| /* |
| * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_UTILITIES_CONCURRENT_HASH_TABLE_INLINE_HPP |
| #define SHARE_UTILITIES_CONCURRENT_HASH_TABLE_INLINE_HPP |
| |
| #include "memory/allocation.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/orderAccess.hpp" |
| #include "runtime/prefetch.inline.hpp" |
| #include "utilities/concurrentHashTable.hpp" |
| #include "utilities/globalCounter.inline.hpp" |
| #include "utilities/numberSeq.hpp" |
| #include "utilities/spinYield.hpp" |
| |
| // 2^30 = 1G buckets |
| #define SIZE_BIG_LOG2 30 |
| // 2^5 = 32 buckets |
| #define SIZE_SMALL_LOG2 5 |
| |
| // Number from spinYield.hpp. In some loops SpinYield would be unfair. |
| #define SPINPAUSES_PER_YIELD 8192 |
| |
| #ifdef ASSERT |
| #ifdef _LP64 |
| // Two low bits are not usable. |
| static const void* POISON_PTR = (void*)UCONST64(0xfbadbadbadbadbac); |
| #else |
| // Two low bits are not usable. |
| static const void* POISON_PTR = (void*)0xffbadbac; |
| #endif |
| #endif |
| |
| // Node |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Node::next() const |
| { |
| return OrderAccess::load_acquire(&_next); |
| } |
| |
| // Bucket |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::first_raw() const |
| { |
| return OrderAccess::load_acquire(&_first); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::release_assign_node_ptr( |
| typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* const volatile * dst, |
| typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* node) const |
| { |
| // Due to this assert this methods is not static. |
| assert(is_locked(), "Must be locked."); |
| Node** tmp = (Node**)dst; |
| OrderAccess::release_store(tmp, clear_set_state(node, *dst)); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::first() const |
| { |
| // We strip the states bit before returning the ptr. |
| return clear_state(OrderAccess::load_acquire(&_first)); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::have_redirect() const |
| { |
| return is_state(first_raw(), STATE_REDIRECT_BIT); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::is_locked() const |
| { |
| return is_state(first_raw(), STATE_LOCK_BIT); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::lock() |
| { |
| int i = 0; |
| // SpinYield would be unfair here |
| while (!this->trylock()) { |
| if ((++i) == SPINPAUSES_PER_YIELD) { |
| // On contemporary OS yielding will give CPU to another runnable thread if |
| // there is no CPU available. |
| os::naked_yield(); |
| i = 0; |
| } else { |
| SpinPause(); |
| } |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::release_assign_last_node_next( |
| typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* node) |
| { |
| assert(is_locked(), "Must be locked."); |
| Node* const volatile * ret = first_ptr(); |
| while (clear_state(*ret) != NULL) { |
| ret = clear_state(*ret)->next_ptr(); |
| } |
| release_assign_node_ptr(ret, node); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::cas_first(typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* node, |
| typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* expect |
| ) |
| { |
| if (is_locked()) { |
| return false; |
| } |
| if (Atomic::cmpxchg(node, &_first, expect) == expect) { |
| return true; |
| } |
| return false; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::trylock() |
| { |
| if (is_locked()) { |
| return false; |
| } |
| // We will expect a clean first pointer. |
| Node* tmp = first(); |
| if (Atomic::cmpxchg(set_state(tmp, STATE_LOCK_BIT), &_first, tmp) == tmp) { |
| return true; |
| } |
| return false; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::unlock() |
| { |
| assert(is_locked(), "Must be locked."); |
| assert(!have_redirect(), |
| "Unlocking a bucket after it has reached terminal state."); |
| OrderAccess::release_store(&_first, clear_state(first())); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| Bucket::redirect() |
| { |
| assert(is_locked(), "Must be locked."); |
| OrderAccess::release_store(&_first, set_state(_first, STATE_REDIRECT_BIT)); |
| } |
| |
| // InternalTable |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline ConcurrentHashTable<VALUE, CONFIG, F>:: |
| InternalTable::InternalTable(size_t log2_size) |
| : _log2_size(log2_size), _size(((size_t)1ul) << _log2_size), |
| _hash_mask(~(~((size_t)0) << _log2_size)) |
| { |
| assert(_log2_size >= SIZE_SMALL_LOG2 && _log2_size <= SIZE_BIG_LOG2, |
| "Bad size"); |
| _buckets = NEW_C_HEAP_ARRAY(Bucket, _size, F); |
| // Use placement new for each element instead of new[] which could use more |
| // memory than allocated. |
| for (size_t i = 0; i < _size; ++i) { |
| new (_buckets + i) Bucket(); |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline ConcurrentHashTable<VALUE, CONFIG, F>:: |
| InternalTable::~InternalTable() |
| { |
| FREE_C_HEAP_ARRAY(Bucket, _buckets); |
| } |
| |
| // ScopedCS |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline ConcurrentHashTable<VALUE, CONFIG, F>:: |
| ScopedCS::ScopedCS(Thread* thread, ConcurrentHashTable<VALUE, CONFIG, F>* cht) |
| : _thread(thread), _cht(cht) |
| { |
| GlobalCounter::critical_section_begin(_thread); |
| // This version is published now. |
| if (OrderAccess::load_acquire(&_cht->_invisible_epoch) != NULL) { |
| OrderAccess::release_store_fence(&_cht->_invisible_epoch, (Thread*)NULL); |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline ConcurrentHashTable<VALUE, CONFIG, F>:: |
| ScopedCS::~ScopedCS() |
| { |
| GlobalCounter::critical_section_end(_thread); |
| } |
| |
| // BaseConfig |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void* ConcurrentHashTable<VALUE, CONFIG, F>:: |
| BaseConfig::allocate_node(size_t size, const VALUE& value) |
| { |
| return AllocateHeap(size, F); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| BaseConfig::free_node(void* memory, const VALUE& value) |
| { |
| FreeHeap(memory); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC> |
| inline VALUE* ConcurrentHashTable<VALUE, CONFIG, F>:: |
| MultiGetHandle::get(LOOKUP_FUNC& lookup_f, bool* grow_hint) |
| { |
| return ScopedCS::_cht->internal_get(ScopedCS::_thread, lookup_f, grow_hint); |
| } |
| |
| // HaveDeletables |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename EVALUATE_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| HaveDeletables<true, EVALUATE_FUNC>::have_deletable(Bucket* bucket, |
| EVALUATE_FUNC& eval_f, |
| Bucket* prefetch_bucket) |
| { |
| // Instantiated for pointer type (true), so we can use prefetch. |
| // When visiting all Nodes doing this prefetch give around 30%. |
| Node* pref = prefetch_bucket != NULL ? prefetch_bucket->first() : NULL; |
| for (Node* next = bucket->first(); next != NULL ; next = next->next()) { |
| if (pref != NULL) { |
| Prefetch::read(*pref->value(), 0); |
| pref = pref->next(); |
| } |
| // Read next() Node* once. May be racing with a thread moving the next |
| // pointers. |
| Node* next_pref = next->next(); |
| if (next_pref != NULL) { |
| Prefetch::read(*next_pref->value(), 0); |
| } |
| if (eval_f(next->value())) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <bool b, typename EVALUATE_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| HaveDeletables<b, EVALUATE_FUNC>::have_deletable(Bucket* bucket, |
| EVALUATE_FUNC& eval_f, |
| Bucket* preb) |
| { |
| for (Node* next = bucket->first(); next != NULL ; next = next->next()) { |
| if (eval_f(next->value())) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // ConcurrentHashTable |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| write_synchonize_on_visible_epoch(Thread* thread) |
| { |
| assert(_resize_lock_owner == thread, "Re-size lock not held"); |
| OrderAccess::fence(); // Prevent below load from floating up. |
| // If no reader saw this version we can skip write_synchronize. |
| if (OrderAccess::load_acquire(&_invisible_epoch) == thread) { |
| return; |
| } |
| assert(_invisible_epoch == NULL, "Two thread doing bulk operations"); |
| // We set this/next version that we are synchronizing for to not published. |
| // A reader will zero this flag if it reads this/next version. |
| OrderAccess::release_store(&_invisible_epoch, thread); |
| GlobalCounter::write_synchronize(); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| try_resize_lock(Thread* locker) |
| { |
| if (_resize_lock->try_lock()) { |
| if (_resize_lock_owner != NULL) { |
| assert(locker != _resize_lock_owner, "Already own lock"); |
| // We got mutex but internal state is locked. |
| _resize_lock->unlock(); |
| return false; |
| } |
| } else { |
| return false; |
| } |
| _invisible_epoch = 0; |
| _resize_lock_owner = locker; |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| lock_resize_lock(Thread* locker) |
| { |
| size_t i = 0; |
| // If lock is hold by some other thread, the chances that it is return quick |
| // is low. So we will prefer yielding. |
| SpinYield yield(1, 512); |
| do { |
| _resize_lock->lock_without_safepoint_check(); |
| // If holder of lock dropped mutex for safepoint mutex might be unlocked, |
| // and _resize_lock_owner will contain the owner. |
| if (_resize_lock_owner != NULL) { |
| assert(locker != _resize_lock_owner, "Already own lock"); |
| // We got mutex but internal state is locked. |
| _resize_lock->unlock(); |
| yield.wait(); |
| } else { |
| break; |
| } |
| } while(true); |
| _resize_lock_owner = locker; |
| _invisible_epoch = 0; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| unlock_resize_lock(Thread* locker) |
| { |
| _invisible_epoch = 0; |
| assert(locker == _resize_lock_owner, "Not unlocked by locker."); |
| _resize_lock_owner = NULL; |
| _resize_lock->unlock(); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| free_nodes() |
| { |
| // We assume we are not MT during freeing. |
| for (size_t node_it = 0; node_it < _table->_size; node_it++) { |
| Bucket* bucket = _table->get_buckets() + node_it; |
| Node* node = bucket->first(); |
| while (node != NULL) { |
| Node* free_node = node; |
| node = node->next(); |
| Node::destroy_node(free_node); |
| } |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_table() const |
| { |
| return OrderAccess::load_acquire(&_table); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_new_table() const |
| { |
| return OrderAccess::load_acquire(&_new_table); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::InternalTable* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| set_table_from_new() |
| { |
| InternalTable* old_table = _table; |
| // Publish the new table. |
| OrderAccess::release_store(&_table, _new_table); |
| // All must see this. |
| GlobalCounter::write_synchronize(); |
| // _new_table not read any more. |
| _new_table = NULL; |
| DEBUG_ONLY(_new_table = (InternalTable*)POISON_PTR;) |
| return old_table; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_grow_range(Thread* thread, size_t start, size_t stop) |
| { |
| assert(stop <= _table->_size, "Outside backing array"); |
| assert(_new_table != NULL, "Grow not proper setup before start"); |
| // The state is also copied here. Hence all buckets in new table will be |
| // locked. I call the siblings odd/even, where even have high bit 0 and odd |
| // have high bit 1. |
| for (size_t even_index = start; even_index < stop; even_index++) { |
| Bucket* bucket = _table->get_bucket(even_index); |
| |
| bucket->lock(); |
| |
| size_t odd_index = even_index + _table->_size; |
| _new_table->get_buckets()[even_index] = *bucket; |
| _new_table->get_buckets()[odd_index] = *bucket; |
| |
| // Moves lockers go to new table, where they will wait until unlock() below. |
| bucket->redirect(); /* Must release stores above */ |
| |
| // When this is done we have separated the nodes into corresponding buckets |
| // in new table. |
| if (!unzip_bucket(thread, _table, _new_table, even_index, odd_index)) { |
| // If bucket is empty, unzip does nothing. |
| // We must make sure readers go to new table before we poison the bucket. |
| DEBUG_ONLY(GlobalCounter::write_synchronize();) |
| } |
| |
| // Unlock for writes into the new table buckets. |
| _new_table->get_bucket(even_index)->unlock(); |
| _new_table->get_bucket(odd_index)->unlock(); |
| |
| DEBUG_ONLY( |
| bucket->release_assign_node_ptr( |
| _table->get_bucket(even_index)->first_ptr(), (Node*)POISON_PTR); |
| ) |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC, typename DELETE_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_remove(Thread* thread, LOOKUP_FUNC& lookup_f, DELETE_FUNC& delete_f) |
| { |
| Bucket* bucket = get_bucket_locked(thread, lookup_f.get_hash()); |
| assert(bucket->is_locked(), "Must be locked."); |
| Node* const volatile * rem_n_prev = bucket->first_ptr(); |
| Node* rem_n = bucket->first(); |
| bool have_dead = false; |
| while (rem_n != NULL) { |
| if (lookup_f.equals(rem_n->value(), &have_dead)) { |
| bucket->release_assign_node_ptr(rem_n_prev, rem_n->next()); |
| break; |
| } else { |
| rem_n_prev = rem_n->next_ptr(); |
| rem_n = rem_n->next(); |
| } |
| } |
| |
| bucket->unlock(); |
| |
| if (rem_n == NULL) { |
| return false; |
| } |
| // Publish the deletion. |
| GlobalCounter::write_synchronize(); |
| delete_f(rem_n->value()); |
| Node::destroy_node(rem_n); |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename EVALUATE_FUNC, typename DELETE_FUNC> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| do_bulk_delete_locked_for(Thread* thread, size_t start_idx, size_t stop_idx, |
| EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f, bool is_mt) |
| { |
| // Here we have resize lock so table is SMR safe, and there is no new |
| // table. Can do this in parallel if we want. |
| assert((is_mt && _resize_lock_owner != NULL) || |
| (!is_mt && _resize_lock_owner == thread), "Re-size lock not held"); |
| Node* ndel[BULK_DELETE_LIMIT]; |
| InternalTable* table = get_table(); |
| assert(start_idx < stop_idx, "Must be"); |
| assert(stop_idx <= _table->_size, "Must be"); |
| // Here manual do critical section since we don't want to take the cost of |
| // locking the bucket if there is nothing to delete. But we can have |
| // concurrent single deletes. The _invisible_epoch can only be used by the |
| // owner of _resize_lock, us here. There we should not changed it in our |
| // own read-side. |
| GlobalCounter::critical_section_begin(thread); |
| for (size_t bucket_it = start_idx; bucket_it < stop_idx; bucket_it++) { |
| Bucket* bucket = table->get_bucket(bucket_it); |
| Bucket* prefetch_bucket = (bucket_it+1) < stop_idx ? |
| table->get_bucket(bucket_it+1) : NULL; |
| |
| if (!HaveDeletables<IsPointer<VALUE>::value, EVALUATE_FUNC>:: |
| have_deletable(bucket, eval_f, prefetch_bucket)) { |
| // Nothing to remove in this bucket. |
| continue; |
| } |
| |
| GlobalCounter::critical_section_end(thread); |
| // We left critical section but the bucket cannot be removed while we hold |
| // the _resize_lock. |
| bucket->lock(); |
| size_t nd = delete_check_nodes(bucket, eval_f, BULK_DELETE_LIMIT, ndel); |
| bucket->unlock(); |
| if (is_mt) { |
| GlobalCounter::write_synchronize(); |
| } else { |
| write_synchonize_on_visible_epoch(thread); |
| } |
| for (size_t node_it = 0; node_it < nd; node_it++) { |
| del_f(ndel[node_it]->value()); |
| Node::destroy_node(ndel[node_it]); |
| DEBUG_ONLY(ndel[node_it] = (Node*)POISON_PTR;) |
| } |
| GlobalCounter::critical_section_begin(thread); |
| } |
| GlobalCounter::critical_section_end(thread); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| delete_in_bucket(Thread* thread, Bucket* bucket, LOOKUP_FUNC& lookup_f) |
| { |
| size_t dels = 0; |
| Node* ndel[BULK_DELETE_LIMIT]; |
| Node* const volatile * rem_n_prev = bucket->first_ptr(); |
| Node* rem_n = bucket->first(); |
| while (rem_n != NULL) { |
| bool is_dead = false; |
| lookup_f.equals(rem_n->value(), &is_dead); |
| if (is_dead) { |
| ndel[dels++] = rem_n; |
| Node* next_node = rem_n->next(); |
| bucket->release_assign_node_ptr(rem_n_prev, next_node); |
| rem_n = next_node; |
| if (dels == BULK_DELETE_LIMIT) { |
| break; |
| } |
| } else { |
| rem_n_prev = rem_n->next_ptr(); |
| rem_n = rem_n->next(); |
| } |
| } |
| if (dels > 0) { |
| GlobalCounter::write_synchronize(); |
| for (size_t node_it = 0; node_it < dels; node_it++) { |
| Node::destroy_node(ndel[node_it]); |
| DEBUG_ONLY(ndel[node_it] = (Node*)POISON_PTR;) |
| } |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Bucket* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_bucket(uintx hash) const |
| { |
| InternalTable* table = get_table(); |
| Bucket* bucket = get_bucket_in(table, hash); |
| if (bucket->have_redirect()) { |
| table = get_new_table(); |
| bucket = get_bucket_in(table, hash); |
| } |
| return bucket; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline typename ConcurrentHashTable<VALUE, CONFIG, F>::Bucket* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_bucket_locked(Thread* thread, const uintx hash) |
| { |
| Bucket* bucket; |
| int i = 0; |
| // SpinYield would be unfair here |
| while(true) { |
| { |
| // We need a critical section to protect the table itself. But if we fail |
| // we must leave critical section otherwise we would deadlock. |
| ScopedCS cs(thread, this); |
| bucket = get_bucket(hash); |
| if (bucket->trylock()) { |
| break; /* ends critical section */ |
| } |
| } /* ends critical section */ |
| if ((++i) == SPINPAUSES_PER_YIELD) { |
| // On contemporary OS yielding will give CPU to another runnable thread if |
| // there is no CPU available. |
| os::naked_yield(); |
| i = 0; |
| } else { |
| SpinPause(); |
| } |
| } |
| return bucket; |
| } |
| |
| // Always called within critical section |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC> |
| typename ConcurrentHashTable<VALUE, CONFIG, F>::Node* |
| ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_node(const Bucket* const bucket, LOOKUP_FUNC& lookup_f, |
| bool* have_dead, size_t* loops) const |
| { |
| size_t loop_count = 0; |
| Node* node = bucket->first(); |
| while (node != NULL) { |
| bool is_dead = false; |
| ++loop_count; |
| if (lookup_f.equals(node->value(), &is_dead)) { |
| break; |
| } |
| if (is_dead && !(*have_dead)) { |
| *have_dead = true; |
| } |
| node = node->next(); |
| } |
| if (loops != NULL) { |
| *loops = loop_count; |
| } |
| return node; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| unzip_bucket(Thread* thread, InternalTable* old_table, |
| InternalTable* new_table, size_t even_index, size_t odd_index) |
| { |
| Node* aux = old_table->get_bucket(even_index)->first(); |
| if (aux == NULL) { |
| // This is an empty bucket and in debug we poison first ptr in bucket. |
| // Therefore we must make sure no readers are looking at this bucket. |
| // If we don't do a write_synch here, caller must do it. |
| return false; |
| } |
| Node* delete_me = NULL; |
| Node* const volatile * even = new_table->get_bucket(even_index)->first_ptr(); |
| Node* const volatile * odd = new_table->get_bucket(odd_index)->first_ptr(); |
| while (aux != NULL) { |
| bool dead_hash = false; |
| size_t aux_hash = CONFIG::get_hash(*aux->value(), &dead_hash); |
| Node* aux_next = aux->next(); |
| if (dead_hash) { |
| delete_me = aux; |
| // This item is dead, move both list to next |
| new_table->get_bucket(odd_index)->release_assign_node_ptr(odd, |
| aux_next); |
| new_table->get_bucket(even_index)->release_assign_node_ptr(even, |
| aux_next); |
| } else { |
| size_t aux_index = bucket_idx_hash(new_table, aux_hash); |
| if (aux_index == even_index) { |
| // This is a even, so move odd to aux/even next |
| new_table->get_bucket(odd_index)->release_assign_node_ptr(odd, |
| aux_next); |
| // Keep in even list |
| even = aux->next_ptr(); |
| } else if (aux_index == odd_index) { |
| // This is a odd, so move odd to aux/odd next |
| new_table->get_bucket(even_index)->release_assign_node_ptr(even, |
| aux_next); |
| // Keep in odd list |
| odd = aux->next_ptr(); |
| } else { |
| fatal("aux_index does not match even or odd indices"); |
| } |
| } |
| aux = aux_next; |
| |
| // We can only move 1 pointer otherwise a reader might be moved to the wrong |
| // chain. E.g. looking for even hash value but got moved to the odd bucket |
| // chain. |
| write_synchonize_on_visible_epoch(thread); |
| if (delete_me != NULL) { |
| Node::destroy_node(delete_me); |
| delete_me = NULL; |
| } |
| } |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_shrink_prolog(Thread* thread, size_t log2_size) |
| { |
| if (!try_resize_lock(thread)) { |
| return false; |
| } |
| assert(_resize_lock_owner == thread, "Re-size lock not held"); |
| if (_table->_log2_size == _log2_start_size || |
| _table->_log2_size <= log2_size) { |
| unlock_resize_lock(thread); |
| return false; |
| } |
| _new_table = new InternalTable(_table->_log2_size - 1); |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_shrink_epilog(Thread* thread) |
| { |
| assert(_resize_lock_owner == thread, "Re-size lock not held"); |
| |
| InternalTable* old_table = set_table_from_new(); |
| _size_limit_reached = false; |
| unlock_resize_lock(thread); |
| #ifdef ASSERT |
| for (size_t i = 0; i < old_table->_size; i++) { |
| assert(old_table->get_bucket(i++)->first() == POISON_PTR, |
| "No poison found"); |
| } |
| #endif |
| // ABA safe, old_table not visible to any other threads. |
| delete old_table; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_shrink_range(Thread* thread, size_t start, size_t stop) |
| { |
| // The state is also copied here. |
| // Hence all buckets in new table will be locked. |
| for (size_t bucket_it = start; bucket_it < stop; bucket_it++) { |
| size_t even_hash_index = bucket_it; // High bit 0 |
| size_t odd_hash_index = bucket_it + _new_table->_size; // High bit 1 |
| |
| Bucket* b_old_even = _table->get_bucket(even_hash_index); |
| Bucket* b_old_odd = _table->get_bucket(odd_hash_index); |
| |
| b_old_even->lock(); |
| b_old_odd->lock(); |
| |
| _new_table->get_buckets()[bucket_it] = *b_old_even; |
| |
| // Put chains together. |
| _new_table->get_bucket(bucket_it)-> |
| release_assign_last_node_next(*(b_old_odd->first_ptr())); |
| |
| b_old_even->redirect(); |
| b_old_odd->redirect(); |
| |
| write_synchonize_on_visible_epoch(thread); |
| |
| // Unlock for writes into new smaller table. |
| _new_table->get_bucket(bucket_it)->unlock(); |
| |
| DEBUG_ONLY(b_old_even->release_assign_node_ptr(b_old_even->first_ptr(), |
| (Node*)POISON_PTR);) |
| DEBUG_ONLY(b_old_odd->release_assign_node_ptr(b_old_odd->first_ptr(), |
| (Node*)POISON_PTR);) |
| } |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_shrink(Thread* thread, size_t log2_size) |
| { |
| if (!internal_shrink_prolog(thread, log2_size)) { |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| return false; |
| } |
| assert(_resize_lock_owner == thread, "Should be locked by me"); |
| internal_shrink_range(thread, 0, _new_table->_size); |
| internal_shrink_epilog(thread); |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_grow_prolog(Thread* thread, size_t log2_size) |
| { |
| // This double checking of _size_limit_reached/is_max_size_reached() |
| // we only do in grow path, since grow means high load on table |
| // while shrink means low load. |
| if (is_max_size_reached()) { |
| return false; |
| } |
| if (!try_resize_lock(thread)) { |
| // Either we have an ongoing resize or an operation which doesn't want us |
| // to resize now. |
| return false; |
| } |
| if (is_max_size_reached() || _table->_log2_size >= log2_size) { |
| unlock_resize_lock(thread); |
| return false; |
| } |
| |
| _new_table = new InternalTable(_table->_log2_size + 1); |
| |
| if (_new_table->_log2_size == _log2_size_limit) { |
| _size_limit_reached = true; |
| } |
| |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_grow_epilog(Thread* thread) |
| { |
| assert(_resize_lock_owner == thread, "Should be locked"); |
| |
| InternalTable* old_table = set_table_from_new(); |
| unlock_resize_lock(thread); |
| #ifdef ASSERT |
| for (size_t i = 0; i < old_table->_size; i++) { |
| assert(old_table->get_bucket(i++)->first() == POISON_PTR, |
| "No poison found"); |
| } |
| #endif |
| // ABA safe, old_table not visible to any other threads. |
| delete old_table; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_grow(Thread* thread, size_t log2_size) |
| { |
| if (!internal_grow_prolog(thread, log2_size)) { |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| return false; |
| } |
| assert(_resize_lock_owner == thread, "Should be locked by me"); |
| internal_grow_range(thread, 0, _table->_size); |
| internal_grow_epilog(thread); |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| return true; |
| } |
| |
| // Always called within critical section |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC> |
| inline VALUE* ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_get(Thread* thread, LOOKUP_FUNC& lookup_f, bool* grow_hint) |
| { |
| bool clean = false; |
| size_t loops = 0; |
| VALUE* ret = NULL; |
| |
| const Bucket* bucket = get_bucket(lookup_f.get_hash()); |
| Node* node = get_node(bucket, lookup_f, &clean, &loops); |
| if (node != NULL) { |
| ret = node->value(); |
| } |
| if (grow_hint != NULL) { |
| *grow_hint = loops > _grow_hint; |
| } |
| |
| return ret; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC, typename VALUE_FUNC, typename CALLBACK_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| internal_insert(Thread* thread, LOOKUP_FUNC& lookup_f, VALUE_FUNC& value_f, |
| CALLBACK_FUNC& callback, bool* grow_hint) |
| { |
| bool ret = false; |
| bool clean = false; |
| bool locked; |
| size_t loops = 0; |
| size_t i = 0; |
| Node* new_node = NULL; |
| uintx hash = lookup_f.get_hash(); |
| while (true) { |
| { |
| ScopedCS cs(thread, this); /* protected the table/bucket */ |
| Bucket* bucket = get_bucket(hash); |
| |
| Node* first_at_start = bucket->first(); |
| Node* old = get_node(bucket, lookup_f, &clean, &loops); |
| if (old == NULL) { |
| // No duplicate found. |
| if (new_node == NULL) { |
| new_node = Node::create_node(value_f(), first_at_start); |
| } else { |
| new_node->set_next(first_at_start); |
| } |
| if (bucket->cas_first(new_node, first_at_start)) { |
| callback(true, new_node->value()); |
| new_node = NULL; |
| ret = true; |
| break; /* leave critical section */ |
| } |
| // CAS failed we must leave critical section and retry. |
| locked = bucket->is_locked(); |
| } else { |
| // There is a duplicate. |
| callback(false, old->value()); |
| break; /* leave critical section */ |
| } |
| } /* leave critical section */ |
| i++; |
| if (locked) { |
| os::naked_yield(); |
| } else { |
| SpinPause(); |
| } |
| } |
| |
| if (new_node != NULL) { |
| // CAS failed and a duplicate was inserted, we must free this node. |
| Node::destroy_node(new_node); |
| } else if (i == 0 && clean) { |
| // We only do cleaning on fast inserts. |
| Bucket* bucket = get_bucket_locked(thread, lookup_f.get_hash()); |
| assert(bucket->is_locked(), "Must be locked."); |
| delete_in_bucket(thread, bucket, lookup_f); |
| bucket->unlock(); |
| } |
| |
| if (grow_hint != NULL) { |
| *grow_hint = loops > _grow_hint; |
| } |
| |
| return ret; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| visit_nodes(Bucket* bucket, FUNC& visitor_f) |
| { |
| Node* current_node = bucket->first(); |
| while (current_node != NULL) { |
| if (!visitor_f(current_node->value())) { |
| return false; |
| } |
| current_node = current_node->next(); |
| } |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename FUNC> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| do_scan_locked(Thread* thread, FUNC& scan_f) |
| { |
| assert(_resize_lock_owner == thread, "Re-size lock not held"); |
| // We can do a critical section over the entire loop but that would block |
| // updates for a long time. Instead we choose to block resizes. |
| InternalTable* table = get_table(); |
| for (size_t bucket_it = 0; bucket_it < table->_size; bucket_it++) { |
| ScopedCS cs(thread, this); |
| if (!visit_nodes(table->get_bucket(bucket_it), scan_f)) { |
| break; /* ends critical section */ |
| } |
| } /* ends critical section */ |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename EVALUATE_FUNC> |
| inline size_t ConcurrentHashTable<VALUE, CONFIG, F>:: |
| delete_check_nodes(Bucket* bucket, EVALUATE_FUNC& eval_f, |
| size_t num_del, Node** ndel) |
| { |
| size_t dels = 0; |
| Node* const volatile * rem_n_prev = bucket->first_ptr(); |
| Node* rem_n = bucket->first(); |
| while (rem_n != NULL) { |
| if (eval_f(rem_n->value())) { |
| ndel[dels++] = rem_n; |
| Node* next_node = rem_n->next(); |
| bucket->release_assign_node_ptr(rem_n_prev, next_node); |
| rem_n = next_node; |
| if (dels == num_del) { |
| break; |
| } |
| } else { |
| rem_n_prev = rem_n->next_ptr(); |
| rem_n = rem_n->next(); |
| } |
| } |
| return dels; |
| } |
| |
| // Constructor |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline ConcurrentHashTable<VALUE, CONFIG, F>:: |
| ConcurrentHashTable(size_t log2size, size_t log2size_limit, size_t grow_hint) |
| : _new_table(NULL), _log2_start_size(log2size), |
| _log2_size_limit(log2size_limit), _grow_hint(grow_hint), |
| _size_limit_reached(false), _resize_lock_owner(NULL), |
| _invisible_epoch(0) |
| { |
| _resize_lock = |
| new Mutex(Mutex::leaf, "ConcurrentHashTable", false, |
| Monitor::_safepoint_check_never); |
| _table = new InternalTable(log2size); |
| assert(log2size_limit >= log2size, "bad ergo"); |
| _size_limit_reached = _table->_log2_size == _log2_size_limit; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline ConcurrentHashTable<VALUE, CONFIG, F>:: |
| ~ConcurrentHashTable() |
| { |
| delete _resize_lock; |
| free_nodes(); |
| delete _table; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline size_t ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_size_log2(Thread* thread) |
| { |
| ScopedCS cs(thread, this); |
| return _table->_log2_size; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| shrink(Thread* thread, size_t size_limit_log2) |
| { |
| size_t tmp = size_limit_log2 == 0 ? _log2_start_size : size_limit_log2; |
| bool ret = internal_shrink(thread, tmp); |
| return ret; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| grow(Thread* thread, size_t size_limit_log2) |
| { |
| size_t tmp = size_limit_log2 == 0 ? _log2_size_limit : size_limit_log2; |
| return internal_grow(thread, tmp); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC, typename FOUND_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get(Thread* thread, LOOKUP_FUNC& lookup_f, FOUND_FUNC& found_f, bool* grow_hint) |
| { |
| bool ret = false; |
| ScopedCS cs(thread, this); |
| VALUE* val = internal_get(thread, lookup_f, grow_hint); |
| if (val != NULL) { |
| found_f(val); |
| ret = true; |
| } |
| return ret; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename LOOKUP_FUNC> |
| inline VALUE ConcurrentHashTable<VALUE, CONFIG, F>:: |
| get_copy(Thread* thread, LOOKUP_FUNC& lookup_f, bool* grow_hint) |
| { |
| ScopedCS cs(thread, this); |
| VALUE* val = internal_get(thread, lookup_f, grow_hint); |
| return val != NULL ? *val : CONFIG::notfound(); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| unsafe_insert(const VALUE& value) { |
| bool dead_hash = false; |
| size_t hash = CONFIG::get_hash(value, &dead_hash); |
| if (dead_hash) { |
| return false; |
| } |
| // This is an unsafe operation. |
| InternalTable* table = get_table(); |
| Bucket* bucket = get_bucket_in(table, hash); |
| assert(!bucket->have_redirect() && !bucket->is_locked(), "bad"); |
| Node* new_node = Node::create_node(value, bucket->first()); |
| if (!bucket->cas_first(new_node, bucket->first())) { |
| assert(false, "bad"); |
| } |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename SCAN_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| try_scan(Thread* thread, SCAN_FUNC& scan_f) |
| { |
| if (!try_resize_lock(thread)) { |
| return false; |
| } |
| do_scan_locked(thread, scan_f); |
| unlock_resize_lock(thread); |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename SCAN_FUNC> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| do_scan(Thread* thread, SCAN_FUNC& scan_f) |
| { |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| lock_resize_lock(thread); |
| do_scan_locked(thread, scan_f); |
| unlock_resize_lock(thread); |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename EVALUATE_FUNC, typename DELETE_FUNC> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| try_bulk_delete(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) |
| { |
| if (!try_resize_lock(thread)) { |
| return false; |
| } |
| do_bulk_delete_locked(thread, eval_f, del_f); |
| unlock_resize_lock(thread); |
| assert(_resize_lock_owner != thread, "Re-size lock held"); |
| return true; |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename EVALUATE_FUNC, typename DELETE_FUNC> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| bulk_delete(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) |
| { |
| lock_resize_lock(thread); |
| do_bulk_delete_locked(thread, eval_f, del_f); |
| unlock_resize_lock(thread); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| template <typename VALUE_SIZE_FUNC> |
| inline void ConcurrentHashTable<VALUE, CONFIG, F>:: |
| statistics_to(Thread* thread, VALUE_SIZE_FUNC& vs_f, |
| outputStream* st, const char* table_name) |
| { |
| NumberSeq summary; |
| size_t literal_bytes = 0; |
| if (!try_resize_lock(thread)) { |
| st->print_cr("statistics unavailable at this moment"); |
| return; |
| } |
| |
| InternalTable* table = get_table(); |
| for (size_t bucket_it = 0; bucket_it < table->_size; bucket_it++) { |
| ScopedCS cs(thread, this); |
| size_t count = 0; |
| Bucket* bucket = table->get_bucket(bucket_it); |
| if (bucket->have_redirect() || bucket->is_locked()) { |
| continue; |
| } |
| Node* current_node = bucket->first(); |
| while (current_node != NULL) { |
| ++count; |
| literal_bytes += vs_f(current_node->value()); |
| current_node = current_node->next(); |
| } |
| summary.add((double)count); |
| } |
| |
| double num_buckets = summary.num(); |
| double num_entries = summary.sum(); |
| |
| size_t bucket_bytes = num_buckets * sizeof(Bucket); |
| size_t entry_bytes = num_entries * sizeof(Node); |
| size_t total_bytes = literal_bytes + bucket_bytes + entry_bytes; |
| |
| size_t bucket_size = (num_buckets <= 0) ? 0 : (bucket_bytes / num_buckets); |
| size_t entry_size = (num_entries <= 0) ? 0 : (entry_bytes / num_entries); |
| |
| st->print_cr("%s statistics:", table_name); |
| st->print_cr("Number of buckets : %9" PRIuPTR " = %9" PRIuPTR |
| " bytes, each " SIZE_FORMAT, |
| (size_t)num_buckets, bucket_bytes, bucket_size); |
| st->print_cr("Number of entries : %9" PRIuPTR " = %9" PRIuPTR |
| " bytes, each " SIZE_FORMAT, |
| (size_t)num_entries, entry_bytes, entry_size); |
| if (literal_bytes != 0) { |
| double literal_avg = (num_entries <= 0) ? 0 : (literal_bytes / num_entries); |
| st->print_cr("Number of literals : %9" PRIuPTR " = %9" PRIuPTR |
| " bytes, avg %7.3f", |
| (size_t)num_entries, literal_bytes, literal_avg); |
| } |
| st->print_cr("Total footprsize_t : %9s = %9" PRIuPTR " bytes", "" |
| , total_bytes); |
| st->print_cr("Average bucket size : %9.3f", summary.avg()); |
| st->print_cr("Variance of bucket size : %9.3f", summary.variance()); |
| st->print_cr("Std. dev. of bucket size: %9.3f", summary.sd()); |
| st->print_cr("Maximum bucket size : %9" PRIuPTR, |
| (size_t)summary.maximum()); |
| unlock_resize_lock(thread); |
| } |
| |
| template <typename VALUE, typename CONFIG, MEMFLAGS F> |
| inline bool ConcurrentHashTable<VALUE, CONFIG, F>:: |
| try_move_nodes_to(Thread* thread, ConcurrentHashTable<VALUE, CONFIG, F>* to_cht) |
| { |
| if (!try_resize_lock(thread)) { |
| return false; |
| } |
| assert(_new_table == NULL || _new_table == POISON_PTR, "Must be NULL"); |
| for (size_t bucket_it = 0; bucket_it < _table->_size; bucket_it++) { |
| Bucket* bucket = _table->get_bucket(bucket_it); |
| assert(!bucket->have_redirect() && !bucket->is_locked(), "Table must be uncontended"); |
| while (bucket->first() != NULL) { |
| Node* move_node = bucket->first(); |
| bool ok = bucket->cas_first(move_node->next(), move_node); |
| assert(ok, "Uncontended cas must work"); |
| bool dead_hash = false; |
| size_t insert_hash = CONFIG::get_hash(*move_node->value(), &dead_hash); |
| if (!dead_hash) { |
| Bucket* insert_bucket = to_cht->get_bucket(insert_hash); |
| assert(!bucket->have_redirect() && !bucket->is_locked(), "Not bit should be present"); |
| move_node->set_next(insert_bucket->first()); |
| ok = insert_bucket->cas_first(move_node, insert_bucket->first()); |
| assert(ok, "Uncontended cas must work"); |
| } |
| } |
| } |
| unlock_resize_lock(thread); |
| return true; |
| } |
| |
| #endif // include guard |