src/share/vm/classfile/placeholders.cpp

Tue, 23 Nov 2010 13:22:55 -0800

author
stefank
date
Tue, 23 Nov 2010 13:22:55 -0800
changeset 2314
f95d63e2154a
parent 1907
c18cbe5936b8
child 2497
3582bf76420e
permissions
-rw-r--r--

6989984: Use standard include model for Hospot
Summary: Replaced MakeDeps and the includeDB files with more standardized solutions.
Reviewed-by: coleenp, kvn, kamg

duke@435 1 /*
stefank@2314 2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "classfile/placeholders.hpp"
stefank@2314 27 #include "classfile/systemDictionary.hpp"
stefank@2314 28 #include "oops/oop.inline.hpp"
stefank@2314 29 #include "runtime/fieldType.hpp"
stefank@2314 30 #include "utilities/hashtable.inline.hpp"
duke@435 31
duke@435 32 // Placeholder methods
duke@435 33
duke@435 34 PlaceholderEntry* PlaceholderTable::new_entry(int hash, symbolOop name,
duke@435 35 oop loader, bool havesupername,
duke@435 36 symbolOop supername) {
duke@435 37 PlaceholderEntry* entry = (PlaceholderEntry*)Hashtable::new_entry(hash, name);
duke@435 38 entry->set_loader(loader);
duke@435 39 entry->set_havesupername(havesupername);
duke@435 40 entry->set_supername(supername);
duke@435 41 entry->set_superThreadQ(NULL);
duke@435 42 entry->set_loadInstanceThreadQ(NULL);
duke@435 43 entry->set_defineThreadQ(NULL);
duke@435 44 entry->set_definer(NULL);
duke@435 45 entry->set_instanceKlass(NULL);
duke@435 46 return entry;
duke@435 47 }
duke@435 48
duke@435 49
duke@435 50 // Placeholder objects represent classes currently being loaded.
duke@435 51 // All threads examining the placeholder table must hold the
duke@435 52 // SystemDictionary_lock, so we don't need special precautions
duke@435 53 // on store ordering here.
duke@435 54 void PlaceholderTable::add_entry(int index, unsigned int hash,
duke@435 55 symbolHandle class_name, Handle class_loader,
duke@435 56 bool havesupername, symbolHandle supername){
duke@435 57 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 58 assert(!class_name.is_null(), "adding NULL obj");
duke@435 59
duke@435 60 // Both readers and writers are locked so it's safe to just
duke@435 61 // create the placeholder and insert it in the list without a membar.
duke@435 62 PlaceholderEntry* entry = new_entry(hash, class_name(), class_loader(), havesupername, supername());
duke@435 63 add_entry(index, entry);
duke@435 64 }
duke@435 65
duke@435 66
duke@435 67 // Remove a placeholder object.
duke@435 68 void PlaceholderTable::remove_entry(int index, unsigned int hash,
duke@435 69 symbolHandle class_name,
duke@435 70 Handle class_loader) {
duke@435 71 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 72 PlaceholderEntry** p = bucket_addr(index);
duke@435 73 while (*p) {
duke@435 74 PlaceholderEntry *probe = *p;
duke@435 75 if (probe->hash() == hash && probe->equals(class_name(), class_loader())) {
duke@435 76 // Delete entry
duke@435 77 *p = probe->next();
duke@435 78 free_entry(probe);
duke@435 79 return;
duke@435 80 }
duke@435 81 p = probe->next_addr();
duke@435 82 }
duke@435 83 }
duke@435 84
duke@435 85 PlaceholderEntry* PlaceholderTable::get_entry(int index, unsigned int hash,
duke@435 86 symbolHandle class_name,
duke@435 87 Handle class_loader) {
duke@435 88 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 89
duke@435 90 symbolOop class_name_ = class_name();
duke@435 91 oop class_loader_ = class_loader();
duke@435 92
duke@435 93 for (PlaceholderEntry *place_probe = bucket(index);
duke@435 94 place_probe != NULL;
duke@435 95 place_probe = place_probe->next()) {
duke@435 96 if (place_probe->hash() == hash &&
duke@435 97 place_probe->equals(class_name_, class_loader_)) {
duke@435 98 return place_probe;
duke@435 99 }
duke@435 100 }
duke@435 101 return NULL;
duke@435 102 }
duke@435 103
duke@435 104 symbolOop PlaceholderTable::find_entry(int index, unsigned int hash,
duke@435 105 symbolHandle class_name,
duke@435 106 Handle class_loader) {
duke@435 107 PlaceholderEntry* probe = get_entry(index, hash, class_name, class_loader);
duke@435 108 return (probe? probe->klass(): symbolOop(NULL));
duke@435 109 }
duke@435 110
duke@435 111 // find_and_add returns probe pointer - old or new
duke@435 112 // If no entry exists, add a placeholder entry
duke@435 113 // If entry exists, reuse entry
duke@435 114 // For both, push SeenThread for classloadAction
duke@435 115 // if havesupername: this is used for circularity for instanceklass loading
duke@435 116 PlaceholderEntry* PlaceholderTable::find_and_add(int index, unsigned int hash, symbolHandle name, Handle loader, classloadAction action, symbolHandle supername, Thread* thread) {
duke@435 117 PlaceholderEntry* probe = get_entry(index, hash, name, loader);
duke@435 118 if (probe == NULL) {
duke@435 119 // Nothing found, add place holder
duke@435 120 add_entry(index, hash, name, loader, (action == LOAD_SUPER), supername);
duke@435 121 probe = get_entry(index, hash, name, loader);
duke@435 122 } else {
duke@435 123 if (action == LOAD_SUPER) {
duke@435 124 probe->set_havesupername(true);
duke@435 125 probe->set_supername(supername());
duke@435 126 }
duke@435 127 }
duke@435 128 if (probe) probe->add_seen_thread(thread, action);
duke@435 129 return probe;
duke@435 130 }
duke@435 131
duke@435 132
duke@435 133 // placeholder used to track class loading internal states
duke@435 134 // placeholder existence now for loading superclass/superinterface
duke@435 135 // superthreadQ tracks class circularity, while loading superclass/superinterface
duke@435 136 // loadInstanceThreadQ tracks load_instance_class calls
duke@435 137 // definer() tracks the single thread that owns define token
duke@435 138 // defineThreadQ tracks waiters on defining thread's results
duke@435 139 // 1st claimant creates placeholder
duke@435 140 // find_and_add adds SeenThread entry for appropriate queue
duke@435 141 // All claimants remove SeenThread after completing action
duke@435 142 // On removal: if definer and all queues empty, remove entry
duke@435 143 // Note: you can be in both placeholders and systemDictionary
duke@435 144 // see parse_stream for redefine classes
duke@435 145 // Therefore - must always check SD first
duke@435 146 // Ignores the case where entry is not found
duke@435 147 void PlaceholderTable::find_and_remove(int index, unsigned int hash,
duke@435 148 symbolHandle name, Handle loader, Thread* thread) {
duke@435 149 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 150 PlaceholderEntry *probe = get_entry(index, hash, name, loader);
duke@435 151 if (probe != NULL) {
duke@435 152 // No other threads using this entry
duke@435 153 if ((probe->superThreadQ() == NULL) && (probe->loadInstanceThreadQ() == NULL)
duke@435 154 && (probe->defineThreadQ() == NULL) && (probe->definer() == NULL)) {
duke@435 155 remove_entry(index, hash, name, loader);
duke@435 156 }
duke@435 157 }
duke@435 158 }
duke@435 159
duke@435 160 PlaceholderTable::PlaceholderTable(int table_size)
duke@435 161 : TwoOopHashtable(table_size, sizeof(PlaceholderEntry)) {
duke@435 162 }
duke@435 163
duke@435 164
duke@435 165 void PlaceholderTable::oops_do(OopClosure* f) {
duke@435 166 for (int index = 0; index < table_size(); index++) {
duke@435 167 for (PlaceholderEntry* probe = bucket(index);
duke@435 168 probe != NULL;
duke@435 169 probe = probe->next()) {
duke@435 170 probe->oops_do(f);
duke@435 171 }
duke@435 172 }
duke@435 173 }
duke@435 174
duke@435 175
duke@435 176 void PlaceholderEntry::oops_do(OopClosure* blk) {
duke@435 177 assert(klass() != NULL, "should have a non-null klass");
duke@435 178 blk->do_oop((oop*)klass_addr());
duke@435 179 if (_loader != NULL) {
duke@435 180 blk->do_oop(loader_addr());
duke@435 181 }
duke@435 182 if (_supername != NULL) {
duke@435 183 blk->do_oop((oop*)supername_addr());
duke@435 184 }
duke@435 185 if (_instanceKlass != NULL) {
duke@435 186 blk->do_oop((oop*)instanceKlass_addr());
duke@435 187 }
duke@435 188 }
duke@435 189
duke@435 190 // do all entries in the placeholder table
duke@435 191 void PlaceholderTable::entries_do(void f(symbolOop, oop)) {
duke@435 192 for (int index = 0; index < table_size(); index++) {
duke@435 193 for (PlaceholderEntry* probe = bucket(index);
duke@435 194 probe != NULL;
duke@435 195 probe = probe->next()) {
duke@435 196 f(probe->klass(), probe->loader());
duke@435 197 }
duke@435 198 }
duke@435 199 }
duke@435 200
duke@435 201
duke@435 202 #ifndef PRODUCT
duke@435 203 // Note, doesn't append a cr
duke@435 204 void PlaceholderEntry::print() const {
duke@435 205 klass()->print_value();
duke@435 206 if (loader() != NULL) {
duke@435 207 tty->print(", loader ");
duke@435 208 loader()->print_value();
duke@435 209 }
duke@435 210 if (supername() != NULL) {
duke@435 211 tty->print(", supername ");
duke@435 212 supername()->print_value();
duke@435 213 }
duke@435 214 if (definer() != NULL) {
duke@435 215 tty->print(", definer ");
duke@435 216 definer()->print_value();
duke@435 217 }
duke@435 218 if (instanceKlass() != NULL) {
duke@435 219 tty->print(", instanceKlass ");
duke@435 220 instanceKlass()->print_value();
duke@435 221 }
duke@435 222 tty->print("\n");
duke@435 223 tty->print("loadInstanceThreadQ threads:");
duke@435 224 loadInstanceThreadQ()->printActionQ();
duke@435 225 tty->print("\n");
duke@435 226 tty->print("superThreadQ threads:");
duke@435 227 superThreadQ()->printActionQ();
duke@435 228 tty->print("\n");
duke@435 229 tty->print("defineThreadQ threads:");
duke@435 230 defineThreadQ()->printActionQ();
duke@435 231 tty->print("\n");
duke@435 232 }
duke@435 233 #endif
duke@435 234
duke@435 235 void PlaceholderEntry::verify() const {
duke@435 236 guarantee(loader() == NULL || loader()->is_instance(),
duke@435 237 "checking type of _loader");
duke@435 238 guarantee(instanceKlass() == NULL
duke@435 239 || Klass::cast(instanceKlass())->oop_is_instance(),
duke@435 240 "checking type of instanceKlass result");
duke@435 241 klass()->verify();
duke@435 242 }
duke@435 243
duke@435 244 void PlaceholderTable::verify() {
duke@435 245 int element_count = 0;
duke@435 246 for (int pindex = 0; pindex < table_size(); pindex++) {
duke@435 247 for (PlaceholderEntry* probe = bucket(pindex);
duke@435 248 probe != NULL;
duke@435 249 probe = probe->next()) {
duke@435 250 probe->verify();
duke@435 251 element_count++; // both klasses and place holders count
duke@435 252 }
duke@435 253 }
duke@435 254 guarantee(number_of_entries() == element_count,
duke@435 255 "Verify of system dictionary failed");
duke@435 256 }
duke@435 257
duke@435 258
duke@435 259 #ifndef PRODUCT
duke@435 260 void PlaceholderTable::print() {
duke@435 261 for (int pindex = 0; pindex < table_size(); pindex++) {
duke@435 262 for (PlaceholderEntry* probe = bucket(pindex);
duke@435 263 probe != NULL;
duke@435 264 probe = probe->next()) {
duke@435 265 if (Verbose) tty->print("%4d: ", pindex);
duke@435 266 tty->print(" place holder ");
duke@435 267
duke@435 268 probe->print();
duke@435 269 tty->cr();
duke@435 270 }
duke@435 271 }
duke@435 272 }
duke@435 273 #endif

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