1 /* 2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_UTILITIES_CONCURRENT_HASH_TABLE_INLINE_HPP 26 #define SHARE_UTILITIES_CONCURRENT_HASH_TABLE_INLINE_HPP 27 28 #include "memory/allocation.inline.hpp" 29 #include "runtime/atomic.hpp" 30 #include "runtime/orderAccess.inline.hpp" 31 #include "runtime/prefetch.inline.hpp" 32 #include "utilities/concurrentHashTable.hpp" 33 #include "utilities/globalCounter.inline.hpp" 34 #include "utilities/numberSeq.hpp" 35 #include "utilities/spinYield.hpp" 36 37 // 2^30 = 1G buckets 38 #define SIZE_BIG_LOG2 30 39 // 2^5 = 32 buckets 40 #define SIZE_SMALL_LOG2 5 41 42 // Number from spinYield.hpp. In some loops SpinYield would be unfair. 43 #define SPINPAUSES_PER_YIELD 8192 44 45 #ifdef ASSERT 46 #ifdef _LP64 47 // Two low bits are not usable. 48 static const void* POISON_PTR = (void*)UCONST64(0xfbadbadbadbadbac); 49 #else 50 // Two low bits are not usable. 51 static const void* POISON_PTR = (void*)0xffbadbac; 52 #endif 53 #endif 54 55 // Node 56 template <typename VALUE, typename CONFIG, MEMFLAGS F> 57 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* 58 ConcurrentHashTable<VALUE, CONFIG, F>:: 59 Node::next() const 60 { 61 return OrderAccess::load_acquire(&_next); 62 } 63 64 // Bucket 65 template <typename VALUE, typename CONFIG, MEMFLAGS F> 66 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* 67 ConcurrentHashTable<VALUE, CONFIG, F>:: 68 Bucket::first_raw() const 69 { 70 return OrderAccess::load_acquire(&_first); 71 } 72 73 template <typename VALUE, typename CONFIG, MEMFLAGS F> 74 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 75 Bucket::release_assign_node_ptr( 76 typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* const volatile * dst, 77 typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* node) const 78 { 79 // Due to this assert this methods is not static. 80 assert(is_locked(), "Must be locked."); 81 Node** tmp = (Node**)dst; 82 OrderAccess::release_store(tmp, clear_set_state(node, *dst)); 83 } 84 85 template <typename VALUE, typename CONFIG, MEMFLAGS F> 86 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* 87 ConcurrentHashTable<VALUE, CONFIG, F>:: 88 Bucket::first() const 89 { 90 // We strip the states bit before returning the ptr. 91 return clear_state(OrderAccess::load_acquire(&_first)); 92 } 93 94 template <typename VALUE, typename CONFIG, MEMFLAGS F> 95 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 96 Bucket::have_redirect() const 97 { 98 return is_state(first_raw(), STATE_REDIRECT_BIT); 99 } 100 101 template <typename VALUE, typename CONFIG, MEMFLAGS F> 102 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 103 Bucket::is_locked() const 104 { 105 return is_state(first_raw(), STATE_LOCK_BIT); 106 } 107 108 template <typename VALUE, typename CONFIG, MEMFLAGS F> 109 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 110 Bucket::lock() 111 { 112 int i = 0; 113 // SpinYield would be unfair here 114 while (!this->trylock()) { 115 if ((++i) == SPINPAUSES_PER_YIELD) { 116 // On contemporary OS yielding will give CPU to another runnable thread if 117 // there is no CPU available. 118 os::naked_yield(); 119 i = 0; 120 } else { 121 SpinPause(); 122 } 123 } 124 } 125 126 template <typename VALUE, typename CONFIG, MEMFLAGS F> 127 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 128 Bucket::release_assign_last_node_next( 129 typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* node) 130 { 131 assert(is_locked(), "Must be locked."); 132 Node* const volatile * ret = first_ptr(); 133 while (clear_state(*ret) != NULL) { 134 ret = clear_state(*ret)->next_ptr(); 135 } 136 release_assign_node_ptr(ret, node); 137 } 138 139 template <typename VALUE, typename CONFIG, MEMFLAGS F> 140 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 141 Bucket::cas_first(typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* node, 142 typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* expect 143 ) 144 { 145 if (is_locked()) { 146 return false; 147 } 148 if (Atomic::cmpxchg(node, &_first, expect) == expect) { 149 return true; 150 } 151 return false; 152 } 153 154 template <typename VALUE, typename CONFIG, MEMFLAGS F> 155 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 156 Bucket::trylock() 157 { 158 if (is_locked()) { 159 return false; 160 } 161 // We will expect a clean first pointer. 162 Node* tmp = first(); 163 if (Atomic::cmpxchg(set_state(tmp, STATE_LOCK_BIT), &_first, tmp) == tmp) { 164 return true; 165 } 166 return false; 167 } 168 169 template <typename VALUE, typename CONFIG, MEMFLAGS F> 170 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 171 Bucket::unlock() 172 { 173 assert(is_locked(), "Must be locked."); 174 assert(!have_redirect(), 175 "Unlocking a bucket after it has reached terminal state."); 176 OrderAccess::release_store(&_first, clear_state(first())); 177 } 178 179 template <typename VALUE, typename CONFIG, MEMFLAGS F> 180 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 181 Bucket::redirect() 182 { 183 assert(is_locked(), "Must be locked."); 184 OrderAccess::release_store(&_first, set_state(_first, STATE_REDIRECT_BIT)); 185 } 186 187 // InternalTable 188 template <typename VALUE, typename CONFIG, MEMFLAGS F> 189 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 190 InternalTable::InternalTable(size_t log2_size) 191 : _log2_size(log2_size), _size(((size_t)1ul) << _log2_size), 192 _hash_mask(~(~((size_t)0) << _log2_size)) 193 { 194 assert(_log2_size >= SIZE_SMALL_LOG2 && _log2_size <= SIZE_BIG_LOG2, 195 "Bad size"); 196 void* memory = NEW_C_HEAP_ARRAY(Bucket, _size, F); 197 _buckets = new (memory) Bucket[_size]; 198 } 199 200 template <typename VALUE, typename CONFIG, MEMFLAGS F> 201 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 202 InternalTable::~InternalTable() 203 { 204 FREE_C_HEAP_ARRAY(Bucket, _buckets); 205 } 206 207 // ScopedCS 208 template <typename VALUE, typename CONFIG, MEMFLAGS F> 209 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 210 ScopedCS::ScopedCS(Thread* thread, ConcurrentHashTable<VALUE, CONFIG, F>* cht) 211 : _thread(thread), _cht(cht) 212 { 213 GlobalCounter::critical_section_begin(_thread); 214 // This version is published now. 215 if (OrderAccess::load_acquire(&_cht->_invisible_epoch) != NULL) { 216 OrderAccess::release_store_fence(&_cht->_invisible_epoch, (Thread*)NULL); 217 } 218 } 219 220 template <typename VALUE, typename CONFIG, MEMFLAGS F> 221 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 222 ScopedCS::~ScopedCS() 223 { 224 GlobalCounter::critical_section_end(_thread); 225 } 226 227 // BaseConfig 228 template <typename VALUE, typename CONFIG, MEMFLAGS F> 229 inline void* ConcurrentHashTable<VALUE, CONFIG, F>:: 230 BaseConfig::allocate_node(size_t size, const VALUE& value) 231 { 232 return AllocateHeap(size, F); 233 } 234 235 template <typename VALUE, typename CONFIG, MEMFLAGS F> 236 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 237 BaseConfig::free_node(void* memory, const VALUE& value) 238 { 239 FreeHeap(memory); 240 } 241 242 template <typename VALUE, typename CONFIG, MEMFLAGS F> 243 template <typename LOOKUP_FUNC> 244 inline VALUE* ConcurrentHashTable<VALUE, CONFIG, F>:: 245 MultiGetHandle::get(LOOKUP_FUNC& lookup_f, bool* grow_hint) 246 { 247 return ScopedCS::_cht->internal_get(ScopedCS::_thread, lookup_f, grow_hint); 248 } 249 250 // HaveDeletables 251 template <typename VALUE, typename CONFIG, MEMFLAGS F> 252 template <typename EVALUATE_FUNC> 253 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 254 HaveDeletables<true, EVALUATE_FUNC>::have_deletable(Bucket* bucket, 255 EVALUATE_FUNC& eval_f, 256 Bucket* prefetch_bucket) 257 { 258 // Instantiated for pointer type (true), so we can use prefetch. 259 // When visiting all Nodes doing this prefetch give around 30%. 260 Node* pref = prefetch_bucket != NULL ? prefetch_bucket->first() : NULL; 261 for (Node* next = bucket->first(); next != NULL ; next = next->next()) { 262 if (pref != NULL) { 263 Prefetch::read(*pref->value(), 0); 264 pref = pref->next(); 265 } 266 if (next->next() != NULL) { 267 Prefetch::read(*next->next()->value(), 0); 268 } 269 if (eval_f(next->value())) { 270 return true; 271 } 272 } 273 return false; 274 } 275 276 template <typename VALUE, typename CONFIG, MEMFLAGS F> 277 template <bool b, typename EVALUATE_FUNC> 278 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 279 HaveDeletables<b, EVALUATE_FUNC>::have_deletable(Bucket* bucket, 280 EVALUATE_FUNC& eval_f, 281 Bucket* preb) 282 { 283 for (Node* next = bucket->first(); next != NULL ; next = next->next()) { 284 if (eval_f(next->value())) { 285 return true; 286 } 287 } 288 return false; 289 } 290 291 // ConcurrentHashTable 292 template <typename VALUE, typename CONFIG, MEMFLAGS F> 293 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 294 write_synchonize_on_visible_epoch(Thread* thread) 295 { 296 assert(_resize_lock_owner == thread, "Re-size lock not held"); 297 OrderAccess::fence(); // Prevent below load from floating up. 298 // If no reader saw this version we can skip write_synchronize. 299 if (OrderAccess::load_acquire(&_invisible_epoch) == thread) { 300 return; 301 } 302 assert(_invisible_epoch == NULL, "Two thread doing bulk operations"); 303 // We set this/next version that we are synchronizing for to not published. 304 // A reader will zero this flag if it reads this/next version. 305 OrderAccess::release_store(&_invisible_epoch, thread); 306 GlobalCounter::write_synchronize(); 307 } 308 309 template <typename VALUE, typename CONFIG, MEMFLAGS F> 310 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 311 try_resize_lock(Thread* locker) 312 { 313 if (_resize_lock->try_lock()) { 314 if (_resize_lock_owner != NULL) { 315 assert(locker != _resize_lock_owner, "Already own lock"); 316 // We got mutex but internal state is locked. 317 _resize_lock->unlock(); 318 return false; 319 } 320 } else { 321 return false; 322 } 323 _invisible_epoch = 0; 324 _resize_lock_owner = locker; 325 return true; 326 } 327 328 template <typename VALUE, typename CONFIG, MEMFLAGS F> 329 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 330 lock_resize_lock(Thread* locker) 331 { 332 size_t i = 0; 333 // If lock is hold by some other thread, the chances that it is return quick 334 // is low. So we will prefer yielding. 335 SpinYield yield(1, 512); 336 do { 337 _resize_lock->lock_without_safepoint_check(); 338 // If holder of lock dropped mutex for safepoint mutex might be unlocked, 339 // and _resize_lock_owner will contain the owner. 340 if (_resize_lock_owner != NULL) { 341 assert(locker != _resize_lock_owner, "Already own lock"); 342 // We got mutex but internal state is locked. 343 _resize_lock->unlock(); 344 yield.wait(); 345 } else { 346 break; 347 } 348 } while(true); 349 _resize_lock_owner = locker; 350 _invisible_epoch = 0; 351 } 352 353 template <typename VALUE, typename CONFIG, MEMFLAGS F> 354 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 355 unlock_resize_lock(Thread* locker) 356 { 357 _invisible_epoch = 0; 358 assert(locker == _resize_lock_owner, "Not unlocked by locker."); 359 _resize_lock_owner = NULL; 360 _resize_lock->unlock(); 361 } 362 363 template <typename VALUE, typename CONFIG, MEMFLAGS F> 364 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 365 free_nodes() 366 { 367 // We assume we are not MT during freeing. 368 for (size_t node_it = 0; node_it < _table->_size; node_it++) { 369 Bucket* bucket = _table->get_buckets() + node_it; 370 Node* node = bucket->first(); 371 while (node != NULL) { 372 Node* free_node = node; 373 node = node->next(); 374 Node::destroy_node(free_node); 375 } 376 } 377 } 378 379 template <typename VALUE, typename CONFIG, MEMFLAGS F> 380 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* 381 ConcurrentHashTable<VALUE, CONFIG, F>:: 382 get_table() const 383 { 384 return OrderAccess::load_acquire(&_table); 385 } 386 387 template <typename VALUE, typename CONFIG, MEMFLAGS F> 388 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* 389 ConcurrentHashTable<VALUE, CONFIG, F>:: 390 get_new_table() const 391 { 392 return OrderAccess::load_acquire(&_new_table); 393 } 394 395 template <typename VALUE, typename CONFIG, MEMFLAGS F> 396 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* 397 ConcurrentHashTable<VALUE, CONFIG, F>:: 398 set_table_from_new() 399 { 400 InternalTable* old_table = _table; 401 // Publish the new table. 402 OrderAccess::release_store(&_table, _new_table); 403 // All must see this. 404 GlobalCounter::write_synchronize(); 405 // _new_table not read any more. 406 _new_table = NULL; 407 DEBUG_ONLY(_new_table = (InternalTable*)POISON_PTR;) 408 return old_table; 409 } 410 411 template <typename VALUE, typename CONFIG, MEMFLAGS F> 412 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 413 internal_grow_range(Thread* thread, size_t start, size_t stop) 414 { 415 assert(stop <= _table->_size, "Outside backing array"); 416 assert(_new_table != NULL, "Grow not proper setup before start"); 417 // The state is also copied here. Hence all buckets in new table will be 418 // locked. I call the siblings odd/even, where even have high bit 0 and odd 419 // have high bit 1. 420 for (size_t even_index = start; even_index < stop; even_index++) { 421 Bucket* bucket = _table->get_bucket(even_index); 422 423 bucket->lock(); 424 425 size_t odd_index = even_index + _table->_size; 426 _new_table->get_buckets()[even_index] = *bucket; 427 _new_table->get_buckets()[odd_index] = *bucket; 428 429 // Moves lockers go to new table, where they will wait until unlock() below. 430 bucket->redirect(); /* Must release stores above */ 431 432 // When this is done we have separated the nodes into corresponding buckets 433 // in new table. 434 if (!unzip_bucket(thread, _table, _new_table, even_index, odd_index)) { 435 // If bucket is empty, unzip does nothing. 436 // We must make sure readers go to new table before we poison the bucket. 437 DEBUG_ONLY(GlobalCounter::write_synchronize();) 438 } 439 440 // Unlock for writes into the new table buckets. 441 _new_table->get_bucket(even_index)->unlock(); 442 _new_table->get_bucket(odd_index)->unlock(); 443 444 DEBUG_ONLY( 445 bucket->release_assign_node_ptr( 446 _table->get_bucket(even_index)->first_ptr(), (Node*)POISON_PTR); 447 ) 448 } 449 } 450 451 template <typename VALUE, typename CONFIG, MEMFLAGS F> 452 template <typename LOOKUP_FUNC, typename DELETE_FUNC> 453 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 454 internal_remove(Thread* thread, LOOKUP_FUNC& lookup_f, DELETE_FUNC& delete_f) 455 { 456 Bucket* bucket = get_bucket_locked(thread, lookup_f.get_hash()); 457 assert(bucket->is_locked(), "Must be locked."); 458 Node* const volatile * rem_n_prev = bucket->first_ptr(); 459 Node* rem_n = bucket->first(); 460 bool have_dead = false; 461 while (rem_n != NULL) { 462 if (lookup_f.equals(rem_n->value(), &have_dead)) { 463 bucket->release_assign_node_ptr(rem_n_prev, rem_n->next()); 464 break; 465 } else { 466 rem_n_prev = rem_n->next_ptr(); 467 rem_n = rem_n->next(); 468 } 469 } 470 471 bucket->unlock(); 472 473 if (rem_n == NULL) { 474 return false; 475 } 476 // Publish the deletion. 477 GlobalCounter::write_synchronize(); 478 delete_f(rem_n->value()); 479 Node::destroy_node(rem_n); 480 return true; 481 } 482 483 template <typename VALUE, typename CONFIG, MEMFLAGS F> 484 template <typename EVALUATE_FUNC, typename DELETE_FUNC> 485 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 486 do_bulk_delete_locked_for(Thread* thread, size_t start_idx, size_t stop_idx, 487 EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) 488 { 489 // Here we have resize lock so table is SMR safe, and there is no new 490 // table. Can do this in parallel if we want. 491 assert(_resize_lock_owner == thread, "Re-size lock not held"); 492 Node* ndel[BULK_DELETE_LIMIT]; 493 InternalTable* table = get_table(); 494 assert(start_idx < stop_idx, "Must be"); 495 assert(stop_idx <= _table->_size, "Must be"); 496 // Here manual do critical section since we don't want to take the cost of 497 // locking the bucket if there is nothing to delete. But we can have 498 // concurrent single deletes. The _invisible_epoch can only be used by the 499 // owner of _resize_lock, us here. There we should not changed it in our 500 // own read-side. 501 GlobalCounter::critical_section_begin(thread); 502 for (size_t bucket_it = start_idx; bucket_it < stop_idx; bucket_it++) { 503 Bucket* bucket = table->get_bucket(bucket_it); 504 Bucket* prefetch_bucket = (bucket_it+1) < stop_idx ? 505 table->get_bucket(bucket_it+1) : NULL; 506 507 if (!HaveDeletables<IsPointer<VALUE>::value, EVALUATE_FUNC>:: 508 have_deletable(bucket, eval_f, prefetch_bucket)) { 509 // Nothing to remove in this bucket. 510 continue; 511 } 512 513 GlobalCounter::critical_section_end(thread); 514 // We left critical section but the bucket cannot be removed while we hold 515 // the _resize_lock. 516 bucket->lock(); 517 size_t nd = delete_check_nodes(bucket, eval_f, BULK_DELETE_LIMIT, ndel); 518 bucket->unlock(); 519 write_synchonize_on_visible_epoch(thread); 520 for (size_t node_it = 0; node_it < nd; node_it++) { 521 del_f(ndel[node_it]->value()); 522 Node::destroy_node(ndel[node_it]); 523 DEBUG_ONLY(ndel[node_it] = (Node*)POISON_PTR;) 524 } 525 GlobalCounter::critical_section_begin(thread); 526 } 527 GlobalCounter::critical_section_end(thread); 528 } 529 530 template <typename VALUE, typename CONFIG, MEMFLAGS F> 531 template <typename LOOKUP_FUNC> 532 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 533 delete_in_bucket(Thread* thread, Bucket* bucket, LOOKUP_FUNC& lookup_f) 534 { 535 size_t dels = 0; 536 Node* ndel[BULK_DELETE_LIMIT]; 537 Node* const volatile * rem_n_prev = bucket->first_ptr(); 538 Node* rem_n = bucket->first(); 539 while (rem_n != NULL) { 540 bool is_dead = false; 541 lookup_f.equals(rem_n->value(), &is_dead); 542 if (is_dead) { 543 ndel[dels++] = rem_n; 544 bucket->release_assign_node_ptr(rem_n_prev, rem_n->next()); 545 rem_n = rem_n->next(); 546 if (dels == BULK_DELETE_LIMIT) { 547 break; 548 } 549 } else { 550 rem_n_prev = rem_n->next_ptr(); 551 rem_n = rem_n->next(); 552 } 553 } 554 if (dels > 0) { 555 GlobalCounter::write_synchronize(); 556 for (size_t node_it = 0; node_it < dels; node_it++) { 557 Node::destroy_node(ndel[node_it]); 558 DEBUG_ONLY(ndel[node_it] = (Node*)POISON_PTR;) 559 } 560 } 561 } 562 563 template <typename VALUE, typename CONFIG, MEMFLAGS F> 564 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Bucket* 565 ConcurrentHashTable<VALUE, CONFIG, F>:: 566 get_bucket(uintx hash) const 567 { 568 InternalTable* table = get_table(); 569 Bucket* bucket = get_bucket_in(table, hash); 570 if (bucket->have_redirect()) { 571 table = get_new_table(); 572 bucket = get_bucket_in(table, hash); 573 } 574 return bucket; 575 } 576 577 template <typename VALUE, typename CONFIG, MEMFLAGS F> 578 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Bucket* 579 ConcurrentHashTable<VALUE, CONFIG, F>:: 580 get_bucket_locked(Thread* thread, const uintx hash) 581 { 582 Bucket* bucket; 583 int i = 0; 584 // SpinYield would be unfair here 585 while(true) { 586 { 587 // We need a critical section to protect the table itself. But if we fail 588 // we must leave critical section otherwise we would deadlock. 589 ScopedCS cs(thread, this); 590 bucket = get_bucket(hash); 591 if (bucket->trylock()) { 592 break; /* ends critical section */ 593 } 594 } /* ends critical section */ 595 if ((++i) == SPINPAUSES_PER_YIELD) { 596 // On contemporary OS yielding will give CPU to another runnable thread if 597 // there is no CPU available. 598 os::naked_yield(); 599 i = 0; 600 } else { 601 SpinPause(); 602 } 603 } 604 return bucket; 605 } 606 607 // Always called within critical section 608 template <typename VALUE, typename CONFIG, MEMFLAGS F> 609 template <typename LOOKUP_FUNC> 610 typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* 611 ConcurrentHashTable<VALUE, CONFIG, F>:: 612 get_node(const Bucket* const bucket, LOOKUP_FUNC& lookup_f, 613 bool* have_dead, size_t* loops) const 614 { 615 size_t loop_count = 0; 616 Node* node = bucket->first(); 617 while (node != NULL) { 618 bool is_dead = false; 619 ++loop_count; 620 if (lookup_f.equals(node->value(), &is_dead)) { 621 break; 622 } 623 if (is_dead && !(*have_dead)) { 624 *have_dead = true; 625 } 626 node = node->next(); 627 } 628 if (loops != NULL) { 629 *loops = loop_count; 630 } 631 return node; 632 } 633 634 template <typename VALUE, typename CONFIG, MEMFLAGS F> 635 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 636 unzip_bucket(Thread* thread, InternalTable* old_table, 637 InternalTable* new_table, size_t even_index, size_t odd_index) 638 { 639 Node* aux = old_table->get_bucket(even_index)->first(); 640 if (aux == NULL) { 641 // This is an empty bucket and in debug we poison first ptr in bucket. 642 // Therefore we must make sure no readers are looking at this bucket. 643 // If we don't do a write_synch here, caller must do it. 644 return false; 645 } 646 Node* delete_me = NULL; 647 Node* const volatile * even = new_table->get_bucket(even_index)->first_ptr(); 648 Node* const volatile * odd = new_table->get_bucket(odd_index)->first_ptr(); 649 while (aux != NULL) { 650 bool dead_hash = false; 651 size_t aux_hash = CONFIG::get_hash(*aux->value(), &dead_hash); 652 if (dead_hash) { 653 delete_me = aux; 654 // This item is dead, move both list to next 655 new_table->get_bucket(odd_index)->release_assign_node_ptr(odd, 656 aux->next()); 657 new_table->get_bucket(even_index)->release_assign_node_ptr(even, 658 aux->next()); 659 } else { 660 size_t aux_index = bucket_idx_hash(new_table, aux_hash); 661 if (aux_index == even_index) { 662 // This is a even, so move odd to aux/even next 663 new_table->get_bucket(odd_index)->release_assign_node_ptr(odd, 664 aux->next()); 665 // Keep in even list 666 even = aux->next_ptr(); 667 } else if (aux_index == odd_index) { 668 // This is a odd, so move odd to aux/odd next 669 new_table->get_bucket(even_index)->release_assign_node_ptr(even, 670 aux->next()); 671 // Keep in odd list 672 odd = aux->next_ptr(); 673 } else { 674 fatal("aux_index does not match even or odd indices"); 675 } 676 } 677 aux = aux->next(); 678 679 // We can only move 1 pointer otherwise a reader might be moved to the wrong 680 // chain. E.g. looking for even hash value but got moved to the odd bucket 681 // chain. 682 write_synchonize_on_visible_epoch(thread); 683 if (delete_me != NULL) { 684 Node::destroy_node(delete_me); 685 delete_me = NULL; 686 } 687 } 688 return true; 689 } 690 691 template <typename VALUE, typename CONFIG, MEMFLAGS F> 692 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 693 internal_shrink_prolog(Thread* thread, size_t log2_size) 694 { 695 if (!try_resize_lock(thread)) { 696 return false; 697 } 698 assert(_resize_lock_owner == thread, "Re-size lock not held"); 699 if (_table->_log2_size == _log2_start_size || 700 _table->_log2_size <= log2_size) { 701 unlock_resize_lock(thread); 702 return false; 703 } 704 _new_table = new InternalTable(_table->_log2_size - 1); 705 return true; 706 } 707 708 template <typename VALUE, typename CONFIG, MEMFLAGS F> 709 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 710 internal_shrink_epilog(Thread* thread) 711 { 712 assert(_resize_lock_owner == thread, "Re-size lock not held"); 713 714 InternalTable* old_table = set_table_from_new(); 715 _size_limit_reached = false; 716 unlock_resize_lock(thread); 717 #ifdef ASSERT 718 for (size_t i = 0; i < old_table->_size; i++) { 719 assert(old_table->get_bucket(i++)->first() == POISON_PTR, 720 "No poison found"); 721 } 722 #endif 723 // ABA safe, old_table not visible to any other threads. 724 delete old_table; 725 } 726 727 template <typename VALUE, typename CONFIG, MEMFLAGS F> 728 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 729 internal_shrink_range(Thread* thread, size_t start, size_t stop) 730 { 731 // The state is also copied here. 732 // Hence all buckets in new table will be locked. 733 for (size_t bucket_it = start; bucket_it < stop; bucket_it++) { 734 size_t even_hash_index = bucket_it; // High bit 0 735 size_t odd_hash_index = bucket_it + _new_table->_size; // High bit 1 736 737 Bucket* b_old_even = _table->get_bucket(even_hash_index); 738 Bucket* b_old_odd = _table->get_bucket(odd_hash_index); 739 740 b_old_even->lock(); 741 b_old_odd->lock(); 742 743 _new_table->get_buckets()[bucket_it] = *b_old_even; 744 745 // Put chains together. 746 _new_table->get_bucket(bucket_it)-> 747 release_assign_last_node_next(*(b_old_odd->first_ptr())); 748 749 b_old_even->redirect(); 750 b_old_odd->redirect(); 751 752 write_synchonize_on_visible_epoch(thread); 753 754 // Unlock for writes into new smaller table. 755 _new_table->get_bucket(bucket_it)->unlock(); 756 757 DEBUG_ONLY(b_old_even->release_assign_node_ptr(b_old_even->first_ptr(), 758 (Node*)POISON_PTR);) 759 DEBUG_ONLY(b_old_odd->release_assign_node_ptr(b_old_odd->first_ptr(), 760 (Node*)POISON_PTR);) 761 } 762 } 763 764 template <typename VALUE, typename CONFIG, MEMFLAGS F> 765 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 766 internal_shrink(Thread* thread, size_t log2_size) 767 { 768 if (!internal_shrink_prolog(thread, log2_size)) { 769 assert(_resize_lock_owner != thread, "Re-size lock held"); 770 return false; 771 } 772 assert(_resize_lock_owner == thread, "Should be locked by me"); 773 internal_shrink_range(thread, 0, _new_table->_size); 774 internal_shrink_epilog(thread); 775 assert(_resize_lock_owner != thread, "Re-size lock held"); 776 return true; 777 } 778 779 template <typename VALUE, typename CONFIG, MEMFLAGS F> 780 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 781 internal_grow_prolog(Thread* thread, size_t log2_size) 782 { 783 // This double checking of _size_limit_reached/is_max_size_reached() 784 // we only do in grow path, since grow means high load on table 785 // while shrink means low load. 786 if (is_max_size_reached()) { 787 return false; 788 } 789 if (!try_resize_lock(thread)) { 790 // Either we have an ongoing resize or an operation which doesn't want us 791 // to resize now. 792 return false; 793 } 794 if (is_max_size_reached() || _table->_log2_size >= log2_size) { 795 unlock_resize_lock(thread); 796 return false; 797 } 798 799 _new_table = new InternalTable(_table->_log2_size + 1); 800 801 if (_new_table->_log2_size == _log2_size_limit) { 802 _size_limit_reached = true; 803 } 804 805 return true; 806 } 807 808 template <typename VALUE, typename CONFIG, MEMFLAGS F> 809 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 810 internal_grow_epilog(Thread* thread) 811 { 812 assert(_resize_lock_owner == thread, "Should be locked"); 813 814 InternalTable* old_table = set_table_from_new(); 815 unlock_resize_lock(thread); 816 #ifdef ASSERT 817 for (size_t i = 0; i < old_table->_size; i++) { 818 assert(old_table->get_bucket(i++)->first() == POISON_PTR, 819 "No poison found"); 820 } 821 #endif 822 // ABA safe, old_table not visible to any other threads. 823 delete old_table; 824 } 825 826 template <typename VALUE, typename CONFIG, MEMFLAGS F> 827 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 828 internal_grow(Thread* thread, size_t log2_size) 829 { 830 if (!internal_grow_prolog(thread, log2_size)) { 831 assert(_resize_lock_owner != thread, "Re-size lock held"); 832 return false; 833 } 834 assert(_resize_lock_owner == thread, "Should be locked by me"); 835 internal_grow_range(thread, 0, _table->_size); 836 internal_grow_epilog(thread); 837 assert(_resize_lock_owner != thread, "Re-size lock held"); 838 return true; 839 } 840 841 // Always called within critical section 842 template <typename VALUE, typename CONFIG, MEMFLAGS F> 843 template <typename LOOKUP_FUNC> 844 inline VALUE* ConcurrentHashTable<VALUE, CONFIG, F>:: 845 internal_get(Thread* thread, LOOKUP_FUNC& lookup_f, bool* grow_hint) 846 { 847 bool clean = false; 848 size_t loops = 0; 849 VALUE* ret = NULL; 850 851 const Bucket* bucket = get_bucket(lookup_f.get_hash()); 852 Node* node = get_node(bucket, lookup_f, &clean, &loops); 853 if (node != NULL) { 854 ret = node->value(); 855 } 856 if (grow_hint != NULL) { 857 *grow_hint = loops > _grow_hint; 858 } 859 860 return ret; 861 } 862 863 template <typename VALUE, typename CONFIG, MEMFLAGS F> 864 template <typename LOOKUP_FUNC, typename VALUE_FUNC, typename CALLBACK_FUNC> 865 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 866 internal_insert(Thread* thread, LOOKUP_FUNC& lookup_f, VALUE_FUNC& value_f, 867 CALLBACK_FUNC& callback, bool* grow_hint) 868 { 869 bool ret = false; 870 bool clean = false; 871 bool locked; 872 size_t loops = 0; 873 size_t i = 0; 874 Node* new_node = NULL; 875 uintx hash = lookup_f.get_hash(); 876 while (true) { 877 { 878 ScopedCS cs(thread, this); /* protected the table/bucket */ 879 Bucket* bucket = get_bucket(hash); 880 881 Node* first_at_start = bucket->first(); 882 Node* old = get_node(bucket, lookup_f, &clean, &loops); 883 if (old == NULL) { 884 // No duplicate found. 885 if (new_node == NULL) { 886 new_node = Node::create_node(value_f(), first_at_start); 887 } else { 888 new_node->set_next(first_at_start); 889 } 890 if (bucket->cas_first(new_node, first_at_start)) { 891 callback(true, new_node->value()); 892 new_node = NULL; 893 ret = true; 894 break; /* leave critical section */ 895 } 896 // CAS failed we must leave critical section and retry. 897 locked = bucket->is_locked(); 898 } else { 899 // There is a duplicate. 900 callback(false, old->value()); 901 break; /* leave critical section */ 902 } 903 } /* leave critical section */ 904 i++; 905 if (locked) { 906 os::naked_yield(); 907 } else { 908 SpinPause(); 909 } 910 } 911 912 if (new_node != NULL) { 913 // CAS failed and a duplicate was inserted, we must free this node. 914 Node::destroy_node(new_node); 915 } else if (i == 0 && clean) { 916 // We only do cleaning on fast inserts. 917 Bucket* bucket = get_bucket_locked(thread, lookup_f.get_hash()); 918 assert(bucket->is_locked(), "Must be locked."); 919 delete_in_bucket(thread, bucket, lookup_f); 920 bucket->unlock(); 921 } 922 923 if (grow_hint != NULL) { 924 *grow_hint = loops > _grow_hint; 925 } 926 927 return ret; 928 } 929 930 template <typename VALUE, typename CONFIG, MEMFLAGS F> 931 template <typename FUNC> 932 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 933 visit_nodes(Bucket* bucket, FUNC& visitor_f) 934 { 935 Node* current_node = bucket->first(); 936 while (current_node != NULL) { 937 if (!visitor_f(current_node->value())) { 938 return false; 939 } 940 current_node = current_node->next(); 941 } 942 return true; 943 } 944 945 template <typename VALUE, typename CONFIG, MEMFLAGS F> 946 template <typename FUNC> 947 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 948 do_scan_locked(Thread* thread, FUNC& scan_f) 949 { 950 assert(_resize_lock_owner == thread, "Re-size lock not held"); 951 // We can do a critical section over the entire loop but that would block 952 // updates for a long time. Instead we choose to block resizes. 953 InternalTable* table = get_table(); 954 for (size_t bucket_it = 0; bucket_it < table->_size; bucket_it++) { 955 ScopedCS cs(thread, this); 956 if (!visit_nodes(table->get_bucket(bucket_it), scan_f)) { 957 break; /* ends critical section */ 958 } 959 } /* ends critical section */ 960 } 961 962 template <typename VALUE, typename CONFIG, MEMFLAGS F> 963 template <typename EVALUATE_FUNC> 964 inline size_t ConcurrentHashTable<VALUE, CONFIG, F>:: 965 delete_check_nodes(Bucket* bucket, EVALUATE_FUNC& eval_f, 966 size_t num_del, Node** ndel) 967 { 968 size_t dels = 0; 969 Node* const volatile * rem_n_prev = bucket->first_ptr(); 970 Node* rem_n = bucket->first(); 971 while (rem_n != NULL) { 972 if (eval_f(rem_n->value())) { 973 ndel[dels++] = rem_n; 974 bucket->release_assign_node_ptr(rem_n_prev, rem_n->next()); 975 rem_n = rem_n->next(); 976 if (dels == num_del) { 977 break; 978 } 979 } else { 980 rem_n_prev = rem_n->next_ptr(); 981 rem_n = rem_n->next(); 982 } 983 } 984 return dels; 985 } 986 987 // Constructor 988 template <typename VALUE, typename CONFIG, MEMFLAGS F> 989 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 990 ConcurrentHashTable(size_t log2size, size_t log2size_limit, size_t grow_hint) 991 : _new_table(NULL), _log2_start_size(log2size), 992 _log2_size_limit(log2size_limit), _grow_hint(grow_hint), 993 _size_limit_reached(false), _resize_lock_owner(NULL), 994 _invisible_epoch(0) 995 { 996 _resize_lock = 997 new Mutex(Mutex::leaf, "ConcurrentHashTable", false, 998 Monitor::_safepoint_check_never); 999 _table = new InternalTable(log2size); 1000 assert(log2size_limit >= log2size, "bad ergo"); 1001 _size_limit_reached = _table->_log2_size == _log2_size_limit; 1002 } 1003 1004 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1005 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 1006 ~ConcurrentHashTable() 1007 { 1008 delete _resize_lock; 1009 free_nodes(); 1010 delete _table; 1011 } 1012 1013 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1014 inline size_t ConcurrentHashTable<VALUE, CONFIG, F>:: 1015 get_size_log2(Thread* thread) 1016 { 1017 ScopedCS cs(thread, this); 1018 return _table->_log2_size; 1019 } 1020 1021 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1022 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1023 shrink(Thread* thread, size_t size_limit_log2) 1024 { 1025 size_t tmp = size_limit_log2 == 0 ? _log2_start_size : size_limit_log2; 1026 bool ret = internal_shrink(thread, tmp); 1027 return ret; 1028 } 1029 1030 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1031 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1032 grow(Thread* thread, size_t size_limit_log2) 1033 { 1034 size_t tmp = size_limit_log2 == 0 ? _log2_size_limit : size_limit_log2; 1035 return internal_grow(thread, tmp); 1036 } 1037 1038 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1039 template <typename LOOKUP_FUNC, typename FOUND_FUNC> 1040 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1041 get(Thread* thread, LOOKUP_FUNC& lookup_f, FOUND_FUNC& found_f, bool* grow_hint) 1042 { 1043 bool ret = false; 1044 ScopedCS cs(thread, this); 1045 VALUE* val = internal_get(thread, lookup_f, grow_hint); 1046 if (val != NULL) { 1047 found_f(val); 1048 ret = true; 1049 } 1050 return ret; 1051 } 1052 1053 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1054 template <typename LOOKUP_FUNC> 1055 inline VALUE ConcurrentHashTable<VALUE, CONFIG, F>:: 1056 get_copy(Thread* thread, LOOKUP_FUNC& lookup_f, bool* grow_hint) 1057 { 1058 ScopedCS cs(thread, this); 1059 VALUE* val = internal_get(thread, lookup_f, grow_hint); 1060 return val != NULL ? *val : CONFIG::notfound(); 1061 } 1062 1063 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1064 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1065 unsafe_insert(const VALUE& value) { 1066 bool dead_hash = false; 1067 size_t hash = CONFIG::get_hash(value, &dead_hash); 1068 if (dead_hash) { 1069 return false; 1070 } 1071 // This is an unsafe operation. 1072 InternalTable* table = get_table(); 1073 Bucket* bucket = get_bucket_in(table, hash); 1074 assert(!bucket->have_redirect() && !bucket->is_locked(), "bad"); 1075 Node* new_node = Node::create_node(value, bucket->first()); 1076 if (!bucket->cas_first(new_node, bucket->first())) { 1077 assert(false, "bad"); 1078 } 1079 return true; 1080 } 1081 1082 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1083 template <typename SCAN_FUNC> 1084 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1085 try_scan(Thread* thread, SCAN_FUNC& scan_f) 1086 { 1087 if (!try_resize_lock(thread)) { 1088 return false; 1089 } 1090 do_scan_locked(thread, scan_f); 1091 unlock_resize_lock(thread); 1092 return true; 1093 } 1094 1095 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1096 template <typename SCAN_FUNC> 1097 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 1098 do_scan(Thread* thread, SCAN_FUNC& scan_f) 1099 { 1100 assert(_resize_lock_owner != thread, "Re-size lock held"); 1101 lock_resize_lock(thread); 1102 do_scan_locked(thread, scan_f); 1103 unlock_resize_lock(thread); 1104 assert(_resize_lock_owner != thread, "Re-size lock held"); 1105 } 1106 1107 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1108 template <typename EVALUATE_FUNC, typename DELETE_FUNC> 1109 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1110 try_bulk_delete(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) 1111 { 1112 if (!try_resize_lock(thread)) { 1113 return false; 1114 } 1115 do_bulk_delete_locked(thread, eval_f, del_f); 1116 unlock_resize_lock(thread); 1117 assert(_resize_lock_owner != thread, "Re-size lock held"); 1118 return true; 1119 } 1120 1121 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1122 template <typename EVALUATE_FUNC, typename DELETE_FUNC> 1123 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 1124 bulk_delete(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) 1125 { 1126 lock_resize_lock(thread); 1127 do_bulk_delete_locked(thread, eval_f, del_f); 1128 unlock_resize_lock(thread); 1129 } 1130 1131 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1132 template <typename VALUE_SIZE_FUNC> 1133 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 1134 statistics_to(Thread* thread, VALUE_SIZE_FUNC& vs_f, 1135 outputStream* st, const char* table_name) 1136 { 1137 NumberSeq summary; 1138 size_t literal_bytes = 0; 1139 if (!try_resize_lock(thread)) { 1140 st->print_cr("statistics unavailable at this moment"); 1141 return; 1142 } 1143 1144 InternalTable* table = get_table(); 1145 for (size_t bucket_it = 0; bucket_it < table->_size; bucket_it++) { 1146 ScopedCS cs(thread, this); 1147 size_t count = 0; 1148 Bucket* bucket = table->get_bucket(bucket_it); 1149 if (bucket->have_redirect() || bucket->is_locked()) { 1150 continue; 1151 } 1152 Node* current_node = bucket->first(); 1153 while (current_node != NULL) { 1154 ++count; 1155 literal_bytes += vs_f(current_node->value()); 1156 current_node = current_node->next(); 1157 } 1158 summary.add((double)count); 1159 } 1160 1161 double num_buckets = summary.num(); 1162 double num_entries = summary.sum(); 1163 1164 size_t bucket_bytes = num_buckets * sizeof(Bucket); 1165 size_t entry_bytes = num_entries * sizeof(Node); 1166 size_t total_bytes = literal_bytes + bucket_bytes + entry_bytes; 1167 1168 size_t bucket_size = (num_buckets <= 0) ? 0 : (bucket_bytes / num_buckets); 1169 size_t entry_size = (num_entries <= 0) ? 0 : (entry_bytes / num_entries); 1170 1171 st->print_cr("%s statistics:", table_name); 1172 st->print_cr("Number of buckets : %9" PRIuPTR " = %9" PRIuPTR 1173 " bytes, each " SIZE_FORMAT, 1174 (size_t)num_buckets, bucket_bytes, bucket_size); 1175 st->print_cr("Number of entries : %9" PRIuPTR " = %9" PRIuPTR 1176 " bytes, each " SIZE_FORMAT, 1177 (size_t)num_entries, entry_bytes, entry_size); 1178 if (literal_bytes != 0) { 1179 double literal_avg = (num_entries <= 0) ? 0 : (literal_bytes / num_entries); 1180 st->print_cr("Number of literals : %9" PRIuPTR " = %9" PRIuPTR 1181 " bytes, avg %7.3f", 1182 (size_t)num_entries, literal_bytes, literal_avg); 1183 } 1184 st->print_cr("Total footprsize_t : %9s = %9" PRIuPTR " bytes", "" 1185 , total_bytes); 1186 st->print_cr("Average bucket size : %9.3f", summary.avg()); 1187 st->print_cr("Variance of bucket size : %9.3f", summary.variance()); 1188 st->print_cr("Std. dev. of bucket size: %9.3f", summary.sd()); 1189 st->print_cr("Maximum bucket size : %9" PRIuPTR, 1190 (size_t)summary.maximum()); 1191 unlock_resize_lock(thread); 1192 } 1193 1194 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1195 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1196 try_move_nodes_to(Thread* thread, ConcurrentHashTable<VALUE, CONFIG, F>* to_cht) 1197 { 1198 if (!try_resize_lock(thread)) { 1199 return false; 1200 } 1201 assert(_new_table == NULL, "Must be NULL"); 1202 for (size_t bucket_it = 0; bucket_it < _table->_size; bucket_it++) { 1203 Bucket* bucket = _table->get_bucket(bucket_it); 1204 assert(!bucket->have_redirect() && !bucket->is_locked(), "Table must be uncontended"); 1205 while (bucket->first() != NULL) { 1206 Node* move_node = bucket->first(); 1207 bool ok = bucket->cas_first(move_node->next(), move_node); 1208 assert(ok, "Uncontended cas must work"); 1209 bool dead_hash = false; 1210 size_t insert_hash = CONFIG::get_hash(*move_node->value(), &dead_hash); 1211 if (!dead_hash) { 1212 Bucket* insert_bucket = to_cht->get_bucket(insert_hash); 1213 assert(!bucket->have_redirect() && !bucket->is_locked(), "Not bit should be present"); 1214 move_node->set_next(insert_bucket->first()); 1215 ok = insert_bucket->cas_first(move_node, insert_bucket->first()); 1216 assert(ok, "Uncontended cas must work"); 1217 } 1218 } 1219 } 1220 unlock_resize_lock(thread); 1221 return true; 1222 } 1223 1224 #endif // include guard