1 /*
2 * Copyright (c) 2001, 2019, 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_GC_G1_G1DIRTYCARDQUEUE_HPP
26 #define SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP
27
28 #include "gc/shared/cardTable.hpp"
29 #include "gc/shared/ptrQueue.hpp"
30 #include "memory/allocation.hpp"
31
32 class G1DirtyCardQueueSet;
33 class G1FreeIdSet;
34 class Thread;
35 class Monitor;
36
37 // A closure class for processing card table entries. Note that we don't
38 // require these closure objects to be stack-allocated.
39 class G1CardTableEntryClosure: public CHeapObj<mtGC> {
40 public:
41 typedef CardTable::CardValue CardValue;
42
43 // Process the card whose card table entry is "card_ptr". If returns
44 // "false", terminate the iteration early.
45 virtual bool do_card_ptr(CardValue* card_ptr, uint worker_i) = 0;
46 };
47
48 // A ptrQueue whose elements are "oops", pointers to object heads.
49 class G1DirtyCardQueue: public PtrQueue {
50 protected:
51 virtual void handle_completed_buffer();
52
53 public:
54 G1DirtyCardQueue(G1DirtyCardQueueSet* qset);
55
56 // Flush before destroying; queue may be used to capture pending work while
57 // doing something else, with auto-flush on completion.
58 ~G1DirtyCardQueue();
59
60 // Process queue entries and release resources.
61 void flush() { flush_impl(); }
62
63 inline G1DirtyCardQueueSet* dirty_card_qset() const;
64
65 // Compiler support.
66 static ByteSize byte_offset_of_index() {
67 return PtrQueue::byte_offset_of_index<G1DirtyCardQueue>();
68 }
69 using PtrQueue::byte_width_of_index;
70
71 static ByteSize byte_offset_of_buf() {
72 return PtrQueue::byte_offset_of_buf<G1DirtyCardQueue>();
73 }
74 using PtrQueue::byte_width_of_buf;
75
76 };
77
78 class G1DirtyCardQueueSet: public PtrQueueSet {
79 Monitor* _cbl_mon; // Protects the fields below.
80 BufferNode* _completed_buffers_head;
81 BufferNode* _completed_buffers_tail;
82 volatile size_t _n_completed_buffers;
83
84 size_t _process_completed_buffers_threshold;
85 volatile bool _process_completed_buffers;
86
87 // If true, notify_all on _cbl_mon when the threshold is reached.
88 bool _notify_when_complete;
89
90 void assert_completed_buffers_list_len_correct_locked() NOT_DEBUG_RETURN;
91
92 void abandon_completed_buffers();
93
94 // Apply the closure to the elements of "node" from it's index to
95 // buffer_size. If all closure applications return true, then
96 // returns true. Stops processing after the first closure
97 // application that returns false, and returns false from this
98 // function. If "consume" is true, the node's index is updated to
99 // exclude the processed elements, e.g. up to the element for which
100 // the closure returned false.
101 bool apply_closure_to_buffer(G1CardTableEntryClosure* cl,
102 BufferNode* node,
103 bool consume,
104 uint worker_i = 0);
105
106 // If there are more than stop_at completed buffers, pop one, apply
107 // the specified closure to its active elements, and return true.
108 // Otherwise return false.
109 //
110 // A completely processed buffer is freed. However, if a closure
111 // invocation returns false, processing is stopped and the partially
112 // processed buffer (with its index updated to exclude the processed
113 // elements, e.g. up to the element for which the closure returned
114 // false) is returned to the completed buffer set.
115 //
116 // If during_pause is true, stop_at must be zero, and the closure
117 // must never return false.
118 bool apply_closure_to_completed_buffer(G1CardTableEntryClosure* cl,
119 uint worker_i,
120 size_t stop_at,
121 bool during_pause);
122
123 bool mut_process_buffer(BufferNode* node);
124
125 // If the queue contains more buffers than configured here, the
126 // mutator must start doing some of the concurrent refinement work,
127 size_t _max_completed_buffers;
128 size_t _completed_buffers_padding;
129 static const size_t MaxCompletedBuffersUnlimited = SIZE_MAX;
130
131 G1FreeIdSet* _free_ids;
132
133 // The number of completed buffers processed by mutator and rs thread,
134 // respectively.
135 jint _processed_buffers_mut;
136 jint _processed_buffers_rs_thread;
137
138 // Current buffer node used for parallel iteration.
139 BufferNode* volatile _cur_par_buffer_node;
140
141 public:
142 G1DirtyCardQueueSet(bool notify_when_complete = true);
143 ~G1DirtyCardQueueSet();
144
145 void initialize(Monitor* cbl_mon,
146 BufferNode::Allocator* allocator,
147 bool init_free_ids = false);
148
149 // The number of parallel ids that can be claimed to allow collector or
150 // mutator threads to do card-processing work.
151 static uint num_par_ids();
152
153 static void handle_zero_index_for_thread(Thread* t);
154
155 // Either process the entire buffer and return true, or enqueue the
156 // buffer and return false. If the buffer is completely processed,
157 // it can be reused in place.
158 bool process_or_enqueue_completed_buffer(BufferNode* node);
159
160 virtual void enqueue_completed_buffer(BufferNode* node);
161
162 // If the number of completed buffers is > stop_at, then remove and
163 // return a completed buffer from the list. Otherwise, return NULL.
164 BufferNode* get_completed_buffer(size_t stop_at = 0);
165
166 // The number of buffers in the list. Racy...
167 size_t completed_buffers_num() const { return _n_completed_buffers; }
168
169 bool process_completed_buffers() { return _process_completed_buffers; }
170 void set_process_completed_buffers(bool x) { _process_completed_buffers = x; }
171
172 // Get/Set the number of completed buffers that triggers log processing.
173 // Log processing should be done when the number of buffers exceeds the
174 // threshold.
175 void set_process_completed_buffers_threshold(size_t sz) {
176 _process_completed_buffers_threshold = sz;
177 }
178 size_t process_completed_buffers_threshold() const {
179 return _process_completed_buffers_threshold;
180 }
181 static const size_t ProcessCompletedBuffersThresholdNever = SIZE_MAX;
182
183 // Notify the consumer if the number of buffers crossed the threshold
184 void notify_if_necessary();
185
186 void merge_bufferlists(G1DirtyCardQueueSet* src);
187
188 // Apply G1RefineCardConcurrentlyClosure to completed buffers until there are stop_at
189 // completed buffers remaining.
190 bool refine_completed_buffer_concurrently(uint worker_i, size_t stop_at);
191
192 // Apply the given closure to all completed buffers. The given closure's do_card_ptr
193 // must never return false. Must only be called during GC.
194 bool apply_closure_during_gc(G1CardTableEntryClosure* cl, uint worker_i);
195
196 void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
197 // Applies the current closure to all completed buffers, non-consumptively.
198 // Can be used in parallel, all callers using the iteration state initialized
199 // by reset_for_par_iteration.
200 void par_apply_closure_to_all_completed_buffers(G1CardTableEntryClosure* cl);
201
202 // If a full collection is happening, reset partial logs, and release
203 // completed ones: the full collection will make them all irrelevant.
204 void abandon_logs();
205
206 // If any threads have partial logs, add them to the global list of logs.
207 void concatenate_logs();
208
209 void set_max_completed_buffers(size_t m) {
210 _max_completed_buffers = m;
211 }
212 size_t max_completed_buffers() const {
213 return _max_completed_buffers;
214 }
215
216 void set_completed_buffers_padding(size_t padding) {
217 _completed_buffers_padding = padding;
218 }
219 size_t completed_buffers_padding() const {
220 return _completed_buffers_padding;
221 }
222
223 jint processed_buffers_mut() {
224 return _processed_buffers_mut;
225 }
226 jint processed_buffers_rs_thread() {
227 return _processed_buffers_rs_thread;
228 }
229
230 };
231
232 inline G1DirtyCardQueueSet* G1DirtyCardQueue::dirty_card_qset() const {
233 return static_cast<G1DirtyCardQueueSet*>(qset());
234 }
235
236 #endif // SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP