1 /*
2 * Copyright (c) 2001, 2012, 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.
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23 */
24
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_DIRTYCARDQUEUE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_DIRTYCARDQUEUE_HPP
27
28 #include "gc_implementation/g1/ptrQueue.hpp"
29 #include "memory/allocation.hpp"
30
31 class FreeIdSet;
32
33 // A closure class for processing card table entries. Note that we don't
34 // require these closure objects to be stack-allocated.
35 class CardTableEntryClosure: public CHeapObj<mtGC> {
36 public:
37 // Process the card whose card table entry is "card_ptr". If returns
38 // "false", terminate the iteration early.
39 virtual bool do_card_ptr(jbyte* card_ptr, uint worker_i = 0) = 0;
40 };
41
42 // A ptrQueue whose elements are "oops", pointers to object heads.
43 class DirtyCardQueue: public PtrQueue {
44 public:
45 DirtyCardQueue(PtrQueueSet* qset_, bool perm = false) :
46 // Dirty card queues are always active, so we create them with their
47 // active field set to true.
48 PtrQueue(qset_, perm, true /* active */) { }
49
50 // Apply the closure to all elements, and reset the index to make the
51 // buffer empty. If a closure application returns "false", return
52 // "false" immediately, halting the iteration. If "consume" is true,
53 // deletes processed entries from logs.
54 bool apply_closure(CardTableEntryClosure* cl,
55 bool consume = true,
56 uint worker_i = 0);
57
58 // Apply the closure to all elements of "buf", down to "index"
59 // (inclusive.) If returns "false", then a closure application returned
60 // "false", and we return immediately. If "consume" is true, entries are
61 // set to NULL as they are processed, so they will not be processed again
62 // later.
63 static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
64 void** buf, size_t index, size_t sz,
65 bool consume = true,
66 uint worker_i = 0);
67 void **get_buf() { return _buf;}
68 void set_buf(void **buf) {_buf = buf;}
69 size_t get_index() { return _index;}
70 void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
71 };
72
73
74
75 class DirtyCardQueueSet: public PtrQueueSet {
76 // The closure used for
77 CardTableEntryClosure* _mut_process_closure;
78
79 DirtyCardQueue _shared_dirty_card_queue;
80
81 // Override.
82 bool mut_process_buffer(void** buf);
83
84 // Protected by the _cbl_mon.
85 FreeIdSet* _free_ids;
86
87 // The number of completed buffers processed by mutator and rs thread,
88 // respectively.
89 jint _processed_buffers_mut;
90 jint _processed_buffers_rs_thread;
91
92 // Current buffer node used for parallel iteration.
93 BufferNode* volatile _cur_par_buffer_node;
94 public:
95 DirtyCardQueueSet(bool notify_when_complete = true);
96
97 void initialize(CardTableEntryClosure* cl, Monitor* cbl_mon, Mutex* fl_lock,
98 int process_completed_threshold,
99 int max_completed_queue,
100 Mutex* lock, PtrQueueSet* fl_owner = NULL);
101
102 // The number of parallel ids that can be claimed to allow collector or
103 // mutator threads to do card-processing work.
104 static uint num_par_ids();
105
106 static void handle_zero_index_for_thread(JavaThread* t);
107
108 // Apply the given closure to all entries in all currently-active buffers.
109 // This should only be applied at a safepoint. (Currently must not be called
110 // in parallel; this should change in the future.) If "consume" is true,
111 // processed entries are discarded.
112 void iterate_closure_all_threads(CardTableEntryClosure* cl,
113 bool consume = true,
114 uint worker_i = 0);
115
116 // If there exists some completed buffer, pop it, then apply the
117 // specified closure to all its elements, nulling out those elements
118 // processed. If all elements are processed, returns "true". If no
119 // completed buffers exist, returns false. If a completed buffer exists,
120 // but is only partially completed before a "yield" happens, the
121 // partially completed buffer (with its processed elements set to NULL)
122 // is returned to the completed buffer set, and this call returns false.
123 bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
124 uint worker_i = 0,
125 int stop_at = 0,
126 bool during_pause = false);
127
128 // Helper routine for the above.
129 bool apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
130 uint worker_i,
131 BufferNode* nd);
132
133 BufferNode* get_completed_buffer(int stop_at);
134
135 // Applies the current closure to all completed buffers,
136 // non-consumptively.
137 void apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
138
139 void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
140 // Applies the current closure to all completed buffers, non-consumptively.
141 // Parallel version.
142 void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
143
144 DirtyCardQueue* shared_dirty_card_queue() {
145 return &_shared_dirty_card_queue;
146 }
147
148 // Deallocate any completed log buffers
149 void clear();
150
151 // If a full collection is happening, reset partial logs, and ignore
152 // completed ones: the full collection will make them all irrelevant.
153 void abandon_logs();
154
155 // If any threads have partial logs, add them to the global list of logs.
156 void concatenate_logs();
157 void clear_n_completed_buffers() { _n_completed_buffers = 0;}
158
159 jint processed_buffers_mut() {
160 return _processed_buffers_mut;
161 }
162 jint processed_buffers_rs_thread() {
163 return _processed_buffers_rs_thread;
164 }
165
166 };
167
168 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_DIRTYCARDQUEUE_HPP