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.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
8 *
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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).
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15 * You should have received a copy of the GNU General Public License version
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24
25 #ifndef SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP
26 #define SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP
27
28 #include "gc/g1/g1FreeIdSet.hpp"
29 #include "gc/shared/ptrQueue.hpp"
30 #include "memory/allocation.hpp"
31
32 class G1CardTableEntryClosure;
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 fields below.
70 BufferNode* _completed_buffers_head;
71 BufferNode* _completed_buffers_tail;
72
73 // Number of actual entries in the list of completed buffers.
74 volatile size_t _num_entries_in_completed_buffers;
75
76 size_t _process_completed_buffers_threshold;
77 volatile bool _process_completed_buffers;
78
79 // If true, notify_all on _cbl_mon when the threshold is reached.
80 bool _notify_when_complete;
81
82 void abandon_completed_buffers();
83
84 // Apply the closure to the elements of "node" from it's index to
85 // buffer_size. If all closure applications return true, then
86 // returns true. Stops processing after the first closure
87 // application that returns false, and returns false from this
88 // function. The node's index is updated to exclude the processed
89 // elements, e.g. up to the element for which the closure returned
90 // false, or one past the last element if the closure always
91 // returned true.
92 bool apply_closure_to_buffer(G1CardTableEntryClosure* cl,
93 BufferNode* node,
94 uint worker_i = 0);
95
96 // If there are more than stop_at completed buffers, pop one, apply
97 // the specified closure to its active elements, and return true.
98 // Otherwise return false.
99 //
100 // A completely processed buffer is freed. However, if a closure
101 // invocation returns false, processing is stopped and the partially
102 // processed buffer (with its index updated to exclude the processed
103 // elements, e.g. up to the element for which the closure returned
104 // false) is returned to the completed buffer set.
105 //
106 // If during_pause is true, stop_at must be zero, and the closure
107 // must never return false.
108 bool apply_closure_to_completed_buffer(G1CardTableEntryClosure* cl,
109 uint worker_i,
110 size_t stop_at,
111 bool during_pause);
112
113 bool mut_process_buffer(BufferNode* node);
114
115 // If the queue contains more buffers than configured here, the
116 // mutator must start doing some of the concurrent refinement work,
117 size_t _max_completed_buffers;
118 size_t _completed_buffers_padding;
119 static const size_t MaxCompletedBuffersUnlimited = SIZE_MAX;
120
121 G1FreeIdSet _free_ids;
122
123 // The number of completed buffers processed by mutator and rs thread,
124 // respectively.
125 jint _processed_buffers_mut;
126 jint _processed_buffers_rs_thread;
127
128 public:
129 G1DirtyCardQueueSet(bool notify_when_complete = true);
130 ~G1DirtyCardQueueSet();
131
132 void initialize(Monitor* cbl_mon, BufferNode::Allocator* allocator);
133
134 // The number of parallel ids that can be claimed to allow collector or
135 // mutator threads to do card-processing work.
136 static uint num_par_ids();
137
138 static void handle_zero_index_for_thread(Thread* t);
139
140 // Either process the entire buffer and return true, or enqueue the
141 // buffer and return false. If the buffer is completely processed,
142 // it can be reused in place.
143 bool process_or_enqueue_completed_buffer(BufferNode* node);
144
145 virtual void enqueue_completed_buffer(BufferNode* node);
146
147 // If the number of completed buffers is > stop_at, then remove and
148 // return a completed buffer from the list. Otherwise, return NULL.
149 BufferNode* get_completed_buffer(size_t stop_at = 0);
150
151 // The number of buffers in the list. Derived as an approximation from the number
152 // of entries in the buffers. Racy.
153 size_t num_completed_buffers() const {
154 return (num_entries_in_completed_buffers() + buffer_size() - 1) / buffer_size();
155 }
156 // The number of entries in completed buffers. Read without synchronization.
157 size_t num_entries_in_completed_buffers() const { return _num_entries_in_completed_buffers; }
158
159 // Verify that _num_entries_in_completed_buffers is equal to the sum of actual entries
160 // in the completed buffers.
161 void verify_num_entries_in_completed_buffers() const NOT_DEBUG_RETURN;
162
163 bool process_completed_buffers() { return _process_completed_buffers; }
164 void set_process_completed_buffers(bool x) { _process_completed_buffers = x; }
165
166 // Get/Set the number of completed buffers that triggers log processing.
167 // Log processing should be done when the number of buffers exceeds the
168 // threshold.
169 void set_process_completed_buffers_threshold(size_t sz) {
170 _process_completed_buffers_threshold = sz;
171 }
172 size_t process_completed_buffers_threshold() const {
173 return _process_completed_buffers_threshold;
174 }
175 static const size_t ProcessCompletedBuffersThresholdNever = SIZE_MAX;
176
177 // Notify the consumer if the number of buffers crossed the threshold
178 void notify_if_necessary();
179
180 void merge_bufferlists(G1RedirtyCardsQueueSet* src);
181
182 // Apply G1RefineCardConcurrentlyClosure to completed buffers until there are stop_at
183 // completed buffers remaining.
184 bool refine_completed_buffer_concurrently(uint worker_i, size_t stop_at);
185
186 // Apply the given closure to all completed buffers. The given closure's do_card_ptr
187 // must never return false. Must only be called during GC.
188 bool apply_closure_during_gc(G1CardTableEntryClosure* cl, uint worker_i);
189
190 // If a full collection is happening, reset partial logs, and release
191 // completed ones: the full collection will make them all irrelevant.
192 void abandon_logs();
193
194 // If any threads have partial logs, add them to the global list of logs.
195 void concatenate_logs();
196
197 void set_max_completed_buffers(size_t m) {
198 _max_completed_buffers = m;
199 }
200 size_t max_completed_buffers() const {
201 return _max_completed_buffers;
202 }
203
204 void set_completed_buffers_padding(size_t padding) {
205 _completed_buffers_padding = padding;
206 }
207 size_t completed_buffers_padding() const {
208 return _completed_buffers_padding;
209 }
210
211 jint processed_buffers_mut() {
212 return _processed_buffers_mut;
213 }
214 jint processed_buffers_rs_thread() {
215 return _processed_buffers_rs_thread;
216 }
217
218 };
219
220 inline G1DirtyCardQueueSet* G1DirtyCardQueue::dirty_card_qset() const {
221 return static_cast<G1DirtyCardQueueSet*>(qset());
222 }
223
224 #endif // SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP