annotate hotspot/src/share/vm/utilities/hashtable.cpp @ 22921:ee35d5c0b1dc

8034839: jvm hangs with gc/gctests/LoadUnloadGC test Summary: Provide fast lookup of checked dependencies via hashmap Reviewed-by: kvn, roland
author anoll
date Wed, 26 Feb 2014 11:29:47 +0100
parents b2cbb3680b4f
children 0f438571f278
rev   line source
duke@1 1 /*
minqi@22757 2 * Copyright (c) 2003, 2014, 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@13199 27 #include "classfile/javaClasses.hpp"
anoll@22921 28 #include "code/dependencies.hpp"
stefank@7397 29 #include "memory/allocation.inline.hpp"
coleenp@13097 30 #include "memory/filemap.hpp"
stefank@7397 31 #include "memory/resourceArea.hpp"
stefank@7397 32 #include "oops/oop.inline.hpp"
stefank@7397 33 #include "runtime/safepoint.hpp"
stefank@7397 34 #include "utilities/dtrace.hpp"
stefank@7397 35 #include "utilities/hashtable.hpp"
stefank@7397 36 #include "utilities/hashtable.inline.hpp"
iklam@17610 37 #include "utilities/numberSeq.hpp"
duke@1 38
coleenp@8076 39
duke@1 40 // This is a generic hashtable, designed to be used for the symbol
duke@1 41 // and string tables.
duke@1 42 //
duke@1 43 // It is implemented as an open hash table with a fixed number of buckets.
duke@1 44 //
duke@1 45 // %note:
duke@1 46 // - HashtableEntrys are allocated in blocks to reduce the space overhead.
duke@1 47
zgu@13195 48 template <MEMFLAGS F> BasicHashtableEntry<F>* BasicHashtable<F>::new_entry(unsigned int hashValue) {
zgu@13195 49 BasicHashtableEntry<F>* entry;
duke@1 50
duke@1 51 if (_free_list) {
duke@1 52 entry = _free_list;
duke@1 53 _free_list = _free_list->next();
duke@1 54 } else {
jrose@1551 55 if (_first_free_entry + _entry_size >= _end_block) {
jrose@1551 56 int block_size = MIN2(512, MAX2((int)_table_size / 2, (int)_number_of_entries));
duke@1 57 int len = _entry_size * block_size;
jrose@1551 58 len = 1 << log2_intptr(len); // round down to power of 2
jrose@1551 59 assert(len >= _entry_size, "");
zgu@13195 60 _first_free_entry = NEW_C_HEAP_ARRAY2(char, len, F, CURRENT_PC);
duke@1 61 _end_block = _first_free_entry + len;
duke@1 62 }
zgu@13195 63 entry = (BasicHashtableEntry<F>*)_first_free_entry;
duke@1 64 _first_free_entry += _entry_size;
duke@1 65 }
duke@1 66
jrose@1551 67 assert(_entry_size % HeapWordSize == 0, "");
duke@1 68 entry->set_hash(hashValue);
duke@1 69 return entry;
duke@1 70 }
duke@1 71
duke@1 72
zgu@13195 73 template <class T, MEMFLAGS F> HashtableEntry<T, F>* Hashtable<T, F>::new_entry(unsigned int hashValue, T obj) {
zgu@13195 74 HashtableEntry<T, F>* entry;
duke@1 75
zgu@13195 76 entry = (HashtableEntry<T, F>*)BasicHashtable<F>::new_entry(hashValue);
coleenp@8076 77 entry->set_literal(obj);
duke@1 78 return entry;
duke@1 79 }
duke@1 80
coleenp@13087 81 // Check to see if the hashtable is unbalanced. The caller set a flag to
coleenp@13087 82 // rehash at the next safepoint. If this bucket is 60 times greater than the
coleenp@13087 83 // expected average bucket length, it's an unbalanced hashtable.
coleenp@13087 84 // This is somewhat an arbitrary heuristic but if one bucket gets to
coleenp@13087 85 // rehash_count which is currently 100, there's probably something wrong.
coleenp@13087 86
zgu@13195 87 template <MEMFLAGS F> bool BasicHashtable<F>::check_rehash_table(int count) {
coleenp@13087 88 assert(table_size() != 0, "underflow");
coleenp@13087 89 if (count > (((double)number_of_entries()/(double)table_size())*rehash_multiple)) {
coleenp@13087 90 // Set a flag for the next safepoint, which should be at some guaranteed
coleenp@13087 91 // safepoint interval.
coleenp@13087 92 return true;
coleenp@13087 93 }
coleenp@13087 94 return false;
coleenp@13087 95 }
coleenp@13087 96
minqi@22757 97 template <class T, MEMFLAGS F> juint Hashtable<T, F>::_seed = 0;
coleenp@13199 98
coleenp@13087 99 // Create a new table and using alternate hash code, populate the new table
coleenp@13087 100 // with the existing elements. This can be used to change the hash code
coleenp@13087 101 // and could in the future change the size of the table.
coleenp@13087 102
zgu@13195 103 template <class T, MEMFLAGS F> void Hashtable<T, F>::move_to(Hashtable<T, F>* new_table) {
coleenp@13199 104
coleenp@13199 105 // Initialize the global seed for hashing.
coleenp@13199 106 _seed = AltHashing::compute_seed();
coleenp@13199 107 assert(seed() != 0, "shouldn't be zero");
coleenp@13199 108
coleenp@13199 109 int saved_entry_count = this->number_of_entries();
coleenp@13087 110
coleenp@13087 111 // Iterate through the table and create a new entry for the new table
coleenp@13087 112 for (int i = 0; i < new_table->table_size(); ++i) {
zgu@13195 113 for (HashtableEntry<T, F>* p = bucket(i); p != NULL; ) {
zgu@13195 114 HashtableEntry<T, F>* next = p->next();
coleenp@13087 115 T string = p->literal();
coleenp@13087 116 // Use alternate hashing algorithm on the symbol in the first table
coleenp@13728 117 unsigned int hashValue = string->new_hash(seed());
coleenp@13087 118 // Get a new index relative to the new table (can also change size)
coleenp@13087 119 int index = new_table->hash_to_index(hashValue);
coleenp@13087 120 p->set_hash(hashValue);
coleenp@13097 121 // Keep the shared bit in the Hashtable entry to indicate that this entry
coleenp@13097 122 // can't be deleted. The shared bit is the LSB in the _next field so
coleenp@13097 123 // walking the hashtable past these entries requires
coleenp@13097 124 // BasicHashtableEntry::make_ptr() call.
coleenp@13097 125 bool keep_shared = p->is_shared();
andrew@13342 126 this->unlink_entry(p);
coleenp@13087 127 new_table->add_entry(index, p);
coleenp@13097 128 if (keep_shared) {
coleenp@13097 129 p->set_shared();
coleenp@13097 130 }
coleenp@13087 131 p = next;
coleenp@13087 132 }
coleenp@13087 133 }
coleenp@13087 134 // give the new table the free list as well
coleenp@13087 135 new_table->copy_freelist(this);
coleenp@13087 136 assert(new_table->number_of_entries() == saved_entry_count, "lost entry on dictionary copy?");
coleenp@13087 137
coleenp@13087 138 // Destroy memory used by the buckets in the hashtable. The memory
coleenp@13087 139 // for the elements has been used in a new table and is not
coleenp@13087 140 // destroyed. The memory reuse will benefit resizing the SystemDictionary
coleenp@13087 141 // to avoid a memory allocation spike at safepoint.
zgu@13195 142 BasicHashtable<F>::free_buckets();
coleenp@13087 143 }
coleenp@13087 144
zgu@13195 145 template <MEMFLAGS F> void BasicHashtable<F>::free_buckets() {
coleenp@13097 146 if (NULL != _buckets) {
coleenp@13097 147 // Don't delete the buckets in the shared space. They aren't
coleenp@13097 148 // allocated by os::malloc
coleenp@13097 149 if (!UseSharedSpaces ||
coleenp@13097 150 !FileMapInfo::current_info()->is_in_shared_space(_buckets)) {
zgu@13195 151 FREE_C_HEAP_ARRAY(HashtableBucket, _buckets, F);
coleenp@13097 152 }
coleenp@13097 153 _buckets = NULL;
coleenp@13097 154 }
coleenp@13097 155 }
coleenp@13097 156
coleenp@13097 157
duke@1 158 // Reverse the order of elements in the hash buckets.
duke@1 159
zgu@13195 160 template <MEMFLAGS F> void BasicHashtable<F>::reverse() {
duke@1 161
duke@1 162 for (int i = 0; i < _table_size; ++i) {
zgu@13195 163 BasicHashtableEntry<F>* new_list = NULL;
zgu@13195 164 BasicHashtableEntry<F>* p = bucket(i);
duke@1 165 while (p != NULL) {
zgu@13195 166 BasicHashtableEntry<F>* next = p->next();
duke@1 167 p->set_next(new_list);
duke@1 168 new_list = p;
duke@1 169 p = next;
duke@1 170 }
duke@1 171 *bucket_addr(i) = new_list;
duke@1 172 }
duke@1 173 }
duke@1 174
duke@1 175
duke@1 176 // Copy the table to the shared space.
duke@1 177
zgu@13195 178 template <MEMFLAGS F> void BasicHashtable<F>::copy_table(char** top, char* end) {
duke@1 179
duke@1 180 // Dump the hash table entries.
duke@1 181
duke@1 182 intptr_t *plen = (intptr_t*)(*top);
duke@1 183 *top += sizeof(*plen);
duke@1 184
duke@1 185 int i;
duke@1 186 for (i = 0; i < _table_size; ++i) {
zgu@13195 187 for (BasicHashtableEntry<F>** p = _buckets[i].entry_addr();
duke@1 188 *p != NULL;
duke@1 189 p = (*p)->next_addr()) {
duke@1 190 if (*top + entry_size() > end) {
coleenp@8076 191 report_out_of_shared_space(SharedMiscData);
duke@1 192 }
zgu@13195 193 *p = (BasicHashtableEntry<F>*)memcpy(*top, *p, entry_size());
duke@1 194 *top += entry_size();
duke@1 195 }
duke@1 196 }
duke@1 197 *plen = (char*)(*top) - (char*)plen - sizeof(*plen);
duke@1 198
duke@1 199 // Set the shared bit.
duke@1 200
duke@1 201 for (i = 0; i < _table_size; ++i) {
zgu@13195 202 for (BasicHashtableEntry<F>* p = bucket(i); p != NULL; p = p->next()) {
duke@1 203 p->set_shared();
duke@1 204 }
duke@1 205 }
duke@1 206 }
duke@1 207
duke@1 208
duke@1 209
duke@1 210 // Reverse the order of elements in the hash buckets.
duke@1 211
zgu@13195 212 template <class T, MEMFLAGS F> void Hashtable<T, F>::reverse(void* boundary) {
duke@1 213
zgu@13195 214 for (int i = 0; i < this->table_size(); ++i) {
zgu@13195 215 HashtableEntry<T, F>* high_list = NULL;
zgu@13195 216 HashtableEntry<T, F>* low_list = NULL;
zgu@13195 217 HashtableEntry<T, F>* last_low_entry = NULL;
zgu@13195 218 HashtableEntry<T, F>* p = bucket(i);
duke@1 219 while (p != NULL) {
zgu@13195 220 HashtableEntry<T, F>* next = p->next();
duke@1 221 if ((void*)p->literal() >= boundary) {
duke@1 222 p->set_next(high_list);
duke@1 223 high_list = p;
duke@1 224 } else {
duke@1 225 p->set_next(low_list);
duke@1 226 low_list = p;
duke@1 227 if (last_low_entry == NULL) {
duke@1 228 last_low_entry = p;
duke@1 229 }
duke@1 230 }
duke@1 231 p = next;
duke@1 232 }
duke@1 233 if (low_list != NULL) {
duke@1 234 *bucket_addr(i) = low_list;
duke@1 235 last_low_entry->set_next(high_list);
duke@1 236 } else {
duke@1 237 *bucket_addr(i) = high_list;
duke@1 238 }
duke@1 239 }
duke@1 240 }
duke@1 241
iklam@17610 242 template <class T, MEMFLAGS F> int Hashtable<T, F>::literal_size(Symbol *symbol) {
iklam@17610 243 return symbol->size() * HeapWordSize;
iklam@17610 244 }
iklam@17610 245
iklam@17610 246 template <class T, MEMFLAGS F> int Hashtable<T, F>::literal_size(oop oop) {
iklam@17610 247 // NOTE: this would over-count if (pre-JDK8) java_lang_Class::has_offset_field() is true,
iklam@17610 248 // and the String.value array is shared by several Strings. However, starting from JDK8,
iklam@17610 249 // the String.value array is not shared anymore.
iklam@17610 250 assert(oop != NULL && oop->klass() == SystemDictionary::String_klass(), "only strings are supported");
iklam@17610 251 return (oop->size() + java_lang_String::value(oop)->size()) * HeapWordSize;
iklam@17610 252 }
iklam@17610 253
iklam@17610 254 // Dump footprint and bucket length statistics
iklam@17610 255 //
iklam@17610 256 // Note: if you create a new subclass of Hashtable<MyNewType, F>, you will need to
iklam@17610 257 // add a new function Hashtable<T, F>::literal_size(MyNewType lit)
iklam@17610 258
iklam@17610 259 template <class T, MEMFLAGS F> void Hashtable<T, F>::dump_table(outputStream* st, const char *table_name) {
iklam@17610 260 NumberSeq summary;
iklam@17610 261 int literal_bytes = 0;
iklam@17610 262 for (int i = 0; i < this->table_size(); ++i) {
iklam@17610 263 int count = 0;
iklam@17610 264 for (HashtableEntry<T, F>* e = bucket(i);
iklam@17610 265 e != NULL; e = e->next()) {
iklam@17610 266 count++;
iklam@17610 267 literal_bytes += literal_size(e->literal());
iklam@17610 268 }
iklam@17610 269 summary.add((double)count);
iklam@17610 270 }
iklam@17610 271 double num_buckets = summary.num();
iklam@17610 272 double num_entries = summary.sum();
iklam@17610 273
iklam@17610 274 int bucket_bytes = (int)num_buckets * sizeof(bucket(0));
iklam@17610 275 int entry_bytes = (int)num_entries * sizeof(HashtableEntry<T, F>);
iklam@17610 276 int total_bytes = literal_bytes + bucket_bytes + entry_bytes;
iklam@17610 277
iklam@17610 278 double bucket_avg = (num_buckets <= 0) ? 0 : (bucket_bytes / num_buckets);
iklam@17610 279 double entry_avg = (num_entries <= 0) ? 0 : (entry_bytes / num_entries);
iklam@17610 280 double literal_avg = (num_entries <= 0) ? 0 : (literal_bytes / num_entries);
iklam@17610 281
iklam@17610 282 st->print_cr("%s statistics:", table_name);
iklam@17610 283 st->print_cr("Number of buckets : %9d = %9d bytes, avg %7.3f", (int)num_buckets, bucket_bytes, bucket_avg);
iklam@17610 284 st->print_cr("Number of entries : %9d = %9d bytes, avg %7.3f", (int)num_entries, entry_bytes, entry_avg);
iklam@17610 285 st->print_cr("Number of literals : %9d = %9d bytes, avg %7.3f", (int)num_entries, literal_bytes, literal_avg);
iklam@17610 286 st->print_cr("Total footprint : %9s = %9d bytes", "", total_bytes);
iklam@17610 287 st->print_cr("Average bucket size : %9.3f", summary.avg());
iklam@17610 288 st->print_cr("Variance of bucket size : %9.3f", summary.variance());
iklam@17610 289 st->print_cr("Std. dev. of bucket size: %9.3f", summary.sd());
iklam@17610 290 st->print_cr("Maximum bucket size : %9d", (int)summary.maximum());
iklam@17610 291 }
iklam@17610 292
duke@1 293
duke@1 294 // Dump the hash table buckets.
duke@1 295
zgu@13195 296 template <MEMFLAGS F> void BasicHashtable<F>::copy_buckets(char** top, char* end) {
zgu@13195 297 intptr_t len = _table_size * sizeof(HashtableBucket<F>);
duke@1 298 *(intptr_t*)(*top) = len;
duke@1 299 *top += sizeof(intptr_t);
duke@1 300
duke@1 301 *(intptr_t*)(*top) = _number_of_entries;
duke@1 302 *top += sizeof(intptr_t);
duke@1 303
duke@1 304 if (*top + len > end) {
coleenp@8076 305 report_out_of_shared_space(SharedMiscData);
duke@1 306 }
zgu@13195 307 _buckets = (HashtableBucket<F>*)memcpy(*top, _buckets, len);
duke@1 308 *top += len;
duke@1 309 }
duke@1 310
duke@1 311
duke@1 312 #ifndef PRODUCT
duke@1 313
zgu@13195 314 template <class T, MEMFLAGS F> void Hashtable<T, F>::print() {
duke@1 315 ResourceMark rm;
duke@1 316
zgu@13195 317 for (int i = 0; i < BasicHashtable<F>::table_size(); i++) {
zgu@13195 318 HashtableEntry<T, F>* entry = bucket(i);
duke@1 319 while(entry != NULL) {
duke@1 320 tty->print("%d : ", i);
duke@1 321 entry->literal()->print();
duke@1 322 tty->cr();
duke@1 323 entry = entry->next();
duke@1 324 }
duke@1 325 }
duke@1 326 }
duke@1 327
duke@1 328
zgu@13195 329 template <MEMFLAGS F> void BasicHashtable<F>::verify() {
duke@1 330 int count = 0;
duke@1 331 for (int i = 0; i < table_size(); i++) {
zgu@13195 332 for (BasicHashtableEntry<F>* p = bucket(i); p != NULL; p = p->next()) {
duke@1 333 ++count;
duke@1 334 }
duke@1 335 }
duke@1 336 assert(count == number_of_entries(), "number of hashtable entries incorrect");
duke@1 337 }
duke@1 338
duke@1 339
duke@1 340 #endif // PRODUCT
duke@1 341
duke@1 342 #ifdef ASSERT
duke@1 343
zgu@13195 344 template <MEMFLAGS F> void BasicHashtable<F>::verify_lookup_length(double load) {
duke@1 345 if ((double)_lookup_length / (double)_lookup_count > load * 2.0) {
duke@1 346 warning("Performance bug: SystemDictionary lookup_count=%d "
duke@1 347 "lookup_length=%d average=%lf load=%f",
duke@1 348 _lookup_count, _lookup_length,
duke@1 349 (double) _lookup_length / _lookup_count, load);
duke@1 350 }
duke@1 351 }
duke@1 352
duke@1 353 #endif
anoll@22921 354
anoll@22921 355
anoll@22921 356 template<class T, class M> GenericHashtable<T, M>::GenericHashtable(int size, bool C_heap, MEMFLAGS memflag) {
anoll@22921 357 assert(size > 0, " Invalid hashtable size");
anoll@22921 358 _size = size;
anoll@22921 359 _C_heap = C_heap;
anoll@22921 360 _memflag = memflag;
anoll@22921 361 // Perform subtype-specific resource allocation
anoll@22921 362 _items = (C_heap) ? NEW_C_HEAP_ARRAY(T*, size, memflag) : NEW_RESOURCE_ARRAY(T*, size);
anoll@22921 363 memset(_items, 0, sizeof(T*) * size);
anoll@22921 364
anoll@22921 365 DEBUG_ONLY(_num_items = 0;)
anoll@22921 366 }
anoll@22921 367
anoll@22921 368 template<class T, class M> GenericHashtable<T, M>::~GenericHashtable() {
anoll@22921 369 if (on_C_heap()) {
anoll@22921 370 // Check backing array
anoll@22921 371 for (int i = 0; i < size(); i++) {
anoll@22921 372 T* item = head(i);
anoll@22921 373 // Delete all items in linked list
anoll@22921 374 while (item != NULL) {
anoll@22921 375 T* next_item = item->next();
anoll@22921 376 delete item;
anoll@22921 377 DEBUG_ONLY(_num_items--);
anoll@22921 378 item = next_item;
anoll@22921 379 }
anoll@22921 380 }
anoll@22921 381 FREE_C_HEAP_ARRAY(T*, _items, _memflag);
anoll@22921 382 _items = NULL;
anoll@22921 383 assert (_num_items == 0, "Not all memory released");
anoll@22921 384 }
anoll@22921 385 }
anoll@22921 386
anoll@22921 387 /**
anoll@22921 388 * Return a pointer to the item 'I' that is stored in the hashtable for
anoll@22921 389 * which match_item->equals(I) == true. If no such item is found, NULL
anoll@22921 390 * is returned.
anoll@22921 391 */
anoll@22921 392 template<class T, class F> T* GenericHashtable<T, F>::contains(T* match_item) {
anoll@22921 393 if (match_item != NULL) {
anoll@22921 394 int idx = index(match_item);
anoll@22921 395 return contains_impl(match_item, idx);
anoll@22921 396 }
anoll@22921 397 return NULL;
anoll@22921 398 }
anoll@22921 399
anoll@22921 400 /**
anoll@22921 401 * Add item to the hashtable. Return 'true' if the item was added
anoll@22921 402 * and false otherwise.
anoll@22921 403 */
anoll@22921 404 template<class T, class F> bool GenericHashtable<T, F>::add(T* item) {
anoll@22921 405 if (item != NULL) {
anoll@22921 406 int idx = index(item);
anoll@22921 407 T* found_item = contains_impl(item, idx);
anoll@22921 408 if (found_item == NULL) {
anoll@22921 409 T* list_head = head(idx);
anoll@22921 410 item->set_next(list_head);
anoll@22921 411 item->set_prev(NULL);
anoll@22921 412
anoll@22921 413 if (list_head != NULL) {
anoll@22921 414 list_head->set_prev(item);
anoll@22921 415 }
anoll@22921 416 set_head(item, idx);
anoll@22921 417 DEBUG_ONLY(_num_items++);
anoll@22921 418 return true;
anoll@22921 419 }
anoll@22921 420 }
anoll@22921 421 return false;
anoll@22921 422 }
anoll@22921 423
anoll@22921 424 /**
anoll@22921 425 * Removes an item 'I' from the hashtable, if present. 'I' is removed, if
anoll@22921 426 * match_item->equals(I) == true. Removing an item from the hashtable does
anoll@22921 427 * not free memory.
anoll@22921 428 */
anoll@22921 429 template<class T, class F> T* GenericHashtable<T, F>::remove(T* match_item) {
anoll@22921 430 if (match_item != NULL) {
anoll@22921 431 int idx = index(match_item);
anoll@22921 432 T* found_item = contains_impl(match_item, idx);
anoll@22921 433 if (found_item != NULL) {
anoll@22921 434 // Remove item from linked list
anoll@22921 435 T* prev = found_item->prev();
anoll@22921 436 T* next = found_item->next();
anoll@22921 437 if (prev != NULL) {
anoll@22921 438 prev->set_next(next);
anoll@22921 439 } else {
anoll@22921 440 set_head(next, idx);
anoll@22921 441 }
anoll@22921 442 if (next != NULL) {
anoll@22921 443 next->set_prev(prev);
anoll@22921 444 }
anoll@22921 445
anoll@22921 446 DEBUG_ONLY(_num_items--);
anoll@22921 447 return found_item;
anoll@22921 448 }
anoll@22921 449 }
anoll@22921 450 return NULL;
anoll@22921 451 }
anoll@22921 452
anoll@22921 453
anoll@22921 454 template<class T, class F> T* GenericHashtable<T, F>::contains_impl(T* item, int idx) {
anoll@22921 455 T* current_item = head(idx);
anoll@22921 456 while (current_item != NULL) {
anoll@22921 457 if (current_item->equals(item)) {
anoll@22921 458 return current_item;
anoll@22921 459 }
anoll@22921 460 current_item = current_item->next();
anoll@22921 461 }
anoll@22921 462 return NULL;
anoll@22921 463 }
anoll@22921 464
anoll@22921 465
coleenp@8076 466 // Explicitly instantiate these types
coleenp@13728 467 template class Hashtable<ConstantPool*, mtClass>;
zgu@13195 468 template class Hashtable<Symbol*, mtSymbol>;
coleenp@13728 469 template class Hashtable<Klass*, mtClass>;
zgu@13195 470 template class Hashtable<oop, mtClass>;
hseigel@20282 471 #if defined(SOLARIS) || defined(CHECK_UNHANDLED_OOPS)
zgu@13195 472 template class Hashtable<oop, mtSymbol>;
hseigel@20282 473 #endif // SOLARIS || CHECK_UNHANDLED_OOPS
zgu@13195 474 template class Hashtable<oopDesc*, mtSymbol>;
zgu@13195 475 template class Hashtable<Symbol*, mtClass>;
zgu@13195 476 template class HashtableEntry<Symbol*, mtSymbol>;
zgu@13195 477 template class HashtableEntry<Symbol*, mtClass>;
zgu@13195 478 template class HashtableEntry<oop, mtSymbol>;
zgu@13195 479 template class BasicHashtableEntry<mtSymbol>;
zgu@13195 480 template class BasicHashtableEntry<mtCode>;
zgu@13195 481 template class BasicHashtable<mtClass>;
zgu@13195 482 template class BasicHashtable<mtSymbol>;
zgu@13195 483 template class BasicHashtable<mtCode>;
zgu@13195 484 template class BasicHashtable<mtInternal>;
anoll@22921 485
anoll@22921 486 template class GenericHashtable<DependencySignature, ResourceObj>;