1 /* 2 * Copyright (c) 2017, 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 #ifndef SHARE_GC_Z_ZMARKTERMINATE_INLINE_HPP 25 #define SHARE_GC_Z_ZMARKTERMINATE_INLINE_HPP 26 27 #include "runtime/atomic.hpp" 28 #include "runtime/orderAccess.hpp" 29 30 inline ZMarkTerminate::ZMarkTerminate() : 31 _nworkers(0), 32 _nworking_stage0(0), 33 _nworking_stage1(0) {} 34 35 inline bool ZMarkTerminate::enter_stage(volatile uint* nworking_stage) { 36 return Atomic::sub(1u, nworking_stage) == 0; 37 } 38 39 inline void ZMarkTerminate::exit_stage(volatile uint* nworking_stage) { 40 Atomic::add(nworking_stage, 1u); 41 } 42 43 inline bool ZMarkTerminate::try_exit_stage(volatile uint* nworking_stage) { 44 uint nworking = Atomic::load(nworking_stage); 45 46 for (;;) { 47 if (nworking == 0) { 48 return false; 49 } 50 51 const uint new_nworking = nworking + 1; 52 const uint prev_nworking = Atomic::cmpxchg(new_nworking, nworking_stage, nworking); 53 if (prev_nworking == nworking) { 54 // Success 55 return true; 56 } 57 58 // Retry 59 nworking = prev_nworking; 60 } 61 } 62 63 inline void ZMarkTerminate::reset(uint nworkers) { 64 _nworkers = _nworking_stage0 = _nworking_stage1 = nworkers; 65 } 66 67 inline bool ZMarkTerminate::enter_stage0() { 68 return enter_stage(&_nworking_stage0); 69 } 70 71 inline void ZMarkTerminate::exit_stage0() { 72 exit_stage(&_nworking_stage0); 73 } 74 75 inline bool ZMarkTerminate::try_exit_stage0() { 76 return try_exit_stage(&_nworking_stage0); 77 } 78 79 inline bool ZMarkTerminate::enter_stage1() { 80 return enter_stage(&_nworking_stage1); 81 } 82 83 inline bool ZMarkTerminate::try_exit_stage1() { 84 return try_exit_stage(&_nworking_stage1); 85 } 86 87 #endif // SHARE_GC_Z_ZMARKTERMINATE_INLINE_HPP