1 /* 2 * Copyright (c) 2001, 2020, 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_GC_G1_G1CONCURRENTREFINETHREAD_HPP 26 #define SHARE_GC_G1_G1CONCURRENTREFINETHREAD_HPP 27 28 #include "gc/shared/concurrentGCThread.hpp" 29 #include "utilities/ticks.hpp" 30 31 // Forward Decl. 32 class G1ConcurrentRefine; 33 class G1ConcurrentRefineStats; 34 35 // One or more G1 Concurrent Refinement Threads may be active if concurrent 36 // refinement is in progress. 37 class G1ConcurrentRefineThread: public ConcurrentGCThread { 38 friend class VMStructs; 39 friend class G1CollectedHeap; 40 41 double _vtime_start; // Initial virtual time. 42 double _vtime_accum; // Accumulated virtual time. 43 44 G1ConcurrentRefineStats* _refinement_stats; 45 46 uint _worker_id; 47 48 // _notifier and _should_notify form a single-reader / multi-writer 49 // notification mechanism. The owning concurrent refinement thread is the 50 // single reader. The writers are (other) threads that call activate() on 51 // the thread. The i-th concurrent refinement thread is responsible for 52 // activating thread i+1 if the number of buffers in the queue exceeds a 53 // threshold for that i+1th thread. The 0th (primary) thread is activated 54 // by threads that add cards to the dirty card queue set when the primary 55 // thread's threshold is exceeded. activate() is also used to wake up the 56 // threads during termination, so even the non-primary thread case is 57 // multi-writer. 58 Semaphore* _notifier; 59 volatile bool _should_notify; 60 61 // Called when no refinement work found for this thread. 62 // Returns true if should deactivate. 63 bool maybe_deactivate(bool more_work); 64 65 G1ConcurrentRefine* _cr; 66 67 void wait_for_completed_buffers(); 68 69 virtual void run_service(); 70 virtual void stop_service(); 71 72 public: 73 G1ConcurrentRefineThread(G1ConcurrentRefine* cg1r, uint worker_id); 74 virtual ~G1ConcurrentRefineThread(); 75 76 // Activate this thread. 77 void activate(); 78 refinement_stats() const79 G1ConcurrentRefineStats* refinement_stats() const { 80 return _refinement_stats; 81 } 82 83 // Total virtual time so far. vtime_accum()84 double vtime_accum() { return _vtime_accum; } 85 }; 86 87 #endif // SHARE_GC_G1_G1CONCURRENTREFINETHREAD_HPP 88