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.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 // Read next() Node* once. May be racing with a thread moving the next 267 // pointers. 268 Node* next_pref = next->next(); 269 if (next_pref != NULL) { 270 Prefetch::read(*next_pref->value(), 0); 271 } 272 if (eval_f(next->value())) { 273 return true; 274 } 275 } 276 return false; 277 } 278 279 template <typename VALUE, typename CONFIG, MEMFLAGS F> 280 template <bool b, typename EVALUATE_FUNC> 281 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 282 HaveDeletables<b, EVALUATE_FUNC>::have_deletable(Bucket* bucket, 283 EVALUATE_FUNC& eval_f, 284 Bucket* preb) 285 { 286 for (Node* next = bucket->first(); next != NULL ; next = next->next()) { 287 if (eval_f(next->value())) { 288 return true; 289 } 290 } 291 return false; 292 } 293 294 // ConcurrentHashTable 295 template <typename VALUE, typename CONFIG, MEMFLAGS F> 296 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 297 write_synchonize_on_visible_epoch(Thread* thread) 298 { 299 assert(_resize_lock_owner == thread, "Re-size lock not held"); 300 OrderAccess::fence(); // Prevent below load from floating up. 301 // If no reader saw this version we can skip write_synchronize. 302 if (OrderAccess::load_acquire(&_invisible_epoch) == thread) { 303 return; 304 } 305 assert(_invisible_epoch == NULL, "Two thread doing bulk operations"); 306 // We set this/next version that we are synchronizing for to not published. 307 // A reader will zero this flag if it reads this/next version. 308 OrderAccess::release_store(&_invisible_epoch, thread); 309 GlobalCounter::write_synchronize(); 310 } 311 312 template <typename VALUE, typename CONFIG, MEMFLAGS F> 313 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 314 try_resize_lock(Thread* locker) 315 { 316 if (_resize_lock->try_lock()) { 317 if (_resize_lock_owner != NULL) { 318 assert(locker != _resize_lock_owner, "Already own lock"); 319 // We got mutex but internal state is locked. 320 _resize_lock->unlock(); 321 return false; 322 } 323 } else { 324 return false; 325 } 326 _invisible_epoch = 0; 327 _resize_lock_owner = locker; 328 return true; 329 } 330 331 template <typename VALUE, typename CONFIG, MEMFLAGS F> 332 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 333 lock_resize_lock(Thread* locker) 334 { 335 size_t i = 0; 336 // If lock is hold by some other thread, the chances that it is return quick 337 // is low. So we will prefer yielding. 338 SpinYield yield(1, 512); 339 do { 340 _resize_lock->lock_without_safepoint_check(); 341 // If holder of lock dropped mutex for safepoint mutex might be unlocked, 342 // and _resize_lock_owner will contain the owner. 343 if (_resize_lock_owner != NULL) { 344 assert(locker != _resize_lock_owner, "Already own lock"); 345 // We got mutex but internal state is locked. 346 _resize_lock->unlock(); 347 yield.wait(); 348 } else { 349 break; 350 } 351 } while(true); 352 _resize_lock_owner = locker; 353 _invisible_epoch = 0; 354 } 355 356 template <typename VALUE, typename CONFIG, MEMFLAGS F> 357 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 358 unlock_resize_lock(Thread* locker) 359 { 360 _invisible_epoch = 0; 361 assert(locker == _resize_lock_owner, "Not unlocked by locker."); 362 _resize_lock_owner = NULL; 363 _resize_lock->unlock(); 364 } 365 366 template <typename VALUE, typename CONFIG, MEMFLAGS F> 367 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 368 free_nodes() 369 { 370 // We assume we are not MT during freeing. 371 for (size_t node_it = 0; node_it < _table->_size; node_it++) { 372 Bucket* bucket = _table->get_buckets() + node_it; 373 Node* node = bucket->first(); 374 while (node != NULL) { 375 Node* free_node = node; 376 node = node->next(); 377 Node::destroy_node(free_node); 378 } 379 } 380 } 381 382 template <typename VALUE, typename CONFIG, MEMFLAGS F> 383 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* 384 ConcurrentHashTable<VALUE, CONFIG, F>:: 385 get_table() const 386 { 387 return OrderAccess::load_acquire(&_table); 388 } 389 390 template <typename VALUE, typename CONFIG, MEMFLAGS F> 391 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* 392 ConcurrentHashTable<VALUE, CONFIG, F>:: 393 get_new_table() const 394 { 395 return OrderAccess::load_acquire(&_new_table); 396 } 397 398 template <typename VALUE, typename CONFIG, MEMFLAGS F> 399 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* 400 ConcurrentHashTable<VALUE, CONFIG, F>:: 401 set_table_from_new() 402 { 403 InternalTable* old_table = _table; 404 // Publish the new table. 405 OrderAccess::release_store(&_table, _new_table); 406 // All must see this. 407 GlobalCounter::write_synchronize(); 408 // _new_table not read any more. 409 _new_table = NULL; 410 DEBUG_ONLY(_new_table = (InternalTable*)POISON_PTR;) 411 return old_table; 412 } 413 414 template <typename VALUE, typename CONFIG, MEMFLAGS F> 415 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 416 internal_grow_range(Thread* thread, size_t start, size_t stop) 417 { 418 assert(stop <= _table->_size, "Outside backing array"); 419 assert(_new_table != NULL, "Grow not proper setup before start"); 420 // The state is also copied here. Hence all buckets in new table will be 421 // locked. I call the siblings odd/even, where even have high bit 0 and odd 422 // have high bit 1. 423 for (size_t even_index = start; even_index < stop; even_index++) { 424 Bucket* bucket = _table->get_bucket(even_index); 425 426 bucket->lock(); 427 428 size_t odd_index = even_index + _table->_size; 429 _new_table->get_buckets()[even_index] = *bucket; 430 _new_table->get_buckets()[odd_index] = *bucket; 431 432 // Moves lockers go to new table, where they will wait until unlock() below. 433 bucket->redirect(); /* Must release stores above */ 434 435 // When this is done we have separated the nodes into corresponding buckets 436 // in new table. 437 if (!unzip_bucket(thread, _table, _new_table, even_index, odd_index)) { 438 // If bucket is empty, unzip does nothing. 439 // We must make sure readers go to new table before we poison the bucket. 440 DEBUG_ONLY(GlobalCounter::write_synchronize();) 441 } 442 443 // Unlock for writes into the new table buckets. 444 _new_table->get_bucket(even_index)->unlock(); 445 _new_table->get_bucket(odd_index)->unlock(); 446 447 DEBUG_ONLY( 448 bucket->release_assign_node_ptr( 449 _table->get_bucket(even_index)->first_ptr(), (Node*)POISON_PTR); 450 ) 451 } 452 } 453 454 template <typename VALUE, typename CONFIG, MEMFLAGS F> 455 template <typename LOOKUP_FUNC, typename DELETE_FUNC> 456 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 457 internal_remove(Thread* thread, LOOKUP_FUNC& lookup_f, DELETE_FUNC& delete_f) 458 { 459 Bucket* bucket = get_bucket_locked(thread, lookup_f.get_hash()); 460 assert(bucket->is_locked(), "Must be locked."); 461 Node* const volatile * rem_n_prev = bucket->first_ptr(); 462 Node* rem_n = bucket->first(); 463 bool have_dead = false; 464 while (rem_n != NULL) { 465 if (lookup_f.equals(rem_n->value(), &have_dead)) { 466 bucket->release_assign_node_ptr(rem_n_prev, rem_n->next()); 467 break; 468 } else { 469 rem_n_prev = rem_n->next_ptr(); 470 rem_n = rem_n->next(); 471 } 472 } 473 474 bucket->unlock(); 475 476 if (rem_n == NULL) { 477 return false; 478 } 479 // Publish the deletion. 480 GlobalCounter::write_synchronize(); 481 delete_f(rem_n->value()); 482 Node::destroy_node(rem_n); 483 return true; 484 } 485 486 template <typename VALUE, typename CONFIG, MEMFLAGS F> 487 template <typename EVALUATE_FUNC, typename DELETE_FUNC> 488 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 489 do_bulk_delete_locked_for(Thread* thread, size_t start_idx, size_t stop_idx, 490 EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f, bool is_mt) 491 { 492 // Here we have resize lock so table is SMR safe, and there is no new 493 // table. Can do this in parallel if we want. 494 assert((is_mt && _resize_lock_owner != NULL) || 495 (!is_mt && _resize_lock_owner == thread), "Re-size lock not held"); 496 Node* ndel[BULK_DELETE_LIMIT]; 497 InternalTable* table = get_table(); 498 assert(start_idx < stop_idx, "Must be"); 499 assert(stop_idx <= _table->_size, "Must be"); 500 // Here manual do critical section since we don't want to take the cost of 501 // locking the bucket if there is nothing to delete. But we can have 502 // concurrent single deletes. The _invisible_epoch can only be used by the 503 // owner of _resize_lock, us here. There we should not changed it in our 504 // own read-side. 505 GlobalCounter::critical_section_begin(thread); 506 for (size_t bucket_it = start_idx; bucket_it < stop_idx; bucket_it++) { 507 Bucket* bucket = table->get_bucket(bucket_it); 508 Bucket* prefetch_bucket = (bucket_it+1) < stop_idx ? 509 table->get_bucket(bucket_it+1) : NULL; 510 511 if (!HaveDeletables<IsPointer<VALUE>::value, EVALUATE_FUNC>:: 512 have_deletable(bucket, eval_f, prefetch_bucket)) { 513 // Nothing to remove in this bucket. 514 continue; 515 } 516 517 GlobalCounter::critical_section_end(thread); 518 // We left critical section but the bucket cannot be removed while we hold 519 // the _resize_lock. 520 bucket->lock(); 521 size_t nd = delete_check_nodes(bucket, eval_f, BULK_DELETE_LIMIT, ndel); 522 bucket->unlock(); 523 if (is_mt) { 524 GlobalCounter::write_synchronize(); 525 } else { 526 write_synchonize_on_visible_epoch(thread); 527 } 528 for (size_t node_it = 0; node_it < nd; node_it++) { 529 del_f(ndel[node_it]->value()); 530 Node::destroy_node(ndel[node_it]); 531 DEBUG_ONLY(ndel[node_it] = (Node*)POISON_PTR;) 532 } 533 GlobalCounter::critical_section_begin(thread); 534 } 535 GlobalCounter::critical_section_end(thread); 536 } 537 538 template <typename VALUE, typename CONFIG, MEMFLAGS F> 539 template <typename LOOKUP_FUNC> 540 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 541 delete_in_bucket(Thread* thread, Bucket* bucket, LOOKUP_FUNC& lookup_f) 542 { 543 size_t dels = 0; 544 Node* ndel[BULK_DELETE_LIMIT]; 545 Node* const volatile * rem_n_prev = bucket->first_ptr(); 546 Node* rem_n = bucket->first(); 547 while (rem_n != NULL) { 548 bool is_dead = false; 549 lookup_f.equals(rem_n->value(), &is_dead); 550 if (is_dead) { 551 ndel[dels++] = rem_n; 552 Node* next_node = rem_n->next(); 553 bucket->release_assign_node_ptr(rem_n_prev, next_node); 554 rem_n = next_node; 555 if (dels == BULK_DELETE_LIMIT) { 556 break; 557 } 558 } else { 559 rem_n_prev = rem_n->next_ptr(); 560 rem_n = rem_n->next(); 561 } 562 } 563 if (dels > 0) { 564 GlobalCounter::write_synchronize(); 565 for (size_t node_it = 0; node_it < dels; node_it++) { 566 Node::destroy_node(ndel[node_it]); 567 DEBUG_ONLY(ndel[node_it] = (Node*)POISON_PTR;) 568 } 569 } 570 } 571 572 template <typename VALUE, typename CONFIG, MEMFLAGS F> 573 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Bucket* 574 ConcurrentHashTable<VALUE, CONFIG, F>:: 575 get_bucket(uintx hash) const 576 { 577 InternalTable* table = get_table(); 578 Bucket* bucket = get_bucket_in(table, hash); 579 if (bucket->have_redirect()) { 580 table = get_new_table(); 581 bucket = get_bucket_in(table, hash); 582 } 583 return bucket; 584 } 585 586 template <typename VALUE, typename CONFIG, MEMFLAGS F> 587 inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Bucket* 588 ConcurrentHashTable<VALUE, CONFIG, F>:: 589 get_bucket_locked(Thread* thread, const uintx hash) 590 { 591 Bucket* bucket; 592 int i = 0; 593 // SpinYield would be unfair here 594 while(true) { 595 { 596 // We need a critical section to protect the table itself. But if we fail 597 // we must leave critical section otherwise we would deadlock. 598 ScopedCS cs(thread, this); 599 bucket = get_bucket(hash); 600 if (bucket->trylock()) { 601 break; /* ends critical section */ 602 } 603 } /* ends critical section */ 604 if ((++i) == SPINPAUSES_PER_YIELD) { 605 // On contemporary OS yielding will give CPU to another runnable thread if 606 // there is no CPU available. 607 os::naked_yield(); 608 i = 0; 609 } else { 610 SpinPause(); 611 } 612 } 613 return bucket; 614 } 615 616 // Always called within critical section 617 template <typename VALUE, typename CONFIG, MEMFLAGS F> 618 template <typename LOOKUP_FUNC> 619 typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* 620 ConcurrentHashTable<VALUE, CONFIG, F>:: 621 get_node(const Bucket* const bucket, LOOKUP_FUNC& lookup_f, 622 bool* have_dead, size_t* loops) const 623 { 624 size_t loop_count = 0; 625 Node* node = bucket->first(); 626 while (node != NULL) { 627 bool is_dead = false; 628 ++loop_count; 629 if (lookup_f.equals(node->value(), &is_dead)) { 630 break; 631 } 632 if (is_dead && !(*have_dead)) { 633 *have_dead = true; 634 } 635 node = node->next(); 636 } 637 if (loops != NULL) { 638 *loops = loop_count; 639 } 640 return node; 641 } 642 643 template <typename VALUE, typename CONFIG, MEMFLAGS F> 644 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 645 unzip_bucket(Thread* thread, InternalTable* old_table, 646 InternalTable* new_table, size_t even_index, size_t odd_index) 647 { 648 Node* aux = old_table->get_bucket(even_index)->first(); 649 if (aux == NULL) { 650 // This is an empty bucket and in debug we poison first ptr in bucket. 651 // Therefore we must make sure no readers are looking at this bucket. 652 // If we don't do a write_synch here, caller must do it. 653 return false; 654 } 655 Node* delete_me = NULL; 656 Node* const volatile * even = new_table->get_bucket(even_index)->first_ptr(); 657 Node* const volatile * odd = new_table->get_bucket(odd_index)->first_ptr(); 658 while (aux != NULL) { 659 bool dead_hash = false; 660 size_t aux_hash = CONFIG::get_hash(*aux->value(), &dead_hash); 661 Node* aux_next = aux->next(); 662 if (dead_hash) { 663 delete_me = aux; 664 // This item is dead, move both list to next 665 new_table->get_bucket(odd_index)->release_assign_node_ptr(odd, 666 aux_next); 667 new_table->get_bucket(even_index)->release_assign_node_ptr(even, 668 aux_next); 669 } else { 670 size_t aux_index = bucket_idx_hash(new_table, aux_hash); 671 if (aux_index == even_index) { 672 // This is a even, so move odd to aux/even next 673 new_table->get_bucket(odd_index)->release_assign_node_ptr(odd, 674 aux_next); 675 // Keep in even list 676 even = aux->next_ptr(); 677 } else if (aux_index == odd_index) { 678 // This is a odd, so move odd to aux/odd next 679 new_table->get_bucket(even_index)->release_assign_node_ptr(even, 680 aux_next); 681 // Keep in odd list 682 odd = aux->next_ptr(); 683 } else { 684 fatal("aux_index does not match even or odd indices"); 685 } 686 } 687 aux = aux_next; 688 689 // We can only move 1 pointer otherwise a reader might be moved to the wrong 690 // chain. E.g. looking for even hash value but got moved to the odd bucket 691 // chain. 692 write_synchonize_on_visible_epoch(thread); 693 if (delete_me != NULL) { 694 Node::destroy_node(delete_me); 695 delete_me = NULL; 696 } 697 } 698 return true; 699 } 700 701 template <typename VALUE, typename CONFIG, MEMFLAGS F> 702 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 703 internal_shrink_prolog(Thread* thread, size_t log2_size) 704 { 705 if (!try_resize_lock(thread)) { 706 return false; 707 } 708 assert(_resize_lock_owner == thread, "Re-size lock not held"); 709 if (_table->_log2_size == _log2_start_size || 710 _table->_log2_size <= log2_size) { 711 unlock_resize_lock(thread); 712 return false; 713 } 714 _new_table = new InternalTable(_table->_log2_size - 1); 715 return true; 716 } 717 718 template <typename VALUE, typename CONFIG, MEMFLAGS F> 719 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 720 internal_shrink_epilog(Thread* thread) 721 { 722 assert(_resize_lock_owner == thread, "Re-size lock not held"); 723 724 InternalTable* old_table = set_table_from_new(); 725 _size_limit_reached = false; 726 unlock_resize_lock(thread); 727 #ifdef ASSERT 728 for (size_t i = 0; i < old_table->_size; i++) { 729 assert(old_table->get_bucket(i++)->first() == POISON_PTR, 730 "No poison found"); 731 } 732 #endif 733 // ABA safe, old_table not visible to any other threads. 734 delete old_table; 735 } 736 737 template <typename VALUE, typename CONFIG, MEMFLAGS F> 738 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 739 internal_shrink_range(Thread* thread, size_t start, size_t stop) 740 { 741 // The state is also copied here. 742 // Hence all buckets in new table will be locked. 743 for (size_t bucket_it = start; bucket_it < stop; bucket_it++) { 744 size_t even_hash_index = bucket_it; // High bit 0 745 size_t odd_hash_index = bucket_it + _new_table->_size; // High bit 1 746 747 Bucket* b_old_even = _table->get_bucket(even_hash_index); 748 Bucket* b_old_odd = _table->get_bucket(odd_hash_index); 749 750 b_old_even->lock(); 751 b_old_odd->lock(); 752 753 _new_table->get_buckets()[bucket_it] = *b_old_even; 754 755 // Put chains together. 756 _new_table->get_bucket(bucket_it)-> 757 release_assign_last_node_next(*(b_old_odd->first_ptr())); 758 759 b_old_even->redirect(); 760 b_old_odd->redirect(); 761 762 write_synchonize_on_visible_epoch(thread); 763 764 // Unlock for writes into new smaller table. 765 _new_table->get_bucket(bucket_it)->unlock(); 766 767 DEBUG_ONLY(b_old_even->release_assign_node_ptr(b_old_even->first_ptr(), 768 (Node*)POISON_PTR);) 769 DEBUG_ONLY(b_old_odd->release_assign_node_ptr(b_old_odd->first_ptr(), 770 (Node*)POISON_PTR);) 771 } 772 } 773 774 template <typename VALUE, typename CONFIG, MEMFLAGS F> 775 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 776 internal_shrink(Thread* thread, size_t log2_size) 777 { 778 if (!internal_shrink_prolog(thread, log2_size)) { 779 assert(_resize_lock_owner != thread, "Re-size lock held"); 780 return false; 781 } 782 assert(_resize_lock_owner == thread, "Should be locked by me"); 783 internal_shrink_range(thread, 0, _new_table->_size); 784 internal_shrink_epilog(thread); 785 assert(_resize_lock_owner != thread, "Re-size lock held"); 786 return true; 787 } 788 789 template <typename VALUE, typename CONFIG, MEMFLAGS F> 790 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 791 internal_grow_prolog(Thread* thread, size_t log2_size) 792 { 793 // This double checking of _size_limit_reached/is_max_size_reached() 794 // we only do in grow path, since grow means high load on table 795 // while shrink means low load. 796 if (is_max_size_reached()) { 797 return false; 798 } 799 if (!try_resize_lock(thread)) { 800 // Either we have an ongoing resize or an operation which doesn't want us 801 // to resize now. 802 return false; 803 } 804 if (is_max_size_reached() || _table->_log2_size >= log2_size) { 805 unlock_resize_lock(thread); 806 return false; 807 } 808 809 _new_table = new InternalTable(_table->_log2_size + 1); 810 811 if (_new_table->_log2_size == _log2_size_limit) { 812 _size_limit_reached = true; 813 } 814 815 return true; 816 } 817 818 template <typename VALUE, typename CONFIG, MEMFLAGS F> 819 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 820 internal_grow_epilog(Thread* thread) 821 { 822 assert(_resize_lock_owner == thread, "Should be locked"); 823 824 InternalTable* old_table = set_table_from_new(); 825 unlock_resize_lock(thread); 826 #ifdef ASSERT 827 for (size_t i = 0; i < old_table->_size; i++) { 828 assert(old_table->get_bucket(i++)->first() == POISON_PTR, 829 "No poison found"); 830 } 831 #endif 832 // ABA safe, old_table not visible to any other threads. 833 delete old_table; 834 } 835 836 template <typename VALUE, typename CONFIG, MEMFLAGS F> 837 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 838 internal_grow(Thread* thread, size_t log2_size) 839 { 840 if (!internal_grow_prolog(thread, log2_size)) { 841 assert(_resize_lock_owner != thread, "Re-size lock held"); 842 return false; 843 } 844 assert(_resize_lock_owner == thread, "Should be locked by me"); 845 internal_grow_range(thread, 0, _table->_size); 846 internal_grow_epilog(thread); 847 assert(_resize_lock_owner != thread, "Re-size lock held"); 848 return true; 849 } 850 851 // Always called within critical section 852 template <typename VALUE, typename CONFIG, MEMFLAGS F> 853 template <typename LOOKUP_FUNC> 854 inline VALUE* ConcurrentHashTable<VALUE, CONFIG, F>:: 855 internal_get(Thread* thread, LOOKUP_FUNC& lookup_f, bool* grow_hint) 856 { 857 bool clean = false; 858 size_t loops = 0; 859 VALUE* ret = NULL; 860 861 const Bucket* bucket = get_bucket(lookup_f.get_hash()); 862 Node* node = get_node(bucket, lookup_f, &clean, &loops); 863 if (node != NULL) { 864 ret = node->value(); 865 } 866 if (grow_hint != NULL) { 867 *grow_hint = loops > _grow_hint; 868 } 869 870 return ret; 871 } 872 873 template <typename VALUE, typename CONFIG, MEMFLAGS F> 874 template <typename LOOKUP_FUNC, typename VALUE_FUNC, typename CALLBACK_FUNC> 875 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 876 internal_insert(Thread* thread, LOOKUP_FUNC& lookup_f, VALUE_FUNC& value_f, 877 CALLBACK_FUNC& callback, bool* grow_hint) 878 { 879 bool ret = false; 880 bool clean = false; 881 bool locked; 882 size_t loops = 0; 883 size_t i = 0; 884 Node* new_node = NULL; 885 uintx hash = lookup_f.get_hash(); 886 while (true) { 887 { 888 ScopedCS cs(thread, this); /* protected the table/bucket */ 889 Bucket* bucket = get_bucket(hash); 890 891 Node* first_at_start = bucket->first(); 892 Node* old = get_node(bucket, lookup_f, &clean, &loops); 893 if (old == NULL) { 894 // No duplicate found. 895 if (new_node == NULL) { 896 new_node = Node::create_node(value_f(), first_at_start); 897 } else { 898 new_node->set_next(first_at_start); 899 } 900 if (bucket->cas_first(new_node, first_at_start)) { 901 callback(true, new_node->value()); 902 new_node = NULL; 903 ret = true; 904 break; /* leave critical section */ 905 } 906 // CAS failed we must leave critical section and retry. 907 locked = bucket->is_locked(); 908 } else { 909 // There is a duplicate. 910 callback(false, old->value()); 911 break; /* leave critical section */ 912 } 913 } /* leave critical section */ 914 i++; 915 if (locked) { 916 os::naked_yield(); 917 } else { 918 SpinPause(); 919 } 920 } 921 922 if (new_node != NULL) { 923 // CAS failed and a duplicate was inserted, we must free this node. 924 Node::destroy_node(new_node); 925 } else if (i == 0 && clean) { 926 // We only do cleaning on fast inserts. 927 Bucket* bucket = get_bucket_locked(thread, lookup_f.get_hash()); 928 assert(bucket->is_locked(), "Must be locked."); 929 delete_in_bucket(thread, bucket, lookup_f); 930 bucket->unlock(); 931 } 932 933 if (grow_hint != NULL) { 934 *grow_hint = loops > _grow_hint; 935 } 936 937 return ret; 938 } 939 940 template <typename VALUE, typename CONFIG, MEMFLAGS F> 941 template <typename FUNC> 942 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 943 visit_nodes(Bucket* bucket, FUNC& visitor_f) 944 { 945 Node* current_node = bucket->first(); 946 while (current_node != NULL) { 947 if (!visitor_f(current_node->value())) { 948 return false; 949 } 950 current_node = current_node->next(); 951 } 952 return true; 953 } 954 955 template <typename VALUE, typename CONFIG, MEMFLAGS F> 956 template <typename FUNC> 957 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 958 do_scan_locked(Thread* thread, FUNC& scan_f) 959 { 960 assert(_resize_lock_owner == thread, "Re-size lock not held"); 961 // We can do a critical section over the entire loop but that would block 962 // updates for a long time. Instead we choose to block resizes. 963 InternalTable* table = get_table(); 964 for (size_t bucket_it = 0; bucket_it < table->_size; bucket_it++) { 965 ScopedCS cs(thread, this); 966 if (!visit_nodes(table->get_bucket(bucket_it), scan_f)) { 967 break; /* ends critical section */ 968 } 969 } /* ends critical section */ 970 } 971 972 template <typename VALUE, typename CONFIG, MEMFLAGS F> 973 template <typename EVALUATE_FUNC> 974 inline size_t ConcurrentHashTable<VALUE, CONFIG, F>:: 975 delete_check_nodes(Bucket* bucket, EVALUATE_FUNC& eval_f, 976 size_t num_del, Node** ndel) 977 { 978 size_t dels = 0; 979 Node* const volatile * rem_n_prev = bucket->first_ptr(); 980 Node* rem_n = bucket->first(); 981 while (rem_n != NULL) { 982 if (eval_f(rem_n->value())) { 983 ndel[dels++] = rem_n; 984 Node* next_node = rem_n->next(); 985 bucket->release_assign_node_ptr(rem_n_prev, next_node); 986 rem_n = next_node; 987 if (dels == num_del) { 988 break; 989 } 990 } else { 991 rem_n_prev = rem_n->next_ptr(); 992 rem_n = rem_n->next(); 993 } 994 } 995 return dels; 996 } 997 998 // Constructor 999 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1000 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 1001 ConcurrentHashTable(size_t log2size, size_t log2size_limit, size_t grow_hint) 1002 : _new_table(NULL), _log2_start_size(log2size), 1003 _log2_size_limit(log2size_limit), _grow_hint(grow_hint), 1004 _size_limit_reached(false), _resize_lock_owner(NULL), 1005 _invisible_epoch(0) 1006 { 1007 _resize_lock = 1008 new Mutex(Mutex::leaf, "ConcurrentHashTable", false, 1009 Monitor::_safepoint_check_never); 1010 _table = new InternalTable(log2size); 1011 assert(log2size_limit >= log2size, "bad ergo"); 1012 _size_limit_reached = _table->_log2_size == _log2_size_limit; 1013 } 1014 1015 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1016 inline ConcurrentHashTable<VALUE, CONFIG, F>:: 1017 ~ConcurrentHashTable() 1018 { 1019 delete _resize_lock; 1020 free_nodes(); 1021 delete _table; 1022 } 1023 1024 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1025 inline size_t ConcurrentHashTable<VALUE, CONFIG, F>:: 1026 get_size_log2(Thread* thread) 1027 { 1028 ScopedCS cs(thread, this); 1029 return _table->_log2_size; 1030 } 1031 1032 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1033 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1034 shrink(Thread* thread, size_t size_limit_log2) 1035 { 1036 size_t tmp = size_limit_log2 == 0 ? _log2_start_size : size_limit_log2; 1037 bool ret = internal_shrink(thread, tmp); 1038 return ret; 1039 } 1040 1041 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1042 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1043 grow(Thread* thread, size_t size_limit_log2) 1044 { 1045 size_t tmp = size_limit_log2 == 0 ? _log2_size_limit : size_limit_log2; 1046 return internal_grow(thread, tmp); 1047 } 1048 1049 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1050 template <typename LOOKUP_FUNC, typename FOUND_FUNC> 1051 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1052 get(Thread* thread, LOOKUP_FUNC& lookup_f, FOUND_FUNC& found_f, bool* grow_hint) 1053 { 1054 bool ret = false; 1055 ScopedCS cs(thread, this); 1056 VALUE* val = internal_get(thread, lookup_f, grow_hint); 1057 if (val != NULL) { 1058 found_f(val); 1059 ret = true; 1060 } 1061 return ret; 1062 } 1063 1064 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1065 template <typename LOOKUP_FUNC> 1066 inline VALUE ConcurrentHashTable<VALUE, CONFIG, F>:: 1067 get_copy(Thread* thread, LOOKUP_FUNC& lookup_f, bool* grow_hint) 1068 { 1069 ScopedCS cs(thread, this); 1070 VALUE* val = internal_get(thread, lookup_f, grow_hint); 1071 return val != NULL ? *val : CONFIG::notfound(); 1072 } 1073 1074 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1075 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1076 unsafe_insert(const VALUE& value) { 1077 bool dead_hash = false; 1078 size_t hash = CONFIG::get_hash(value, &dead_hash); 1079 if (dead_hash) { 1080 return false; 1081 } 1082 // This is an unsafe operation. 1083 InternalTable* table = get_table(); 1084 Bucket* bucket = get_bucket_in(table, hash); 1085 assert(!bucket->have_redirect() && !bucket->is_locked(), "bad"); 1086 Node* new_node = Node::create_node(value, bucket->first()); 1087 if (!bucket->cas_first(new_node, bucket->first())) { 1088 assert(false, "bad"); 1089 } 1090 return true; 1091 } 1092 1093 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1094 template <typename SCAN_FUNC> 1095 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1096 try_scan(Thread* thread, SCAN_FUNC& scan_f) 1097 { 1098 if (!try_resize_lock(thread)) { 1099 return false; 1100 } 1101 do_scan_locked(thread, scan_f); 1102 unlock_resize_lock(thread); 1103 return true; 1104 } 1105 1106 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1107 template <typename SCAN_FUNC> 1108 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 1109 do_scan(Thread* thread, SCAN_FUNC& scan_f) 1110 { 1111 assert(_resize_lock_owner != thread, "Re-size lock held"); 1112 lock_resize_lock(thread); 1113 do_scan_locked(thread, scan_f); 1114 unlock_resize_lock(thread); 1115 assert(_resize_lock_owner != thread, "Re-size lock held"); 1116 } 1117 1118 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1119 template <typename EVALUATE_FUNC, typename DELETE_FUNC> 1120 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1121 try_bulk_delete(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) 1122 { 1123 if (!try_resize_lock(thread)) { 1124 return false; 1125 } 1126 do_bulk_delete_locked(thread, eval_f, del_f); 1127 unlock_resize_lock(thread); 1128 assert(_resize_lock_owner != thread, "Re-size lock held"); 1129 return true; 1130 } 1131 1132 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1133 template <typename EVALUATE_FUNC, typename DELETE_FUNC> 1134 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 1135 bulk_delete(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) 1136 { 1137 lock_resize_lock(thread); 1138 do_bulk_delete_locked(thread, eval_f, del_f); 1139 unlock_resize_lock(thread); 1140 } 1141 1142 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1143 template <typename VALUE_SIZE_FUNC> 1144 inline void ConcurrentHashTable<VALUE, CONFIG, F>:: 1145 statistics_to(Thread* thread, VALUE_SIZE_FUNC& vs_f, 1146 outputStream* st, const char* table_name) 1147 { 1148 NumberSeq summary; 1149 size_t literal_bytes = 0; 1150 if (!try_resize_lock(thread)) { 1151 st->print_cr("statistics unavailable at this moment"); 1152 return; 1153 } 1154 1155 InternalTable* table = get_table(); 1156 for (size_t bucket_it = 0; bucket_it < table->_size; bucket_it++) { 1157 ScopedCS cs(thread, this); 1158 size_t count = 0; 1159 Bucket* bucket = table->get_bucket(bucket_it); 1160 if (bucket->have_redirect() || bucket->is_locked()) { 1161 continue; 1162 } 1163 Node* current_node = bucket->first(); 1164 while (current_node != NULL) { 1165 ++count; 1166 literal_bytes += vs_f(current_node->value()); 1167 current_node = current_node->next(); 1168 } 1169 summary.add((double)count); 1170 } 1171 1172 double num_buckets = summary.num(); 1173 double num_entries = summary.sum(); 1174 1175 size_t bucket_bytes = num_buckets * sizeof(Bucket); 1176 size_t entry_bytes = num_entries * sizeof(Node); 1177 size_t total_bytes = literal_bytes + bucket_bytes + entry_bytes; 1178 1179 size_t bucket_size = (num_buckets <= 0) ? 0 : (bucket_bytes / num_buckets); 1180 size_t entry_size = (num_entries <= 0) ? 0 : (entry_bytes / num_entries); 1181 1182 st->print_cr("%s statistics:", table_name); 1183 st->print_cr("Number of buckets : %9" PRIuPTR " = %9" PRIuPTR 1184 " bytes, each " SIZE_FORMAT, 1185 (size_t)num_buckets, bucket_bytes, bucket_size); 1186 st->print_cr("Number of entries : %9" PRIuPTR " = %9" PRIuPTR 1187 " bytes, each " SIZE_FORMAT, 1188 (size_t)num_entries, entry_bytes, entry_size); 1189 if (literal_bytes != 0) { 1190 double literal_avg = (num_entries <= 0) ? 0 : (literal_bytes / num_entries); 1191 st->print_cr("Number of literals : %9" PRIuPTR " = %9" PRIuPTR 1192 " bytes, avg %7.3f", 1193 (size_t)num_entries, literal_bytes, literal_avg); 1194 } 1195 st->print_cr("Total footprsize_t : %9s = %9" PRIuPTR " bytes", "" 1196 , total_bytes); 1197 st->print_cr("Average bucket size : %9.3f", summary.avg()); 1198 st->print_cr("Variance of bucket size : %9.3f", summary.variance()); 1199 st->print_cr("Std. dev. of bucket size: %9.3f", summary.sd()); 1200 st->print_cr("Maximum bucket size : %9" PRIuPTR, 1201 (size_t)summary.maximum()); 1202 unlock_resize_lock(thread); 1203 } 1204 1205 template <typename VALUE, typename CONFIG, MEMFLAGS F> 1206 inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: 1207 try_move_nodes_to(Thread* thread, ConcurrentHashTable<VALUE, CONFIG, F>* to_cht) 1208 { 1209 if (!try_resize_lock(thread)) { 1210 return false; 1211 } 1212 assert(_new_table == NULL || _new_table == POISON_PTR, "Must be NULL"); 1213 for (size_t bucket_it = 0; bucket_it < _table->_size; bucket_it++) { 1214 Bucket* bucket = _table->get_bucket(bucket_it); 1215 assert(!bucket->have_redirect() && !bucket->is_locked(), "Table must be uncontended"); 1216 while (bucket->first() != NULL) { 1217 Node* move_node = bucket->first(); 1218 bool ok = bucket->cas_first(move_node->next(), move_node); 1219 assert(ok, "Uncontended cas must work"); 1220 bool dead_hash = false; 1221 size_t insert_hash = CONFIG::get_hash(*move_node->value(), &dead_hash); 1222 if (!dead_hash) { 1223 Bucket* insert_bucket = to_cht->get_bucket(insert_hash); 1224 assert(!bucket->have_redirect() && !bucket->is_locked(), "Not bit should be present"); 1225 move_node->set_next(insert_bucket->first()); 1226 ok = insert_bucket->cas_first(move_node, insert_bucket->first()); 1227 assert(ok, "Uncontended cas must work"); 1228 } 1229 } 1230 } 1231 unlock_resize_lock(thread); 1232 return true; 1233 } 1234 1235 #endif // include guard