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 "precompiled.hpp" 26 #include "gc/g1/g1OopClosures.inline.hpp" 27 #include "gc/g1/g1RootClosures.hpp" 28 #include "gc/g1/g1SharedClosures.hpp" 29 30 // Closures used for standard G1 evacuation. 31 class G1EvacuationClosures : public G1EvacuationRootClosures { 32 G1SharedClosures<G1MarkNone> _closures; 33 34 public: 35 G1EvacuationClosures(G1CollectedHeap* g1h, 36 G1ParScanThreadState* pss, 37 bool in_young_gc) : 38 _closures(g1h, pss, in_young_gc, /* must_claim_cld */ false) {} 39 40 OopClosure* weak_oops() { return &_closures._buffered_oops; } 41 OopClosure* strong_oops() { return &_closures._buffered_oops; } 42 43 CLDClosure* weak_clds() { return &_closures._clds; } 44 CLDClosure* strong_clds() { return &_closures._clds; } 45 CLDClosure* second_pass_weak_clds() { return NULL; } 46 47 CodeBlobClosure* strong_codeblobs() { return &_closures._codeblobs; } 48 CodeBlobClosure* weak_codeblobs() { return &_closures._codeblobs; } 49 50 void flush() { _closures._buffered_oops.done(); } 51 double closure_app_seconds() { return _closures._buffered_oops.closure_app_seconds(); } 52 53 OopClosure* raw_strong_oops() { return &_closures._oops; } 54 55 bool trace_metadata() { return false; } 56 }; 57 58 // Closures used during initial mark. 59 // The treatment of "weak" roots is selectable through the template parameter, 60 // this is usually used to control unloading of classes and interned strings. 61 template <G1Mark MarkWeak> 62 class G1InitialMarkClosures : public G1EvacuationRootClosures { 63 G1SharedClosures<G1MarkFromRoot> _strong; 64 G1SharedClosures<MarkWeak> _weak; 65 66 // Filter method to help with returning the appropriate closures 67 // depending on the class template parameter. 68 template <G1Mark Mark, typename T> 69 T* null_if(T* t) { 70 if (Mark == MarkWeak) { 71 return NULL; 72 } 73 return t; 74 } 75 76 public: 77 G1InitialMarkClosures(G1CollectedHeap* g1h, 78 G1ParScanThreadState* pss) : 79 _strong(g1h, pss, /* process_only_dirty_klasses */ false, /* must_claim_cld */ true), 80 _weak(g1h, pss, /* process_only_dirty_klasses */ false, /* must_claim_cld */ true) {} 81 82 OopClosure* weak_oops() { return &_weak._buffered_oops; } 83 OopClosure* strong_oops() { return &_strong._buffered_oops; } 84 85 // If MarkWeak is G1MarkPromotedFromRoot then the weak CLDs must be processed in a second pass. 86 CLDClosure* weak_clds() { return null_if<G1MarkPromotedFromRoot>(&_weak._clds); } 87 CLDClosure* strong_clds() { return &_strong._clds; } 88 89 // If MarkWeak is G1MarkFromRoot then all CLDs are processed by the weak and strong variants 90 // return a NULL closure for the following specialized versions in that case. 91 CLDClosure* second_pass_weak_clds() { return null_if<G1MarkFromRoot>(&_weak._clds); } 92 93 CodeBlobClosure* strong_codeblobs() { return &_strong._codeblobs; } 94 CodeBlobClosure* weak_codeblobs() { return &_weak._codeblobs; } 95 96 void flush() { 97 _strong._buffered_oops.done(); 98 _weak._buffered_oops.done(); 99 } 100 101 double closure_app_seconds() { 102 return _strong._buffered_oops.closure_app_seconds() + 103 _weak._buffered_oops.closure_app_seconds(); 104 } 105 106 OopClosure* raw_strong_oops() { return &_strong._oops; } 107 108 // If we are not marking all weak roots then we are tracing 109 // which metadata is alive. 110 bool trace_metadata() { return MarkWeak == G1MarkPromotedFromRoot; } 111 }; 112 113 G1EvacuationRootClosures* G1EvacuationRootClosures::create_root_closures(G1ParScanThreadState* pss, G1CollectedHeap* g1h) { 114 G1EvacuationRootClosures* res = NULL; 115 if (g1h->collector_state()->in_initial_mark_gc()) { 116 if (ClassUnloadingWithConcurrentMark) { 117 res = new G1InitialMarkClosures<G1MarkPromotedFromRoot>(g1h, pss); 118 } else { 119 res = new G1InitialMarkClosures<G1MarkFromRoot>(g1h, pss); 120 } 121 } else { 122 res = new G1EvacuationClosures(g1h, pss, g1h->collector_state()->in_young_only_phase()); 123 } 124 return res; 125 }