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/*
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* Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "classfile/altHashing.hpp"
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#include "classfile/javaClasses.inline.hpp"
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#include "gc/shared/stringdedup/stringDedup.hpp"
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#include "gc/shared/stringdedup/stringDedupTable.hpp"
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#include "gc/shared/suspendibleThreadSet.hpp"
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#include "logging/log.hpp"
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#include "memory/padded.inline.hpp"
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#include "oops/access.inline.hpp"
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#include "oops/arrayOop.inline.hpp"
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#include "oops/oop.inline.hpp"
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#include "oops/typeArrayOop.hpp"
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#include "runtime/mutexLocker.hpp"
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#include "runtime/safepointVerifiers.hpp"
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//
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// List of deduplication table entries. Links table
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// entries together using their _next fields.
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//
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class StringDedupEntryList : public CHeapObj<mtGC> {
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private:
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StringDedupEntry* _list;
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size_t _length;
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public:
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StringDedupEntryList() :
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_list(NULL),
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_length(0) {
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}
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void add(StringDedupEntry* entry) {
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entry->set_next(_list);
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_list = entry;
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_length++;
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}
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StringDedupEntry* remove() {
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StringDedupEntry* entry = _list;
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if (entry != NULL) {
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_list = entry->next();
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_length--;
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}
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return entry;
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}
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StringDedupEntry* remove_all() {
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StringDedupEntry* list = _list;
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_list = NULL;
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return list;
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}
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size_t length() {
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return _length;
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}
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};
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//
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// Cache of deduplication table entries. This cache provides fast allocation and
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// reuse of table entries to lower the pressure on the underlying allocator.
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// But more importantly, it provides fast/deferred freeing of table entries. This
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// is important because freeing of table entries is done during stop-the-world
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// phases and it is not uncommon for large number of entries to be freed at once.
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// Tables entries that are freed during these phases are placed onto a freelist in
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// the cache. The deduplication thread, which executes in a concurrent phase, will
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// later reuse or free the underlying memory for these entries.
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//
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// The cache allows for single-threaded allocations and multi-threaded frees.
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// Allocations are synchronized by StringDedupTable_lock as part of a table
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// modification.
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//
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class StringDedupEntryCache : public CHeapObj<mtGC> {
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private:
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// One cache/overflow list per GC worker to allow lock less freeing of
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// entries while doing a parallel scan of the table. Using PaddedEnd to
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// avoid false sharing.
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size_t _nlists;
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size_t _max_list_length;
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PaddedEnd<StringDedupEntryList>* _cached;
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PaddedEnd<StringDedupEntryList>* _overflowed;
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public:
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StringDedupEntryCache(size_t max_size);
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~StringDedupEntryCache();
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// Set max number of table entries to cache.
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void set_max_size(size_t max_size);
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// Get a table entry from the cache, or allocate a new entry if the cache is empty.
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StringDedupEntry* alloc();
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// Insert a table entry into the cache.
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void free(StringDedupEntry* entry, uint worker_id);
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// Returns current number of entries in the cache.
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size_t size();
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// Deletes overflowed entries.
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void delete_overflowed();
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};
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StringDedupEntryCache::StringDedupEntryCache(size_t max_size) :
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_nlists(ParallelGCThreads),
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_max_list_length(0),
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_cached(PaddedArray<StringDedupEntryList, mtGC>::create_unfreeable((uint)_nlists)),
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_overflowed(PaddedArray<StringDedupEntryList, mtGC>::create_unfreeable((uint)_nlists)) {
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set_max_size(max_size);
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}
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StringDedupEntryCache::~StringDedupEntryCache() {
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ShouldNotReachHere();
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}
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void StringDedupEntryCache::set_max_size(size_t size) {
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_max_list_length = size / _nlists;
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}
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StringDedupEntry* StringDedupEntryCache::alloc() {
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for (size_t i = 0; i < _nlists; i++) {
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StringDedupEntry* entry = _cached[i].remove();
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if (entry != NULL) {
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return entry;
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}
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}
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return new StringDedupEntry();
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}
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void StringDedupEntryCache::free(StringDedupEntry* entry, uint worker_id) {
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assert(entry->obj() != NULL, "Double free");
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assert(worker_id < _nlists, "Invalid worker id");
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entry->set_obj(NULL);
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entry->set_hash(0);
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if (_cached[worker_id].length() < _max_list_length) {
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// Cache is not full
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_cached[worker_id].add(entry);
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} else {
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// Cache is full, add to overflow list for later deletion
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_overflowed[worker_id].add(entry);
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}
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}
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size_t StringDedupEntryCache::size() {
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size_t size = 0;
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for (size_t i = 0; i < _nlists; i++) {
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size += _cached[i].length();
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}
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return size;
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}
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void StringDedupEntryCache::delete_overflowed() {
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double start = os::elapsedTime();
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uintx count = 0;
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for (size_t i = 0; i < _nlists; i++) {
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StringDedupEntry* entry;
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{
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// The overflow list can be modified during safepoints, therefore
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// we temporarily join the suspendible thread set while removing
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// all entries from the list.
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SuspendibleThreadSetJoiner sts_join;
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entry = _overflowed[i].remove_all();
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}
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// Delete all entries
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while (entry != NULL) {
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StringDedupEntry* next = entry->next();
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delete entry;
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entry = next;
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count++;
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}
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}
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double end = os::elapsedTime();
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log_trace(gc, stringdedup)("Deleted " UINTX_FORMAT " entries, " STRDEDUP_TIME_FORMAT_MS,
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count, STRDEDUP_TIME_PARAM_MS(end - start));
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}
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StringDedupTable* StringDedupTable::_table = NULL;
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StringDedupEntryCache* StringDedupTable::_entry_cache = NULL;
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const size_t StringDedupTable::_min_size = (1 << 10); // 1024
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const size_t StringDedupTable::_max_size = (1 << 24); // 16777216
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const double StringDedupTable::_grow_load_factor = 2.0; // Grow table at 200% load
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const double StringDedupTable::_shrink_load_factor = _grow_load_factor / 3.0; // Shrink table at 67% load
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const double StringDedupTable::_max_cache_factor = 0.1; // Cache a maximum of 10% of the table size
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const uintx StringDedupTable::_rehash_multiple = 60; // Hash bucket has 60 times more collisions than expected
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const uintx StringDedupTable::_rehash_threshold = (uintx)(_rehash_multiple * _grow_load_factor);
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uintx StringDedupTable::_entries_added = 0;
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uintx StringDedupTable::_entries_removed = 0;
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uintx StringDedupTable::_resize_count = 0;
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uintx StringDedupTable::_rehash_count = 0;
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StringDedupTable* StringDedupTable::_resized_table = NULL;
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StringDedupTable* StringDedupTable::_rehashed_table = NULL;
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volatile size_t StringDedupTable::_claimed_index = 0;
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StringDedupTable::StringDedupTable(size_t size, jint hash_seed) :
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_size(size),
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_entries(0),
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_grow_threshold((uintx)(size * _grow_load_factor)),
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_shrink_threshold((uintx)(size * _shrink_load_factor)),
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_rehash_needed(false),
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_hash_seed(hash_seed) {
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assert(is_power_of_2(size), "Table size must be a power of 2");
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_buckets = NEW_C_HEAP_ARRAY(StringDedupEntry*, _size, mtGC);
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memset(_buckets, 0, _size * sizeof(StringDedupEntry*));
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}
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StringDedupTable::~StringDedupTable() {
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FREE_C_HEAP_ARRAY(G1StringDedupEntry*, _buckets);
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}
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void StringDedupTable::create() {
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assert(_table == NULL, "One string deduplication table allowed");
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_entry_cache = new StringDedupEntryCache(_min_size * _max_cache_factor);
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_table = new StringDedupTable(_min_size);
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}
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void StringDedupTable::add(typeArrayOop value, bool latin1, unsigned int hash, StringDedupEntry** list) {
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StringDedupEntry* entry = _entry_cache->alloc();
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entry->set_obj(value);
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entry->set_hash(hash);
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entry->set_latin1(latin1);
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entry->set_next(*list);
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*list = entry;
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_entries++;
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}
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void StringDedupTable::remove(StringDedupEntry** pentry, uint worker_id) {
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StringDedupEntry* entry = *pentry;
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*pentry = entry->next();
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_entry_cache->free(entry, worker_id);
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}
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void StringDedupTable::transfer(StringDedupEntry** pentry, StringDedupTable* dest) {
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StringDedupEntry* entry = *pentry;
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*pentry = entry->next();
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unsigned int hash = entry->hash();
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size_t index = dest->hash_to_index(hash);
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StringDedupEntry** list = dest->bucket(index);
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entry->set_next(*list);
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*list = entry;
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}
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bool StringDedupTable::equals(typeArrayOop value1, typeArrayOop value2) {
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return (oopDesc::equals(value1, value2) ||
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(value1->length() == value2->length() &&
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(!memcmp(value1->base(T_BYTE),
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value2->base(T_BYTE),
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value1->length() * sizeof(jbyte)))));
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}
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typeArrayOop StringDedupTable::lookup(typeArrayOop value, bool latin1, unsigned int hash,
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StringDedupEntry** list, uintx &count) {
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for (StringDedupEntry* entry = *list; entry != NULL; entry = entry->next()) {
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if (entry->hash() == hash && entry->latin1() == latin1) {
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typeArrayOop existing_value = entry->obj();
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if (equals(value, existing_value)) {
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// Apply proper barrier to make sure it is kept alive. Concurrent mark might
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// otherwise declare it dead if there are no other strong references to this object.
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oop* obj_addr = (oop*)entry->obj_addr();
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oop obj = RootAccess<IN_CONCURRENT_ROOT | ON_WEAK_OOP_REF>::oop_load(obj_addr);
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return typeArrayOop(obj);
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}
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}
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count++;
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}
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// Not found
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return NULL;
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}
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typeArrayOop StringDedupTable::lookup_or_add_inner(typeArrayOop value, bool latin1, unsigned int hash) {
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size_t index = hash_to_index(hash);
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StringDedupEntry** list = bucket(index);
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uintx count = 0;
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// Lookup in list
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typeArrayOop existing_value = lookup(value, latin1, hash, list, count);
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// Check if rehash is needed
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if (count > _rehash_threshold) {
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_rehash_needed = true;
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}
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if (existing_value == NULL) {
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// Not found, add new entry
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add(value, latin1, hash, list);
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// Update statistics
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_entries_added++;
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}
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return existing_value;
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}
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unsigned int StringDedupTable::hash_code(typeArrayOop value, bool latin1) {
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unsigned int hash;
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int length = value->length();
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if (latin1) {
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const jbyte* data = (jbyte*)value->base(T_BYTE);
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if (use_java_hash()) {
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hash = java_lang_String::hash_code(data, length);
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} else {
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hash = AltHashing::murmur3_32(_table->_hash_seed, data, length);
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}
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} else {
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length /= sizeof(jchar) / sizeof(jbyte); // Convert number of bytes to number of chars
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const jchar* data = (jchar*)value->base(T_CHAR);
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if (use_java_hash()) {
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hash = java_lang_String::hash_code(data, length);
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} else {
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hash = AltHashing::murmur3_32(_table->_hash_seed, data, length);
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}
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}
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return hash;
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}
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void StringDedupTable::deduplicate(oop java_string, StringDedupStat* stat) {
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assert(java_lang_String::is_instance(java_string), "Must be a string");
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NoSafepointVerifier nsv;
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stat->inc_inspected();
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typeArrayOop value = java_lang_String::value(java_string);
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if (value == NULL) {
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// String has no value
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stat->inc_skipped();
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return;
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}
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bool latin1 = java_lang_String::is_latin1(java_string);
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unsigned int hash = 0;
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if (use_java_hash()) {
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// Get hash code from cache
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hash = java_lang_String::hash(java_string);
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}
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if (hash == 0) {
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// Compute hash
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hash = hash_code(value, latin1);
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stat->inc_hashed();
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if (use_java_hash() && hash != 0) {
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// Store hash code in cache
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java_lang_String::set_hash(java_string, hash);
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}
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}
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typeArrayOop existing_value = lookup_or_add(value, latin1, hash);
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if (existing_value == value) {
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// Same value, already known
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stat->inc_known();
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return;
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}
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// Get size of value array
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uintx size_in_bytes = value->size() * HeapWordSize;
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stat->inc_new(size_in_bytes);
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if (existing_value != NULL) {
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// Existing value found, deduplicate string
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java_lang_String::set_value(java_string, existing_value);
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stat->deduped(value, size_in_bytes);
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}
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}
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bool StringDedupTable::is_resizing() {
|
|
398 |
return _resized_table != NULL;
|
|
399 |
}
|
|
400 |
|
|
401 |
bool StringDedupTable::is_rehashing() {
|
|
402 |
return _rehashed_table != NULL;
|
|
403 |
}
|
|
404 |
|
|
405 |
StringDedupTable* StringDedupTable::prepare_resize() {
|
|
406 |
size_t size = _table->_size;
|
|
407 |
|
|
408 |
// Check if the hashtable needs to be resized
|
|
409 |
if (_table->_entries > _table->_grow_threshold) {
|
|
410 |
// Grow table, double the size
|
|
411 |
size *= 2;
|
|
412 |
if (size > _max_size) {
|
|
413 |
// Too big, don't resize
|
|
414 |
return NULL;
|
|
415 |
}
|
|
416 |
} else if (_table->_entries < _table->_shrink_threshold) {
|
|
417 |
// Shrink table, half the size
|
|
418 |
size /= 2;
|
|
419 |
if (size < _min_size) {
|
|
420 |
// Too small, don't resize
|
|
421 |
return NULL;
|
|
422 |
}
|
|
423 |
} else if (StringDeduplicationResizeALot) {
|
|
424 |
// Force grow
|
|
425 |
size *= 2;
|
|
426 |
if (size > _max_size) {
|
|
427 |
// Too big, force shrink instead
|
|
428 |
size /= 4;
|
|
429 |
}
|
|
430 |
} else {
|
|
431 |
// Resize not needed
|
|
432 |
return NULL;
|
|
433 |
}
|
|
434 |
|
|
435 |
// Update statistics
|
|
436 |
_resize_count++;
|
|
437 |
|
|
438 |
// Update max cache size
|
|
439 |
_entry_cache->set_max_size(size * _max_cache_factor);
|
|
440 |
|
|
441 |
// Allocate the new table. The new table will be populated by workers
|
|
442 |
// calling unlink_or_oops_do() and finally installed by finish_resize().
|
|
443 |
return new StringDedupTable(size, _table->_hash_seed);
|
|
444 |
}
|
|
445 |
|
|
446 |
void StringDedupTable::finish_resize(StringDedupTable* resized_table) {
|
|
447 |
assert(resized_table != NULL, "Invalid table");
|
|
448 |
|
|
449 |
resized_table->_entries = _table->_entries;
|
|
450 |
|
|
451 |
// Free old table
|
|
452 |
delete _table;
|
|
453 |
|
|
454 |
// Install new table
|
|
455 |
_table = resized_table;
|
|
456 |
}
|
|
457 |
|
|
458 |
void StringDedupTable::unlink_or_oops_do(StringDedupUnlinkOrOopsDoClosure* cl, uint worker_id) {
|
|
459 |
// The table is divided into partitions to allow lock-less parallel processing by
|
|
460 |
// multiple worker threads. A worker thread first claims a partition, which ensures
|
|
461 |
// exclusive access to that part of the table, then continues to process it. To allow
|
|
462 |
// shrinking of the table in parallel we also need to make sure that the same worker
|
|
463 |
// thread processes all partitions where entries will hash to the same destination
|
|
464 |
// partition. Since the table size is always a power of two and we always shrink by
|
|
465 |
// dividing the table in half, we know that for a given partition there is only one
|
|
466 |
// other partition whoes entries will hash to the same destination partition. That
|
|
467 |
// other partition is always the sibling partition in the second half of the table.
|
|
468 |
// For example, if the table is divided into 8 partitions, the sibling of partition 0
|
|
469 |
// is partition 4, the sibling of partition 1 is partition 5, etc.
|
|
470 |
size_t table_half = _table->_size / 2;
|
|
471 |
|
|
472 |
// Let each partition be one page worth of buckets
|
|
473 |
size_t partition_size = MIN2(table_half, os::vm_page_size() / sizeof(StringDedupEntry*));
|
|
474 |
assert(table_half % partition_size == 0, "Invalid partition size");
|
|
475 |
|
|
476 |
// Number of entries removed during the scan
|
|
477 |
uintx removed = 0;
|
|
478 |
|
|
479 |
for (;;) {
|
|
480 |
// Grab next partition to scan
|
|
481 |
size_t partition_begin = claim_table_partition(partition_size);
|
|
482 |
size_t partition_end = partition_begin + partition_size;
|
|
483 |
if (partition_begin >= table_half) {
|
|
484 |
// End of table
|
|
485 |
break;
|
|
486 |
}
|
|
487 |
|
|
488 |
// Scan the partition followed by the sibling partition in the second half of the table
|
|
489 |
removed += unlink_or_oops_do(cl, partition_begin, partition_end, worker_id);
|
|
490 |
removed += unlink_or_oops_do(cl, table_half + partition_begin, table_half + partition_end, worker_id);
|
|
491 |
}
|
|
492 |
|
|
493 |
// Delayed update to avoid contention on the table lock
|
|
494 |
if (removed > 0) {
|
|
495 |
MutexLockerEx ml(StringDedupTable_lock, Mutex::_no_safepoint_check_flag);
|
|
496 |
_table->_entries -= removed;
|
|
497 |
_entries_removed += removed;
|
|
498 |
}
|
|
499 |
}
|
|
500 |
|
|
501 |
uintx StringDedupTable::unlink_or_oops_do(StringDedupUnlinkOrOopsDoClosure* cl,
|
|
502 |
size_t partition_begin,
|
|
503 |
size_t partition_end,
|
|
504 |
uint worker_id) {
|
|
505 |
uintx removed = 0;
|
|
506 |
for (size_t bucket = partition_begin; bucket < partition_end; bucket++) {
|
|
507 |
StringDedupEntry** entry = _table->bucket(bucket);
|
|
508 |
while (*entry != NULL) {
|
|
509 |
oop* p = (oop*)(*entry)->obj_addr();
|
|
510 |
if (cl->is_alive(*p)) {
|
|
511 |
cl->keep_alive(p);
|
|
512 |
if (is_resizing()) {
|
|
513 |
// We are resizing the table, transfer entry to the new table
|
|
514 |
_table->transfer(entry, _resized_table);
|
|
515 |
} else {
|
|
516 |
if (is_rehashing()) {
|
|
517 |
// We are rehashing the table, rehash the entry but keep it
|
|
518 |
// in the table. We can't transfer entries into the new table
|
|
519 |
// at this point since we don't have exclusive access to all
|
|
520 |
// destination partitions. finish_rehash() will do a single
|
|
521 |
// threaded transfer of all entries.
|
|
522 |
typeArrayOop value = (typeArrayOop)*p;
|
|
523 |
bool latin1 = (*entry)->latin1();
|
|
524 |
unsigned int hash = hash_code(value, latin1);
|
|
525 |
(*entry)->set_hash(hash);
|
|
526 |
}
|
|
527 |
|
|
528 |
// Move to next entry
|
|
529 |
entry = (*entry)->next_addr();
|
|
530 |
}
|
|
531 |
} else {
|
|
532 |
// Not alive, remove entry from table
|
|
533 |
_table->remove(entry, worker_id);
|
|
534 |
removed++;
|
|
535 |
}
|
|
536 |
}
|
|
537 |
}
|
|
538 |
|
|
539 |
return removed;
|
|
540 |
}
|
|
541 |
|
|
542 |
void StringDedupTable::gc_prologue(bool resize_and_rehash_table) {
|
|
543 |
assert(!is_resizing() && !is_rehashing(), "Already in progress?");
|
|
544 |
|
|
545 |
_claimed_index = 0;
|
|
546 |
if (resize_and_rehash_table) {
|
|
547 |
// If both resize and rehash is needed, only do resize. Rehash of
|
|
548 |
// the table will eventually happen if the situation persists.
|
|
549 |
_resized_table = StringDedupTable::prepare_resize();
|
|
550 |
if (!is_resizing()) {
|
|
551 |
_rehashed_table = StringDedupTable::prepare_rehash();
|
|
552 |
}
|
|
553 |
}
|
|
554 |
}
|
|
555 |
|
|
556 |
void StringDedupTable::gc_epilogue() {
|
|
557 |
assert(!is_resizing() || !is_rehashing(), "Can not both resize and rehash");
|
|
558 |
assert(_claimed_index >= _table->_size / 2 || _claimed_index == 0, "All or nothing");
|
|
559 |
|
|
560 |
if (is_resizing()) {
|
|
561 |
StringDedupTable::finish_resize(_resized_table);
|
|
562 |
_resized_table = NULL;
|
|
563 |
} else if (is_rehashing()) {
|
|
564 |
StringDedupTable::finish_rehash(_rehashed_table);
|
|
565 |
_rehashed_table = NULL;
|
|
566 |
}
|
|
567 |
}
|
|
568 |
|
|
569 |
StringDedupTable* StringDedupTable::prepare_rehash() {
|
|
570 |
if (!_table->_rehash_needed && !StringDeduplicationRehashALot) {
|
|
571 |
// Rehash not needed
|
|
572 |
return NULL;
|
|
573 |
}
|
|
574 |
|
|
575 |
// Update statistics
|
|
576 |
_rehash_count++;
|
|
577 |
|
|
578 |
// Compute new hash seed
|
|
579 |
_table->_hash_seed = AltHashing::compute_seed();
|
|
580 |
|
|
581 |
// Allocate the new table, same size and hash seed
|
|
582 |
return new StringDedupTable(_table->_size, _table->_hash_seed);
|
|
583 |
}
|
|
584 |
|
|
585 |
void StringDedupTable::finish_rehash(StringDedupTable* rehashed_table) {
|
|
586 |
assert(rehashed_table != NULL, "Invalid table");
|
|
587 |
|
|
588 |
// Move all newly rehashed entries into the correct buckets in the new table
|
|
589 |
for (size_t bucket = 0; bucket < _table->_size; bucket++) {
|
|
590 |
StringDedupEntry** entry = _table->bucket(bucket);
|
|
591 |
while (*entry != NULL) {
|
|
592 |
_table->transfer(entry, rehashed_table);
|
|
593 |
}
|
|
594 |
}
|
|
595 |
|
|
596 |
rehashed_table->_entries = _table->_entries;
|
|
597 |
|
|
598 |
// Free old table
|
|
599 |
delete _table;
|
|
600 |
|
|
601 |
// Install new table
|
|
602 |
_table = rehashed_table;
|
|
603 |
}
|
|
604 |
|
|
605 |
size_t StringDedupTable::claim_table_partition(size_t partition_size) {
|
|
606 |
return Atomic::add(partition_size, &_claimed_index) - partition_size;
|
|
607 |
}
|
|
608 |
|
|
609 |
void StringDedupTable::verify() {
|
|
610 |
for (size_t bucket = 0; bucket < _table->_size; bucket++) {
|
|
611 |
// Verify entries
|
|
612 |
StringDedupEntry** entry = _table->bucket(bucket);
|
|
613 |
while (*entry != NULL) {
|
|
614 |
typeArrayOop value = (*entry)->obj();
|
|
615 |
guarantee(value != NULL, "Object must not be NULL");
|
|
616 |
guarantee(Universe::heap()->is_in_reserved(value), "Object must be on the heap");
|
|
617 |
guarantee(!value->is_forwarded(), "Object must not be forwarded");
|
|
618 |
guarantee(value->is_typeArray(), "Object must be a typeArrayOop");
|
|
619 |
bool latin1 = (*entry)->latin1();
|
|
620 |
unsigned int hash = hash_code(value, latin1);
|
|
621 |
guarantee((*entry)->hash() == hash, "Table entry has inorrect hash");
|
|
622 |
guarantee(_table->hash_to_index(hash) == bucket, "Table entry has incorrect index");
|
|
623 |
entry = (*entry)->next_addr();
|
|
624 |
}
|
|
625 |
|
|
626 |
// Verify that we do not have entries with identical oops or identical arrays.
|
|
627 |
// We only need to compare entries in the same bucket. If the same oop or an
|
|
628 |
// identical array has been inserted more than once into different/incorrect
|
|
629 |
// buckets the verification step above will catch that.
|
|
630 |
StringDedupEntry** entry1 = _table->bucket(bucket);
|
|
631 |
while (*entry1 != NULL) {
|
|
632 |
typeArrayOop value1 = (*entry1)->obj();
|
|
633 |
bool latin1_1 = (*entry1)->latin1();
|
|
634 |
StringDedupEntry** entry2 = (*entry1)->next_addr();
|
|
635 |
while (*entry2 != NULL) {
|
|
636 |
typeArrayOop value2 = (*entry2)->obj();
|
|
637 |
bool latin1_2 = (*entry2)->latin1();
|
|
638 |
guarantee(latin1_1 != latin1_2 || !equals(value1, value2), "Table entries must not have identical arrays");
|
|
639 |
entry2 = (*entry2)->next_addr();
|
|
640 |
}
|
|
641 |
entry1 = (*entry1)->next_addr();
|
|
642 |
}
|
|
643 |
}
|
|
644 |
}
|
|
645 |
|
|
646 |
void StringDedupTable::clean_entry_cache() {
|
|
647 |
_entry_cache->delete_overflowed();
|
|
648 |
}
|
|
649 |
|
|
650 |
void StringDedupTable::print_statistics() {
|
|
651 |
Log(gc, stringdedup) log;
|
|
652 |
log.debug(" Table");
|
|
653 |
log.debug(" Memory Usage: " STRDEDUP_BYTES_FORMAT_NS,
|
|
654 |
STRDEDUP_BYTES_PARAM(_table->_size * sizeof(StringDedupEntry*) + (_table->_entries + _entry_cache->size()) * sizeof(StringDedupEntry)));
|
|
655 |
log.debug(" Size: " SIZE_FORMAT ", Min: " SIZE_FORMAT ", Max: " SIZE_FORMAT, _table->_size, _min_size, _max_size);
|
|
656 |
log.debug(" Entries: " UINTX_FORMAT ", Load: " STRDEDUP_PERCENT_FORMAT_NS ", Cached: " UINTX_FORMAT ", Added: " UINTX_FORMAT ", Removed: " UINTX_FORMAT,
|
|
657 |
_table->_entries, percent_of(_table->_entries, _table->_size), _entry_cache->size(), _entries_added, _entries_removed);
|
|
658 |
log.debug(" Resize Count: " UINTX_FORMAT ", Shrink Threshold: " UINTX_FORMAT "(" STRDEDUP_PERCENT_FORMAT_NS "), Grow Threshold: " UINTX_FORMAT "(" STRDEDUP_PERCENT_FORMAT_NS ")",
|
|
659 |
_resize_count, _table->_shrink_threshold, _shrink_load_factor * 100.0, _table->_grow_threshold, _grow_load_factor * 100.0);
|
|
660 |
log.debug(" Rehash Count: " UINTX_FORMAT ", Rehash Threshold: " UINTX_FORMAT ", Hash Seed: 0x%x", _rehash_count, _rehash_threshold, _table->_hash_seed);
|
|
661 |
log.debug(" Age Threshold: " UINTX_FORMAT, StringDeduplicationAgeThreshold);
|
|
662 |
}
|