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.
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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
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23 */
24
25 #ifndef SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP
26 #define SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP
27
28 #include "gc/g1/g1BufferNodeList.hpp"
29 #include "gc/g1/g1FreeIdSet.hpp"
30 #include "gc/shared/ptrQueue.hpp"
31 #include "memory/allocation.hpp"
32
33 class G1DirtyCardQueueSet;
34 class G1RedirtyCardsQueueSet;
35 class Thread;
36 class Monitor;
37
38 // A ptrQueue whose elements are "oops", pointers to object heads.
39 class G1DirtyCardQueue: public PtrQueue {
40 protected:
41 virtual void handle_completed_buffer();
42
43 public:
44 G1DirtyCardQueue(G1DirtyCardQueueSet* qset);
45
46 // Flush before destroying; queue may be used to capture pending work while
47 // doing something else, with auto-flush on completion.
48 ~G1DirtyCardQueue();
49
50 // Process queue entries and release resources.
51 void flush() { flush_impl(); }
52
53 inline G1DirtyCardQueueSet* dirty_card_qset() const;
54
55 // Compiler support.
56 static ByteSize byte_offset_of_index() {
57 return PtrQueue::byte_offset_of_index<G1DirtyCardQueue>();
58 }
59 using PtrQueue::byte_width_of_index;
60
61 static ByteSize byte_offset_of_buf() {
62 return PtrQueue::byte_offset_of_buf<G1DirtyCardQueue>();
63 }
64 using PtrQueue::byte_width_of_buf;
65
66 };
67
68 class G1DirtyCardQueueSet: public PtrQueueSet {
69 Monitor* _cbl_mon; // Protects the list and count members.
70 BufferNode* _completed_buffers_head;
71 BufferNode* _completed_buffers_tail;
72
73 // Number of actual cards in the list of completed buffers.
74 volatile size_t _num_cards;
75
76 size_t _process_cards_threshold;
77 volatile bool _process_completed_buffers;
78
79 void abandon_completed_buffers();
80
81 // Refine the cards in "node" from its index to buffer_size.
82 // Stops processing if SuspendibleThreadSet::should_yield() is true.
83 // Returns true if the entire buffer was processed, false if there
84 // is a pending yield request. The node's index is updated to exclude
85 // the processed elements, e.g. up to the element before processing
86 // stopped, or one past the last element if the entire buffer was
87 // processed. Increments *total_refined_cards by the number of cards
88 // processed and removed from the buffer.
89 bool refine_buffer(BufferNode* node, uint worker_id, size_t* total_refined_cards);
90
91 bool mut_process_buffer(BufferNode* node);
92
93 // If the queue contains more cards than configured here, the
94 // mutator must start doing some of the concurrent refinement work.
95 size_t _max_cards;
96 size_t _max_cards_padding;
97 static const size_t MaxCardsUnlimited = SIZE_MAX;
98
99 G1FreeIdSet _free_ids;
100
101 // Array of cumulative dirty cards refined by mutator threads.
102 // Array has an entry per id in _free_ids.
103 size_t* _mutator_refined_cards_counters;
104
105 public:
106 G1DirtyCardQueueSet(Monitor* cbl_mon, BufferNode::Allocator* allocator);
107 ~G1DirtyCardQueueSet();
108
109 // The number of parallel ids that can be claimed to allow collector or
110 // mutator threads to do card-processing work.
111 static uint num_par_ids();
112
113 static void handle_zero_index_for_thread(Thread* t);
114
115 // Either process the entire buffer and return true, or enqueue the
116 // buffer and return false. If the buffer is completely processed,
117 // it can be reused in place.
118 bool process_or_enqueue_completed_buffer(BufferNode* node);
119
120 virtual void enqueue_completed_buffer(BufferNode* node);
121
122 // If the number of completed buffers is > stop_at, then remove and
123 // return a completed buffer from the list. Otherwise, return NULL.
124 BufferNode* get_completed_buffer(size_t stop_at = 0);
125
126 // The number of cards in completed buffers. Read without synchronization.
127 size_t num_cards() const { return _num_cards; }
128
129 // Verify that _num_cards is equal to the sum of actual cards
130 // in the completed buffers.
131 void verify_num_cards() const NOT_DEBUG_RETURN;
132
133 bool process_completed_buffers() { return _process_completed_buffers; }
134 void set_process_completed_buffers(bool x) { _process_completed_buffers = x; }
135
136 // Get/Set the number of cards that triggers log processing.
137 // Log processing should be done when the number of cards exceeds the
138 // threshold.
139 void set_process_cards_threshold(size_t sz) {
140 _process_cards_threshold = sz;
141 }
142 size_t process_cards_threshold() const {
143 return _process_cards_threshold;
144 }
145 static const size_t ProcessCardsThresholdNever = SIZE_MAX;
146
147 // Notify the consumer if the number of buffers crossed the threshold
148 void notify_if_necessary();
149
150 void merge_bufferlists(G1RedirtyCardsQueueSet* src);
151
152 G1BufferNodeList take_all_completed_buffers();
153
154 // If there are more than stop_at cards in the completed buffers, pop
155 // a buffer, refine its contents, and return true. Otherwise return
156 // false.
157 //
158 // Stops processing a buffer if SuspendibleThreadSet::should_yield(),
159 // returning the incompletely processed buffer to the completed buffer
160 // list, for later processing of the remainder.
161 //
162 // Increments *total_refined_cards by the number of cards processed and
163 // removed from the buffer.
164 bool refine_completed_buffer_concurrently(uint worker_id,
165 size_t stop_at,
166 size_t* total_refined_cards);
167
168 // If a full collection is happening, reset partial logs, and release
169 // completed ones: the full collection will make them all irrelevant.
170 void abandon_logs();
171
172 // If any threads have partial logs, add them to the global list of logs.
173 void concatenate_logs();
174
175 void set_max_cards(size_t m) {
176 _max_cards = m;
177 }
178 size_t max_cards() const {
179 return _max_cards;
180 }
181
182 void set_max_cards_padding(size_t padding) {
183 _max_cards_padding = padding;
184 }
185 size_t max_cards_padding() const {
186 return _max_cards_padding;
187 }
188
189 // Total dirty cards refined by mutator threads.
190 size_t total_mutator_refined_cards() const;
191 };
192
193 inline G1DirtyCardQueueSet* G1DirtyCardQueue::dirty_card_qset() const {
194 return static_cast<G1DirtyCardQueueSet*>(qset());
195 }
196
197 #endif // SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP