 + } break;
1.449 +
1.450 + // At this stage, Class or UnresolvedClass could be here, but not
1.451 + // ClassIndex
1.452 + case JVM_CONSTANT_ClassIndex: // fall through
1.453 +
1.454 + // Invalid is used as the tag for the second constant pool entry
1.455 + // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1.456 + // not be seen by itself.
1.457 + case JVM_CONSTANT_Invalid: // fall through
1.458 +
1.459 + // At this stage, String or UnresolvedString could be here, but not
1.460 + // StringIndex
1.461 + case JVM_CONSTANT_StringIndex: // fall through
1.462 +
1.463 + // At this stage JVM_CONSTANT_UnresolvedClassInError should not be
1.464 + // here
1.465 + case JVM_CONSTANT_UnresolvedClassInError: // fall through
1.466 +
1.467 + default:
1.468 + {
1.469 + // leave a breadcrumb
1.470 + jbyte bad_value = scratch_cp->tag_at(scratch_i).value();
1.471 + ShouldNotReachHere();
1.472 + } break;
1.473 + } // end switch tag value
1.474 +} // end append_entry()
1.475 +
1.476 +
1.477 +void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class) {
1.478 + typeArrayOop save;
1.479 +
1.480 + save = scratch_class->get_method_annotations_of(i);
1.481 + scratch_class->set_method_annotations_of(i, scratch_class->get_method_annotations_of(j));
1.482 + scratch_class->set_method_annotations_of(j, save);
1.483 +
1.484 + save = scratch_class->get_method_parameter_annotations_of(i);
1.485 + scratch_class->set_method_parameter_annotations_of(i, scratch_class->get_method_parameter_annotations_of(j));
1.486 + scratch_class->set_method_parameter_annotations_of(j, save);
1.487 +
1.488 + save = scratch_class->get_method_default_annotations_of(i);
1.489 + scratch_class->set_method_default_annotations_of(i, scratch_class->get_method_default_annotations_of(j));
1.490 + scratch_class->set_method_default_annotations_of(j, save);
1.491 +}
1.492 +
1.493 +
1.494 +jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
1.495 + instanceKlassHandle the_class,
1.496 + instanceKlassHandle scratch_class) {
1.497 + int i;
1.498 +
1.499 + // Check superclasses, or rather their names, since superclasses themselves can be
1.500 + // requested to replace.
1.501 + // Check for NULL superclass first since this might be java.lang.Object
1.502 + if (the_class->super() != scratch_class->super() &&
1.503 + (the_class->super() == NULL || scratch_class->super() == NULL ||
1.504 + Klass::cast(the_class->super())->name() !=
1.505 + Klass::cast(scratch_class->super())->name())) {
1.506 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
1.507 + }
1.508 +
1.509 + // Check if the number, names and order of directly implemented interfaces are the same.
1.510 + // I think in principle we should just check if the sets of names of directly implemented
1.511 + // interfaces are the same, i.e. the order of declaration (which, however, if changed in the
1.512 + // .java file, also changes in .class file) should not matter. However, comparing sets is
1.513 + // technically a bit more difficult, and, more importantly, I am not sure at present that the
1.514 + // order of interfaces does not matter on the implementation level, i.e. that the VM does not
1.515 + // rely on it somewhere.
1.516 + objArrayOop k_interfaces = the_class->local_interfaces();
1.517 + objArrayOop k_new_interfaces = scratch_class->local_interfaces();
1.518 + int n_intfs = k_interfaces->length();
1.519 + if (n_intfs != k_new_interfaces->length()) {
1.520 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
1.521 + }
1.522 + for (i = 0; i < n_intfs; i++) {
1.523 + if (Klass::cast((klassOop) k_interfaces->obj_at(i))->name() !=
1.524 + Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) {
1.525 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
1.526 + }
1.527 + }
1.528 +
1.529 + // Check whether class is in the error init state.
1.530 + if (the_class->is_in_error_state()) {
1.531 + // TBD #5057930: special error code is needed in 1.6
1.532 + return JVMTI_ERROR_INVALID_CLASS;
1.533 + }
1.534 +
1.535 + // Check whether class modifiers are the same.
1.536 + jushort old_flags = (jushort) the_class->access_flags().get_flags();
1.537 + jushort new_flags = (jushort) scratch_class->access_flags().get_flags();
1.538 + if (old_flags != new_flags) {
1.539 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED;
1.540 + }
1.541 +
1.542 + // Check if the number, names, types and order of fields declared in these classes
1.543 + // are the same.
1.544 + typeArrayOop k_old_fields = the_class->fields();
1.545 + typeArrayOop k_new_fields = scratch_class->fields();
1.546 + int n_fields = k_old_fields->length();
1.547 + if (n_fields != k_new_fields->length()) {
1.548 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
1.549 + }
1.550 +
1.551 + for (i = 0; i < n_fields; i += instanceKlass::next_offset) {
1.552 + // access
1.553 + old_flags = k_old_fields->ushort_at(i + instanceKlass::access_flags_offset);
1.554 + new_flags = k_new_fields->ushort_at(i + instanceKlass::access_flags_offset);
1.555 + if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) {
1.556 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
1.557 + }
1.558 + // offset
1.559 + if (k_old_fields->short_at(i + instanceKlass::low_offset) !=
1.560 + k_new_fields->short_at(i + instanceKlass::low_offset) ||
1.561 + k_old_fields->short_at(i + instanceKlass::high_offset) !=
1.562 + k_new_fields->short_at(i + instanceKlass::high_offset)) {
1.563 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
1.564 + }
1.565 + // name and signature
1.566 + jshort name_index = k_old_fields->short_at(i + instanceKlass::name_index_offset);
1.567 + jshort sig_index = k_old_fields->short_at(i +instanceKlass::signature_index_offset);
1.568 + symbolOop name_sym1 = the_class->constants()->symbol_at(name_index);
1.569 + symbolOop sig_sym1 = the_class->constants()->symbol_at(sig_index);
1.570 + name_index = k_new_fields->short_at(i + instanceKlass::name_index_offset);
1.571 + sig_index = k_new_fields->short_at(i + instanceKlass::signature_index_offset);
1.572 + symbolOop name_sym2 = scratch_class->constants()->symbol_at(name_index);
1.573 + symbolOop sig_sym2 = scratch_class->constants()->symbol_at(sig_index);
1.574 + if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
1.575 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
1.576 + }
1.577 + }
1.578 +
1.579 + // Do a parallel walk through the old and new methods. Detect
1.580 + // cases where they match (exist in both), have been added in
1.581 + // the new methods, or have been deleted (exist only in the
1.582 + // old methods). The class file parser places methods in order
1.583 + // by method name, but does not order overloaded methods by
1.584 + // signature. In order to determine what fate befell the methods,
1.585 + // this code places the overloaded new methods that have matching
1.586 + // old methods in the same order as the old methods and places
1.587 + // new overloaded methods at the end of overloaded methods of
1.588 + // that name. The code for this order normalization is adapted
1.589 + // from the algorithm used in instanceKlass::find_method().
1.590 + // Since we are swapping out of order entries as we find them,
1.591 + // we only have to search forward through the overloaded methods.
1.592 + // Methods which are added and have the same name as an existing
1.593 + // method (but different signature) will be put at the end of
1.594 + // the methods with that name, and the name mismatch code will
1.595 + // handle them.
1.596 + objArrayHandle k_old_methods(the_class->methods());
1.597 + objArrayHandle k_new_methods(scratch_class->methods());
1.598 + int n_old_methods = k_old_methods->length();
1.599 + int n_new_methods = k_new_methods->length();
1.600 +
1.601 + int ni = 0;
1.602 + int oi = 0;
1.603 + while (true) {
1.604 + methodOop k_old_method;
1.605 + methodOop k_new_method;
1.606 + enum { matched, added, deleted, undetermined } method_was = undetermined;
1.607 +
1.608 + if (oi >= n_old_methods) {
1.609 + if (ni >= n_new_methods) {
1.610 + break; // we've looked at everything, done
1.611 + }
1.612 + // New method at the end
1.613 + k_new_method = (methodOop) k_new_methods->obj_at(ni);
1.614 + method_was = added;
1.615 + } else if (ni >= n_new_methods) {
1.616 + // Old method, at the end, is deleted
1.617 + k_old_method = (methodOop) k_old_methods->obj_at(oi);
1.618 + method_was = deleted;
1.619 + } else {
1.620 + // There are more methods in both the old and new lists
1.621 + k_old_method = (methodOop) k_old_methods->obj_at(oi);
1.622 + k_new_method = (methodOop) k_new_methods->obj_at(ni);
1.623 + if (k_old_method->name() != k_new_method->name()) {
1.624 + // Methods are sorted by method name, so a mismatch means added
1.625 + // or deleted
1.626 + if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) {
1.627 + method_was = added;
1.628 + } else {
1.629 + method_was = deleted;
1.630 + }
1.631 + } else if (k_old_method->signature() == k_new_method->signature()) {
1.632 + // Both the name and signature match
1.633 + method_was = matched;
1.634 + } else {
1.635 + // The name matches, but the signature doesn't, which means we have to
1.636 + // search forward through the new overloaded methods.
1.637 + int nj; // outside the loop for post-loop check
1.638 + for (nj = ni + 1; nj < n_new_methods; nj++) {
1.639 + methodOop m = (methodOop)k_new_methods->obj_at(nj);
1.640 + if (k_old_method->name() != m->name()) {
1.641 + // reached another method name so no more overloaded methods
1.642 + method_was = deleted;
1.643 + break;
1.644 + }
1.645 + if (k_old_method->signature() == m->signature()) {
1.646 + // found a match so swap the methods
1.647 + k_new_methods->obj_at_put(ni, m);
1.648 + k_new_methods->obj_at_put(nj, k_new_method);
1.649 + k_new_method = m;
1.650 + method_was = matched;
1.651 + break;
1.652 + }
1.653 + }
1.654 +
1.655 + if (nj >= n_new_methods) {
1.656 + // reached the end without a match; so method was deleted
1.657 + method_was = deleted;
1.658 + }
1.659 + }
1.660 + }
1.661 +
1.662 + switch (method_was) {
1.663 + case matched:
1.664 + // methods match, be sure modifiers do too
1.665 + old_flags = (jushort) k_old_method->access_flags().get_flags();
1.666 + new_flags = (jushort) k_new_method->access_flags().get_flags();
1.667 + if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) {
1.668 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED;
1.669 + }
1.670 + {
1.671 + u2 new_num = k_new_method->method_idnum();
1.672 + u2 old_num = k_old_method->method_idnum();
1.673 + if (new_num != old_num) {
1.674 + methodOop idnum_owner = scratch_class->method_with_idnum(old_num);
1.675 + if (idnum_owner != NULL) {
1.676 + // There is already a method assigned this idnum -- switch them
1.677 + idnum_owner->set_method_idnum(new_num);
1.678 + }
1.679 + k_new_method->set_method_idnum(old_num);
1.680 + swap_all_method_annotations(old_num, new_num, scratch_class);
1.681 + }
1.682 + }
1.683 + RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]",
1.684 + k_new_method->name_and_sig_as_C_string(), ni,
1.685 + k_old_method->name_and_sig_as_C_string(), oi));
1.686 + // advance to next pair of methods
1.687 + ++oi;
1.688 + ++ni;
1.689 + break;
1.690 + case added:
1.691 + // method added, see if it is OK
1.692 + new_flags = (jushort) k_new_method->access_flags().get_flags();
1.693 + if ((new_flags & JVM_ACC_PRIVATE) == 0
1.694 + // hack: private should be treated as final, but alas
1.695 + || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
1.696 + ) {
1.697 + // new methods must be private
1.698 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
1.699 + }
1.700 + {
1.701 + u2 num = the_class->next_method_idnum();
1.702 + if (num == constMethodOopDesc::UNSET_IDNUM) {
1.703 + // cannot add any more methods
1.704 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
1.705 + }
1.706 + u2 new_num = k_new_method->method_idnum();
1.707 + methodOop idnum_owner = scratch_class->method_with_idnum(num);
1.708 + if (idnum_owner != NULL) {
1.709 + // There is already a method assigned this idnum -- switch them
1.710 + idnum_owner->set_method_idnum(new_num);
1.711 + }
1.712 + k_new_method->set_method_idnum(num);
1.713 + swap_all_method_annotations(new_num, num, scratch_class);
1.714 + }
1.715 + RC_TRACE(0x00008000, ("Method added: new: %s [%d]",
1.716 + k_new_method->name_and_sig_as_C_string(), ni));
1.717 + ++ni; // advance to next new method
1.718 + break;
1.719 + case deleted:
1.720 + // method deleted, see if it is OK
1.721 + old_flags = (jushort) k_old_method->access_flags().get_flags();
1.722 + if ((old_flags & JVM_ACC_PRIVATE) == 0
1.723 + // hack: private should be treated as final, but alas
1.724 + || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
1.725 + ) {
1.726 + // deleted methods must be private
1.727 + return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
1.728 + }
1.729 + RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]",
1.730 + k_old_method->name_and_sig_as_C_string(), oi));
1.731 + ++oi; // advance to next old method
1.732 + break;
1.733 + default:
1.734 + ShouldNotReachHere();
1.735 + }
1.736 + }
1.737 +
1.738 + return JVMTI_ERROR_NONE;
1.739 +}
1.740 +
1.741 +
1.742 +// Find new constant pool index value for old constant pool index value
1.743 +// by seaching the index map. Returns zero (0) if there is no mapped
1.744 +// value for the old constant pool index.
1.745 +int VM_RedefineClasses::find_new_index(int old_index) {
1.746 + if (_index_map_count == 0) {
1.747 + // map is empty so nothing can be found
1.748 + return 0;
1.749 + }
1.750 +
1.751 + if (old_index < 1 || old_index >= _index_map_p->length()) {
1.752 + // The old_index is out of range so it is not mapped. This should
1.753 + // not happen in regular constant pool merging use, but it can
1.754 + // happen if a corrupt annotation is processed.
1.755 + return 0;
1.756 + }
1.757 +
1.758 + int value = _index_map_p->at(old_index);
1.759 + if (value == -1) {
1.760 + // the old_index is not mapped
1.761 + return 0;
1.762 + }
1.763 +
1.764 + return value;
1.765 +} // end find_new_index()
1.766 +
1.767 +
1.768 +// Returns true if the current mismatch is due to a resolved/unresolved
1.769 +// class pair. Otherwise, returns false.
1.770 +bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1,
1.771 + int index1, constantPoolHandle cp2, int index2) {
1.772 +
1.773 + jbyte t1 = cp1->tag_at(index1).value();
1.774 + if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) {
1.775 + return false; // wrong entry type; not our special case
1.776 + }
1.777 +
1.778 + jbyte t2 = cp2->tag_at(index2).value();
1.779 + if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) {
1.780 + return false; // wrong entry type; not our special case
1.781 + }
1.782 +
1.783 + if (t1 == t2) {
1.784 + return false; // not a mismatch; not our special case
1.785 + }
1.786 +
1.787 + char *s1 = cp1->klass_name_at(index1)->as_C_string();
1.788 + char *s2 = cp2->klass_name_at(index2)->as_C_string();
1.789 + if (strcmp(s1, s2) != 0) {
1.790 + return false; // strings don't match; not our special case
1.791 + }
1.792 +
1.793 + return true; // made it through the gauntlet; this is our special case
1.794 +} // end is_unresolved_class_mismatch()
1.795 +
1.796 +
1.797 +// Returns true if the current mismatch is due to a resolved/unresolved
1.798 +// string pair. Otherwise, returns false.
1.799 +bool VM_RedefineClasses::is_unresolved_string_mismatch(constantPoolHandle cp1,
1.800 + int index1, constantPoolHandle cp2, int index2) {
1.801 +
1.802 + jbyte t1 = cp1->tag_at(index1).value();
1.803 + if (t1 != JVM_CONSTANT_String && t1 != JVM_CONSTANT_UnresolvedString) {
1.804 + return false; // wrong entry type; not our special case
1.805 + }
1.806 +
1.807 + jbyte t2 = cp2->tag_at(index2).value();
1.808 + if (t2 != JVM_CONSTANT_String && t2 != JVM_CONSTANT_UnresolvedString) {
1.809 + return false; // wrong entry type; not our special case
1.810 + }
1.811 +
1.812 + if (t1 == t2) {
1.813 + return false; // not a mismatch; not our special case
1.814 + }
1.815 +
1.816 + char *s1 = cp1->string_at_noresolve(index1);
1.817 + char *s2 = cp2->string_at_noresolve(index2);
1.818 + if (strcmp(s1, s2) != 0) {
1.819 + return false; // strings don't match; not our special case
1.820 + }
1.821 +
1.822 + return true; // made it through the gauntlet; this is our special case
1.823 +} // end is_unresolved_string_mismatch()
1.824 +
1.825 +
1.826 +jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) {
1.827 + // For consistency allocate memory using os::malloc wrapper.
1.828 + _scratch_classes = (instanceKlassHandle *)
1.829 + os::malloc(sizeof(instanceKlassHandle) * _class_count);
1.830 + if (_scratch_classes == NULL) {
1.831 + return JVMTI_ERROR_OUT_OF_MEMORY;
1.832 + }
1.833 +
1.834 + ResourceMark rm(THREAD);
1.835 +
1.836 + JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current());
1.837 + for (int i = 0; i < _class_count; i++) {
1.838 + oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass);
1.839 + // classes for primitives cannot be redefined
1.840 + if (!is_modifiable_class(mirror)) {
1.841 + return JVMTI_ERROR_UNMODIFIABLE_CLASS;
1.842 + }
1.843 + klassOop the_class_oop = java_lang_Class::as_klassOop(mirror);
1.844 + instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
1.845 + symbolHandle the_class_sym = symbolHandle(THREAD, the_class->name());
1.846 +
1.847 + // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1.848 + RC_TRACE_WITH_THREAD(0x00000001, THREAD,
1.849 + ("loading name=%s (avail_mem=" UINT64_FORMAT "K)",
1.850 + the_class->external_name(), os::available_memory() >> 10));
1.851 +
1.852 + ClassFileStream st((u1*) _class_defs[i].class_bytes,
1.853 + _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__");
1.854 +
1.855 + // Parse the stream.
1.856 + Handle the_class_loader(THREAD, the_class->class_loader());
1.857 + Handle protection_domain(THREAD, the_class->protection_domain());
1.858 + // Set redefined class handle in JvmtiThreadState class.
1.859 + // This redefined class is sent to agent event handler for class file
1.860 + // load hook event.
1.861 + state->set_class_being_redefined(&the_class, _class_load_kind);
1.862 +
1.863 + klassOop k = SystemDictionary::parse_stream(the_class_sym,
1.864 + the_class_loader,
1.865 + protection_domain,
1.866 + &st,
1.867 + THREAD);
1.868 + // Clear class_being_redefined just to be sure.
1.869 + state->clear_class_being_redefined();
1.870 +
1.871 + // TODO: if this is retransform, and nothing changed we can skip it
1.872 +
1.873 + instanceKlassHandle scratch_class (THREAD, k);
1.874 +
1.875 + if (HAS_PENDING_EXCEPTION) {
1.876 + symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
1.877 + // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1.878 + RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'",
1.879 + ex_name->as_C_string()));
1.880 + CLEAR_PENDING_EXCEPTION;
1.881 +
1.882 + if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) {
1.883 + return JVMTI_ERROR_UNSUPPORTED_VERSION;
1.884 + } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) {
1.885 + return JVMTI_ERROR_INVALID_CLASS_FORMAT;
1.886 + } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) {
1.887 + return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
1.888 + } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) {
1.889 + // The message will be "XXX (wrong name: YYY)"
1.890 + return JVMTI_ERROR_NAMES_DONT_MATCH;
1.891 + } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1.892 + return JVMTI_ERROR_OUT_OF_MEMORY;
1.893 + } else { // Just in case more exceptions can be thrown..
1.894 + return JVMTI_ERROR_FAILS_VERIFICATION;
1.895 + }
1.896 + }
1.897 +
1.898 + // Ensure class is linked before redefine
1.899 + if (!the_class->is_linked()) {
1.900 + the_class->link_class(THREAD);
1.901 + if (HAS_PENDING_EXCEPTION) {
1.902 + symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
1.903 + // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1.904 + RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'",
1.905 + ex_name->as_C_string()));
1.906 + CLEAR_PENDING_EXCEPTION;
1.907 + if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1.908 + return JVMTI_ERROR_OUT_OF_MEMORY;
1.909 + } else {
1.910 + return JVMTI_ERROR_INTERNAL;
1.911 + }
1.912 + }
1.913 + }
1.914 +
1.915 + // Do the validity checks in compare_and_normalize_class_versions()
1.916 + // before verifying the byte codes. By doing these checks first, we
1.917 + // limit the number of functions that require redirection from
1.918 + // the_class to scratch_class. In particular, we don't have to
1.919 + // modify JNI GetSuperclass() and thus won't change its performance.
1.920 + jvmtiError res = compare_and_normalize_class_versions(the_class,
1.921 + scratch_class);
1.922 + if (res != JVMTI_ERROR_NONE) {
1.923 + return res;
1.924 + }
1.925 +
1.926 + // verify what the caller passed us
1.927 + {
1.928 + // The bug 6214132 caused the verification to fail.
1.929 + // Information about the_class and scratch_class is temporarily
1.930 + // recorded into jvmtiThreadState. This data is used to redirect
1.931 + // the_class to scratch_class in the JVM_* functions called by the
1.932 + // verifier. Please, refer to jvmtiThreadState.hpp for the detailed
1.933 + // description.
1.934 + RedefineVerifyMark rvm(&the_class, &scratch_class, state);
1.935 + Verifier::verify(
1.936 + scratch_class, Verifier::ThrowException, THREAD);
1.937 + }
1.938 +
1.939 + if (HAS_PENDING_EXCEPTION) {
1.940 + symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
1.941 + // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1.942 + RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1.943 + ("verify_byte_codes exception: '%s'", ex_name->as_C_string()));
1.944 + CLEAR_PENDING_EXCEPTION;
1.945 + if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1.946 + return JVMTI_ERROR_OUT_OF_MEMORY;
1.947 + } else {
1.948 + // tell the caller the bytecodes are bad
1.949 + return JVMTI_ERROR_FAILS_VERIFICATION;
1.950 + }
1.951 + }
1.952 +
1.953 + res = merge_cp_and_rewrite(the_class, scratch_class, THREAD);
1.954 + if (res != JVMTI_ERROR_NONE) {
1.955 + return res;
1.956 + }
1.957 +
1.958 + if (VerifyMergedCPBytecodes) {
1.959 + // verify what we have done during constant pool merging
1.960 + {
1.961 + RedefineVerifyMark rvm(&the_class, &scratch_class, state);
1.962 + Verifier::verify(scratch_class, Verifier::ThrowException, THREAD);
1.963 + }
1.964 +
1.965 + if (HAS_PENDING_EXCEPTION) {
1.966 + symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
1.967 + // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1.968 + RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1.969 + ("verify_byte_codes post merge-CP exception: '%s'",
1.970 + ex_name->as_C_string()));
1.971 + CLEAR_PENDING_EXCEPTION;
1.972 + if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1.973 + return JVMTI_ERROR_OUT_OF_MEMORY;
1.974 + } else {
1.975 + // tell the caller that constant pool merging screwed up
1.976 + return JVMTI_ERROR_INTERNAL;
1.977 + }
1.978 + }
1.979 + }
1.980 +
1.981 + Rewriter::rewrite(scratch_class, THREAD);
1.982 + if (HAS_PENDING_EXCEPTION) {
1.983 + symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
1.984 + CLEAR_PENDING_EXCEPTION;
1.985 + if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1.986 + return JVMTI_ERROR_OUT_OF_MEMORY;
1.987 + } else {
1.988 + return JVMTI_ERROR_INTERNAL;
1.989 + }
1.990 + }
1.991 +
1.992 + _scratch_classes[i] = scratch_class;
1.993 +
1.994 + // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1.995 + RC_TRACE_WITH_THREAD(0x00000001, THREAD,
1.996 + ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)",
1.997 + the_class->external_name(), os::available_memory() >> 10));
1.998 + }
1.999 +
1.1000 + return JVMTI_ERROR_NONE;
1.1001 +}
1.1002 +
1.1003 +
1.1004 +// Map old_index to new_index as needed. scratch_cp is only needed
1.1005 +// for RC_TRACE() calls.
1.1006 +void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp,
1.1007 + int old_index, int new_index) {
1.1008 + if (find_new_index(old_index) != 0) {
1.1009 + // old_index is already mapped
1.1010 + return;
1.1011 + }
1.1012 +
1.1013 + if (old_index == new_index) {
1.1014 + // no mapping is needed
1.1015 + return;
1.1016 + }
1.1017 +
1.1018 + _index_map_p->at_put(old_index, new_index);
1.1019 + _index_map_count++;
1.1020 +
1.1021 + RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d",
1.1022 + scratch_cp->tag_at(old_index).value(), old_index, new_index));
1.1023 +} // end map_index()
1.1024 +
1.1025 +
1.1026 +// Merge old_cp and scratch_cp and return the results of the merge via
1.1027 +// merge_cp_p. The number of entries in *merge_cp_p is returned via
1.1028 +// merge_cp_length_p. The entries in old_cp occupy the same locations
1.1029 +// in *merge_cp_p. Also creates a map of indices from entries in
1.1030 +// scratch_cp to the corresponding entry in *merge_cp_p. Index map
1.1031 +// entries are only created for entries in scratch_cp that occupy a
1.1032 +// different location in *merged_cp_p.
1.1033 +bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp,
1.1034 + constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p,
1.1035 + int *merge_cp_length_p, TRAPS) {
1.1036 +
1.1037 + if (merge_cp_p == NULL) {
1.1038 + assert(false, "caller must provide scatch constantPool");
1.1039 + return false; // robustness
1.1040 + }
1.1041 + if (merge_cp_length_p == NULL) {
1.1042 + assert(false, "caller must provide scatch CP length");
1.1043 + return false; // robustness
1.1044 + }
1.1045 + // Worst case we need old_cp->length() + scratch_cp()->length(),
1.1046 + // but the caller might be smart so make sure we have at least
1.1047 + // the minimum.
1.1048 + if ((*merge_cp_p)->length() < old_cp->length()) {
1.1049 + assert(false, "merge area too small");
1.1050 + return false; // robustness
1.1051 + }
1.1052 +
1.1053 + RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1.1054 + ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(),
1.1055 + scratch_cp->length()));
1.1056 +
1.1057 + {
1.1058 + // Pass 0:
1.1059 + // The old_cp is copied to *merge_cp_p; this means that any code
1.1060 + // using old_cp does not have to change. This work looks like a
1.1061 + // perfect fit for constantPoolOop::copy_cp_to(), but we need to
1.1062 + // handle one special case:
1.1063 + // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass
1.1064 + // This will make verification happy.
1.1065 +
1.1066 + int old_i; // index into old_cp
1.1067 +
1.1068 + // index zero (0) is not used in constantPools
1.1069 + for (old_i = 1; old_i < old_cp->length(); old_i++) {
1.1070 + // leave debugging crumb
1.1071 + jbyte old_tag = old_cp->tag_at(old_i).value();
1.1072 + switch (old_tag) {
1.1073 + case JVM_CONSTANT_Class:
1.1074 + // revert the copy to JVM_CONSTANT_UnresolvedClass
1.1075 + (*merge_cp_p)->unresolved_klass_at_put(old_i,
1.1076 + old_cp->klass_name_at(old_i));
1.1077 + break;
1.1078 +
1.1079 + case JVM_CONSTANT_Double:
1.1080 + case JVM_CONSTANT_Long:
1.1081 + // just copy the entry to *merge_cp_p, but double and long take
1.1082 + // two constant pool entries
1.1083 + old_cp->copy_entry_to(old_i, *merge_cp_p, old_i, CHECK_0);
1.1084 + old_i++;
1.1085 + break;
1.1086 +
1.1087 + default:
1.1088 + // just copy the entry to *merge_cp_p
1.1089 + old_cp->copy_entry_to(old_i, *merge_cp_p, old_i, CHECK_0);
1.1090 + break;
1.1091 + }
1.1092 + } // end for each old_cp entry
1.1093 +
1.1094 + // We don't need to sanity check that *merge_cp_length_p is within
1.1095 + // *merge_cp_p bounds since we have the minimum on-entry check above.
1.1096 + (*merge_cp_length_p) = old_i;
1.1097 + }
1.1098 +
1.1099 + // merge_cp_len should be the same as old_cp->length() at this point
1.1100 + // so this trace message is really a "warm-and-breathing" message.
1.1101 + RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1.1102 + ("after pass 0: merge_cp_len=%d", *merge_cp_length_p));
1.1103 +
1.1104 + int scratch_i; // index into scratch_cp
1.1105 + {
1.1106 + // Pass 1a:
1.1107 + // Compare scratch_cp entries to the old_cp entries that we have
1.1108 + // already copied to *merge_cp_p. In this pass, we are eliminating
1.1109 + // exact duplicates (matching entry at same index) so we only
1.1110 + // compare entries in the common indice range.
1.1111 + int increment = 1;
1.1112 + int pass1a_length = MIN2(old_cp->length(), scratch_cp->length());
1.1113 + for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) {
1.1114 + switch (scratch_cp->tag_at(scratch_i).value()) {
1.1115 + case JVM_CONSTANT_Double:
1.1116 + case JVM_CONSTANT_Long:
1.1117 + // double and long take two constant pool entries
1.1118 + increment = 2;
1.1119 + break;
1.1120 +
1.1121 + default:
1.1122 + increment = 1;
1.1123 + break;
1.1124 + }
1.1125 +
1.1126 + bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p,
1.1127 + scratch_i, CHECK_0);
1.1128 + if (match) {
1.1129 + // found a match at the same index so nothing more to do
1.1130 + continue;
1.1131 + } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i,
1.1132 + *merge_cp_p, scratch_i)) {
1.1133 + // The mismatch in compare_entry_to() above is because of a
1.1134 + // resolved versus unresolved class entry at the same index
1.1135 + // with the same string value. Since Pass 0 reverted any
1.1136 + // class entries to unresolved class entries in *merge_cp_p,
1.1137 + // we go with the unresolved class entry.
1.1138 + continue;
1.1139 + } else if (is_unresolved_string_mismatch(scratch_cp, scratch_i,
1.1140 + *merge_cp_p, scratch_i)) {
1.1141 + // The mismatch in compare_entry_to() above is because of a
1.1142 + // resolved versus unresolved string entry at the same index
1.1143 + // with the same string value. We can live with whichever
1.1144 + // happens to be at scratch_i in *merge_cp_p.
1.1145 + continue;
1.1146 + }
1.1147 +
1.1148 + int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p,
1.1149 + CHECK_0);
1.1150 + if (found_i != 0) {
1.1151 + guarantee(found_i != scratch_i,
1.1152 + "compare_entry_to() and find_matching_entry() do not agree");
1.1153 +
1.1154 + // Found a matching entry somewhere else in *merge_cp_p so
1.1155 + // just need a mapping entry.
1.1156 + map_index(scratch_cp, scratch_i, found_i);
1.1157 + continue;
1.1158 + }
1.1159 +
1.1160 + // The find_matching_entry() call above could fail to find a match
1.1161 + // due to a resolved versus unresolved class or string entry situation
1.1162 + // like we solved above with the is_unresolved_*_mismatch() calls.
1.1163 + // However, we would have to call is_unresolved_*_mismatch() over
1.1164 + // all of *merge_cp_p (potentially) and that doesn't seem to be
1.1165 + // worth the time.
1.1166 +
1.1167 + // No match found so we have to append this entry and any unique
1.1168 + // referenced entries to *merge_cp_p.
1.1169 + append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1.1170 + CHECK_0);
1.1171 + }
1.1172 + }
1.1173 +
1.1174 + RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1.1175 + ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1.1176 + *merge_cp_length_p, scratch_i, _index_map_count));
1.1177 +
1.1178 + if (scratch_i < scratch_cp->length()) {
1.1179 + // Pass 1b:
1.1180 + // old_cp is smaller than scratch_cp so there are entries in
1.1181 + // scratch_cp that we have not yet processed. We take care of
1.1182 + // those now.
1.1183 + int increment = 1;
1.1184 + for (; scratch_i < scratch_cp->length(); scratch_i += increment) {
1.1185 + switch (scratch_cp->tag_at(scratch_i).value()) {
1.1186 + case JVM_CONSTANT_Double:
1.1187 + case JVM_CONSTANT_Long:
1.1188 + // double and long take two constant pool entries
1.1189 + increment = 2;
1.1190 + break;
1.1191 +
1.1192 + default:
1.1193 + increment = 1;
1.1194 + break;
1.1195 + }
1.1196 +
1.1197 + int found_i =
1.1198 + scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0);
1.1199 + if (found_i != 0) {
1.1200 + // Found a matching entry somewhere else in *merge_cp_p so
1.1201 + // just need a mapping entry.
1.1202 + map_index(scratch_cp, scratch_i, found_i);
1.1203 + continue;
1.1204 + }
1.1205 +
1.1206 + // No match found so we have to append this entry and any unique
1.1207 + // referenced entries to *merge_cp_p.
1.1208 + append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1.1209 + CHECK_0);
1.1210 + }
1.1211 +
1.1212 + RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1.1213 + ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1.1214 + *merge_cp_length_p, scratch_i, _index_map_count));
1.1215 + }
1.1216 +
1.1217 + return true;
1.1218 +} // end merge_constant_pools()
1.1219 +
1.1220 +
1.1221 +// Merge constant pools between the_class and scratch_class and
1.1222 +// potentially rewrite bytecodes in scratch_class to use the merged
1.1223 +// constant pool.
1.1224 +jvmtiError VM_RedefineClasses::merge_cp_and_rewrite(
1.1225 + instanceKlassHandle the_class, instanceKlassHandle scratch_class,
1.1226 + TRAPS) {
1.1227 + // worst case merged constant pool length is old and new combined
1.1228 + int merge_cp_length = the_class->constants()->length()
1.1229 + + scratch_class->constants()->length();
1.1230 +
1.1231 + constantPoolHandle old_cp(THREAD, the_class->constants());
1.1232 + constantPoolHandle scratch_cp(THREAD, scratch_class->constants());
1.1233 +
1.1234 + // Constant pools are not easily reused so we allocate a new one
1.1235 + // each time.
1.1236 + constantPoolHandle merge_cp(THREAD,
1.1237 + oopFactory::new_constantPool(merge_cp_length, THREAD));
1.1238 + int orig_length = old_cp->orig_length();
1.1239 + if (orig_length == 0) {
1.1240 + // This old_cp is an actual original constant pool. We save
1.1241 + // the original length in the merged constant pool so that
1.1242 + // merge_constant_pools() can be more efficient. If a constant
1.1243 + // pool has a non-zero orig_length() value, then that constant
1.1244 + // pool was created by a merge operation in RedefineClasses.
1.1245 + merge_cp->set_orig_length(old_cp->length());
1.1246 + } else {
1.1247 + // This old_cp is a merged constant pool from a previous
1.1248 + // RedefineClasses() calls so just copy the orig_length()
1.1249 + // value.
1.1250 + merge_cp->set_orig_length(old_cp->orig_length());
1.1251 + }
1.1252 +
1.1253 + ResourceMark rm(THREAD);
1.1254 + _index_map_count = 0;
1.1255 + _index_map_p = new intArray(scratch_cp->length(), -1);
1.1256 +
1.1257 + bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp,
1.1258 + &merge_cp_length, THREAD);
1.1259 + if (!result) {
1.1260 + // The merge can fail due to memory allocation failure or due
1.1261 + // to robustness checks.
1.1262 + return JVMTI_ERROR_INTERNAL;
1.1263 + }
1.1264 +
1.1265 + RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1.1266 + ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count));
1.1267 +
1.1268 + if (_index_map_count == 0) {
1.1269 + // there is nothing to map between the new and merged constant pools
1.1270 +
1.1271 + if (old_cp->length() == scratch_cp->length()) {
1.1272 + // The old and new constant pools are the same length and the
1.1273 + // index map is empty. This means that the three constant pools
1.1274 + // are equivalent (but not the same). Unfortunately, the new
1.1275 + // constant pool has not gone through link resolution nor have
1.1276 + // the new class bytecodes gone through constant pool cache
1.1277 + // rewriting so we can't use the old constant pool with the new
1.1278 + // class.
1.1279 +
1.1280 + merge_cp = constantPoolHandle(); // toss the merged constant pool
1.1281 + } else if (old_cp->length() < scratch_cp->length()) {
1.1282 + // The old constant pool has fewer entries than the new constant
1.1283 + // pool and the index map is empty. This means the new constant
1.1284 + // pool is a superset of the old constant pool. However, the old
1.1285 + // class bytecodes have already gone through constant pool cache
1.1286 + // rewriting so we can't use the new constant pool with the old
1.1287 + // class.
1.1288 +
1.1289 + merge_cp = constantPoolHandle(); // toss the merged constant pool
1.1290 + } else {
1.1291 + // The old constant pool has more entries than the new constant
1.1292 + // pool and the index map is empty. This means that both the old
1.1293 + // and merged constant pools are supersets of the new constant
1.1294 + // pool.
1.1295 +
1.1296 + // Replace the new constant pool with a shrunken copy of the
1.1297 + // merged constant pool; the previous new constant pool will
1.1298 + // get GCed.
1.1299 + set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true,
1.1300 + THREAD);
1.1301 + // drop local ref to the merged constant pool
1.1302 + merge_cp = constantPoolHandle();
1.1303 + }
1.1304 + } else {
1.1305 + if (RC_TRACE_ENABLED(0x00040000)) {
1.1306 + // don't want to loop unless we are tracing
1.1307 + int count = 0;
1.1308 + for (int i = 1; i < _index_map_p->length(); i++) {
1.1309 + int value = _index_map_p->at(i);
1.1310 +
1.1311 + if (value != -1) {
1.1312 + RC_TRACE_WITH_THREAD(0x00040000, THREAD,
1.1313 + ("index_map[%d]: old=%d new=%d", count, i, value));
1.1314 + count++;
1.1315 + }
1.1316 + }
1.1317 + }
1.1318 +
1.1319 + // We have entries mapped between the new and merged constant pools
1.1320 + // so we have to rewrite some constant pool references.
1.1321 + if (!rewrite_cp_refs(scratch_class, THREAD)) {
1.1322 + return JVMTI_ERROR_INTERNAL;
1.1323 + }
1.1324 +
1.1325 + // Replace the new constant pool with a shrunken copy of the
1.1326 + // merged constant pool so now the rewritten bytecodes have
1.1327 + // valid references; the previous new constant pool will get
1.1328 + // GCed.
1.1329 + set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true,
1.1330 + THREAD);
1.1331 + }
1.1332 +
1.1333 + return JVMTI_ERROR_NONE;
1.1334 +} // end merge_cp_and_rewrite()
1.1335 +
1.1336 +
1.1337 +// Rewrite constant pool references in klass scratch_class.
1.1338 +bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
1.1339 + TRAPS) {
1.1340 +
1.1341 + // rewrite constant pool references in the methods:
1.1342 + if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) {
1.1343 + // propogate failure back to caller
1.1344 + return false;
1.1345 + }
1.1346 +
1.1347 + // rewrite constant pool references in the class_annotations:
1.1348 + if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) {
1.1349 + // propogate failure back to caller
1.1350 + return false;
1.1351 + }
1.1352 +
1.1353 + // rewrite constant pool references in the fields_annotations:
1.1354 + if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) {
1.1355 + // propogate failure back to caller
1.1356 + return false;
1.1357 + }
1.1358 +
1.1359 + // rewrite constant pool references in the methods_annotations:
1.1360 + if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) {
1.1361 + // propogate failure back to caller
1.1362 + return false;
1.1363 + }
1.1364 +
1.1365 + // rewrite constant pool references in the methods_parameter_annotations:
1.1366 + if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class,
1.1367 + THREAD)) {
1.1368 + // propogate failure back to caller
1.1369 + return false;
1.1370 + }
1.1371 +
1.1372 + // rewrite constant pool references in the methods_default_annotations:
1.1373 + if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class,
1.1374 + THREAD)) {
1.1375 + // propogate failure back to caller
1.1376 + return false;
1.1377 + }
1.1378 +
1.1379 + return true;
1.1380 +} // end rewrite_cp_refs()
1.1381 +
1.1382 +
1.1383 +// Rewrite constant pool references in the methods.
1.1384 +bool VM_RedefineClasses::rewrite_cp_refs_in_methods(
1.1385 + instanceKlassHandle scratch_class, TRAPS) {
1.1386 +
1.1387 + objArrayHandle methods(THREAD, scratch_class->methods());
1.1388 +
1.1389 + if (methods.is_null() || methods->length() == 0) {
1.1390 + // no methods so nothing to do
1.1391 + return true;
1.1392 + }
1.1393 +
1.1394 + // rewrite constant pool references in the methods:
1.1395 + for (int i = methods->length() - 1; i >= 0; i--) {
1.1396 + methodHandle method(THREAD, (methodOop)methods->obj_at(i));
1.1397 + methodHandle new_method;
1.1398 + rewrite_cp_refs_in_method(method, &new_method, CHECK_false);
1.1399 + if (!new_method.is_null()) {
1.1400 + // the method has been replaced so save the new method version
1.1401 + methods->obj_at_put(i, new_method());
1.1402 + }
1.1403 + }
1.1404 +
1.1405 + return true;
1.1406 +}
1.1407 +
1.1408 +
1.1409 +// Rewrite constant pool references in the specific method. This code
1.1410 +// was adapted from Rewriter::rewrite_method().
1.1411 +void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method,
1.1412 + methodHandle *new_method_p, TRAPS) {
1.1413 +
1.1414 + *new_method_p = methodHandle(); // default is no new method
1.1415 +
1.1416 + // We cache a pointer to the bytecodes here in code_base. If GC
1.1417 + // moves the methodOop, then the bytecodes will also move which
1.1418 + // will likely cause a crash. We create a No_Safepoint_Verifier
1.1419 + // object to detect whether we pass a possible safepoint in this
1.1420 + // code block.
1.1421 + No_Safepoint_Verifier nsv;
1.1422 +
1.1423 + // Bytecodes and their length
1.1424 + address code_base = method->code_base();
1.1425 + int code_length = method->code_size();
1.1426 +
1.1427 + int bc_length;
1.1428 + for (int bci = 0; bci < code_length; bci += bc_length) {
1.1429 + address bcp = code_base + bci;
1.1430 + Bytecodes::Code c = (Bytecodes::Code)(*bcp);
1.1431 +
1.1432 + bc_length = Bytecodes::length_for(c);
1.1433 + if (bc_length == 0) {
1.1434 + // More complicated bytecodes report a length of zero so
1.1435 + // we have to try again a slightly different way.
1.1436 + bc_length = Bytecodes::length_at(bcp);
1.1437 + }
1.1438 +
1.1439 + assert(bc_length != 0, "impossible bytecode length");
1.1440 +
1.1441 + switch (c) {
1.1442 + case Bytecodes::_ldc:
1.1443 + {
1.1444 + int cp_index = *(bcp + 1);
1.1445 + int new_index = find_new_index(cp_index);
1.1446 +
1.1447 + if (StressLdcRewrite && new_index == 0) {
1.1448 + // If we are stressing ldc -> ldc_w rewriting, then we
1.1449 + // always need a new_index value.
1.1450 + new_index = cp_index;
1.1451 + }
1.1452 + if (new_index != 0) {
1.1453 + // the original index is mapped so we have more work to do
1.1454 + if (!StressLdcRewrite && new_index <= max_jubyte) {
1.1455 + // The new value can still use ldc instead of ldc_w
1.1456 + // unless we are trying to stress ldc -> ldc_w rewriting
1.1457 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.1458 + ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1.1459 + bcp, cp_index, new_index));
1.1460 + *(bcp + 1) = new_index;
1.1461 + } else {
1.1462 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.1463 + ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d",
1.1464 + Bytecodes::name(c), bcp, cp_index, new_index));
1.1465 + // the new value needs ldc_w instead of ldc
1.1466 + u_char inst_buffer[4]; // max instruction size is 4 bytes
1.1467 + bcp = (address)inst_buffer;
1.1468 + // construct new instruction sequence
1.1469 + *bcp = Bytecodes::_ldc_w;
1.1470 + bcp++;
1.1471 + // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w.
1.1472 + // See comment below for difference between put_Java_u2()
1.1473 + // and put_native_u2().
1.1474 + Bytes::put_Java_u2(bcp, new_index);
1.1475 +
1.1476 + Relocator rc(method, NULL /* no RelocatorListener needed */);
1.1477 + methodHandle m;
1.1478 + {
1.1479 + Pause_No_Safepoint_Verifier pnsv(&nsv);
1.1480 +
1.1481 + // ldc is 2 bytes and ldc_w is 3 bytes
1.1482 + m = rc.insert_space_at(bci, 3, inst_buffer, THREAD);
1.1483 + if (m.is_null() || HAS_PENDING_EXCEPTION) {
1.1484 + guarantee(false, "insert_space_at() failed");
1.1485 + }
1.1486 + }
1.1487 +
1.1488 + // return the new method so that the caller can update
1.1489 + // the containing class
1.1490 + *new_method_p = method = m;
1.1491 + // switch our bytecode processing loop from the old method
1.1492 + // to the new method
1.1493 + code_base = method->code_base();
1.1494 + code_length = method->code_size();
1.1495 + bcp = code_base + bci;
1.1496 + c = (Bytecodes::Code)(*bcp);
1.1497 + bc_length = Bytecodes::length_for(c);
1.1498 + assert(bc_length != 0, "sanity check");
1.1499 + } // end we need ldc_w instead of ldc
1.1500 + } // end if there is a mapped index
1.1501 + } break;
1.1502 +
1.1503 + // these bytecodes have a two-byte constant pool index
1.1504 + case Bytecodes::_anewarray : // fall through
1.1505 + case Bytecodes::_checkcast : // fall through
1.1506 + case Bytecodes::_getfield : // fall through
1.1507 + case Bytecodes::_getstatic : // fall through
1.1508 + case Bytecodes::_instanceof : // fall through
1.1509 + case Bytecodes::_invokeinterface: // fall through
1.1510 + case Bytecodes::_invokespecial : // fall through
1.1511 + case Bytecodes::_invokestatic : // fall through
1.1512 + case Bytecodes::_invokevirtual : // fall through
1.1513 + case Bytecodes::_ldc_w : // fall through
1.1514 + case Bytecodes::_ldc2_w : // fall through
1.1515 + case Bytecodes::_multianewarray : // fall through
1.1516 + case Bytecodes::_new : // fall through
1.1517 + case Bytecodes::_putfield : // fall through
1.1518 + case Bytecodes::_putstatic :
1.1519 + {
1.1520 + address p = bcp + 1;
1.1521 + int cp_index = Bytes::get_Java_u2(p);
1.1522 + int new_index = find_new_index(cp_index);
1.1523 + if (new_index != 0) {
1.1524 + // the original index is mapped so update w/ new value
1.1525 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.1526 + ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1.1527 + bcp, cp_index, new_index));
1.1528 + // Rewriter::rewrite_method() uses put_native_u2() in this
1.1529 + // situation because it is reusing the constant pool index
1.1530 + // location for a native index into the constantPoolCache.
1.1531 + // Since we are updating the constant pool index prior to
1.1532 + // verification and constantPoolCache initialization, we
1.1533 + // need to keep the new index in Java byte order.
1.1534 + Bytes::put_Java_u2(p, new_index);
1.1535 + }
1.1536 + } break;
1.1537 + }
1.1538 + } // end for each bytecode
1.1539 +} // end rewrite_cp_refs_in_method()
1.1540 +
1.1541 +
1.1542 +// Rewrite constant pool references in the class_annotations field.
1.1543 +bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations(
1.1544 + instanceKlassHandle scratch_class, TRAPS) {
1.1545 +
1.1546 + typeArrayHandle class_annotations(THREAD,
1.1547 + scratch_class->class_annotations());
1.1548 + if (class_annotations.is_null() || class_annotations->length() == 0) {
1.1549 + // no class_annotations so nothing to do
1.1550 + return true;
1.1551 + }
1.1552 +
1.1553 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1554 + ("class_annotations length=%d", class_annotations->length()));
1.1555 +
1.1556 + int byte_i = 0; // byte index into class_annotations
1.1557 + return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i,
1.1558 + THREAD);
1.1559 +}
1.1560 +
1.1561 +
1.1562 +// Rewrite constant pool references in an annotations typeArray. This
1.1563 +// "structure" is adapted from the RuntimeVisibleAnnotations_attribute
1.1564 +// that is described in section 4.8.15 of the 2nd-edition of the VM spec:
1.1565 +//
1.1566 +// annotations_typeArray {
1.1567 +// u2 num_annotations;
1.1568 +// annotation annotations[num_annotations];
1.1569 +// }
1.1570 +//
1.1571 +bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray(
1.1572 + typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) {
1.1573 +
1.1574 + if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1.1575 + // not enough room for num_annotations field
1.1576 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1577 + ("length() is too small for num_annotations field"));
1.1578 + return false;
1.1579 + }
1.1580 +
1.1581 + u2 num_annotations = Bytes::get_Java_u2((address)
1.1582 + annotations_typeArray->byte_at_addr(byte_i_ref));
1.1583 + byte_i_ref += 2;
1.1584 +
1.1585 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1586 + ("num_annotations=%d", num_annotations));
1.1587 +
1.1588 + int calc_num_annotations = 0;
1.1589 + for (; calc_num_annotations < num_annotations; calc_num_annotations++) {
1.1590 + if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1.1591 + byte_i_ref, THREAD)) {
1.1592 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1593 + ("bad annotation_struct at %d", calc_num_annotations));
1.1594 + // propogate failure back to caller
1.1595 + return false;
1.1596 + }
1.1597 + }
1.1598 + assert(num_annotations == calc_num_annotations, "sanity check");
1.1599 +
1.1600 + return true;
1.1601 +} // end rewrite_cp_refs_in_annotations_typeArray()
1.1602 +
1.1603 +
1.1604 +// Rewrite constant pool references in the annotation struct portion of
1.1605 +// an annotations_typeArray. This "structure" is from section 4.8.15 of
1.1606 +// the 2nd-edition of the VM spec:
1.1607 +//
1.1608 +// struct annotation {
1.1609 +// u2 type_index;
1.1610 +// u2 num_element_value_pairs;
1.1611 +// {
1.1612 +// u2 element_name_index;
1.1613 +// element_value value;
1.1614 +// } element_value_pairs[num_element_value_pairs];
1.1615 +// }
1.1616 +//
1.1617 +bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct(
1.1618 + typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) {
1.1619 + if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) {
1.1620 + // not enough room for smallest annotation_struct
1.1621 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1622 + ("length() is too small for annotation_struct"));
1.1623 + return false;
1.1624 + }
1.1625 +
1.1626 + u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray,
1.1627 + byte_i_ref, "mapped old type_index=%d", THREAD);
1.1628 +
1.1629 + u2 num_element_value_pairs = Bytes::get_Java_u2((address)
1.1630 + annotations_typeArray->byte_at_addr(
1.1631 + byte_i_ref));
1.1632 + byte_i_ref += 2;
1.1633 +
1.1634 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1635 + ("type_index=%d num_element_value_pairs=%d", type_index,
1.1636 + num_element_value_pairs));
1.1637 +
1.1638 + int calc_num_element_value_pairs = 0;
1.1639 + for (; calc_num_element_value_pairs < num_element_value_pairs;
1.1640 + calc_num_element_value_pairs++) {
1.1641 + if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1.1642 + // not enough room for another element_name_index, let alone
1.1643 + // the rest of another component
1.1644 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1645 + ("length() is too small for element_name_index"));
1.1646 + return false;
1.1647 + }
1.1648 +
1.1649 + u2 element_name_index = rewrite_cp_ref_in_annotation_data(
1.1650 + annotations_typeArray, byte_i_ref,
1.1651 + "mapped old element_name_index=%d", THREAD);
1.1652 +
1.1653 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1654 + ("element_name_index=%d", element_name_index));
1.1655 +
1.1656 + if (!rewrite_cp_refs_in_element_value(annotations_typeArray,
1.1657 + byte_i_ref, THREAD)) {
1.1658 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1659 + ("bad element_value at %d", calc_num_element_value_pairs));
1.1660 + // propogate failure back to caller
1.1661 + return false;
1.1662 + }
1.1663 + } // end for each component
1.1664 + assert(num_element_value_pairs == calc_num_element_value_pairs,
1.1665 + "sanity check");
1.1666 +
1.1667 + return true;
1.1668 +} // end rewrite_cp_refs_in_annotation_struct()
1.1669 +
1.1670 +
1.1671 +// Rewrite a constant pool reference at the current position in
1.1672 +// annotations_typeArray if needed. Returns the original constant
1.1673 +// pool reference if a rewrite was not needed or the new constant
1.1674 +// pool reference if a rewrite was needed.
1.1675 +u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data(
1.1676 + typeArrayHandle annotations_typeArray, int &byte_i_ref,
1.1677 + const char * trace_mesg, TRAPS) {
1.1678 +
1.1679 + address cp_index_addr = (address)
1.1680 + annotations_typeArray->byte_at_addr(byte_i_ref);
1.1681 + u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr);
1.1682 + u2 new_cp_index = find_new_index(old_cp_index);
1.1683 + if (new_cp_index != 0) {
1.1684 + RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index));
1.1685 + Bytes::put_Java_u2(cp_index_addr, new_cp_index);
1.1686 + old_cp_index = new_cp_index;
1.1687 + }
1.1688 + byte_i_ref += 2;
1.1689 + return old_cp_index;
1.1690 +}
1.1691 +
1.1692 +
1.1693 +// Rewrite constant pool references in the element_value portion of an
1.1694 +// annotations_typeArray. This "structure" is from section 4.8.15.1 of
1.1695 +// the 2nd-edition of the VM spec:
1.1696 +//
1.1697 +// struct element_value {
1.1698 +// u1 tag;
1.1699 +// union {
1.1700 +// u2 const_value_index;
1.1701 +// {
1.1702 +// u2 type_name_index;
1.1703 +// u2 const_name_index;
1.1704 +// } enum_const_value;
1.1705 +// u2 class_info_index;
1.1706 +// annotation annotation_value;
1.1707 +// struct {
1.1708 +// u2 num_values;
1.1709 +// element_value values[num_values];
1.1710 +// } array_value;
1.1711 +// } value;
1.1712 +// }
1.1713 +//
1.1714 +bool VM_RedefineClasses::rewrite_cp_refs_in_element_value(
1.1715 + typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) {
1.1716 +
1.1717 + if ((byte_i_ref + 1) > annotations_typeArray->length()) {
1.1718 + // not enough room for a tag let alone the rest of an element_value
1.1719 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1720 + ("length() is too small for a tag"));
1.1721 + return false;
1.1722 + }
1.1723 +
1.1724 + u1 tag = annotations_typeArray->byte_at(byte_i_ref);
1.1725 + byte_i_ref++;
1.1726 + RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag));
1.1727 +
1.1728 + switch (tag) {
1.1729 + // These BaseType tag values are from Table 4.2 in VM spec:
1.1730 + case 'B': // byte
1.1731 + case 'C': // char
1.1732 + case 'D': // double
1.1733 + case 'F': // float
1.1734 + case 'I': // int
1.1735 + case 'J': // long
1.1736 + case 'S': // short
1.1737 + case 'Z': // boolean
1.1738 +
1.1739 + // The remaining tag values are from Table 4.8 in the 2nd-edition of
1.1740 + // the VM spec:
1.1741 + case 's':
1.1742 + {
1.1743 + // For the above tag values (including the BaseType values),
1.1744 + // value.const_value_index is right union field.
1.1745 +
1.1746 + if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1.1747 + // not enough room for a const_value_index
1.1748 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1749 + ("length() is too small for a const_value_index"));
1.1750 + return false;
1.1751 + }
1.1752 +
1.1753 + u2 const_value_index = rewrite_cp_ref_in_annotation_data(
1.1754 + annotations_typeArray, byte_i_ref,
1.1755 + "mapped old const_value_index=%d", THREAD);
1.1756 +
1.1757 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1758 + ("const_value_index=%d", const_value_index));
1.1759 + } break;
1.1760 +
1.1761 + case 'e':
1.1762 + {
1.1763 + // for the above tag value, value.enum_const_value is right union field
1.1764 +
1.1765 + if ((byte_i_ref + 4) > annotations_typeArray->length()) {
1.1766 + // not enough room for a enum_const_value
1.1767 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1768 + ("length() is too small for a enum_const_value"));
1.1769 + return false;
1.1770 + }
1.1771 +
1.1772 + u2 type_name_index = rewrite_cp_ref_in_annotation_data(
1.1773 + annotations_typeArray, byte_i_ref,
1.1774 + "mapped old type_name_index=%d", THREAD);
1.1775 +
1.1776 + u2 const_name_index = rewrite_cp_ref_in_annotation_data(
1.1777 + annotations_typeArray, byte_i_ref,
1.1778 + "mapped old const_name_index=%d", THREAD);
1.1779 +
1.1780 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1781 + ("type_name_index=%d const_name_index=%d", type_name_index,
1.1782 + const_name_index));
1.1783 + } break;
1.1784 +
1.1785 + case 'c':
1.1786 + {
1.1787 + // for the above tag value, value.class_info_index is right union field
1.1788 +
1.1789 + if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1.1790 + // not enough room for a class_info_index
1.1791 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1792 + ("length() is too small for a class_info_index"));
1.1793 + return false;
1.1794 + }
1.1795 +
1.1796 + u2 class_info_index = rewrite_cp_ref_in_annotation_data(
1.1797 + annotations_typeArray, byte_i_ref,
1.1798 + "mapped old class_info_index=%d", THREAD);
1.1799 +
1.1800 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1801 + ("class_info_index=%d", class_info_index));
1.1802 + } break;
1.1803 +
1.1804 + case '@':
1.1805 + // For the above tag value, value.attr_value is the right union
1.1806 + // field. This is a nested annotation.
1.1807 + if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1.1808 + byte_i_ref, THREAD)) {
1.1809 + // propogate failure back to caller
1.1810 + return false;
1.1811 + }
1.1812 + break;
1.1813 +
1.1814 + case '[':
1.1815 + {
1.1816 + if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1.1817 + // not enough room for a num_values field
1.1818 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1819 + ("length() is too small for a num_values field"));
1.1820 + return false;
1.1821 + }
1.1822 +
1.1823 + // For the above tag value, value.array_value is the right union
1.1824 + // field. This is an array of nested element_value.
1.1825 + u2 num_values = Bytes::get_Java_u2((address)
1.1826 + annotations_typeArray->byte_at_addr(byte_i_ref));
1.1827 + byte_i_ref += 2;
1.1828 + RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values));
1.1829 +
1.1830 + int calc_num_values = 0;
1.1831 + for (; calc_num_values < num_values; calc_num_values++) {
1.1832 + if (!rewrite_cp_refs_in_element_value(
1.1833 + annotations_typeArray, byte_i_ref, THREAD)) {
1.1834 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1835 + ("bad nested element_value at %d", calc_num_values));
1.1836 + // propogate failure back to caller
1.1837 + return false;
1.1838 + }
1.1839 + }
1.1840 + assert(num_values == calc_num_values, "sanity check");
1.1841 + } break;
1.1842 +
1.1843 + default:
1.1844 + RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag));
1.1845 + return false;
1.1846 + } // end decode tag field
1.1847 +
1.1848 + return true;
1.1849 +} // end rewrite_cp_refs_in_element_value()
1.1850 +
1.1851 +
1.1852 +// Rewrite constant pool references in a fields_annotations field.
1.1853 +bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations(
1.1854 + instanceKlassHandle scratch_class, TRAPS) {
1.1855 +
1.1856 + objArrayHandle fields_annotations(THREAD,
1.1857 + scratch_class->fields_annotations());
1.1858 +
1.1859 + if (fields_annotations.is_null() || fields_annotations->length() == 0) {
1.1860 + // no fields_annotations so nothing to do
1.1861 + return true;
1.1862 + }
1.1863 +
1.1864 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1865 + ("fields_annotations length=%d", fields_annotations->length()));
1.1866 +
1.1867 + for (int i = 0; i < fields_annotations->length(); i++) {
1.1868 + typeArrayHandle field_annotations(THREAD,
1.1869 + (typeArrayOop)fields_annotations->obj_at(i));
1.1870 + if (field_annotations.is_null() || field_annotations->length() == 0) {
1.1871 + // this field does not have any annotations so skip it
1.1872 + continue;
1.1873 + }
1.1874 +
1.1875 + int byte_i = 0; // byte index into field_annotations
1.1876 + if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i,
1.1877 + THREAD)) {
1.1878 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1879 + ("bad field_annotations at %d", i));
1.1880 + // propogate failure back to caller
1.1881 + return false;
1.1882 + }
1.1883 + }
1.1884 +
1.1885 + return true;
1.1886 +} // end rewrite_cp_refs_in_fields_annotations()
1.1887 +
1.1888 +
1.1889 +// Rewrite constant pool references in a methods_annotations field.
1.1890 +bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations(
1.1891 + instanceKlassHandle scratch_class, TRAPS) {
1.1892 +
1.1893 + objArrayHandle methods_annotations(THREAD,
1.1894 + scratch_class->methods_annotations());
1.1895 +
1.1896 + if (methods_annotations.is_null() || methods_annotations->length() == 0) {
1.1897 + // no methods_annotations so nothing to do
1.1898 + return true;
1.1899 + }
1.1900 +
1.1901 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1902 + ("methods_annotations length=%d", methods_annotations->length()));
1.1903 +
1.1904 + for (int i = 0; i < methods_annotations->length(); i++) {
1.1905 + typeArrayHandle method_annotations(THREAD,
1.1906 + (typeArrayOop)methods_annotations->obj_at(i));
1.1907 + if (method_annotations.is_null() || method_annotations->length() == 0) {
1.1908 + // this method does not have any annotations so skip it
1.1909 + continue;
1.1910 + }
1.1911 +
1.1912 + int byte_i = 0; // byte index into method_annotations
1.1913 + if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i,
1.1914 + THREAD)) {
1.1915 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1916 + ("bad method_annotations at %d", i));
1.1917 + // propogate failure back to caller
1.1918 + return false;
1.1919 + }
1.1920 + }
1.1921 +
1.1922 + return true;
1.1923 +} // end rewrite_cp_refs_in_methods_annotations()
1.1924 +
1.1925 +
1.1926 +// Rewrite constant pool references in a methods_parameter_annotations
1.1927 +// field. This "structure" is adapted from the
1.1928 +// RuntimeVisibleParameterAnnotations_attribute described in section
1.1929 +// 4.8.17 of the 2nd-edition of the VM spec:
1.1930 +//
1.1931 +// methods_parameter_annotations_typeArray {
1.1932 +// u1 num_parameters;
1.1933 +// {
1.1934 +// u2 num_annotations;
1.1935 +// annotation annotations[num_annotations];
1.1936 +// } parameter_annotations[num_parameters];
1.1937 +// }
1.1938 +//
1.1939 +bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations(
1.1940 + instanceKlassHandle scratch_class, TRAPS) {
1.1941 +
1.1942 + objArrayHandle methods_parameter_annotations(THREAD,
1.1943 + scratch_class->methods_parameter_annotations());
1.1944 +
1.1945 + if (methods_parameter_annotations.is_null()
1.1946 + || methods_parameter_annotations->length() == 0) {
1.1947 + // no methods_parameter_annotations so nothing to do
1.1948 + return true;
1.1949 + }
1.1950 +
1.1951 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1952 + ("methods_parameter_annotations length=%d",
1.1953 + methods_parameter_annotations->length()));
1.1954 +
1.1955 + for (int i = 0; i < methods_parameter_annotations->length(); i++) {
1.1956 + typeArrayHandle method_parameter_annotations(THREAD,
1.1957 + (typeArrayOop)methods_parameter_annotations->obj_at(i));
1.1958 + if (method_parameter_annotations.is_null()
1.1959 + || method_parameter_annotations->length() == 0) {
1.1960 + // this method does not have any parameter annotations so skip it
1.1961 + continue;
1.1962 + }
1.1963 +
1.1964 + if (method_parameter_annotations->length() < 1) {
1.1965 + // not enough room for a num_parameters field
1.1966 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1967 + ("length() is too small for a num_parameters field at %d", i));
1.1968 + return false;
1.1969 + }
1.1970 +
1.1971 + int byte_i = 0; // byte index into method_parameter_annotations
1.1972 +
1.1973 + u1 num_parameters = method_parameter_annotations->byte_at(byte_i);
1.1974 + byte_i++;
1.1975 +
1.1976 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1977 + ("num_parameters=%d", num_parameters));
1.1978 +
1.1979 + int calc_num_parameters = 0;
1.1980 + for (; calc_num_parameters < num_parameters; calc_num_parameters++) {
1.1981 + if (!rewrite_cp_refs_in_annotations_typeArray(
1.1982 + method_parameter_annotations, byte_i, THREAD)) {
1.1983 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.1984 + ("bad method_parameter_annotations at %d", calc_num_parameters));
1.1985 + // propogate failure back to caller
1.1986 + return false;
1.1987 + }
1.1988 + }
1.1989 + assert(num_parameters == calc_num_parameters, "sanity check");
1.1990 + }
1.1991 +
1.1992 + return true;
1.1993 +} // end rewrite_cp_refs_in_methods_parameter_annotations()
1.1994 +
1.1995 +
1.1996 +// Rewrite constant pool references in a methods_default_annotations
1.1997 +// field. This "structure" is adapted from the AnnotationDefault_attribute
1.1998 +// that is described in section 4.8.19 of the 2nd-edition of the VM spec:
1.1999 +//
1.2000 +// methods_default_annotations_typeArray {
1.2001 +// element_value default_value;
1.2002 +// }
1.2003 +//
1.2004 +bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations(
1.2005 + instanceKlassHandle scratch_class, TRAPS) {
1.2006 +
1.2007 + objArrayHandle methods_default_annotations(THREAD,
1.2008 + scratch_class->methods_default_annotations());
1.2009 +
1.2010 + if (methods_default_annotations.is_null()
1.2011 + || methods_default_annotations->length() == 0) {
1.2012 + // no methods_default_annotations so nothing to do
1.2013 + return true;
1.2014 + }
1.2015 +
1.2016 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.2017 + ("methods_default_annotations length=%d",
1.2018 + methods_default_annotations->length()));
1.2019 +
1.2020 + for (int i = 0; i < methods_default_annotations->length(); i++) {
1.2021 + typeArrayHandle method_default_annotations(THREAD,
1.2022 + (typeArrayOop)methods_default_annotations->obj_at(i));
1.2023 + if (method_default_annotations.is_null()
1.2024 + || method_default_annotations->length() == 0) {
1.2025 + // this method does not have any default annotations so skip it
1.2026 + continue;
1.2027 + }
1.2028 +
1.2029 + int byte_i = 0; // byte index into method_default_annotations
1.2030 +
1.2031 + if (!rewrite_cp_refs_in_element_value(
1.2032 + method_default_annotations, byte_i, THREAD)) {
1.2033 + RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1.2034 + ("bad default element_value at %d", i));
1.2035 + // propogate failure back to caller
1.2036 + return false;
1.2037 + }
1.2038 + }
1.2039 +
1.2040 + return true;
1.2041 +} // end rewrite_cp_refs_in_methods_default_annotations()
1.2042 +
1.2043 +
1.2044 +// Rewrite constant pool references in the method's stackmap table.
1.2045 +// These "structures" are adapted from the StackMapTable_attribute that
1.2046 +// is described in section 4.8.4 of the 6.0 version of the VM spec
1.2047 +// (dated 2005.10.26):
1.2048 +// file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
1.2049 +//
1.2050 +// stack_map {
1.2051 +// u2 number_of_entries;
1.2052 +// stack_map_frame entries[number_of_entries];
1.2053 +// }
1.2054 +//
1.2055 +void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table(
1.2056 + methodHandle method, TRAPS) {
1.2057 +
1.2058 + if (!method->has_stackmap_table()) {
1.2059 + return;
1.2060 + }
1.2061 +
1.2062 + typeArrayOop stackmap_data = method->stackmap_data();
1.2063 + address stackmap_p = (address)stackmap_data->byte_at_addr(0);
1.2064 + address stackmap_end = stackmap_p + stackmap_data->length();
1.2065 +
1.2066 + assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries");
1.2067 + u2 number_of_entries = Bytes::get_Java_u2(stackmap_p);
1.2068 + stackmap_p += 2;
1.2069 +
1.2070 + RC_TRACE_WITH_THREAD(0x04000000, THREAD,
1.2071 + ("number_of_entries=%u", number_of_entries));
1.2072 +
1.2073 + // walk through each stack_map_frame
1.2074 + u2 calc_number_of_entries = 0;
1.2075 + for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) {
1.2076 + // The stack_map_frame structure is a u1 frame_type followed by
1.2077 + // 0 or more bytes of data:
1.2078 + //
1.2079 + // union stack_map_frame {
1.2080 + // same_frame;
1.2081 + // same_locals_1_stack_item_frame;
1.2082 + // same_locals_1_stack_item_frame_extended;
1.2083 + // chop_frame;
1.2084 + // same_frame_extended;
1.2085 + // append_frame;
1.2086 + // full_frame;
1.2087 + // }
1.2088 +
1.2089 + assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type");
1.2090 + // The Linux compiler does not like frame_type to be u1 or u2. It
1.2091 + // issues the following warning for the first if-statement below:
1.2092 + //
1.2093 + // "warning: comparison is always true due to limited range of data type"
1.2094 + //
1.2095 + u4 frame_type = *stackmap_p;
1.2096 + stackmap_p++;
1.2097 +
1.2098 + // same_frame {
1.2099 + // u1 frame_type = SAME; /* 0-63 */
1.2100 + // }
1.2101 + if (frame_type >= 0 && frame_type <= 63) {
1.2102 + // nothing more to do for same_frame
1.2103 + }
1.2104 +
1.2105 + // same_locals_1_stack_item_frame {
1.2106 + // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */
1.2107 + // verification_type_info stack[1];
1.2108 + // }
1.2109 + else if (frame_type >= 64 && frame_type <= 127) {
1.2110 + rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
1.2111 + calc_number_of_entries, frame_type, THREAD);
1.2112 + }
1.2113 +
1.2114 + // reserved for future use
1.2115 + else if (frame_type >= 128 && frame_type <= 246) {
1.2116 + // nothing more to do for reserved frame_types
1.2117 + }
1.2118 +
1.2119 + // same_locals_1_stack_item_frame_extended {
1.2120 + // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */
1.2121 + // u2 offset_delta;
1.2122 + // verification_type_info stack[1];
1.2123 + // }
1.2124 + else if (frame_type == 247) {
1.2125 + stackmap_p += 2;
1.2126 + rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
1.2127 + calc_number_of_entries, frame_type, THREAD);
1.2128 + }
1.2129 +
1.2130 + // chop_frame {
1.2131 + // u1 frame_type = CHOP; /* 248-250 */
1.2132 + // u2 offset_delta;
1.2133 + // }
1.2134 + else if (frame_type >= 248 && frame_type <= 250) {
1.2135 + stackmap_p += 2;
1.2136 + }
1.2137 +
1.2138 + // same_frame_extended {
1.2139 + // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/
1.2140 + // u2 offset_delta;
1.2141 + // }
1.2142 + else if (frame_type == 251) {
1.2143 + stackmap_p += 2;
1.2144 + }
1.2145 +
1.2146 + // append_frame {
1.2147 + // u1 frame_type = APPEND; /* 252-254 */
1.2148 + // u2 offset_delta;
1.2149 + // verification_type_info locals[frame_type - 251];
1.2150 + // }
1.2151 + else if (frame_type >= 252 && frame_type <= 254) {
1.2152 + assert(stackmap_p + 2 <= stackmap_end,
1.2153 + "no room for offset_delta");
1.2154 + stackmap_p += 2;
1.2155 + u1 len = frame_type - 251;
1.2156 + for (u1 i = 0; i < len; i++) {
1.2157 + rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
1.2158 + calc_number_of_entries, frame_type, THREAD);
1.2159 + }
1.2160 + }
1.2161 +
1.2162 + // full_frame {
1.2163 + // u1 frame_type = FULL_FRAME; /* 255 */
1.2164 + // u2 offset_delta;
1.2165 + // u2 number_of_locals;
1.2166 + // verification_type_info locals[number_of_locals];
1.2167 + // u2 number_of_stack_items;
1.2168 + // verification_type_info stack[number_of_stack_items];
1.2169 + // }
1.2170 + else if (frame_type == 255) {
1.2171 + assert(stackmap_p + 2 + 2 <= stackmap_end,
1.2172 + "no room for smallest full_frame");
1.2173 + stackmap_p += 2;
1.2174 +
1.2175 + u2 number_of_locals = Bytes::get_Java_u2(stackmap_p);
1.2176 + stackmap_p += 2;
1.2177 +
1.2178 + for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) {
1.2179 + rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
1.2180 + calc_number_of_entries, frame_type, THREAD);
1.2181 + }
1.2182 +
1.2183 + // Use the largest size for the number_of_stack_items, but only get
1.2184 + // the right number of bytes.
1.2185 + u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p);
1.2186 + stackmap_p += 2;
1.2187 +
1.2188 + for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) {
1.2189 + rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
1.2190 + calc_number_of_entries, frame_type, THREAD);
1.2191 + }
1.2192 + }
1.2193 + } // end while there is a stack_map_frame
1.2194 + assert(number_of_entries == calc_number_of_entries, "sanity check");
1.2195 +} // end rewrite_cp_refs_in_stack_map_table()
1.2196 +
1.2197 +
1.2198 +// Rewrite constant pool references in the verification type info
1.2199 +// portion of the method's stackmap table. These "structures" are
1.2200 +// adapted from the StackMapTable_attribute that is described in
1.2201 +// section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26):
1.2202 +// file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
1.2203 +//
1.2204 +// The verification_type_info structure is a u1 tag followed by 0 or
1.2205 +// more bytes of data:
1.2206 +//
1.2207 +// union verification_type_info {
1.2208 +// Top_variable_info;
1.2209 +// Integer_variable_info;
1.2210 +// Float_variable_info;
1.2211 +// Long_variable_info;
1.2212 +// Double_variable_info;
1.2213 +// Null_variable_info;
1.2214 +// UninitializedThis_variable_info;
1.2215 +// Object_variable_info;
1.2216 +// Uninitialized_variable_info;
1.2217 +// }
1.2218 +//
1.2219 +void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info(
1.2220 + address& stackmap_p_ref, address stackmap_end, u2 frame_i,
1.2221 + u1 frame_type, TRAPS) {
1.2222 +
1.2223 + assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag");
1.2224 + u1 tag = *stackmap_p_ref;
1.2225 + stackmap_p_ref++;
1.2226 +
1.2227 + switch (tag) {
1.2228 + // Top_variable_info {
1.2229 + // u1 tag = ITEM_Top; /* 0 */
1.2230 + // }
1.2231 + // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top
1.2232 + case 0: // fall through
1.2233 +
1.2234 + // Integer_variable_info {
1.2235 + // u1 tag = ITEM_Integer; /* 1 */
1.2236 + // }
1.2237 + case ITEM_Integer: // fall through
1.2238 +
1.2239 + // Float_variable_info {
1.2240 + // u1 tag = ITEM_Float; /* 2 */
1.2241 + // }
1.2242 + case ITEM_Float: // fall through
1.2243 +
1.2244 + // Double_variable_info {
1.2245 + // u1 tag = ITEM_Double; /* 3 */
1.2246 + // }
1.2247 + case ITEM_Double: // fall through
1.2248 +
1.2249 + // Long_variable_info {
1.2250 + // u1 tag = ITEM_Long; /* 4 */
1.2251 + // }
1.2252 + case ITEM_Long: // fall through
1.2253 +
1.2254 + // Null_variable_info {
1.2255 + // u1 tag = ITEM_Null; /* 5 */
1.2256 + // }
1.2257 + case ITEM_Null: // fall through
1.2258 +
1.2259 + // UninitializedThis_variable_info {
1.2260 + // u1 tag = ITEM_UninitializedThis; /* 6 */
1.2261 + // }
1.2262 + case ITEM_UninitializedThis:
1.2263 + // nothing more to do for the above tag types
1.2264 + break;
1.2265 +
1.2266 + // Object_variable_info {
1.2267 + // u1 tag = ITEM_Object; /* 7 */
1.2268 + // u2 cpool_index;
1.2269 + // }
1.2270 + case ITEM_Object:
1.2271 + {
1.2272 + assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index");
1.2273 + u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref);
1.2274 + u2 new_cp_index = find_new_index(cpool_index);
1.2275 + if (new_cp_index != 0) {
1.2276 + RC_TRACE_WITH_THREAD(0x04000000, THREAD,
1.2277 + ("mapped old cpool_index=%d", cpool_index));
1.2278 + Bytes::put_Java_u2(stackmap_p_ref, new_cp_index);
1.2279 + cpool_index = new_cp_index;
1.2280 + }
1.2281 + stackmap_p_ref += 2;
1.2282 +
1.2283 + RC_TRACE_WITH_THREAD(0x04000000, THREAD,
1.2284 + ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i,
1.2285 + frame_type, cpool_index));
1.2286 + } break;
1.2287 +
1.2288 + // Uninitialized_variable_info {
1.2289 + // u1 tag = ITEM_Uninitialized; /* 8 */
1.2290 + // u2 offset;
1.2291 + // }
1.2292 + case ITEM_Uninitialized:
1.2293 + assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset");
1.2294 + stackmap_p_ref += 2;
1.2295 + break;
1.2296 +
1.2297 + default:
1.2298 + RC_TRACE_WITH_THREAD(0x04000000, THREAD,
1.2299 + ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag));
1.2300 + ShouldNotReachHere();
1.2301 + break;
1.2302 + } // end switch (tag)
1.2303 +} // end rewrite_cp_refs_in_verification_type_info()
1.2304 +
1.2305 +
1.2306 +// Change the constant pool associated with klass scratch_class to
1.2307 +// scratch_cp. If shrink is true, then scratch_cp_length elements
1.2308 +// are copied from scratch_cp to a smaller constant pool and the
1.2309 +// smaller constant pool is associated with scratch_class.
1.2310 +void VM_RedefineClasses::set_new_constant_pool(
1.2311 + instanceKlassHandle scratch_class, constantPoolHandle scratch_cp,
1.2312 + int scratch_cp_length, bool shrink, TRAPS) {
1.2313 + assert(!shrink || scratch_cp->length() >= scratch_cp_length, "sanity check");
1.2314 +
1.2315 + if (shrink) {
1.2316 + // scratch_cp is a merged constant pool and has enough space for a
1.2317 + // worst case merge situation. We want to associate the minimum
1.2318 + // sized constant pool with the klass to save space.
1.2319 + constantPoolHandle smaller_cp(THREAD,
1.2320 + oopFactory::new_constantPool(scratch_cp_length, THREAD));
1.2321 + // preserve orig_length() value in the smaller copy
1.2322 + int orig_length = scratch_cp->orig_length();
1.2323 + assert(orig_length != 0, "sanity check");
1.2324 + smaller_cp->set_orig_length(orig_length);
1.2325 + scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD);
1.2326 + scratch_cp = smaller_cp;
1.2327 + }
1.2328 +
1.2329 + // attach new constant pool to klass
1.2330 + scratch_cp->set_pool_holder(scratch_class());
1.2331 +
1.2332 + // attach klass to new constant pool
1.2333 + scratch_class->set_constants(scratch_cp());
1.2334 +
1.2335 + int i; // for portability
1.2336 +
1.2337 + // update each field in klass to use new constant pool indices as needed
1.2338 + typeArrayHandle fields(THREAD, scratch_class->fields());
1.2339 + int n_fields = fields->length();
1.2340 + for (i = 0; i < n_fields; i += instanceKlass::next_offset) {
1.2341 + jshort cur_index = fields->short_at(i + instanceKlass::name_index_offset);
1.2342 + jshort new_index = find_new_index(cur_index);
1.2343 + if (new_index != 0) {
1.2344 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2345 + ("field-name_index change: %d to %d", cur_index, new_index));
1.2346 + fields->short_at_put(i + instanceKlass::name_index_offset, new_index);
1.2347 + }
1.2348 + cur_index = fields->short_at(i + instanceKlass::signature_index_offset);
1.2349 + new_index = find_new_index(cur_index);
1.2350 + if (new_index != 0) {
1.2351 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2352 + ("field-signature_index change: %d to %d", cur_index, new_index));
1.2353 + fields->short_at_put(i + instanceKlass::signature_index_offset,
1.2354 + new_index);
1.2355 + }
1.2356 + cur_index = fields->short_at(i + instanceKlass::initval_index_offset);
1.2357 + new_index = find_new_index(cur_index);
1.2358 + if (new_index != 0) {
1.2359 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2360 + ("field-initval_index change: %d to %d", cur_index, new_index));
1.2361 + fields->short_at_put(i + instanceKlass::initval_index_offset, new_index);
1.2362 + }
1.2363 + cur_index = fields->short_at(i + instanceKlass::generic_signature_offset);
1.2364 + new_index = find_new_index(cur_index);
1.2365 + if (new_index != 0) {
1.2366 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2367 + ("field-generic_signature change: %d to %d", cur_index, new_index));
1.2368 + fields->short_at_put(i + instanceKlass::generic_signature_offset,
1.2369 + new_index);
1.2370 + }
1.2371 + } // end for each field
1.2372 +
1.2373 + // Update constant pool indices in the inner classes info to use
1.2374 + // new constant indices as needed. The inner classes info is a
1.2375 + // quadruple:
1.2376 + // (inner_class_info, outer_class_info, inner_name, inner_access_flags)
1.2377 + typeArrayOop inner_class_list = scratch_class->inner_classes();
1.2378 + int icl_length = (inner_class_list == NULL) ? 0 : inner_class_list->length();
1.2379 + if (icl_length > 0) {
1.2380 + typeArrayHandle inner_class_list_h(THREAD, inner_class_list);
1.2381 + for (int i = 0; i < icl_length;
1.2382 + i += instanceKlass::inner_class_next_offset) {
1.2383 + int cur_index = inner_class_list_h->ushort_at(i
1.2384 + + instanceKlass::inner_class_inner_class_info_offset);
1.2385 + if (cur_index == 0) {
1.2386 + continue; // JVM spec. allows null inner class refs so skip it
1.2387 + }
1.2388 + int new_index = find_new_index(cur_index);
1.2389 + if (new_index != 0) {
1.2390 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2391 + ("inner_class_info change: %d to %d", cur_index, new_index));
1.2392 + inner_class_list_h->ushort_at_put(i
1.2393 + + instanceKlass::inner_class_inner_class_info_offset, new_index);
1.2394 + }
1.2395 + cur_index = inner_class_list_h->ushort_at(i
1.2396 + + instanceKlass::inner_class_outer_class_info_offset);
1.2397 + new_index = find_new_index(cur_index);
1.2398 + if (new_index != 0) {
1.2399 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2400 + ("outer_class_info change: %d to %d", cur_index, new_index));
1.2401 + inner_class_list_h->ushort_at_put(i
1.2402 + + instanceKlass::inner_class_outer_class_info_offset, new_index);
1.2403 + }
1.2404 + cur_index = inner_class_list_h->ushort_at(i
1.2405 + + instanceKlass::inner_class_inner_name_offset);
1.2406 + new_index = find_new_index(cur_index);
1.2407 + if (new_index != 0) {
1.2408 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2409 + ("inner_name change: %d to %d", cur_index, new_index));
1.2410 + inner_class_list_h->ushort_at_put(i
1.2411 + + instanceKlass::inner_class_inner_name_offset, new_index);
1.2412 + }
1.2413 + } // end for each inner class
1.2414 + } // end if we have inner classes
1.2415 +
1.2416 + // Attach each method in klass to the new constant pool and update
1.2417 + // to use new constant pool indices as needed:
1.2418 + objArrayHandle methods(THREAD, scratch_class->methods());
1.2419 + for (i = methods->length() - 1; i >= 0; i--) {
1.2420 + methodHandle method(THREAD, (methodOop)methods->obj_at(i));
1.2421 + method->set_constants(scratch_cp());
1.2422 +
1.2423 + int new_index = find_new_index(method->name_index());
1.2424 + if (new_index != 0) {
1.2425 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2426 + ("method-name_index change: %d to %d", method->name_index(),
1.2427 + new_index));
1.2428 + method->set_name_index(new_index);
1.2429 + }
1.2430 + new_index = find_new_index(method->signature_index());
1.2431 + if (new_index != 0) {
1.2432 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2433 + ("method-signature_index change: %d to %d",
1.2434 + method->signature_index(), new_index));
1.2435 + method->set_signature_index(new_index);
1.2436 + }
1.2437 + new_index = find_new_index(method->generic_signature_index());
1.2438 + if (new_index != 0) {
1.2439 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2440 + ("method-generic_signature_index change: %d to %d",
1.2441 + method->generic_signature_index(), new_index));
1.2442 + method->set_generic_signature_index(new_index);
1.2443 + }
1.2444 +
1.2445 + // Update constant pool indices in the method's checked exception
1.2446 + // table to use new constant indices as needed.
1.2447 + int cext_length = method->checked_exceptions_length();
1.2448 + if (cext_length > 0) {
1.2449 + CheckedExceptionElement * cext_table =
1.2450 + method->checked_exceptions_start();
1.2451 + for (int j = 0; j < cext_length; j++) {
1.2452 + int cur_index = cext_table[j].class_cp_index;
1.2453 + int new_index = find_new_index(cur_index);
1.2454 + if (new_index != 0) {
1.2455 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2456 + ("cext-class_cp_index change: %d to %d", cur_index, new_index));
1.2457 + cext_table[j].class_cp_index = (u2)new_index;
1.2458 + }
1.2459 + } // end for each checked exception table entry
1.2460 + } // end if there are checked exception table entries
1.2461 +
1.2462 + // Update each catch type index in the method's exception table
1.2463 + // to use new constant pool indices as needed. The exception table
1.2464 + // holds quadruple entries of the form:
1.2465 + // (beg_bci, end_bci, handler_bci, klass_index)
1.2466 + const int beg_bci_offset = 0;
1.2467 + const int end_bci_offset = 1;
1.2468 + const int handler_bci_offset = 2;
1.2469 + const int klass_index_offset = 3;
1.2470 + const int entry_size = 4;
1.2471 +
1.2472 + typeArrayHandle ex_table (THREAD, method->exception_table());
1.2473 + int ext_length = ex_table->length();
1.2474 + assert(ext_length % entry_size == 0, "exception table format has changed");
1.2475 +
1.2476 + for (int j = 0; j < ext_length; j += entry_size) {
1.2477 + int cur_index = ex_table->int_at(j + klass_index_offset);
1.2478 + int new_index = find_new_index(cur_index);
1.2479 + if (new_index != 0) {
1.2480 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2481 + ("ext-klass_index change: %d to %d", cur_index, new_index));
1.2482 + ex_table->int_at_put(j + klass_index_offset, new_index);
1.2483 + }
1.2484 + } // end for each exception table entry
1.2485 +
1.2486 + // Update constant pool indices in the method's local variable
1.2487 + // table to use new constant indices as needed. The local variable
1.2488 + // table hold sextuple entries of the form:
1.2489 + // (start_pc, length, name_index, descriptor_index, signature_index, slot)
1.2490 + int lvt_length = method->localvariable_table_length();
1.2491 + if (lvt_length > 0) {
1.2492 + LocalVariableTableElement * lv_table =
1.2493 + method->localvariable_table_start();
1.2494 + for (int j = 0; j < lvt_length; j++) {
1.2495 + int cur_index = lv_table[j].name_cp_index;
1.2496 + int new_index = find_new_index(cur_index);
1.2497 + if (new_index != 0) {
1.2498 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2499 + ("lvt-name_cp_index change: %d to %d", cur_index, new_index));
1.2500 + lv_table[j].name_cp_index = (u2)new_index;
1.2501 + }
1.2502 + cur_index = lv_table[j].descriptor_cp_index;
1.2503 + new_index = find_new_index(cur_index);
1.2504 + if (new_index != 0) {
1.2505 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2506 + ("lvt-descriptor_cp_index change: %d to %d", cur_index,
1.2507 + new_index));
1.2508 + lv_table[j].descriptor_cp_index = (u2)new_index;
1.2509 + }
1.2510 + cur_index = lv_table[j].signature_cp_index;
1.2511 + new_index = find_new_index(cur_index);
1.2512 + if (new_index != 0) {
1.2513 + RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1.2514 + ("lvt-signature_cp_index change: %d to %d", cur_index, new_index));
1.2515 + lv_table[j].signature_cp_index = (u2)new_index;
1.2516 + }
1.2517 + } // end for each local variable table entry
1.2518 + } // end if there are local variable table entries
1.2519 +
1.2520 + rewrite_cp_refs_in_stack_map_table(method, THREAD);
1.2521 + } // end for each method
1.2522 +} // end set_new_constant_pool()
1.2523 +
1.2524 +
1.2525 +// Unevolving classes may point to methods of the_class directly
1.2526 +// from their constant pool caches, itables, and/or vtables. We
1.2527 +// use the SystemDictionary::classes_do() facility and this helper
1.2528 +// to fix up these pointers.
1.2529 +//
1.2530 +// Note: We currently don't support updating the vtable in
1.2531 +// arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp.
1.2532 +void VM_RedefineClasses::adjust_cpool_cache_and_vtable(klassOop k_oop,
1.2533 + oop initiating_loader, TRAPS) {
1.2534 + Klass *k = k_oop->klass_part();
1.2535 + if (k->oop_is_instance()) {
1.2536 + HandleMark hm(THREAD);
1.2537 + instanceKlass *ik = (instanceKlass *) k;
1.2538 +
1.2539 + // HotSpot specific optimization! HotSpot does not currently
1.2540 + // support delegation from the bootstrap class loader to a
1.2541 + // user-defined class loader. This means that if the bootstrap
1.2542 + // class loader is the initiating class loader, then it will also
1.2543 + // be the defining class loader. This also means that classes
1.2544 + // loaded by the bootstrap class loader cannot refer to classes
1.2545 + // loaded by a user-defined class loader. Note: a user-defined
1.2546 + // class loader can delegate to the bootstrap class loader.
1.2547 + //
1.2548 + // If the current class being redefined has a user-defined class
1.2549 + // loader as its defining class loader, then we can skip all
1.2550 + // classes loaded by the bootstrap class loader.
1.2551 + bool is_user_defined =
1.2552 + instanceKlass::cast(_the_class_oop)->class_loader() != NULL;
1.2553 + if (is_user_defined && ik->class_loader() == NULL) {
1.2554 + return;
1.2555 + }
1.2556 +
1.2557 + // This is a very busy routine. We don't want too much tracing
1.2558 + // printed out.
1.2559 + bool trace_name_printed = false;
1.2560 +
1.2561 + // Very noisy: only enable this call if you are trying to determine
1.2562 + // that a specific class gets found by this routine.
1.2563 + // RC_TRACE macro has an embedded ResourceMark
1.2564 + // RC_TRACE_WITH_THREAD(0x00100000, THREAD,
1.2565 + // ("adjust check: name=%s", ik->external_name()));
1.2566 + // trace_name_printed = true;
1.2567 +
1.2568 + // Fix the vtable embedded in the_class and subclasses of the_class,
1.2569 + // if one exists. We discard scratch_class and we don't keep an
1.2570 + // instanceKlass around to hold obsolete methods so we don't have
1.2571 + // any other instanceKlass embedded vtables to update. The vtable
1.2572 + // holds the methodOops for virtual (but not final) methods.
1.2573 + if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) {
1.2574 + // ik->vtable() creates a wrapper object; rm cleans it up
1.2575 + ResourceMark rm(THREAD);
1.2576 + ik->vtable()->adjust_method_entries(_matching_old_methods,
1.2577 + _matching_new_methods,
1.2578 + _matching_methods_length,
1.2579 + &trace_name_printed);
1.2580 + }
1.2581 +
1.2582 + // If the current class has an itable and we are either redefining an
1.2583 + // interface or if the current class is a subclass of the_class, then
1.2584 + // we potentially have to fix the itable. If we are redefining an
1.2585 + // interface, then we have to call adjust_method_entries() for
1.2586 + // every instanceKlass that has an itable since there isn't a
1.2587 + // subclass relationship between an interface and an instanceKlass.
1.2588 + if (ik->itable_length() > 0 && (Klass::cast(_the_class_oop)->is_interface()
1.2589 + || ik->is_subclass_of(_the_class_oop))) {
1.2590 + // ik->itable() creates a wrapper object; rm cleans it up
1.2591 + ResourceMark rm(THREAD);
1.2592 + ik->itable()->adjust_method_entries(_matching_old_methods,
1.2593 + _matching_new_methods,
1.2594 + _matching_methods_length,
1.2595 + &trace_name_printed);
1.2596 + }
1.2597 +
1.2598 + // The constant pools in other classes (other_cp) can refer to
1.2599 + // methods in the_class. We have to update method information in
1.2600 + // other_cp's cache. If other_cp has a previous version, then we
1.2601 + // have to repeat the process for each previous version. The
1.2602 + // constant pool cache holds the methodOops for non-virtual
1.2603 + // methods and for virtual, final methods.
1.2604 + //
1.2605 + // Special case: if the current class is the_class, then new_cp
1.2606 + // has already been attached to the_class and old_cp has already
1.2607 + // been added as a previous version. The new_cp doesn't have any
1.2608 + // cached references to old methods so it doesn't need to be
1.2609 + // updated. We can simply start with the previous version(s) in
1.2610 + // that case.
1.2611 + constantPoolHandle other_cp;
1.2612 + constantPoolCacheOop cp_cache;
1.2613 +
1.2614 + if (k_oop != _the_class_oop) {
1.2615 + // this klass' constant pool cache may need adjustment
1.2616 + other_cp = constantPoolHandle(ik->constants());
1.2617 + cp_cache = other_cp->cache();
1.2618 + if (cp_cache != NULL) {
1.2619 + cp_cache->adjust_method_entries(_matching_old_methods,
1.2620 + _matching_new_methods,
1.2621 + _matching_methods_length,
1.2622 + &trace_name_printed);
1.2623 + }
1.2624 + }
1.2625 + {
1.2626 + ResourceMark rm(THREAD);
1.2627 + // PreviousVersionInfo objects returned via PreviousVersionWalker
1.2628 + // contain a GrowableArray of handles. We have to clean up the
1.2629 + // GrowableArray _after_ the PreviousVersionWalker destructor
1.2630 + // has destroyed the handles.
1.2631 + {
1.2632 + // the previous versions' constant pool caches may need adjustment
1.2633 + PreviousVersionWalker pvw(ik);
1.2634 + for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
1.2635 + pv_info != NULL; pv_info = pvw.next_previous_version()) {
1.2636 + other_cp = pv_info->prev_constant_pool_handle();
1.2637 + cp_cache = other_cp->cache();
1.2638 + if (cp_cache != NULL) {
1.2639 + cp_cache->adjust_method_entries(_matching_old_methods,
1.2640 + _matching_new_methods,
1.2641 + _matching_methods_length,
1.2642 + &trace_name_printed);
1.2643 + }
1.2644 + }
1.2645 + } // pvw is cleaned up
1.2646 + } // rm is cleaned up
1.2647 + }
1.2648 +}
1.2649 +
1.2650 +void VM_RedefineClasses::update_jmethod_ids() {
1.2651 + for (int j = 0; j < _matching_methods_length; ++j) {
1.2652 + methodOop old_method = _matching_old_methods[j];
1.2653 + jmethodID jmid = old_method->find_jmethod_id_or_null();
1.2654 + if (jmid != NULL) {
1.2655 + // There is a jmethodID, change it to point to the new method
1.2656 + methodHandle new_method_h(_matching_new_methods[j]);
1.2657 + JNIHandles::change_method_associated_with_jmethod_id(jmid, new_method_h);
1.2658 + assert(JNIHandles::resolve_jmethod_id(jmid) == _matching_new_methods[j],
1.2659 + "should be replaced");
1.2660 + }
1.2661 + }
1.2662 +}
1.2663 +
1.2664 +void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
1.2665 + BitMap *emcp_methods, int * emcp_method_count_p) {
1.2666 + *emcp_method_count_p = 0;
1.2667 + int obsolete_count = 0;
1.2668 + int old_index = 0;
1.2669 + for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
1.2670 + methodOop old_method = _matching_old_methods[j];
1.2671 + methodOop new_method = _matching_new_methods[j];
1.2672 + methodOop old_array_method;
1.2673 +
1.2674 + // Maintain an old_index into the _old_methods array by skipping
1.2675 + // deleted methods
1.2676 + while ((old_array_method = (methodOop) _old_methods->obj_at(old_index))
1.2677 + != old_method) {
1.2678 + ++old_index;
1.2679 + }
1.2680 +
1.2681 + if (MethodComparator::methods_EMCP(old_method, new_method)) {
1.2682 + // The EMCP definition from JSR-163 requires the bytecodes to be
1.2683 + // the same with the exception of constant pool indices which may
1.2684 + // differ. However, the constants referred to by those indices
1.2685 + // must be the same.
1.2686 + //
1.2687 + // We use methods_EMCP() for comparison since constant pool
1.2688 + // merging can remove duplicate constant pool entries that were
1.2689 + // present in the old method and removed from the rewritten new
1.2690 + // method. A faster binary comparison function would consider the
1.2691 + // old and new methods to be different when they are actually
1.2692 + // EMCP.
1.2693 + //
1.2694 + // The old and new methods are EMCP and you would think that we
1.2695 + // could get rid of one of them here and now and save some space.
1.2696 + // However, the concept of EMCP only considers the bytecodes and
1.2697 + // the constant pool entries in the comparison. Other things,
1.2698 + // e.g., the line number table (LNT) or the local variable table
1.2699 + // (LVT) don't count in the comparison. So the new (and EMCP)
1.2700 + // method can have a new LNT that we need so we can't just
1.2701 + // overwrite the new method with the old method.
1.2702 + //
1.2703 + // When this routine is called, we have already attached the new
1.2704 + // methods to the_class so the old methods are effectively
1.2705 + // overwritten. However, if an old method is still executing,
1.2706 + // then the old method cannot be collected until sometime after
1.2707 + // the old method call has returned. So the overwriting of old
1.2708 + // methods by new methods will save us space except for those
1.2709 + // (hopefully few) old methods that are still executing.
1.2710 + //
1.2711 + // A method refers to a constMethodOop and this presents another
1.2712 + // possible avenue to space savings. The constMethodOop in the
1.2713 + // new method contains possibly new attributes (LNT, LVT, etc).
1.2714 + // At first glance, it seems possible to save space by replacing
1.2715 + // the constMethodOop in the old method with the constMethodOop
1.2716 + // from the new method. The old and new methods would share the
1.2717 + // same constMethodOop and we would save the space occupied by
1.2718 + // the old constMethodOop. However, the constMethodOop contains
1.2719 + // a back reference to the containing method. Sharing the
1.2720 + // constMethodOop between two methods could lead to confusion in
1.2721 + // the code that uses the back reference. This would lead to
1.2722 + // brittle code that could be broken in non-obvious ways now or
1.2723 + // in the future.
1.2724 + //
1.2725 + // Another possibility is to copy the constMethodOop from the new
1.2726 + // method to the old method and then overwrite the new method with
1.2727 + // the old method. Since the constMethodOop contains the bytecodes
1.2728 + // for the method embedded in the oop, this option would change
1.2729 + // the bytecodes out from under any threads executing the old
1.2730 + // method and make the thread's bcp invalid. Since EMCP requires
1.2731 + // that the bytecodes be the same modulo constant pool indices, it
1.2732 + // is straight forward to compute the correct new bcp in the new
1.2733 + // constMethodOop from the old bcp in the old constMethodOop. The
1.2734 + // time consuming part would be searching all the frames in all
1.2735 + // of the threads to find all of the calls to the old method.
1.2736 + //
1.2737 + // It looks like we will have to live with the limited savings
1.2738 + // that we get from effectively overwriting the old methods
1.2739 + // when the new methods are attached to the_class.
1.2740 +
1.2741 + // track which methods are EMCP for add_previous_version() call
1.2742 + emcp_methods->set_bit(old_index);
1.2743 + (*emcp_method_count_p)++;
1.2744 +
1.2745 + // An EMCP method is _not_ obsolete. An obsolete method has a
1.2746 + // different jmethodID than the current method. An EMCP method
1.2747 + // has the same jmethodID as the current method. Having the
1.2748 + // same jmethodID for all EMCP versions of a method allows for
1.2749 + // a consistent view of the EMCP methods regardless of which
1.2750 + // EMCP method you happen to have in hand. For example, a
1.2751 + // breakpoint set in one EMCP method will work for all EMCP
1.2752 + // versions of the method including the current one.
1.2753 + } else {
1.2754 + // mark obsolete methods as such
1.2755 + old_method->set_is_obsolete();
1.2756 + obsolete_count++;
1.2757 +
1.2758 + // obsolete methods need a unique idnum
1.2759 + u2 num = instanceKlass::cast(_the_class_oop)->next_method_idnum();
1.2760 + if (num != constMethodOopDesc::UNSET_IDNUM) {
1.2761 +// u2 old_num = old_method->method_idnum();
1.2762 + old_method->set_method_idnum(num);
1.2763 +// TO DO: attach obsolete annotations to obsolete method's new idnum
1.2764 + }
1.2765 + // With tracing we try not to "yack" too much. The position of
1.2766 + // this trace assumes there are fewer obsolete methods than
1.2767 + // EMCP methods.
1.2768 + RC_TRACE(0x00000100, ("mark %s(%s) as obsolete",
1.2769 + old_method->name()->as_C_string(),
1.2770 + old_method->signature()->as_C_string()));
1.2771 + }
1.2772 + old_method->set_is_old();
1.2773 + }
1.2774 + for (int i = 0; i < _deleted_methods_length; ++i) {
1.2775 + methodOop old_method = _deleted_methods[i];
1.2776 +
1.2777 + assert(old_method->vtable_index() < 0,
1.2778 + "cannot delete methods with vtable entries");;
1.2779 +
1.2780 + // Mark all deleted methods as old and obsolete
1.2781 + old_method->set_is_old();
1.2782 + old_method->set_is_obsolete();
1.2783 + ++obsolete_count;
1.2784 + // With tracing we try not to "yack" too much. The position of
1.2785 + // this trace assumes there are fewer obsolete methods than
1.2786 + // EMCP methods.
1.2787 + RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete",
1.2788 + old_method->name()->as_C_string(),
1.2789 + old_method->signature()->as_C_string()));
1.2790 + }
1.2791 + assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(),
1.2792 + "sanity check");
1.2793 + RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p,
1.2794 + obsolete_count));
1.2795 +}
1.2796 +
1.2797 +// This internal class transfers the native function registration from old methods
1.2798 +// to new methods. It is designed to handle both the simple case of unchanged
1.2799 +// native methods and the complex cases of native method prefixes being added and/or
1.2800 +// removed.
1.2801 +// It expects only to be used during the VM_RedefineClasses op (a safepoint).
1.2802 +//
1.2803 +// This class is used after the new methods have been installed in "the_class".
1.2804 +//
1.2805 +// So, for example, the following must be handled. Where 'm' is a method and
1.2806 +// a number followed by an underscore is a prefix.
1.2807 +//
1.2808 +// Old Name New Name
1.2809 +// Simple transfer to new method m -> m
1.2810 +// Add prefix m -> 1_m
1.2811 +// Remove prefix 1_m -> m
1.2812 +// Simultaneous add of prefixes m -> 3_2_1_m
1.2813 +// Simultaneous removal of prefixes 3_2_1_m -> m
1.2814 +// Simultaneous add and remove 1_m -> 2_m
1.2815 +// Same, caused by prefix removal only 3_2_1_m -> 3_2_m
1.2816 +//
1.2817 +class TransferNativeFunctionRegistration {
1.2818 + private:
1.2819 + instanceKlassHandle the_class;
1.2820 + int prefix_count;
1.2821 + char** prefixes;
1.2822 +
1.2823 + // Recursively search the binary tree of possibly prefixed method names.
1.2824 + // Iteration could be used if all agents were well behaved. Full tree walk is
1.2825 + // more resilent to agents not cleaning up intermediate methods.
1.2826 + // Branch at each depth in the binary tree is:
1.2827 + // (1) without the prefix.
1.2828 + // (2) with the prefix.
1.2829 + // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...)
1.2830 + methodOop search_prefix_name_space(int depth, char* name_str, size_t name_len,
1.2831 + symbolOop signature) {
1.2832 + symbolOop name_symbol = SymbolTable::probe(name_str, (int)name_len);
1.2833 + if (name_symbol != NULL) {
1.2834 + methodOop method = Klass::cast(the_class())->lookup_method(name_symbol, signature);
1.2835 + if (method != NULL) {
1.2836 + // Even if prefixed, intermediate methods must exist.
1.2837 + if (method->is_native()) {
1.2838 + // Wahoo, we found a (possibly prefixed) version of the method, return it.
1.2839 + return method;
1.2840 + }
1.2841 + if (depth < prefix_count) {
1.2842 + // Try applying further prefixes (other than this one).
1.2843 + method = search_prefix_name_space(depth+1, name_str, name_len, signature);
1.2844 + if (method != NULL) {
1.2845 + return method; // found
1.2846 + }
1.2847 +
1.2848 + // Try adding this prefix to the method name and see if it matches
1.2849 + // another method name.
1.2850 + char* prefix = prefixes[depth];
1.2851 + size_t prefix_len = strlen(prefix);
1.2852 + size_t trial_len = name_len + prefix_len;
1.2853 + char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
1.2854 + strcpy(trial_name_str, prefix);
1.2855 + strcat(trial_name_str, name_str);
1.2856 + method = search_prefix_name_space(depth+1, trial_name_str, trial_len,
1.2857 + signature);
1.2858 + if (method != NULL) {
1.2859 + // If found along this branch, it was prefixed, mark as such
1.2860 + method->set_is_prefixed_native();
1.2861 + return method; // found
1.2862 + }
1.2863 + }
1.2864 + }
1.2865 + }
1.2866 + return NULL; // This whole branch bore nothing
1.2867 + }
1.2868 +
1.2869 + // Return the method name with old prefixes stripped away.
1.2870 + char* method_name_without_prefixes(methodOop method) {
1.2871 + symbolOop name = method->name();
1.2872 + char* name_str = name->as_utf8();
1.2873 +
1.2874 + // Old prefixing may be defunct, strip prefixes, if any.
1.2875 + for (int i = prefix_count-1; i >= 0; i--) {
1.2876 + char* prefix = prefixes[i];
1.2877 + size_t prefix_len = strlen(prefix);
1.2878 + if (strncmp(prefix, name_str, prefix_len) == 0) {
1.2879 + name_str += prefix_len;
1.2880 + }
1.2881 + }
1.2882 + return name_str;
1.2883 + }
1.2884 +
1.2885 + // Strip any prefixes off the old native method, then try to find a
1.2886 + // (possibly prefixed) new native that matches it.
1.2887 + methodOop strip_and_search_for_new_native(methodOop method) {
1.2888 + ResourceMark rm;
1.2889 + char* name_str = method_name_without_prefixes(method);
1.2890 + return search_prefix_name_space(0, name_str, strlen(name_str),
1.2891 + method->signature());
1.2892 + }
1.2893 +
1.2894 + public:
1.2895 +
1.2896 + // Construct a native method transfer processor for this class.
1.2897 + TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
1.2898 + assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
1.2899 +
1.2900 + the_class = _the_class;
1.2901 + prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
1.2902 + }
1.2903 +
1.2904 + // Attempt to transfer any of the old or deleted methods that are native
1.2905 + void transfer_registrations(methodOop* old_methods, int methods_length) {
1.2906 + for (int j = 0; j < methods_length; j++) {
1.2907 + methodOop old_method = old_methods[j];
1.2908 +
1.2909 + if (old_method->is_native() && old_method->has_native_function()) {
1.2910 + methodOop new_method = strip_and_search_for_new_native(old_method);
1.2911 + if (new_method != NULL) {
1.2912 + // Actually set the native function in the new method.
1.2913 + // Redefine does not send events (except CFLH), certainly not this
1.2914 + // behind the scenes re-registration.
1.2915 + new_method->set_native_function(old_method->native_function(),
1.2916 + !methodOopDesc::native_bind_event_is_interesting);
1.2917 + }
1.2918 + }
1.2919 + }
1.2920 + }
1.2921 +};
1.2922 +
1.2923 +// Don't lose the association between a native method and its JNI function.
1.2924 +void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) {
1.2925 + TransferNativeFunctionRegistration transfer(the_class);
1.2926 + transfer.transfer_registrations(_deleted_methods, _deleted_methods_length);
1.2927 + transfer.transfer_registrations(_matching_old_methods, _matching_methods_length);
1.2928 +}
1.2929 +
1.2930 +// Deoptimize all compiled code that depends on this class.
1.2931 +//
1.2932 +// If the can_redefine_classes capability is obtained in the onload
1.2933 +// phase then the compiler has recorded all dependencies from startup.
1.2934 +// In that case we need only deoptimize and throw away all compiled code
1.2935 +// that depends on the class.
1.2936 +//
1.2937 +// If can_redefine_classes is obtained sometime after the onload
1.2938 +// phase then the dependency information may be incomplete. In that case
1.2939 +// the first call to RedefineClasses causes all compiled code to be
1.2940 +// thrown away. As can_redefine_classes has been obtained then
1.2941 +// all future compilations will record dependencies so second and
1.2942 +// subsequent calls to RedefineClasses need only throw away code
1.2943 +// that depends on the class.
1.2944 +//
1.2945 +void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
1.2946 + assert_locked_or_safepoint(Compile_lock);
1.2947 +
1.2948 + // All dependencies have been recorded from startup or this is a second or
1.2949 + // subsequent use of RedefineClasses
1.2950 + if (JvmtiExport::all_dependencies_are_recorded()) {
1.2951 + Universe::flush_evol_dependents_on(k_h);
1.2952 + } else {
1.2953 + CodeCache::mark_all_nmethods_for_deoptimization();
1.2954 +
1.2955 + ResourceMark rm(THREAD);
1.2956 + DeoptimizationMarker dm;
1.2957 +
1.2958 + // Deoptimize all activations depending on marked nmethods
1.2959 + Deoptimization::deoptimize_dependents();
1.2960 +
1.2961 + // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1.2962 + CodeCache::make_marked_nmethods_not_entrant();
1.2963 +
1.2964 + // From now on we know that the dependency information is complete
1.2965 + JvmtiExport::set_all_dependencies_are_recorded(true);
1.2966 + }
1.2967 +}
1.2968 +
1.2969 +void VM_RedefineClasses::compute_added_deleted_matching_methods() {
1.2970 + methodOop old_method;
1.2971 + methodOop new_method;
1.2972 +
1.2973 + _matching_old_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
1.2974 + _matching_new_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
1.2975 + _added_methods = NEW_RESOURCE_ARRAY(methodOop, _new_methods->length());
1.2976 + _deleted_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
1.2977 +
1.2978 + _matching_methods_length = 0;
1.2979 + _deleted_methods_length = 0;
1.2980 + _added_methods_length = 0;
1.2981 +
1.2982 + int nj = 0;
1.2983 + int oj = 0;
1.2984 + while (true) {
1.2985 + if (oj >= _old_methods->length()) {
1.2986 + if (nj >= _new_methods->length()) {
1.2987 + break; // we've looked at everything, done
1.2988 + }
1.2989 + // New method at the end
1.2990 + new_method = (methodOop) _new_methods->obj_at(nj);
1.2991 + _added_methods[_added_methods_length++] = new_method;
1.2992 + ++nj;
1.2993 + } else if (nj >= _new_methods->length()) {
1.2994 + // Old method, at the end, is deleted
1.2995 + old_method = (methodOop) _old_methods->obj_at(oj);
1.2996 + _deleted_methods[_deleted_methods_length++] = old_method;
1.2997 + ++oj;
1.2998 + } else {
1.2999 + old_method = (methodOop) _old_methods->obj_at(oj);
1.3000 + new_method = (methodOop) _new_methods->obj_at(nj);
1.3001 + if (old_method->name() == new_method->name()) {
1.3002 + if (old_method->signature() == new_method->signature()) {
1.3003 + _matching_old_methods[_matching_methods_length ] = old_method;
1.3004 + _matching_new_methods[_matching_methods_length++] = new_method;
1.3005 + ++nj;
1.3006 + ++oj;
1.3007 + } else {
1.3008 + // added overloaded have already been moved to the end,
1.3009 + // so this is a deleted overloaded method
1.3010 + _deleted_methods[_deleted_methods_length++] = old_method;
1.3011 + ++oj;
1.3012 + }
1.3013 + } else { // names don't match
1.3014 + if (old_method->name()->fast_compare(new_method->name()) > 0) {
1.3015 + // new method
1.3016 + _added_methods[_added_methods_length++] = new_method;
1.3017 + ++nj;
1.3018 + } else {
1.3019 + // deleted method
1.3020 + _deleted_methods[_deleted_methods_length++] = old_method;
1.3021 + ++oj;
1.3022 + }
1.3023 + }
1.3024 + }
1.3025 + }
1.3026 + assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
1.3027 + assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
1.3028 +}
1.3029 +
1.3030 +
1.3031 +
1.3032 +// Install the redefinition of a class:
1.3033 +// - house keeping (flushing breakpoints and caches, deoptimizing
1.3034 +// dependent compiled code)
1.3035 +// - replacing parts in the_class with parts from scratch_class
1.3036 +// - adding a weak reference to track the obsolete but interesting
1.3037 +// parts of the_class
1.3038 +// - adjusting constant pool caches and vtables in other classes
1.3039 +// that refer to methods in the_class. These adjustments use the
1.3040 +// SystemDictionary::classes_do() facility which only allows
1.3041 +// a helper method to be specified. The interesting parameters
1.3042 +// that we would like to pass to the helper method are saved in
1.3043 +// static global fields in the VM operation.
1.3044 +void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
1.3045 + instanceKlassHandle scratch_class, TRAPS) {
1.3046 +
1.3047 + RC_TIMER_START(_timer_rsc_phase1);
1.3048 +
1.3049 + oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass);
1.3050 + klassOop the_class_oop = java_lang_Class::as_klassOop(the_class_mirror);
1.3051 + instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
1.3052 +
1.3053 +#ifndef JVMTI_KERNEL
1.3054 + // Remove all breakpoints in methods of this class
1.3055 + JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
1.3056 + jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop);
1.3057 +#endif // !JVMTI_KERNEL
1.3058 +
1.3059 + if (the_class_oop == Universe::reflect_invoke_cache()->klass()) {
1.3060 + // We are redefining java.lang.reflect.Method. Method.invoke() is
1.3061 + // cached and users of the cache care about each active version of
1.3062 + // the method so we have to track this previous version.
1.3063 + // Do this before methods get switched
1.3064 + Universe::reflect_invoke_cache()->add_previous_version(
1.3065 + the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum()));
1.3066 + }
1.3067 +
1.3068 + // Deoptimize all compiled code that depends on this class
1.3069 + flush_dependent_code(the_class, THREAD);
1.3070 +
1.3071 + _old_methods = the_class->methods();
1.3072 + _new_methods = scratch_class->methods();
1.3073 + _the_class_oop = the_class_oop;
1.3074 + compute_added_deleted_matching_methods();
1.3075 + update_jmethod_ids();
1.3076 +
1.3077 + // Attach new constant pool to the original klass. The original
1.3078 + // klass still refers to the old constant pool (for now).
1.3079 + scratch_class->constants()->set_pool_holder(the_class());
1.3080 +
1.3081 +#if 0
1.3082 + // In theory, with constant pool merging in place we should be able
1.3083 + // to save space by using the new, merged constant pool in place of
1.3084 + // the old constant pool(s). By "pool(s)" I mean the constant pool in
1.3085 + // the klass version we are replacing now and any constant pool(s) in
1.3086 + // previous versions of klass. Nice theory, doesn't work in practice.
1.3087 + // When this code is enabled, even simple programs throw NullPointer
1.3088 + // exceptions. I'm guessing that this is caused by some constant pool
1.3089 + // cache difference between the new, merged constant pool and the
1.3090 + // constant pool that was just being used by the klass. I'm keeping
1.3091 + // this code around to archive the idea, but the code has to remain
1.3092 + // disabled for now.
1.3093 +
1.3094 + // Attach each old method to the new constant pool. This can be
1.3095 + // done here since we are past the bytecode verification and
1.3096 + // constant pool optimization phases.
1.3097 + for (int i = _old_methods->length() - 1; i >= 0; i--) {
1.3098 + methodOop method = (methodOop)_old_methods->obj_at(i);
1.3099 + method->set_constants(scratch_class->constants());
1.3100 + }
1.3101 +
1.3102 + {
1.3103 + // walk all previous versions of the klass
1.3104 + instanceKlass *ik = (instanceKlass *)the_class()->klass_part();
1.3105 + PreviousVersionWalker pvw(ik);
1.3106 + instanceKlassHandle ikh;
1.3107 + do {
1.3108 + ikh = pvw.next_previous_version();
1.3109 + if (!ikh.is_null()) {
1.3110 + ik = ikh();
1.3111 +
1.3112 + // attach previous version of klass to the new constant pool
1.3113 + ik->set_constants(scratch_class->constants());
1.3114 +
1.3115 + // Attach each method in the previous version of klass to the
1.3116 + // new constant pool
1.3117 + objArrayOop prev_methods = ik->methods();
1.3118 + for (int i = prev_methods->length() - 1; i >= 0; i--) {
1.3119 + methodOop method = (methodOop)prev_methods->obj_at(i);
1.3120 + method->set_constants(scratch_class->constants());
1.3121 + }
1.3122 + }
1.3123 + } while (!ikh.is_null());
1.3124 + }
1.3125 +#endif
1.3126 +
1.3127 + // Replace methods and constantpool
1.3128 + the_class->set_methods(_new_methods);
1.3129 + scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods,
1.3130 + // and to be able to undo operation easily.
1.3131 +
1.3132 + constantPoolOop old_constants = the_class->constants();
1.3133 + the_class->set_constants(scratch_class->constants());
1.3134 + scratch_class->set_constants(old_constants); // See the previous comment.
1.3135 +#if 0
1.3136 + // We are swapping the guts of "the new class" with the guts of "the
1.3137 + // class". Since the old constant pool has just been attached to "the
1.3138 + // new class", it seems logical to set the pool holder in the old
1.3139 + // constant pool also. However, doing this will change the observable
1.3140 + // class hierarchy for any old methods that are still executing. A
1.3141 + // method can query the identity of its "holder" and this query uses
1.3142 + // the method's constant pool link to find the holder. The change in
1.3143 + // holding class from "the class" to "the new class" can confuse
1.3144 + // things.
1.3145 + //
1.3146 + // Setting the old constant pool's holder will also cause
1.3147 + // verification done during vtable initialization below to fail.
1.3148 + // During vtable initialization, the vtable's class is verified to be
1.3149 + // a subtype of the method's holder. The vtable's class is "the
1.3150 + // class" and the method's holder is gotten from the constant pool
1.3151 + // link in the method itself. For "the class"'s directly implemented
1.3152 + // methods, the method holder is "the class" itself (as gotten from
1.3153 + // the new constant pool). The check works fine in this case. The
1.3154 + // check also works fine for methods inherited from super classes.
1.3155 + //
1.3156 + // Miranda methods are a little more complicated. A miranda method is
1.3157 + // provided by an interface when the class implementing the interface
1.3158 + // does not provide its own method. These interfaces are implemented
1.3159 + // internally as an instanceKlass. These special instanceKlasses
1.3160 + // share the constant pool of the class that "implements" the
1.3161 + // interface. By sharing the constant pool, the method holder of a
1.3162 + // miranda method is the class that "implements" the interface. In a
1.3163 + // non-redefine situation, the subtype check works fine. However, if
1.3164 + // the old constant pool's pool holder is modified, then the check
1.3165 + // fails because there is no class hierarchy relationship between the
1.3166 + // vtable's class and "the new class".
1.3167 +
1.3168 + old_constants->set_pool_holder(scratch_class());
1.3169 +#endif
1.3170 +
1.3171 + // track which methods are EMCP for add_previous_version() call below
1.3172 + BitMap emcp_methods(_old_methods->length());
1.3173 + int emcp_method_count = 0;
1.3174 + emcp_methods.clear(); // clears 0..(length() - 1)
1.3175 + check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count);
1.3176 + transfer_old_native_function_registrations(the_class);
1.3177 +
1.3178 + // The class file bytes from before any retransformable agents mucked
1.3179 + // with them was cached on the scratch class, move to the_class.
1.3180 + // Note: we still want to do this if nothing needed caching since it
1.3181 + // should get cleared in the_class too.
1.3182 + the_class->set_cached_class_file(scratch_class->get_cached_class_file_bytes(),
1.3183 + scratch_class->get_cached_class_file_len());
1.3184 +
1.3185 + // Replace inner_classes
1.3186 + typeArrayOop old_inner_classes = the_class->inner_classes();
1.3187 + the_class->set_inner_classes(scratch_class->inner_classes());
1.3188 + scratch_class->set_inner_classes(old_inner_classes);
1.3189 +
1.3190 + // Initialize the vtable and interface table after
1.3191 + // methods have been rewritten
1.3192 + {
1.3193 + ResourceMark rm(THREAD);
1.3194 + // no exception should happen here since we explicitly
1.3195 + // do not check loader constraints.
1.3196 + // compare_and_normalize_class_versions has already checked:
1.3197 + // - classloaders unchanged, signatures unchanged
1.3198 + // - all instanceKlasses for redefined classes reused & contents updated
1.3199 + the_class->vtable()->initialize_vtable(false, THREAD);
1.3200 + the_class->itable()->initialize_itable(false, THREAD);
1.3201 + assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::threaddeath_klass())), "redefine exception");
1.3202 + }
1.3203 +
1.3204 + // Leave arrays of jmethodIDs and itable index cache unchanged
1.3205 +
1.3206 + // Copy the "source file name" attribute from new class version
1.3207 + the_class->set_source_file_name(scratch_class->source_file_name());
1.3208 +
1.3209 + // Copy the "source debug extension" attribute from new class version
1.3210 + the_class->set_source_debug_extension(
1.3211 + scratch_class->source_debug_extension());
1.3212 +
1.3213 + // Use of javac -g could be different in the old and the new
1.3214 + if (scratch_class->access_flags().has_localvariable_table() !=
1.3215 + the_class->access_flags().has_localvariable_table()) {
1.3216 +
1.3217 + AccessFlags flags = the_class->access_flags();
1.3218 + if (scratch_class->access_flags().has_localvariable_table()) {
1.3219 + flags.set_has_localvariable_table();
1.3220 + } else {
1.3221 + flags.clear_has_localvariable_table();
1.3222 + }
1.3223 + the_class->set_access_flags(flags);
1.3224 + }
1.3225 +
1.3226 + // Replace class annotation fields values
1.3227 + typeArrayOop old_class_annotations = the_class->class_annotations();
1.3228 + the_class->set_class_annotations(scratch_class->class_annotations());
1.3229 + scratch_class->set_class_annotations(old_class_annotations);
1.3230 +
1.3231 + // Replace fields annotation fields values
1.3232 + objArrayOop old_fields_annotations = the_class->fields_annotations();
1.3233 + the_class->set_fields_annotations(scratch_class->fields_annotations());
1.3234 + scratch_class->set_fields_annotations(old_fields_annotations);
1.3235 +
1.3236 + // Replace methods annotation fields values
1.3237 + objArrayOop old_methods_annotations = the_class->methods_annotations();
1.3238 + the_class->set_methods_annotations(scratch_class->methods_annotations());
1.3239 + scratch_class->set_methods_annotations(old_methods_annotations);
1.3240 +
1.3241 + // Replace methods parameter annotation fields values
1.3242 + objArrayOop old_methods_parameter_annotations =
1.3243 + the_class->methods_parameter_annotations();
1.3244 + the_class->set_methods_parameter_annotations(
1.3245 + scratch_class->methods_parameter_annotations());
1.3246 + scratch_class->set_methods_parameter_annotations(old_methods_parameter_annotations);
1.3247 +
1.3248 + // Replace methods default annotation fields values
1.3249 + objArrayOop old_methods_default_annotations =
1.3250 + the_class->methods_default_annotations();
1.3251 + the_class->set_methods_default_annotations(
1.3252 + scratch_class->methods_default_annotations());
1.3253 + scratch_class->set_methods_default_annotations(old_methods_default_annotations);
1.3254 +
1.3255 + // Replace minor version number of class file
1.3256 + u2 old_minor_version = the_class->minor_version();
1.3257 + the_class->set_minor_version(scratch_class->minor_version());
1.3258 + scratch_class->set_minor_version(old_minor_version);
1.3259 +
1.3260 + // Replace major version number of class file
1.3261 + u2 old_major_version = the_class->major_version();
1.3262 + the_class->set_major_version(scratch_class->major_version());
1.3263 + scratch_class->set_major_version(old_major_version);
1.3264 +
1.3265 + // Replace CP indexes for class and name+type of enclosing method
1.3266 + u2 old_class_idx = the_class->enclosing_method_class_index();
1.3267 + u2 old_method_idx = the_class->enclosing_method_method_index();
1.3268 + the_class->set_enclosing_method_indices(
1.3269 + scratch_class->enclosing_method_class_index(),
1.3270 + scratch_class->enclosing_method_method_index());
1.3271 + scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx);
1.3272 +
1.3273 + // keep track of previous versions of this class
1.3274 + the_class->add_previous_version(scratch_class, &emcp_methods,
1.3275 + emcp_method_count);
1.3276 +
1.3277 + RC_TIMER_STOP(_timer_rsc_phase1);
1.3278 + RC_TIMER_START(_timer_rsc_phase2);
1.3279 +
1.3280 + // Adjust constantpool caches and vtables for all classes
1.3281 + // that reference methods of the evolved class.
1.3282 + SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD);
1.3283 +
1.3284 + if (the_class->oop_map_cache() != NULL) {
1.3285 + // Flush references to any obsolete methods from the oop map cache
1.3286 + // so that obsolete methods are not pinned.
1.3287 + the_class->oop_map_cache()->flush_obsolete_entries();
1.3288 + }
1.3289 +
1.3290 + // increment the classRedefinedCount field in the_class and in any
1.3291 + // direct and indirect subclasses of the_class
1.3292 + increment_class_counter((instanceKlass *)the_class()->klass_part(), THREAD);
1.3293 +
1.3294 + // RC_TRACE macro has an embedded ResourceMark
1.3295 + RC_TRACE_WITH_THREAD(0x00000001, THREAD,
1.3296 + ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)",
1.3297 + the_class->external_name(),
1.3298 + java_lang_Class::classRedefinedCount(the_class_mirror),
1.3299 + os::available_memory() >> 10));
1.3300 +
1.3301 + RC_TIMER_STOP(_timer_rsc_phase2);
1.3302 +} // end redefine_single_class()
1.3303 +
1.3304 +
1.3305 +// Increment the classRedefinedCount field in the specific instanceKlass
1.3306 +// and in all direct and indirect subclasses.
1.3307 +void VM_RedefineClasses::increment_class_counter(instanceKlass *ik, TRAPS) {
1.3308 + oop class_mirror = ik->java_mirror();
1.3309 + klassOop class_oop = java_lang_Class::as_klassOop(class_mirror);
1.3310 + int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1;
1.3311 + java_lang_Class::set_classRedefinedCount(class_mirror, new_count);
1.3312 +
1.3313 + if (class_oop != _the_class_oop) {
1.3314 + // _the_class_oop count is printed at end of redefine_single_class()
1.3315 + RC_TRACE_WITH_THREAD(0x00000008, THREAD,
1.3316 + ("updated count in subclass=%s to %d", ik->external_name(), new_count));
1.3317 + }
1.3318 +
1.3319 + for (Klass *subk = ik->subklass(); subk != NULL;
1.3320 + subk = subk->next_sibling()) {
1.3321 + klassOop sub = subk->as_klassOop();
1.3322 + instanceKlass *subik = (instanceKlass *)sub->klass_part();
1.3323 +
1.3324 + // recursively do subclasses of the current subclass
1.3325 + increment_class_counter(subik, THREAD);
1.3326 + }
1.3327 +}
1.3328 +
1.3329 +#ifndef PRODUCT
1.3330 +void VM_RedefineClasses::check_class(klassOop k_oop,
1.3331 + oop initiating_loader, TRAPS) {
1.3332 + Klass *k = k_oop->klass_part();
1.3333 + if (k->oop_is_instance()) {
1.3334 + HandleMark hm(THREAD);
1.3335 + instanceKlass *ik = (instanceKlass *) k;
1.3336 +
1.3337 + if (ik->vtable_length() > 0) {
1.3338 + ResourceMark rm(THREAD);
1.3339 + if (!ik->vtable()->check_no_old_entries()) {
1.3340 + tty->print_cr("klassVtable::check_no_old_entries failure -- OLD method found -- class: %s", ik->signature_name());
1.3341 + ik->vtable()->dump_vtable();
1.3342 + dump_methods();
1.3343 + assert(false, "OLD method found");
1.3344 + }
1.3345 + }
1.3346 + }
1.3347 +}
1.3348 +
1.3349 +void VM_RedefineClasses::dump_methods() {
1.3350 + int j;
1.3351 + tty->print_cr("_old_methods --");
1.3352 + for (j = 0; j < _old_methods->length(); ++j) {
1.3353 + methodOop m = (methodOop) _old_methods->obj_at(j);
1.3354 + tty->print("%4d (%5d) ", j, m->vtable_index());
1.3355 + m->access_flags().print_on(tty);
1.3356 + tty->print(" -- ");
1.3357 + m->print_name(tty);
1.3358 + tty->cr();
1.3359 + }
1.3360 + tty->print_cr("_new_methods --");
1.3361 + for (j = 0; j < _new_methods->length(); ++j) {
1.3362 + methodOop m = (methodOop) _new_methods->obj_at(j);
1.3363 + tty->print("%4d (%5d) ", j, m->vtable_index());
1.3364 + m->access_flags().print_on(tty);
1.3365 + tty->print(" -- ");
1.3366 + m->print_name(tty);
1.3367 + tty->cr();
1.3368 + }
1.3369 + tty->print_cr("_matching_(old/new)_methods --");
1.3370 + for (j = 0; j < _matching_methods_length; ++j) {
1.3371 + methodOop m = _matching_old_methods[j];
1.3372 + tty->print("%4d (%5d) ", j, m->vtable_index());
1.3373 + m->access_flags().print_on(tty);
1.3374 + tty->print(" -- ");
1.3375 + m->print_name(tty);
1.3376 + tty->cr();
1.3377 + m = _matching_new_methods[j];
1.3378 + tty->print(" (%5d) ", m->vtable_index());
1.3379 + m->access_flags().print_on(tty);
1.3380 + tty->cr();
1.3381 + }
1.3382 + tty->print_cr("_deleted_methods --");
1.3383 + for (j = 0; j < _deleted_methods_length; ++j) {
1.3384 + methodOop m = _deleted_methods[j];
1.3385 + tty->print("%4d (%5d) ", j, m->vtable_index());
1.3386 + m->access_flags().print_on(tty);
1.3387 + tty->print(" -- ");
1.3388 + m->print_name(tty);
1.3389 + tty->cr();
1.3390 + }
1.3391 + tty->print_cr("_added_methods --");
1.3392 + for (j = 0; j < _added_methods_length; ++j) {
1.3393 + methodOop m = _added_methods[j];
1.3394 + tty->print("%4d (%5d) ", j, m->vtable_index());
1.3395 + m->access_flags().print_on(tty);
1.3396 + tty->print(" -- ");
1.3397 + m->print_name(tty);
1.3398 + tty->cr();
1.3399 + }
1.3400 +}
1.3401 +#endif
