1 /*
2 * Copyright (c) 2001, 2015, 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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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 all elements, and reset the index to make the
56 // buffer empty. If a closure application returns "false", return
57 // "false" immediately, halting the iteration. If "consume" is true,
58 // deletes processed entries from logs.
59 bool apply_closure(CardTableEntryClosure* cl,
60 bool consume = true,
61 uint worker_i = 0);
62
63 // Apply the closure to all elements of "buf", down to "index"
64 // (inclusive.) If returns "false", then a closure application returned
65 // "false", and we return immediately. If "consume" is true, entries are
66 // set to NULL as they are processed, so they will not be processed again
67 // later.
68 static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
69 void** buf, size_t index, size_t sz,
70 bool consume = true,
71 uint worker_i = 0);
72 void **get_buf() { return _buf;}
73 size_t get_index() { return _index;}
74 void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
75 };
76
77
78
79 class DirtyCardQueueSet: public PtrQueueSet {
80 // The closure used in mut_process_buffer().
81 CardTableEntryClosure* _mut_process_closure;
82
83 DirtyCardQueue _shared_dirty_card_queue;
84
85 // Override.
86 bool mut_process_buffer(void** buf);
87
88 // Protected by the _cbl_mon.
89 FreeIdSet* _free_ids;
90
91 // The number of completed buffers processed by mutator and rs thread,
92 // respectively.
93 jint _processed_buffers_mut;
94 jint _processed_buffers_rs_thread;
95
96 // Current buffer node used for parallel iteration.
97 BufferNode* volatile _cur_par_buffer_node;
98 public:
99 DirtyCardQueueSet(bool notify_when_complete = true);
100
101 void initialize(CardTableEntryClosure* cl,
102 Monitor* cbl_mon,
103 Mutex* fl_lock,
104 int process_completed_threshold,
105 int max_completed_queue,
106 Mutex* lock,
107 DirtyCardQueueSet* fl_owner = NULL);
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(JavaThread* t);
114
115 // Apply the given closure to all entries in all currently-active buffers.
116 // This should only be applied at a safepoint. (Currently must not be called
117 // in parallel; this should change in the future.) If "consume" is true,
118 // processed entries are discarded.
119 void iterate_closure_all_threads(CardTableEntryClosure* cl,
120 bool consume = true,
121 uint worker_i = 0);
122
123 // If there exists some completed buffer, pop it, then apply the
124 // specified closure to all its elements, nulling out those elements
125 // processed. If all elements are processed, returns "true". If no
126 // completed buffers exist, returns false. If a completed buffer exists,
127 // but is only partially completed before a "yield" happens, the
128 // partially completed buffer (with its processed elements set to NULL)
129 // is returned to the completed buffer set, and this call returns false.
130 bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
131 uint worker_i = 0,
132 int stop_at = 0,
133 bool during_pause = false);
134
135 // Helper routine for the above.
136 bool apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
137 uint worker_i,
138 BufferNode* nd);
139
140 BufferNode* get_completed_buffer(int stop_at);
141
142 // Applies the current closure to all completed buffers,
143 // non-consumptively.
144 void apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
145
146 void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
147 // Applies the current closure to all completed buffers, non-consumptively.
148 // Parallel version.
149 void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
150
151 DirtyCardQueue* shared_dirty_card_queue() {
152 return &_shared_dirty_card_queue;
153 }
154
155 // Deallocate any completed log buffers
156 void clear();
157
158 // If a full collection is happening, reset partial logs, and ignore
159 // completed ones: the full collection will make them all irrelevant.
160 void abandon_logs();
161
162 // If any threads have partial logs, add them to the global list of logs.
163 void concatenate_logs();
164 void clear_n_completed_buffers() { _n_completed_buffers = 0;}
165
166 jint processed_buffers_mut() {
167 return _processed_buffers_mut;
168 }
169 jint processed_buffers_rs_thread() {
170 return _processed_buffers_rs_thread;
171 }
172
173 };
174
175 #endif // SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP