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.
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23 */
24
25 #ifndef SHARE_UTILITIES_CONCURRENT_HASH_TABLE_TASKS_INLINE_HPP
26 #define SHARE_UTILITIES_CONCURRENT_HASH_TABLE_TASKS_INLINE_HPP
27
28 #include "utilities/globalDefinitions.hpp"
29 #include "utilities/concurrentHashTable.inline.hpp"
30
31 // This inline file contains BulkDeleteTask and GrowTasks which are both bucket
32 // operations, which they are serialized with each other.
33
34 // Base class for pause and/or parallel bulk operations.
35 template <typename VALUE, typename CONFIG, MEMFLAGS F>
36 class ConcurrentHashTable<VALUE, CONFIG, F>::BucketsOperation {
37 protected:
38 ConcurrentHashTable<VALUE, CONFIG, F>* _cht;
39
40 // Default size of _task_size_log2
41 static const size_t DEFAULT_TASK_SIZE_LOG2 = 12;
42
43 // The table is split into ranges, every increment is one range.
44 volatile size_t _next_to_claim;
45 size_t _task_size_log2; // Number of buckets.
46 size_t _stop_task; // Last task
47 size_t _size_log2; // Table size.
48 bool _is_mt;
49
50 BucketsOperation(ConcurrentHashTable<VALUE, CONFIG, F>* cht, bool is_mt = false)
51 : _cht(cht), _is_mt(is_mt), _next_to_claim(0), _task_size_log2(DEFAULT_TASK_SIZE_LOG2),
52 _stop_task(0), _size_log2(0) {}
53
54 // Returns true if you succeeded to claim the range start -> (stop-1).
55 bool claim(size_t* start, size_t* stop) {
56 size_t claimed = Atomic::add((size_t)1, &_next_to_claim) - 1;
57 if (claimed >= _stop_task) {
58 return false;
59 }
60 *start = claimed * (((size_t)1) << _task_size_log2);
61 *stop = ((*start) + (((size_t)1) << _task_size_log2));
62 return true;
63 }
64
65 // Calculate starting values.
66 void setup() {
67 _size_log2 = _cht->_table->_log2_size;
68 _task_size_log2 = MIN2(_task_size_log2, _size_log2);
69 size_t tmp = _size_log2 > _task_size_log2 ?
70 _size_log2 - _task_size_log2 : 0;
71 _stop_task = (((size_t)1) << tmp);
72 }
73
74 // Returns false if all ranges are claimed.
75 bool have_more_work() {
76 return OrderAccess::load_acquire(&_next_to_claim) >= _stop_task;
77 }
78
79 // If we have changed size.
80 bool is_same_table() {
81 // Not entirely true.
82 return _size_log2 != _cht->_table->_log2_size;
83 }
84
85 void thread_owns_resize_lock(Thread* thread) {
86 assert(BucketsOperation::_cht->_resize_lock_owner == thread,
87 "Should be locked by me");
88 assert(BucketsOperation::_cht->_resize_lock->owned_by_self(),
89 "Operations lock not held");
90 }
91 void thread_owns_only_state_lock(Thread* thread) {
92 assert(BucketsOperation::_cht->_resize_lock_owner == thread,
93 "Should be locked by me");
94 assert(!BucketsOperation::_cht->_resize_lock->owned_by_self(),
95 "Operations lock held");
96 }
97 void thread_do_not_own_resize_lock(Thread* thread) {
98 assert(!BucketsOperation::_cht->_resize_lock->owned_by_self(),
99 "Operations lock held");
100 assert(BucketsOperation::_cht->_resize_lock_owner != thread,
101 "Should not be locked by me");
102 }
103 };
104
105 // For doing pausable/parallel bulk delete.
106 template <typename VALUE, typename CONFIG, MEMFLAGS F>
107 class ConcurrentHashTable<VALUE, CONFIG, F>::BulkDeleteTask :
108 public BucketsOperation
109 {
110 public:
111 BulkDeleteTask(ConcurrentHashTable<VALUE, CONFIG, F>* cht, bool is_mt = false)
112 : BucketsOperation(cht, is_mt) {
113 }
114 // Before start prepare must be called.
115 bool prepare(Thread* thread) {
116 bool lock = BucketsOperation::_cht->try_resize_lock(thread);
117 if (!lock) {
118 return false;
119 }
120 this->setup();
121 this->thread_owns_resize_lock(thread);
122 return true;
123 }
124
125 // Does one range destroying all matching EVALUATE_FUNC and
126 // DELETE_FUNC is called be destruction. Returns true if there is more work.
127 template <typename EVALUATE_FUNC, typename DELETE_FUNC>
128 bool do_task(Thread* thread, EVALUATE_FUNC& eval_f, DELETE_FUNC& del_f) {
129 size_t start, stop;
130 assert(BucketsOperation::_cht->_resize_lock_owner != NULL,
131 "Should be locked");
132 if (!this->claim(&start, &stop)) {
133 return false;
134 }
135 BucketsOperation::_cht->do_bulk_delete_locked_for(thread, start, stop,
136 eval_f, del_f,
137 BucketsOperation::_is_mt);
138 return true;
139 }
140
141 // Pauses this operations for a safepoint.
142 void pause(Thread* thread) {
143 this->thread_owns_resize_lock(thread);
144 // This leaves internal state locked.
145 BucketsOperation::_cht->unlock_resize_lock(thread);
146 this->thread_do_not_own_resize_lock(thread);
147 }
148
149 // Continues this operations after a safepoint.
150 bool cont(Thread* thread) {
151 this->thread_do_not_own_resize_lock(thread);
152 if (!BucketsOperation::_cht->try_resize_lock(thread)) {
153 this->thread_do_not_own_resize_lock(thread);
154 return false;
155 }
156 if (BucketsOperation::is_same_table()) {
157 BucketsOperation::_cht->unlock_resize_lock(thread);
158 this->thread_do_not_own_resize_lock(thread);
159 return false;
160 }
161 this->thread_owns_resize_lock(thread);
162 return true;
163 }
164
165 // Must be called after ranges are done.
166 void done(Thread* thread) {
167 this->thread_owns_resize_lock(thread);
168 BucketsOperation::_cht->unlock_resize_lock(thread);
169 this->thread_do_not_own_resize_lock(thread);
170 }
171 };
172
173 template <typename VALUE, typename CONFIG, MEMFLAGS F>
174 class ConcurrentHashTable<VALUE, CONFIG, F>::GrowTask :
175 public BucketsOperation
176 {
177 public:
178 GrowTask(ConcurrentHashTable<VALUE, CONFIG, F>* cht) : BucketsOperation(cht) {
179 }
180 // Before start prepare must be called.
181 bool prepare(Thread* thread) {
182 if (!BucketsOperation::_cht->internal_grow_prolog(
183 thread, BucketsOperation::_cht->_log2_size_limit)) {
184 return false;
185 }
186 this->thread_owns_resize_lock(thread);
187 BucketsOperation::setup();
188 return true;
189 }
190
191 // Re-sizes a portion of the table. Returns true if there is more work.
192 bool do_task(Thread* thread) {
193 size_t start, stop;
194 assert(BucketsOperation::_cht->_resize_lock_owner != NULL,
195 "Should be locked");
196 if (!this->claim(&start, &stop)) {
197 return false;
198 }
199 BucketsOperation::_cht->internal_grow_range(thread, start, stop);
200 assert(BucketsOperation::_cht->_resize_lock_owner != NULL,
201 "Should be locked");
202 return true;
203 }
204
205 // Pauses growing for safepoint
206 void pause(Thread* thread) {
207 // This leaves internal state locked.
208 this->thread_owns_resize_lock(thread);
209 BucketsOperation::_cht->_resize_lock->unlock();
210 this->thread_owns_only_state_lock(thread);
211 }
212
213 // Continues growing after safepoint.
214 void cont(Thread* thread) {
215 this->thread_owns_only_state_lock(thread);
216 // If someone slips in here directly after safepoint.
217 while (!BucketsOperation::_cht->_resize_lock->try_lock())
218 { /* for ever */ };
219 this->thread_owns_resize_lock(thread);
220 }
221
222 // Must be called after do_task returns false.
223 void done(Thread* thread) {
224 this->thread_owns_resize_lock(thread);
225 BucketsOperation::_cht->internal_grow_epilog(thread);
226 this->thread_do_not_own_resize_lock(thread);
227 }
228 };
229
230 #endif // include guard