1 /*
2 * Copyright (c) 2001, 2016, 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
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23 */
24
25 #ifndef SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP
26 #define SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP
27
28 #include "gc/g1/ptrQueue.hpp"
29 #include "memory/allocation.hpp"
30
31 class FreeIdSet;
32 class DirtyCardQueueSet;
33
34 // A closure class for processing card table entries. Note that we don't
35 // require these closure objects to be stack-allocated.
36 class CardTableEntryClosure: public CHeapObj<mtGC> {
37 public:
38 // Process the card whose card table entry is "card_ptr". If returns
39 // "false", terminate the iteration early.
40 virtual bool do_card_ptr(jbyte* card_ptr, uint worker_i = 0) = 0;
41 };
42
43 // A ptrQueue whose elements are "oops", pointers to object heads.
44 class DirtyCardQueue: public PtrQueue {
45 public:
46 DirtyCardQueue(DirtyCardQueueSet* qset, bool permanent = false);
47
48 // Flush before destroying; queue may be used to capture pending work while
49 // doing something else, with auto-flush on completion.
50 ~DirtyCardQueue();
51
52 // Process queue entries and release resources.
53 void flush() { flush_impl(); }
54
55 // Apply the closure to the elements from _index to _sz. If all
56 // closure applications return true, then returns true. Stops
57 // processing after the first closure application that returns
58 // false, and returns false from this function. If "consume" is
59 // true, _index is updated to follow the last processed element.
60 bool apply_closure(CardTableEntryClosure* cl,
61 bool consume = true,
62 uint worker_i = 0);
63
64 // Apply the closure to the elements of "node" from it's index to
65 // buffer_size. If all closure applications return true, then
66 // returns true. Stops processing after the first closure
67 // application that returns false, and returns false from this
68 // function. If "consume" is true, the node's index is updated to
69 // follow the last processed element.
70 static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
71 BufferNode* node,
72 size_t buffer_size,
73 bool consume = true,
74 uint worker_i = 0);
75 void **get_buf() { return _buf;}
76 size_t get_index() { return _index;}
77 void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
78
79 // Compiler support.
80 static ByteSize byte_offset_of_index() {
81 return PtrQueue::byte_offset_of_index<DirtyCardQueue>();
82 }
83 using PtrQueue::byte_width_of_index;
84
85 static ByteSize byte_offset_of_buf() {
86 return PtrQueue::byte_offset_of_buf<DirtyCardQueue>();
87 }
88 using PtrQueue::byte_width_of_buf;
89
90 };
91
92
93
94 class DirtyCardQueueSet: public PtrQueueSet {
95 // The closure used in mut_process_buffer().
96 CardTableEntryClosure* _mut_process_closure;
97
98 DirtyCardQueue _shared_dirty_card_queue;
99
100 bool mut_process_buffer(BufferNode* node);
101
102 // Protected by the _cbl_mon.
103 FreeIdSet* _free_ids;
104
105 // The number of completed buffers processed by mutator and rs thread,
106 // respectively.
107 jint _processed_buffers_mut;
108 jint _processed_buffers_rs_thread;
109
110 // Current buffer node used for parallel iteration.
111 BufferNode* volatile _cur_par_buffer_node;
112
113 void concatenate_log(DirtyCardQueue& dcq);
114
115 public:
116 DirtyCardQueueSet(bool notify_when_complete = true);
117
118 void initialize(CardTableEntryClosure* cl,
119 Monitor* cbl_mon,
120 Mutex* fl_lock,
121 int process_completed_threshold,
122 int max_completed_queue,
123 Mutex* lock,
124 DirtyCardQueueSet* fl_owner,
125 bool init_free_ids = false);
126
127 // The number of parallel ids that can be claimed to allow collector or
128 // mutator threads to do card-processing work.
129 static uint num_par_ids();
130
131 static void handle_zero_index_for_thread(JavaThread* t);
132
133 // If there exists some completed buffer, pop it, then apply the
134 // specified closure to its active elements. If all active elements
135 // are processed, returns "true". If no completed buffers exist,
136 // returns false. If a completed buffer exists, but is only
137 // partially completed before a "yield" happens, the partially
138 // completed buffer (with its index updated to exclude the processed
139 // elements) is returned to the completed buffer set, and this call
140 // returns false.
141 bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
142 uint worker_i,
143 size_t stop_at,
144 bool during_pause);
145
146 BufferNode* get_completed_buffer(size_t stop_at);
147
148 void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
149 // Applies the current closure to all completed buffers, non-consumptively.
150 // Can be used in parallel, all callers using the iteration state initialized
151 // by reset_for_par_iteration.
152 void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
153
154 DirtyCardQueue* shared_dirty_card_queue() {
155 return &_shared_dirty_card_queue;
156 }
157
158 // Deallocate any completed log buffers
159 void clear();
160
161 // If a full collection is happening, reset partial logs, and ignore
162 // completed ones: the full collection will make them all irrelevant.
163 void abandon_logs();
164
165 // If any threads have partial logs, add them to the global list of logs.
166 void concatenate_logs();
167 void clear_n_completed_buffers() { _n_completed_buffers = 0;}
168
169 jint processed_buffers_mut() {
170 return _processed_buffers_mut;
171 }
172 jint processed_buffers_rs_thread() {
173 return _processed_buffers_rs_thread;
174 }
175
176 };
177
178 #endif // SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP