1 /* 2 * Copyright (c) 2015, 2018, 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 #include "gc/g1/g1CodeBlobClosure.hpp" 26 #include "gc/g1/g1OopClosures.hpp" 27 #include "memory/iterator.hpp" 28 29 class G1CollectedHeap; 30 class G1ParScanThreadState; 31 32 // Simple holder object for a complete set of closures used by the G1 evacuation code. 33 template <G1Mark Mark> 34 class G1SharedClosures { needs_strong_processing()35 static bool needs_strong_processing() { 36 // Request strong code root processing when G1MarkFromRoot is passed in during 37 // initial mark. 38 return Mark == G1MarkFromRoot; 39 } 40 public: 41 G1ParCopyClosure<G1BarrierNone, Mark> _oops; 42 G1ParCopyClosure<G1BarrierCLD, Mark> _oops_in_cld; 43 // We do not need (and actually should not) collect oops from nmethods into the 44 // optional collection set as we already automatically collect the corresponding 45 // nmethods in the region's strong code roots set. So set G1BarrierNoOptRoots in 46 // this closure. 47 // If these were present there would be opportunity for multiple threads to try 48 // to change this oop* at the same time. Since embedded oops are not necessarily 49 // word-aligned, this could lead to word tearing during update and crashes. 50 G1ParCopyClosure<G1BarrierNoOptRoots, Mark> _oops_in_nmethod; 51 52 G1CLDScanClosure _clds; 53 G1CodeBlobClosure _codeblobs; 54 G1SharedClosures(G1CollectedHeap * g1h,G1ParScanThreadState * pss,bool process_only_dirty)55 G1SharedClosures(G1CollectedHeap* g1h, G1ParScanThreadState* pss, bool process_only_dirty) : 56 _oops(g1h, pss), 57 _oops_in_cld(g1h, pss), 58 _oops_in_nmethod(g1h, pss), 59 _clds(&_oops_in_cld, process_only_dirty), 60 _codeblobs(pss->worker_id(), &_oops_in_nmethod, needs_strong_processing()) {} 61 }; 62