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.
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.
22 *
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;
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 void **get_buf() { return _buf;}
56 size_t get_index() { return _index;}
57 void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
58
59 // Compiler support.
60 static ByteSize byte_offset_of_index() {
61 return PtrQueue::byte_offset_of_index<DirtyCardQueue>();
62 }
63 using PtrQueue::byte_width_of_index;
64
65 static ByteSize byte_offset_of_buf() {
66 return PtrQueue::byte_offset_of_buf<DirtyCardQueue>();
67 }
68 using PtrQueue::byte_width_of_buf;
69
70 };
71
72
73
74 class DirtyCardQueueSet: public PtrQueueSet {
75 // The closure used in mut_process_buffer().
76 CardTableEntryClosure* _mut_process_closure;
77
78 DirtyCardQueue _shared_dirty_card_queue;
79
80 // Apply the closure to the elements of "node" from it's index to
81 // buffer_size. If all closure applications return true, then
82 // returns true. Stops processing after the first closure
83 // application that returns false, and returns false from this
84 // function. If "consume" is true, the node's index is updated to
85 // follow the last processed element.
86 bool apply_closure_to_buffer(CardTableEntryClosure* cl,
87 BufferNode* node,
88 bool consume,
89 uint worker_i = 0);
90
91 bool mut_process_buffer(BufferNode* node);
92
93 // Protected by the _cbl_mon.
94 FreeIdSet* _free_ids;
95
96 // The number of completed buffers processed by mutator and rs thread,
97 // respectively.
98 jint _processed_buffers_mut;
99 jint _processed_buffers_rs_thread;
100
101 // Current buffer node used for parallel iteration.
102 BufferNode* volatile _cur_par_buffer_node;
103
104 void concatenate_log(DirtyCardQueue& dcq);
105
106 public:
107 DirtyCardQueueSet(bool notify_when_complete = true);
108
109 void initialize(CardTableEntryClosure* cl,
110 Monitor* cbl_mon,
111 Mutex* fl_lock,
112 int process_completed_threshold,
113 int max_completed_queue,
114 Mutex* lock,
115 DirtyCardQueueSet* fl_owner,
116 bool init_free_ids = false);
117
118 // The number of parallel ids that can be claimed to allow collector or
119 // mutator threads to do card-processing work.
120 static uint num_par_ids();
121
122 static void handle_zero_index_for_thread(JavaThread* t);
123
124 // If there exists some completed buffer, pop it, then apply the
125 // specified closure to its active elements. If all active elements
126 // are processed, returns "true". If no completed buffers exist,
127 // returns false. If a completed buffer exists, but is only
128 // partially completed before a "yield" happens, the partially
129 // completed buffer (with its index updated to exclude the processed
130 // elements) is returned to the completed buffer set, and this call
131 // returns false.
132 bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
133 uint worker_i,
134 size_t stop_at,
135 bool during_pause);
136
137 BufferNode* get_completed_buffer(size_t stop_at);
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 // Can be used in parallel, all callers using the iteration state initialized
142 // by reset_for_par_iteration.
143 void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
144
145 DirtyCardQueue* shared_dirty_card_queue() {
146 return &_shared_dirty_card_queue;
147 }
148
149 // Deallocate any completed log buffers
150 void clear();
151
152 // If a full collection is happening, reset partial logs, and ignore
153 // completed ones: the full collection will make them all irrelevant.
154 void abandon_logs();
155
156 // If any threads have partial logs, add them to the global list of logs.
157 void concatenate_logs();
158 void clear_n_completed_buffers() { _n_completed_buffers = 0;}
159
160 jint processed_buffers_mut() {
161 return _processed_buffers_mut;
162 }
163 jint processed_buffers_rs_thread() {
164 return _processed_buffers_rs_thread;
165 }
166
167 };
168
169 #endif // SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP