Thu, 21 Aug 2014 16:44:41 +0200
8055098: WB API should be extended to provide information about size and age of object.
Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: Leonid Mesnik <leonid.mesnik@oracle.com>
1 /*
2 * Copyright (c) 2001, 2013, 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
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23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINE_HPP
28 #include "gc_implementation/g1/g1HotCardCache.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/thread.hpp"
31 #include "utilities/globalDefinitions.hpp"
33 // Forward decl
34 class ConcurrentG1RefineThread;
35 class G1CollectedHeap;
36 class G1HotCardCache;
37 class G1RegionToSpaceMapper;
38 class G1RemSet;
39 class DirtyCardQueue;
41 class ConcurrentG1Refine: public CHeapObj<mtGC> {
42 ConcurrentG1RefineThread** _threads;
43 uint _n_threads;
44 uint _n_worker_threads;
45 /*
46 * The value of the update buffer queue length falls into one of 3 zones:
47 * green, yellow, red. If the value is in [0, green) nothing is
48 * done, the buffers are left unprocessed to enable the caching effect of the
49 * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement
50 * threads are gradually activated. In [yellow, red) all threads are
51 * running. If the length becomes red (max queue length) the mutators start
52 * processing the buffers.
53 *
54 * There are some interesting cases (when G1UseAdaptiveConcRefinement
55 * is turned off):
56 * 1) green = yellow = red = 0. In this case the mutator will process all
57 * buffers. Except for those that are created by the deferred updates
58 * machinery during a collection.
59 * 2) green = 0. Means no caching. Can be a good way to minimize the
60 * amount of time spent updating rsets during a collection.
61 */
62 int _green_zone;
63 int _yellow_zone;
64 int _red_zone;
66 int _thread_threshold_step;
68 // We delay the refinement of 'hot' cards using the hot card cache.
69 G1HotCardCache _hot_card_cache;
71 // Reset the threshold step value based of the current zone boundaries.
72 void reset_threshold_step();
74 public:
75 ConcurrentG1Refine(G1CollectedHeap* g1h, CardTableEntryClosure* refine_closure);
76 ~ConcurrentG1Refine();
78 void init(G1RegionToSpaceMapper* card_counts_storage);
79 void stop();
81 void reinitialize_threads();
83 // Iterate over all concurrent refinement threads
84 void threads_do(ThreadClosure *tc);
86 // Iterate over all worker refinement threads
87 void worker_threads_do(ThreadClosure * tc);
89 // The RS sampling thread
90 ConcurrentG1RefineThread * sampling_thread() const;
92 static uint thread_num();
94 void print_worker_threads_on(outputStream* st) const;
96 void set_green_zone(int x) { _green_zone = x; }
97 void set_yellow_zone(int x) { _yellow_zone = x; }
98 void set_red_zone(int x) { _red_zone = x; }
100 int green_zone() const { return _green_zone; }
101 int yellow_zone() const { return _yellow_zone; }
102 int red_zone() const { return _red_zone; }
104 uint total_thread_num() const { return _n_threads; }
105 uint worker_thread_num() const { return _n_worker_threads; }
107 int thread_threshold_step() const { return _thread_threshold_step; }
109 G1HotCardCache* hot_card_cache() { return &_hot_card_cache; }
110 };
112 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINE_HPP