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.
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_GC_G1_G1DIRTYCARDQUEUE_HPP
26 #define SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP
27
28 #include "gc/shared/ptrQueue.hpp"
29 #include "memory/allocation.hpp"
30
31 class G1DirtyCardQueueSet;
32 class G1FreeIdSet;
33 class Thread;
34 class Monitor;
35
36 // A closure class for processing card table entries. Note that we don't
37 // require these closure objects to be stack-allocated.
38 class G1CardTableEntryClosure: public CHeapObj<mtGC> {
39 public:
40 // Process the card whose card table entry is "card_ptr". If returns
41 // "false", terminate the iteration early.
42 virtual bool do_card_ptr(jbyte* card_ptr, uint worker_i) = 0;
43 };
44
45 // A ptrQueue whose elements are "oops", pointers to object heads.
46 class G1DirtyCardQueue: public PtrQueue {
47 public:
48 G1DirtyCardQueue(G1DirtyCardQueueSet* qset, bool permanent = false);
49
50 // Flush before destroying; queue may be used to capture pending work while
51 // doing something else, with auto-flush on completion.
52 ~G1DirtyCardQueue();
53
54 // Process queue entries and release resources.
55 void flush() { flush_impl(); }
56
57 // Compiler support.
58 static ByteSize byte_offset_of_index() {
59 return PtrQueue::byte_offset_of_index<G1DirtyCardQueue>();
60 }
61 using PtrQueue::byte_width_of_index;
62
63 static ByteSize byte_offset_of_buf() {
64 return PtrQueue::byte_offset_of_buf<G1DirtyCardQueue>();
65 }
66 using PtrQueue::byte_width_of_buf;
67
68 };
69
70
71
72 class G1DirtyCardQueueSet: public PtrQueueSet {
73 G1DirtyCardQueue _shared_dirty_card_queue;
74
75 // Apply the closure to the elements of "node" from it's index to
76 // buffer_size. If all closure applications return true, then
77 // returns true. Stops processing after the first closure
78 // application that returns false, and returns false from this
79 // function. If "consume" is true, the node's index is updated to
80 // exclude the processed elements, e.g. up to the element for which
81 // the closure returned false.
82 bool apply_closure_to_buffer(G1CardTableEntryClosure* cl,
83 BufferNode* node,
84 bool consume,
85 uint worker_i = 0);
86
87 // If there are more than stop_at completed buffers, pop one, apply
88 // the specified closure to its active elements, and return true.
89 // Otherwise return false.
90 //
91 // A completely processed buffer is freed. However, if a closure
92 // invocation returns false, processing is stopped and the partially
93 // processed buffer (with its index updated to exclude the processed
94 // elements, e.g. up to the element for which the closure returned
95 // false) is returned to the completed buffer set.
96 //
97 // If during_pause is true, stop_at must be zero, and the closure
98 // must never return false.
99 bool apply_closure_to_completed_buffer(G1CardTableEntryClosure* cl,
100 uint worker_i,
101 size_t stop_at,
102 bool during_pause);
103
104 bool mut_process_buffer(BufferNode* node);
105
106 G1FreeIdSet* _free_ids;
107
108 // The number of completed buffers processed by mutator and rs thread,
109 // respectively.
110 jint _processed_buffers_mut;
111 jint _processed_buffers_rs_thread;
112
113 // Current buffer node used for parallel iteration.
114 BufferNode* volatile _cur_par_buffer_node;
115
116 void concatenate_log(G1DirtyCardQueue& dcq);
117
118 public:
119 G1DirtyCardQueueSet(bool notify_when_complete = true);
120 ~G1DirtyCardQueueSet();
121
122 void initialize(Monitor* cbl_mon,
123 BufferNode::Allocator* allocator,
124 Mutex* lock,
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(Thread* t);
132
133 // Apply G1RefineCardConcurrentlyClosure to completed buffers until there are stop_at
134 // completed buffers remaining.
135 bool refine_completed_buffer_concurrently(uint worker_i, size_t stop_at);
136
137 // Apply the given closure to all completed buffers. The given closure's do_card_ptr
138 // must never return false. Must only be called during GC.
139 bool apply_closure_during_gc(G1CardTableEntryClosure* cl, uint worker_i);
140
141 void reset_for_par_iteration() { _cur_par_buffer_node = completed_buffers_head(); }
142 // Applies the current closure to all completed buffers, non-consumptively.
143 // Can be used in parallel, all callers using the iteration state initialized
144 // by reset_for_par_iteration.
145 void par_apply_closure_to_all_completed_buffers(G1CardTableEntryClosure* cl);
146
147 G1DirtyCardQueue* shared_dirty_card_queue() {
148 return &_shared_dirty_card_queue;
149 }
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
158 jint processed_buffers_mut() {
159 return _processed_buffers_mut;
160 }
161 jint processed_buffers_rs_thread() {
162 return _processed_buffers_rs_thread;
163 }
164
165 };
166
167 #endif // SHARE_GC_G1_G1DIRTYCARDQUEUE_HPP