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. 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_CONCURRENTG1REFINE_HPP 26 #define SHARE_VM_GC_G1_CONCURRENTG1REFINE_HPP 27 28 #include "gc/g1/g1HotCardCache.hpp" 29 #include "gc/g1/g1YoungRemSetSamplingThread.hpp" 30 #include "memory/allocation.hpp" 31 #include "runtime/thread.hpp" 32 #include "utilities/globalDefinitions.hpp" 33 34 // Forward decl 35 class ConcurrentG1RefineThread; 36 class G1CollectedHeap; 37 class G1HotCardCache; 38 class G1RegionToSpaceMapper; 39 class G1RemSet; 40 class DirtyCardQueue; 41 42 class ConcurrentG1Refine: public CHeapObj<mtGC> { 43 G1YoungRemSetSamplingThread* _sample_thread; 44 45 ConcurrentG1RefineThread** _threads; 46 uint _n_worker_threads; 47 /* 48 * The value of the update buffer queue length falls into one of 3 zones: 49 * green, yellow, red. If the value is in [0, green) nothing is 50 * done, the buffers are left unprocessed to enable the caching effect of the 51 * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement 52 * threads are gradually activated. In [yellow, red) all threads are 53 * running. If the length becomes red (max queue length) the mutators start 54 * processing the buffers. 55 * 56 * There are some interesting cases (when G1UseAdaptiveConcRefinement 57 * is turned off): 58 * 1) green = yellow = red = 0. In this case the mutator will process all 59 * buffers. Except for those that are created by the deferred updates 60 * machinery during a collection. 61 * 2) green = 0. Means no caching. Can be a good way to minimize the 62 * amount of time spent updating rsets during a collection. 63 */ 64 int _green_zone; 65 int _yellow_zone; 66 int _red_zone; 67 68 int _thread_threshold_step; 69 70 // We delay the refinement of 'hot' cards using the hot card cache. 71 G1HotCardCache _hot_card_cache; 72 73 // Reset the threshold step value based of the current zone boundaries. 74 void reset_threshold_step(); 75 76 ConcurrentG1Refine(G1CollectedHeap* g1h); 77 78 public: 79 ~ConcurrentG1Refine(); 80 81 // Returns ConcurrentG1Refine instance if succeeded to create/initialize ConcurrentG1Refine and ConcurrentG1RefineThread. 82 // Otherwise, returns NULL with error code. 83 static ConcurrentG1Refine* create(G1CollectedHeap* g1h, CardTableEntryClosure* refine_closure, jint* ecode); 84 85 void init(G1RegionToSpaceMapper* card_counts_storage); 86 void stop(); 87 88 void reinitialize_threads(); 89 90 // Iterate over all concurrent refinement threads 91 void threads_do(ThreadClosure *tc); 92 93 // Iterate over all worker refinement threads 94 void worker_threads_do(ThreadClosure * tc); 95 96 // The RS sampling thread has nothing to do with refinement, but is here for now. 97 G1YoungRemSetSamplingThread * sampling_thread() const { return _sample_thread; } 98 99 static uint thread_num(); 100 101 void print_worker_threads_on(outputStream* st) const; 102 103 void set_green_zone(int x) { _green_zone = x; } 104 void set_yellow_zone(int x) { _yellow_zone = x; } 105 void set_red_zone(int x) { _red_zone = x; } 106 107 int green_zone() const { return _green_zone; } 108 int yellow_zone() const { return _yellow_zone; } 109 int red_zone() const { return _red_zone; } 110 111 uint worker_thread_num() const { return _n_worker_threads; } 112 113 int thread_threshold_step() const { return _thread_threshold_step; } 114 115 G1HotCardCache* hot_card_cache() { return &_hot_card_cache; } 116 117 static bool hot_card_cache_enabled() { return G1HotCardCache::default_use_cache(); } 118 }; 119 120 #endif // SHARE_VM_GC_G1_CONCURRENTG1REFINE_HPP