annotate src/hotspot/share/utilities/hashtable.cpp @ 57831:40be0504668d

Automatic merge with records-and-sealed
author mcimadamore
date Tue, 17 Sep 2019 22:26:59 +0000
parents 5c7418757bad
children aba258cd7df8
rev   line source
duke@1 1 /*
coleenp@55693 2 * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
duke@1 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1 4 *
duke@1 5 * This code is free software; you can redistribute it and/or modify it
duke@1 6 * under the terms of the GNU General Public License version 2 only, as
duke@1 7 * published by the Free Software Foundation.
duke@1 8 *
duke@1 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@1 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@1 13 * accompanied this code).
duke@1 14 *
duke@1 15 * You should have received a copy of the GNU General Public License version
duke@1 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@1 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1 18 *
trims@5547 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@5547 20 * or visit www.oracle.com if you need additional information or have any
trims@5547 21 * questions.
duke@1 22 *
duke@1 23 */
duke@1 24
stefank@7397 25 #include "precompiled.hpp"
coleenp@13199 26 #include "classfile/altHashing.hpp"
coleenp@46475 27 #include "classfile/dictionary.hpp"
goetz@35498 28 #include "classfile/javaClasses.inline.hpp"
coleenp@46475 29 #include "classfile/moduleEntry.hpp"
coleenp@46475 30 #include "classfile/packageEntry.hpp"
coleenp@46545 31 #include "classfile/placeholders.hpp"
coleenp@46475 32 #include "classfile/protectionDomainCache.hpp"
gziemski@24426 33 #include "classfile/stringTable.hpp"
rehn@53641 34 #include "code/nmethod.hpp"
stefank@50518 35 #include "logging/log.hpp"
stefank@7397 36 #include "memory/allocation.inline.hpp"
stefank@7397 37 #include "memory/resourceArea.hpp"
stefank@7397 38 #include "oops/oop.inline.hpp"
coleenp@50313 39 #include "oops/weakHandle.inline.hpp"
stefank@7397 40 #include "runtime/safepoint.hpp"
stefank@7397 41 #include "utilities/dtrace.hpp"
stefank@7397 42 #include "utilities/hashtable.hpp"
stefank@7397 43 #include "utilities/hashtable.inline.hpp"
iklam@17610 44 #include "utilities/numberSeq.hpp"
duke@1 45
coleenp@8076 46
mgerdin@26421 47 // This hashtable is implemented as an open hash table with a fixed number of buckets.
duke@1 48
mgerdin@26421 49 template <MEMFLAGS F> BasicHashtableEntry<F>* BasicHashtable<F>::new_entry_free_list() {
mgerdin@26421 50 BasicHashtableEntry<F>* entry = NULL;
mgerdin@26421 51 if (_free_list != NULL) {
duke@1 52 entry = _free_list;
duke@1 53 _free_list = _free_list->next();
mgerdin@26421 54 }
mgerdin@26421 55 return entry;
mgerdin@26421 56 }
mgerdin@26421 57
mgerdin@26421 58 // HashtableEntrys are allocated in blocks to reduce the space overhead.
mgerdin@26421 59 template <MEMFLAGS F> BasicHashtableEntry<F>* BasicHashtable<F>::new_entry(unsigned int hashValue) {
mgerdin@26421 60 BasicHashtableEntry<F>* entry = new_entry_free_list();
mgerdin@26421 61
mgerdin@26421 62 if (entry == NULL) {
jrose@1551 63 if (_first_free_entry + _entry_size >= _end_block) {
jrose@1551 64 int block_size = MIN2(512, MAX2((int)_table_size / 2, (int)_number_of_entries));
duke@1 65 int len = _entry_size * block_size;
roland@53643 66 len = 1 << log2_int(len); // round down to power of 2
jrose@1551 67 assert(len >= _entry_size, "");
zgu@13195 68 _first_free_entry = NEW_C_HEAP_ARRAY2(char, len, F, CURRENT_PC);
iklam@53599 69 _entry_blocks->append(_first_free_entry);
duke@1 70 _end_block = _first_free_entry + len;
duke@1 71 }
zgu@13195 72 entry = (BasicHashtableEntry<F>*)_first_free_entry;
duke@1 73 _first_free_entry += _entry_size;
duke@1 74 }
duke@1 75
jrose@1551 76 assert(_entry_size % HeapWordSize == 0, "");
duke@1 77 entry->set_hash(hashValue);
duke@1 78 return entry;
duke@1 79 }
duke@1 80
duke@1 81
zgu@13195 82 template <class T, MEMFLAGS F> HashtableEntry<T, F>* Hashtable<T, F>::new_entry(unsigned int hashValue, T obj) {
zgu@13195 83 HashtableEntry<T, F>* entry;
duke@1 84
zgu@13195 85 entry = (HashtableEntry<T, F>*)BasicHashtable<F>::new_entry(hashValue);
coleenp@8076 86 entry->set_literal(obj);
duke@1 87 return entry;
duke@1 88 }
duke@1 89
coleenp@46729 90 // Version of hashtable entry allocation that allocates in the C heap directly.
iklam@53599 91 // The block allocator in BasicHashtable has less fragmentation, but the memory is not freed until
iklam@53599 92 // the whole table is freed. Use allocate_new_entry() if you want to individually free the memory
iklam@53599 93 // used by each entry
coleenp@46729 94 template <class T, MEMFLAGS F> HashtableEntry<T, F>* Hashtable<T, F>::allocate_new_entry(unsigned int hashValue, T obj) {
coleenp@46729 95 HashtableEntry<T, F>* entry = (HashtableEntry<T, F>*) NEW_C_HEAP_ARRAY(char, this->entry_size(), F);
coleenp@46729 96
coleenp@46729 97 entry->set_hash(hashValue);
coleenp@46729 98 entry->set_literal(obj);
coleenp@46729 99 entry->set_next(NULL);
coleenp@46729 100 return entry;
coleenp@46729 101 }
coleenp@46729 102
zgu@13195 103 template <MEMFLAGS F> void BasicHashtable<F>::free_buckets() {
coleenp@13097 104 if (NULL != _buckets) {
iklam@53482 105 FREE_C_HEAP_ARRAY(HashtableBucket, _buckets);
coleenp@13097 106 _buckets = NULL;
coleenp@13097 107 }
coleenp@13097 108 }
coleenp@13097 109
coleenp@46742 110 // For oops and Strings the size of the literal is interesting. For other types, nobody cares.
coleenp@46742 111 static int literal_size(ConstantPool*) { return 0; }
coleenp@46742 112 static int literal_size(Klass*) { return 0; }
coleenp@46742 113 static int literal_size(nmethod*) { return 0; }
coleenp@46742 114
coleenp@46742 115 static int literal_size(Symbol *symbol) {
iklam@17610 116 return symbol->size() * HeapWordSize;
iklam@17610 117 }
iklam@17610 118
coleenp@46742 119 static int literal_size(oop obj) {
iklam@17610 120 // NOTE: this would over-count if (pre-JDK8) java_lang_Class::has_offset_field() is true,
iklam@17610 121 // and the String.value array is shared by several Strings. However, starting from JDK8,
iklam@17610 122 // the String.value array is not shared anymore.
coleenp@46742 123 if (obj == NULL) {
coleenp@46742 124 return 0;
coleenp@46742 125 } else if (obj->klass() == SystemDictionary::String_klass()) {
coleenp@46742 126 return (obj->size() + java_lang_String::value(obj)->size()) * HeapWordSize;
coleenp@46742 127 } else {
coleenp@46742 128 return obj->size();
coleenp@46742 129 }
iklam@17610 130 }
iklam@17610 131
coleenp@55693 132 static int literal_size(WeakHandle<vm_class_loader_data> v) {
coleenp@50313 133 return literal_size(v.peek());
coleenp@50313 134 }
coleenp@50313 135
gziemski@47955 136 template <MEMFLAGS F> bool BasicHashtable<F>::resize(int new_size) {
gziemski@47955 137 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
gziemski@47955 138
gziemski@47955 139 // Allocate new buckets
gziemski@47955 140 HashtableBucket<F>* buckets_new = NEW_C_HEAP_ARRAY2_RETURN_NULL(HashtableBucket<F>, new_size, F, CURRENT_PC);
gziemski@47955 141 if (buckets_new == NULL) {
gziemski@47955 142 return false;
gziemski@47955 143 }
gziemski@47955 144
gziemski@47955 145 // Clear the new buckets
gziemski@47955 146 for (int i = 0; i < new_size; i++) {
gziemski@47955 147 buckets_new[i].clear();
gziemski@47955 148 }
gziemski@47955 149
gziemski@47955 150 int table_size_old = _table_size;
gziemski@47955 151 // hash_to_index() uses _table_size, so switch the sizes now
gziemski@47955 152 _table_size = new_size;
gziemski@47955 153
gziemski@47955 154 // Move entries from the old table to a new table
gziemski@47955 155 for (int index_old = 0; index_old < table_size_old; index_old++) {
gziemski@47955 156 for (BasicHashtableEntry<F>* p = _buckets[index_old].get_entry(); p != NULL; ) {
gziemski@47955 157 BasicHashtableEntry<F>* next = p->next();
gziemski@47955 158 bool keep_shared = p->is_shared();
gziemski@47955 159 int index_new = hash_to_index(p->hash());
gziemski@47955 160
gziemski@47955 161 p->set_next(buckets_new[index_new].get_entry());
gziemski@47955 162 buckets_new[index_new].set_entry(p);
gziemski@47955 163
gziemski@47955 164 if (keep_shared) {
gziemski@47955 165 p->set_shared();
gziemski@47955 166 }
gziemski@47955 167 p = next;
gziemski@47955 168 }
gziemski@47955 169 }
gziemski@47955 170
gziemski@47955 171 // The old backets now can be released
gziemski@47955 172 BasicHashtable<F>::free_buckets();
gziemski@47955 173
gziemski@47955 174 // Switch to the new storage
gziemski@47955 175 _buckets = buckets_new;
gziemski@47955 176
gziemski@47955 177 return true;
gziemski@47955 178 }
coleenp@46742 179
iklam@53599 180 template <MEMFLAGS F> bool BasicHashtable<F>::maybe_grow(int max_size, int load_factor) {
iklam@53599 181 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
iklam@53599 182
iklam@53599 183 if (table_size() >= max_size) {
iklam@53599 184 return false;
iklam@53599 185 }
iklam@53599 186 if (number_of_entries() / table_size() > load_factor) {
iklam@53599 187 resize(MIN2<int>(table_size() * 2, max_size));
iklam@53599 188 return true;
iklam@53599 189 } else {
iklam@53599 190 return false;
iklam@53599 191 }
iklam@53599 192 }
iklam@53599 193
gziemski@56117 194 template <class T, MEMFLAGS F> TableStatistics Hashtable<T, F>::statistics_calculate(T (*literal_load_barrier)(HashtableEntry<T, F>*)) {
iklam@17610 195 NumberSeq summary;
iklam@17610 196 int literal_bytes = 0;
iklam@17610 197 for (int i = 0; i < this->table_size(); ++i) {
iklam@17610 198 int count = 0;
mgerdin@26421 199 for (HashtableEntry<T, F>* e = this->bucket(i);
iklam@46746 200 e != NULL; e = e->next()) {
iklam@17610 201 count++;
stefank@50817 202 T l = (literal_load_barrier != NULL) ? literal_load_barrier(e) : e->literal();
stefank@50817 203 literal_bytes += literal_size(l);
iklam@17610 204 }
iklam@17610 205 summary.add((double)count);
iklam@17610 206 }
gziemski@56117 207 return TableStatistics(this->_stats_rate, summary, literal_bytes, sizeof(HashtableBucket<F>), sizeof(HashtableEntry<T, F>));
gziemski@56117 208 }
iklam@17610 209
gziemski@56117 210 // Dump footprint and bucket length statistics
gziemski@56117 211 //
gziemski@56117 212 // Note: if you create a new subclass of Hashtable<MyNewType, F>, you will need to
gziemski@56117 213 // add a new function static int literal_size(MyNewType lit)
gziemski@56117 214 // because I can't get template <class T> int literal_size(T) to pick the specializations for Symbol and oop.
gziemski@56117 215 template <class T, MEMFLAGS F> void Hashtable<T, F>::print_table_statistics(outputStream* st,
gziemski@56117 216 const char *table_name,
gziemski@56117 217 T (*literal_load_barrier)(HashtableEntry<T, F>*)) {
gziemski@56117 218 TableStatistics ts = statistics_calculate(literal_load_barrier);
gziemski@56117 219 ts.print(st, table_name);
iklam@17610 220 }
iklam@17610 221
duke@1 222 #ifndef PRODUCT
coleenp@50313 223 template <class T> void print_literal(T l) {
coleenp@50313 224 l->print();
coleenp@50313 225 }
coleenp@50313 226
coleenp@55693 227 static void print_literal(WeakHandle<vm_class_loader_data> l) {
coleenp@50313 228 l.print();
coleenp@50313 229 }
duke@1 230
zgu@13195 231 template <class T, MEMFLAGS F> void Hashtable<T, F>::print() {
duke@1 232 ResourceMark rm;
duke@1 233
zgu@13195 234 for (int i = 0; i < BasicHashtable<F>::table_size(); i++) {
zgu@13195 235 HashtableEntry<T, F>* entry = bucket(i);
duke@1 236 while(entry != NULL) {
duke@1 237 tty->print("%d : ", i);
coleenp@50313 238 print_literal(entry->literal());
duke@1 239 tty->cr();
duke@1 240 entry = entry->next();
duke@1 241 }
duke@1 242 }
duke@1 243 }
duke@1 244
coleenp@46475 245 template <MEMFLAGS F>
coleenp@46475 246 template <class T> void BasicHashtable<F>::verify_table(const char* table_name) {
coleenp@46475 247 int element_count = 0;
coleenp@46475 248 int max_bucket_count = 0;
coleenp@46545 249 int max_bucket_number = 0;
coleenp@46475 250 for (int index = 0; index < table_size(); index++) {
coleenp@46475 251 int bucket_count = 0;
coleenp@46475 252 for (T* probe = (T*)bucket(index); probe != NULL; probe = probe->next()) {
coleenp@46475 253 probe->verify();
coleenp@46475 254 bucket_count++;
duke@1 255 }
coleenp@46475 256 element_count += bucket_count;
coleenp@46545 257 if (bucket_count > max_bucket_count) {
coleenp@46545 258 max_bucket_count = bucket_count;
coleenp@46545 259 max_bucket_number = index;
coleenp@46545 260 }
duke@1 261 }
coleenp@46475 262 guarantee(number_of_entries() == element_count,
coleenp@46475 263 "Verify of %s failed", table_name);
coleenp@46545 264
coleenp@46545 265 // Log some statistics about the hashtable
coleenp@46545 266 log_info(hashtables)("%s max bucket size %d bucket %d element count %d table size %d", table_name,
coleenp@46545 267 max_bucket_count, max_bucket_number, _number_of_entries, _table_size);
coleenp@46545 268 if (_number_of_entries > 0 && log_is_enabled(Debug, hashtables)) {
coleenp@46545 269 for (int index = 0; index < table_size(); index++) {
coleenp@46545 270 int bucket_count = 0;
coleenp@46545 271 for (T* probe = (T*)bucket(index); probe != NULL; probe = probe->next()) {
coleenp@46545 272 log_debug(hashtables)("bucket %d hash " INTPTR_FORMAT, index, (intptr_t)probe->hash());
coleenp@46545 273 bucket_count++;
coleenp@46545 274 }
coleenp@46545 275 if (bucket_count > 0) {
coleenp@46545 276 log_debug(hashtables)("bucket %d count %d", index, bucket_count);
coleenp@46545 277 }
coleenp@46545 278 }
coleenp@46545 279 }
duke@1 280 }
duke@1 281 #endif // PRODUCT
duke@1 282
coleenp@8076 283 // Explicitly instantiate these types
mgerdin@26422 284 template class Hashtable<nmethod*, mtGC>;
mgerdin@26422 285 template class HashtableEntry<nmethod*, mtGC>;
mgerdin@26422 286 template class BasicHashtable<mtGC>;
coleenp@13728 287 template class Hashtable<ConstantPool*, mtClass>;
zgu@13195 288 template class Hashtable<Symbol*, mtSymbol>;
coleenp@13728 289 template class Hashtable<Klass*, mtClass>;
iklam@34257 290 template class Hashtable<InstanceKlass*, mtClass>;
coleenp@55693 291 template class Hashtable<WeakHandle<vm_class_loader_data>, mtClass>;
coleenp@46729 292 template class Hashtable<Symbol*, mtModule>;
zgu@13195 293 template class Hashtable<oop, mtSymbol>;
zgu@13195 294 template class Hashtable<Symbol*, mtClass>;
zgu@13195 295 template class HashtableEntry<Symbol*, mtSymbol>;
zgu@13195 296 template class HashtableEntry<Symbol*, mtClass>;
zgu@13195 297 template class HashtableEntry<oop, mtSymbol>;
coleenp@55693 298 template class HashtableEntry<WeakHandle<vm_class_loader_data>, mtClass>;
iklam@46746 299 template class HashtableBucket<mtClass>;
zgu@13195 300 template class BasicHashtableEntry<mtSymbol>;
zgu@13195 301 template class BasicHashtableEntry<mtCode>;
zgu@13195 302 template class BasicHashtable<mtClass>;
iklam@34257 303 template class BasicHashtable<mtClassShared>;
zgu@13195 304 template class BasicHashtable<mtSymbol>;
zgu@13195 305 template class BasicHashtable<mtCode>;
zgu@13195 306 template class BasicHashtable<mtInternal>;
hseigel@38733 307 template class BasicHashtable<mtModule>;
kvn@30593 308 template class BasicHashtable<mtCompiler>;
coleenp@46475 309
coleenp@46475 310 template void BasicHashtable<mtClass>::verify_table<DictionaryEntry>(char const*);
coleenp@46475 311 template void BasicHashtable<mtModule>::verify_table<ModuleEntry>(char const*);
coleenp@46475 312 template void BasicHashtable<mtModule>::verify_table<PackageEntry>(char const*);
coleenp@46475 313 template void BasicHashtable<mtClass>::verify_table<ProtectionDomainCacheEntry>(char const*);
coleenp@46545 314 template void BasicHashtable<mtClass>::verify_table<PlaceholderEntry>(char const*);