1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/classfile/loaderConstraints.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,507 @@
1.4 +/*
1.5 + * Copyright 2003-2006 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/_loaderConstraints.cpp.incl"
1.30 +
1.31 +LoaderConstraintTable::LoaderConstraintTable(int nof_buckets)
1.32 + : Hashtable(nof_buckets, sizeof(LoaderConstraintEntry)) {};
1.33 +
1.34 +
1.35 +LoaderConstraintEntry* LoaderConstraintTable::new_entry(
1.36 + unsigned int hash, symbolOop name,
1.37 + klassOop klass, int num_loaders,
1.38 + int max_loaders) {
1.39 + LoaderConstraintEntry* entry;
1.40 + entry = (LoaderConstraintEntry*)Hashtable::new_entry(hash, klass);
1.41 + entry->set_name(name);
1.42 + entry->set_num_loaders(num_loaders);
1.43 + entry->set_max_loaders(max_loaders);
1.44 + return entry;
1.45 +}
1.46 +
1.47 +
1.48 +void LoaderConstraintTable::oops_do(OopClosure* f) {
1.49 + for (int index = 0; index < table_size(); index++) {
1.50 + for (LoaderConstraintEntry* probe = bucket(index);
1.51 + probe != NULL;
1.52 + probe = probe->next()) {
1.53 + f->do_oop((oop*)(probe->name_addr()));
1.54 + if (probe->klass() != NULL) {
1.55 + f->do_oop((oop*)probe->klass_addr());
1.56 + }
1.57 + for (int n = 0; n < probe->num_loaders(); n++) {
1.58 + if (probe->loader(n) != NULL) {
1.59 + f->do_oop(probe->loader_addr(n));
1.60 + }
1.61 + }
1.62 + }
1.63 + }
1.64 +}
1.65 +
1.66 +// We must keep the symbolOop used in the name alive. We'll use the
1.67 +// loaders to decide if a particular entry can be purged.
1.68 +void LoaderConstraintTable::always_strong_classes_do(OopClosure* blk) {
1.69 + // We must keep the symbolOop used in the name alive.
1.70 + for (int cindex = 0; cindex < table_size(); cindex++) {
1.71 + for (LoaderConstraintEntry* lc_probe = bucket(cindex);
1.72 + lc_probe != NULL;
1.73 + lc_probe = lc_probe->next()) {
1.74 + assert (lc_probe->name() != NULL, "corrupted loader constraint table");
1.75 + blk->do_oop((oop*)lc_probe->name_addr());
1.76 + }
1.77 + }
1.78 +}
1.79 +
1.80 +
1.81 +// The loaderConstraintTable must always be accessed with the
1.82 +// SystemDictionary lock held. This is true even for readers as
1.83 +// entries in the table could be being dynamically resized.
1.84 +
1.85 +LoaderConstraintEntry** LoaderConstraintTable::find_loader_constraint(
1.86 + symbolHandle name, Handle loader) {
1.87 +
1.88 + unsigned int hash = compute_hash(name);
1.89 + int index = hash_to_index(hash);
1.90 + LoaderConstraintEntry** pp = bucket_addr(index);
1.91 + while (*pp) {
1.92 + LoaderConstraintEntry* p = *pp;
1.93 + if (p->hash() == hash) {
1.94 + if (p->name() == name()) {
1.95 + for (int i = p->num_loaders() - 1; i >= 0; i--) {
1.96 + if (p->loader(i) == loader()) {
1.97 + return pp;
1.98 + }
1.99 + }
1.100 + }
1.101 + }
1.102 + pp = p->next_addr();
1.103 + }
1.104 + return pp;
1.105 +}
1.106 +
1.107 +
1.108 +void LoaderConstraintTable::purge_loader_constraints(BoolObjectClosure* is_alive) {
1.109 + assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint")
1.110 + // Remove unloaded entries from constraint table
1.111 + for (int index = 0; index < table_size(); index++) {
1.112 + LoaderConstraintEntry** p = bucket_addr(index);
1.113 + while(*p) {
1.114 + LoaderConstraintEntry* probe = *p;
1.115 + klassOop klass = probe->klass();
1.116 + // Remove klass that is no longer alive
1.117 + if (klass != NULL && !is_alive->do_object_b(klass)) {
1.118 + probe->set_klass(NULL);
1.119 + if (TraceLoaderConstraints) {
1.120 + ResourceMark rm;
1.121 + tty->print_cr("[Purging class object from constraint for name %s,"
1.122 + " loader list:",
1.123 + probe->name()->as_C_string());
1.124 + for (int i = 0; i < probe->num_loaders(); i++) {
1.125 + tty->print_cr("[ [%d]: %s", i,
1.126 + SystemDictionary::loader_name(probe->loader(i)));
1.127 + }
1.128 + }
1.129 + }
1.130 + // Remove entries no longer alive from loader array
1.131 + int n = 0;
1.132 + while (n < probe->num_loaders()) {
1.133 + if (probe->loader(n) != NULL) {
1.134 + if (!is_alive->do_object_b(probe->loader(n))) {
1.135 + if (TraceLoaderConstraints) {
1.136 + ResourceMark rm;
1.137 + tty->print_cr("[Purging loader %s from constraint for name %s",
1.138 + SystemDictionary::loader_name(probe->loader(n)),
1.139 + probe->name()->as_C_string()
1.140 + );
1.141 + }
1.142 +
1.143 + // Compact array
1.144 + int num = probe->num_loaders() - 1;
1.145 + probe->set_num_loaders(num);
1.146 + probe->set_loader(n, probe->loader(num));
1.147 + probe->set_loader(num, NULL);
1.148 +
1.149 + if (TraceLoaderConstraints) {
1.150 + ResourceMark rm;
1.151 + tty->print_cr("[New loader list:");
1.152 + for (int i = 0; i < probe->num_loaders(); i++) {
1.153 + tty->print_cr("[ [%d]: %s", i,
1.154 + SystemDictionary::loader_name(probe->loader(i)));
1.155 + }
1.156 + }
1.157 +
1.158 + continue; // current element replaced, so restart without
1.159 + // incrementing n
1.160 + }
1.161 + }
1.162 + n++;
1.163 + }
1.164 + // Check whether entry should be purged
1.165 + if (probe->num_loaders() < 2) {
1.166 + if (TraceLoaderConstraints) {
1.167 + ResourceMark rm;
1.168 + tty->print("[Purging complete constraint for name %s\n",
1.169 + probe->name()->as_C_string());
1.170 + }
1.171 +
1.172 + // Purge entry
1.173 + *p = probe->next();
1.174 + FREE_C_HEAP_ARRAY(oop, probe->loaders());
1.175 + free_entry(probe);
1.176 + } else {
1.177 +#ifdef ASSERT
1.178 + assert(is_alive->do_object_b(probe->name()), "name should be live");
1.179 + if (probe->klass() != NULL) {
1.180 + assert(is_alive->do_object_b(probe->klass()), "klass should be live");
1.181 + }
1.182 + for (n = 0; n < probe->num_loaders(); n++) {
1.183 + if (probe->loader(n) != NULL) {
1.184 + assert(is_alive->do_object_b(probe->loader(n)), "loader should be live");
1.185 + }
1.186 + }
1.187 +#endif
1.188 + // Go to next entry
1.189 + p = probe->next_addr();
1.190 + }
1.191 + }
1.192 + }
1.193 +}
1.194 +
1.195 +bool LoaderConstraintTable::add_entry(symbolHandle class_name,
1.196 + klassOop klass1, Handle class_loader1,
1.197 + klassOop klass2, Handle class_loader2) {
1.198 + int failure_code = 0; // encode different reasons for failing
1.199 +
1.200 + if (klass1 != NULL && klass2 != NULL && klass1 != klass2) {
1.201 + failure_code = 1;
1.202 + } else {
1.203 + klassOop klass = klass1 != NULL ? klass1 : klass2;
1.204 +
1.205 + LoaderConstraintEntry** pp1 = find_loader_constraint(class_name,
1.206 + class_loader1);
1.207 + if (*pp1 != NULL && (*pp1)->klass() != NULL) {
1.208 + if (klass != NULL) {
1.209 + if (klass != (*pp1)->klass()) {
1.210 + failure_code = 2;
1.211 + }
1.212 + } else {
1.213 + klass = (*pp1)->klass();
1.214 + }
1.215 + }
1.216 +
1.217 + LoaderConstraintEntry** pp2 = find_loader_constraint(class_name,
1.218 + class_loader2);
1.219 + if (*pp2 != NULL && (*pp2)->klass() != NULL) {
1.220 + if (klass != NULL) {
1.221 + if (klass != (*pp2)->klass()) {
1.222 + failure_code = 3;
1.223 + }
1.224 + } else {
1.225 + klass = (*pp2)->klass();
1.226 + }
1.227 + }
1.228 +
1.229 + if (failure_code == 0) {
1.230 + if (*pp1 == NULL && *pp2 == NULL) {
1.231 + unsigned int hash = compute_hash(class_name);
1.232 + int index = hash_to_index(hash);
1.233 + LoaderConstraintEntry* p;
1.234 + p = new_entry(hash, class_name(), klass, 2, 2);
1.235 + p->set_loaders(NEW_C_HEAP_ARRAY(oop, 2));
1.236 + p->set_loader(0, class_loader1());
1.237 + p->set_loader(1, class_loader2());
1.238 + p->set_klass(klass);
1.239 + p->set_next(bucket(index));
1.240 + set_entry(index, p);
1.241 + if (TraceLoaderConstraints) {
1.242 + ResourceMark rm;
1.243 + tty->print("[Adding new constraint for name: %s, loader[0]: %s,"
1.244 + " loader[1]: %s ]\n",
1.245 + class_name()->as_C_string(),
1.246 + SystemDictionary::loader_name(class_loader1()),
1.247 + SystemDictionary::loader_name(class_loader2())
1.248 + );
1.249 + }
1.250 + } else if (*pp1 == *pp2) {
1.251 + /* constraint already imposed */
1.252 + if ((*pp1)->klass() == NULL) {
1.253 + (*pp1)->set_klass(klass);
1.254 + if (TraceLoaderConstraints) {
1.255 + ResourceMark rm;
1.256 + tty->print("[Setting class object in existing constraint for"
1.257 + " name: %s and loader %s ]\n",
1.258 + class_name()->as_C_string(),
1.259 + SystemDictionary::loader_name(class_loader1())
1.260 + );
1.261 + }
1.262 + } else {
1.263 + assert((*pp1)->klass() == klass, "loader constraints corrupted");
1.264 + }
1.265 + } else if (*pp1 == NULL) {
1.266 + extend_loader_constraint(*pp2, class_loader1, klass);
1.267 + } else if (*pp2 == NULL) {
1.268 + extend_loader_constraint(*pp1, class_loader2, klass);
1.269 + } else {
1.270 + merge_loader_constraints(pp1, pp2, klass);
1.271 + }
1.272 + }
1.273 + }
1.274 +
1.275 + if (failure_code != 0 && TraceLoaderConstraints) {
1.276 + ResourceMark rm;
1.277 + const char* reason = "";
1.278 + switch(failure_code) {
1.279 + case 1: reason = "the class objects presented by loader[0] and loader[1]"
1.280 + " are different"; break;
1.281 + case 2: reason = "the class object presented by loader[0] does not match"
1.282 + " the stored class object in the constraint"; break;
1.283 + case 3: reason = "the class object presented by loader[1] does not match"
1.284 + " the stored class object in the constraint"; break;
1.285 + default: reason = "unknown reason code";
1.286 + }
1.287 + tty->print("[Failed to add constraint for name: %s, loader[0]: %s,"
1.288 + " loader[1]: %s, Reason: %s ]\n",
1.289 + class_name()->as_C_string(),
1.290 + SystemDictionary::loader_name(class_loader1()),
1.291 + SystemDictionary::loader_name(class_loader2()),
1.292 + reason
1.293 + );
1.294 + }
1.295 +
1.296 + return failure_code == 0;
1.297 +}
1.298 +
1.299 +
1.300 +// return true if the constraint was updated, false if the constraint is
1.301 +// violated
1.302 +bool LoaderConstraintTable::check_or_update(instanceKlassHandle k,
1.303 + Handle loader,
1.304 + symbolHandle name) {
1.305 + LoaderConstraintEntry* p = *(find_loader_constraint(name, loader));
1.306 + if (p && p->klass() != NULL && p->klass() != k()) {
1.307 + if (TraceLoaderConstraints) {
1.308 + ResourceMark rm;
1.309 + tty->print("[Constraint check failed for name %s, loader %s: "
1.310 + "the presented class object differs from that stored ]\n",
1.311 + name()->as_C_string(),
1.312 + SystemDictionary::loader_name(loader()));
1.313 + }
1.314 + return false;
1.315 + } else {
1.316 + if (p && p->klass() == NULL) {
1.317 + p->set_klass(k());
1.318 + if (TraceLoaderConstraints) {
1.319 + ResourceMark rm;
1.320 + tty->print("[Updating constraint for name %s, loader %s, "
1.321 + "by setting class object ]\n",
1.322 + name()->as_C_string(),
1.323 + SystemDictionary::loader_name(loader()));
1.324 + }
1.325 + }
1.326 + return true;
1.327 + }
1.328 +}
1.329 +
1.330 +klassOop LoaderConstraintTable::find_constrained_klass(symbolHandle name,
1.331 + Handle loader) {
1.332 + LoaderConstraintEntry *p = *(find_loader_constraint(name, loader));
1.333 + if (p != NULL && p->klass() != NULL)
1.334 + return p->klass();
1.335 +
1.336 + // No constraints, or else no klass loaded yet.
1.337 + return NULL;
1.338 +}
1.339 +
1.340 +
1.341 +klassOop LoaderConstraintTable::find_constrained_elem_klass(symbolHandle name,
1.342 + symbolHandle elem_name,
1.343 + Handle loader,
1.344 + TRAPS) {
1.345 + LoaderConstraintEntry *p = *(find_loader_constraint(name, loader));
1.346 + if (p != NULL) {
1.347 + assert(p->klass() == NULL, "Expecting null array klass");
1.348 +
1.349 + // The array name has a constraint, but it will not have a class. Check
1.350 + // each loader for an associated elem
1.351 + for (int i = 0; i < p->num_loaders(); i++) {
1.352 + Handle no_protection_domain;
1.353 +
1.354 + klassOop k = SystemDictionary::find(elem_name, p->loader(i), no_protection_domain, THREAD);
1.355 + if (k != NULL) {
1.356 + // Return the first elem klass found.
1.357 + return k;
1.358 + }
1.359 + }
1.360 + }
1.361 +
1.362 + // No constraints, or else no klass loaded yet.
1.363 + return NULL;
1.364 +}
1.365 +
1.366 +
1.367 +void LoaderConstraintTable::ensure_loader_constraint_capacity(
1.368 + LoaderConstraintEntry *p,
1.369 + int nfree) {
1.370 + if (p->max_loaders() - p->num_loaders() < nfree) {
1.371 + int n = nfree + p->num_loaders();
1.372 + oop* new_loaders = NEW_C_HEAP_ARRAY(oop, n);
1.373 + memcpy(new_loaders, p->loaders(), sizeof(oop) * p->num_loaders());
1.374 + p->set_max_loaders(n);
1.375 + FREE_C_HEAP_ARRAY(oop, p->loaders());
1.376 + p->set_loaders(new_loaders);
1.377 + }
1.378 +}
1.379 +
1.380 +
1.381 +void LoaderConstraintTable::extend_loader_constraint(LoaderConstraintEntry* p,
1.382 + Handle loader,
1.383 + klassOop klass) {
1.384 + ensure_loader_constraint_capacity(p, 1);
1.385 + int num = p->num_loaders();
1.386 + p->set_loader(num, loader());
1.387 + p->set_num_loaders(num + 1);
1.388 + if (TraceLoaderConstraints) {
1.389 + ResourceMark rm;
1.390 + tty->print("[Extending constraint for name %s by adding loader[%d]: %s %s",
1.391 + p->name()->as_C_string(),
1.392 + num,
1.393 + SystemDictionary::loader_name(loader()),
1.394 + (p->klass() == NULL ? " and setting class object ]\n" : " ]\n")
1.395 + );
1.396 + }
1.397 + if (p->klass() == NULL) {
1.398 + p->set_klass(klass);
1.399 + } else {
1.400 + assert(klass == NULL || p->klass() == klass, "constraints corrupted");
1.401 + }
1.402 +}
1.403 +
1.404 +
1.405 +void LoaderConstraintTable::merge_loader_constraints(
1.406 + LoaderConstraintEntry** pp1,
1.407 + LoaderConstraintEntry** pp2,
1.408 + klassOop klass) {
1.409 + // make sure *pp1 has higher capacity
1.410 + if ((*pp1)->max_loaders() < (*pp2)->max_loaders()) {
1.411 + LoaderConstraintEntry** tmp = pp2;
1.412 + pp2 = pp1;
1.413 + pp1 = tmp;
1.414 + }
1.415 +
1.416 + LoaderConstraintEntry* p1 = *pp1;
1.417 + LoaderConstraintEntry* p2 = *pp2;
1.418 +
1.419 + ensure_loader_constraint_capacity(p1, p2->num_loaders());
1.420 +
1.421 + for (int i = 0; i < p2->num_loaders(); i++) {
1.422 + int num = p1->num_loaders();
1.423 + p1->set_loader(num, p2->loader(i));
1.424 + p1->set_num_loaders(num + 1);
1.425 + }
1.426 +
1.427 + if (TraceLoaderConstraints) {
1.428 + ResourceMark rm;
1.429 + tty->print_cr("[Merged constraints for name %s, new loader list:",
1.430 + p1->name()->as_C_string()
1.431 + );
1.432 +
1.433 + for (int i = 0; i < p1->num_loaders(); i++) {
1.434 + tty->print_cr("[ [%d]: %s", i,
1.435 + SystemDictionary::loader_name(p1->loader(i)));
1.436 + }
1.437 + if (p1->klass() == NULL) {
1.438 + tty->print_cr("[... and setting class object]");
1.439 + }
1.440 + }
1.441 +
1.442 + // p1->klass() will hold NULL if klass, p2->klass(), and old
1.443 + // p1->klass() are all NULL. In addition, all three must have
1.444 + // matching non-NULL values, otherwise either the constraints would
1.445 + // have been violated, or the constraints had been corrupted (and an
1.446 + // assertion would fail).
1.447 + if (p2->klass() != NULL) {
1.448 + assert(p2->klass() == klass, "constraints corrupted");
1.449 + }
1.450 + if (p1->klass() == NULL) {
1.451 + p1->set_klass(klass);
1.452 + } else {
1.453 + assert(p1->klass() == klass, "constraints corrupted");
1.454 + }
1.455 +
1.456 + *pp2 = p2->next();
1.457 + FREE_C_HEAP_ARRAY(oop, p2->loaders());
1.458 + free_entry(p2);
1.459 + return;
1.460 +}
1.461 +
1.462 +
1.463 +void LoaderConstraintTable::verify(Dictionary* dictionary) {
1.464 + Thread *thread = Thread::current();
1.465 + for (int cindex = 0; cindex < _loader_constraint_size; cindex++) {
1.466 + for (LoaderConstraintEntry* probe = bucket(cindex);
1.467 + probe != NULL;
1.468 + probe = probe->next()) {
1.469 + guarantee(probe->name()->is_symbol(), "should be symbol");
1.470 + if (probe->klass() != NULL) {
1.471 + instanceKlass* ik = instanceKlass::cast(probe->klass());
1.472 + guarantee(ik->name() == probe->name(), "name should match");
1.473 + symbolHandle name (thread, ik->name());
1.474 + Handle loader(thread, ik->class_loader());
1.475 + unsigned int d_hash = dictionary->compute_hash(name, loader);
1.476 + int d_index = dictionary->hash_to_index(d_hash);
1.477 + klassOop k = dictionary->find_class(d_index, d_hash, name, loader);
1.478 + guarantee(k == probe->klass(), "klass should be in dictionary");
1.479 + }
1.480 + for (int n = 0; n< probe->num_loaders(); n++) {
1.481 + guarantee(probe->loader(n)->is_oop_or_null(), "should be oop");
1.482 + }
1.483 + }
1.484 + }
1.485 +}
1.486 +
1.487 +#ifndef PRODUCT
1.488 +
1.489 +// Called with the system dictionary lock held
1.490 +void LoaderConstraintTable::print() {
1.491 + ResourceMark rm;
1.492 +
1.493 + assert_locked_or_safepoint(SystemDictionary_lock);
1.494 + tty->print_cr("Java loader constraints (entries=%d)", _loader_constraint_size);
1.495 + for (int cindex = 0; cindex < _loader_constraint_size; cindex++) {
1.496 + for (LoaderConstraintEntry* probe = bucket(cindex);
1.497 + probe != NULL;
1.498 + probe = probe->next()) {
1.499 + tty->print("%4d: ", cindex);
1.500 + probe->name()->print();
1.501 + tty->print(" , loaders:");
1.502 + for (int n = 0; n < probe->num_loaders(); n++) {
1.503 + probe->loader(n)->print_value();
1.504 + tty->print(", ");
1.505 + }
1.506 + tty->cr();
1.507 + }
1.508 + }
1.509 +}
1.510 +#endif
