rev 59957 : imported patch 8247819-stefank-review
1 /* 2 * Copyright (c) 2015, 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 #include "precompiled.hpp" 26 #include "aot/aotLoader.hpp" 27 #include "classfile/classLoaderDataGraph.hpp" 28 #include "classfile/stringTable.hpp" 29 #include "code/codeCache.hpp" 30 #include "gc/g1/g1BarrierSet.hpp" 31 #include "gc/g1/g1CodeBlobClosure.hpp" 32 #include "gc/g1/g1CollectedHeap.inline.hpp" 33 #include "gc/g1/g1CollectorState.hpp" 34 #include "gc/g1/g1GCParPhaseTimesTracker.hpp" 35 #include "gc/g1/g1GCPhaseTimes.hpp" 36 #include "gc/g1/g1ParScanThreadState.inline.hpp" 37 #include "gc/g1/g1Policy.hpp" 38 #include "gc/g1/g1RootClosures.hpp" 39 #include "gc/g1/g1RootProcessor.hpp" 40 #include "gc/g1/heapRegion.inline.hpp" 41 #include "gc/shared/oopStorage.inline.hpp" 42 #include "gc/shared/oopStorageSet.hpp" 43 #include "gc/shared/oopStorageSetParState.inline.hpp" 44 #include "gc/shared/referenceProcessor.hpp" 45 #include "memory/allocation.inline.hpp" 46 #include "memory/universe.hpp" 47 #include "runtime/mutex.hpp" 48 #include "services/management.hpp" 49 #include "utilities/macros.hpp" 50 51 G1RootProcessor::G1RootProcessor(G1CollectedHeap* g1h, uint n_workers) : 52 _g1h(g1h), 53 _process_strong_tasks(G1RP_PS_NumElements), 54 _srs(n_workers) {} 55 56 void G1RootProcessor::evacuate_roots(G1ParScanThreadState* pss, uint worker_id) { 57 G1GCPhaseTimes* phase_times = _g1h->phase_times(); 58 59 G1EvacPhaseTimesTracker timer(phase_times, pss, G1GCPhaseTimes::ExtRootScan, worker_id); 60 61 G1EvacuationRootClosures* closures = pss->closures(); 62 process_java_roots(closures, phase_times, worker_id); 63 64 process_vm_roots(closures, phase_times, worker_id); 65 66 { 67 // Now the CM ref_processor roots. 68 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CMRefRoots, worker_id); 69 if (_process_strong_tasks.try_claim_task(G1RP_PS_refProcessor_oops_do)) { 70 // We need to treat the discovered reference lists of the 71 // concurrent mark ref processor as roots and keep entries 72 // (which are added by the marking threads) on them live 73 // until they can be processed at the end of marking. 74 _g1h->ref_processor_cm()->weak_oops_do(closures->strong_oops()); 75 } 76 } 77 78 _process_strong_tasks.all_tasks_completed(n_workers()); 79 } 80 81 // Adaptor to pass the closures to the strong roots in the VM. 82 class StrongRootsClosures : public G1RootClosures { 83 OopClosure* _roots; 84 CLDClosure* _clds; 85 CodeBlobClosure* _blobs; 86 public: 87 StrongRootsClosures(OopClosure* roots, CLDClosure* clds, CodeBlobClosure* blobs) : 88 _roots(roots), _clds(clds), _blobs(blobs) {} 89 90 OopClosure* weak_oops() { return NULL; } 91 OopClosure* strong_oops() { return _roots; } 92 93 CLDClosure* weak_clds() { return NULL; } 94 CLDClosure* strong_clds() { return _clds; } 95 96 CodeBlobClosure* strong_codeblobs() { return _blobs; } 97 }; 98 99 void G1RootProcessor::process_strong_roots(OopClosure* oops, 100 CLDClosure* clds, 101 CodeBlobClosure* blobs) { 102 StrongRootsClosures closures(oops, clds, blobs); 103 104 process_java_roots(&closures, NULL, 0); 105 process_vm_roots(&closures, NULL, 0); 106 107 _process_strong_tasks.all_tasks_completed(n_workers()); 108 } 109 110 // Adaptor to pass the closures to all the roots in the VM. 111 class AllRootsClosures : public G1RootClosures { 112 OopClosure* _roots; 113 CLDClosure* _clds; 114 public: 115 AllRootsClosures(OopClosure* roots, CLDClosure* clds) : 116 _roots(roots), _clds(clds) {} 117 118 OopClosure* weak_oops() { return _roots; } 119 OopClosure* strong_oops() { return _roots; } 120 121 // By returning the same CLDClosure for both weak and strong CLDs we ensure 122 // that a single walk of the CLDG will invoke the closure on all CLDs i the 123 // system. 124 CLDClosure* weak_clds() { return _clds; } 125 CLDClosure* strong_clds() { return _clds; } 126 127 // We don't want to visit code blobs more than once, so we return NULL for the 128 // strong case and walk the entire code cache as a separate step. 129 CodeBlobClosure* strong_codeblobs() { return NULL; } 130 }; 131 132 void G1RootProcessor::process_all_roots(OopClosure* oops, 133 CLDClosure* clds, 134 CodeBlobClosure* blobs) { 135 AllRootsClosures closures(oops, clds); 136 137 process_java_roots(&closures, NULL, 0); 138 process_vm_roots(&closures, NULL, 0); 139 140 process_code_cache_roots(blobs, NULL, 0); 141 142 _process_strong_tasks.all_tasks_completed(n_workers()); 143 } 144 145 void G1RootProcessor::process_java_roots(G1RootClosures* closures, 146 G1GCPhaseTimes* phase_times, 147 uint worker_id) { 148 // We need to make make sure that the "strong" nmethods are processed first 149 // using the strong closure. Only after that we process the weakly reachable 150 // nmethods. 151 // We need to strictly separate the strong and weak nmethod processing because 152 // any processing claims that nmethod, i.e. will not be iterated again. 153 // Which means if an nmethod is processed first and claimed, the strong processing 154 // will not happen, and the oops reachable by that nmethod will not be marked 155 // properly. 156 // 157 // That is why we process strong nmethods first, synchronize all threads via a 158 // barrier, and only then allow weak processing. To minimize the wait time at 159 // that barrier we do the strong nmethod processing first, and immediately after- 160 // wards indicate that that thread is done. Hopefully other root processing after 161 // nmethod processing is enough so there is no need to wait. 162 // 163 // This is only required in the concurrent start pause with class unloading enabled. 164 { 165 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ThreadRoots, worker_id); 166 bool is_par = n_workers() > 1; 167 Threads::possibly_parallel_oops_do(is_par, 168 closures->strong_oops(), 169 closures->strong_codeblobs()); 170 } 171 172 { 173 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CLDGRoots, worker_id); 174 if (_process_strong_tasks.try_claim_task(G1RP_PS_ClassLoaderDataGraph_oops_do)) { 175 ClassLoaderDataGraph::roots_cld_do(closures->strong_clds(), closures->weak_clds()); 176 } 177 } 178 } 179 180 void G1RootProcessor::process_vm_roots(G1RootClosures* closures, 181 G1GCPhaseTimes* phase_times, 182 uint worker_id) { 183 OopClosure* strong_roots = closures->strong_oops(); 184 185 { 186 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::UniverseRoots, worker_id); 187 if (_process_strong_tasks.try_claim_task(G1RP_PS_Universe_oops_do)) { 188 Universe::oops_do(strong_roots); 189 } 190 } 191 192 { 193 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ObjectSynchronizerRoots, worker_id); 194 if (_process_strong_tasks.try_claim_task(G1RP_PS_ObjectSynchronizer_oops_do)) { 195 ObjectSynchronizer::oops_do(strong_roots); 196 } 197 } 198 199 { 200 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ManagementRoots, worker_id); 201 if (_process_strong_tasks.try_claim_task(G1RP_PS_Management_oops_do)) { 202 Management::oops_do(strong_roots); 203 } 204 } 205 206 { 207 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JVMTIRoots, worker_id); 208 if (_process_strong_tasks.try_claim_task(G1RP_PS_jvmti_oops_do)) { 209 JvmtiExport::oops_do(strong_roots); 210 } 211 } 212 213 #if INCLUDE_AOT 214 if (UseAOT) { 215 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::AOTCodeRoots, worker_id); 216 if (_process_strong_tasks.try_claim_task(G1RP_PS_aot_oops_do)) { 217 AOTLoader::oops_do(strong_roots); 218 } 219 } 220 #endif 221 222 for (int i = 0; i < _oop_storage_set_strong_par_state.par_state_count(); ++i) { 223 G1GCPhaseTimes::GCParPhases phase = G1GCPhaseTimes::GCParPhases(G1GCPhaseTimes::StrongOopStorageSetRoots + i); 224 G1GCParPhaseTimesTracker x(phase_times, phase, worker_id); 225 _oop_storage_set_strong_par_state.par_state(i)->oops_do(closures->strong_oops()); 226 } 227 } 228 229 void G1RootProcessor::process_code_cache_roots(CodeBlobClosure* code_closure, 230 G1GCPhaseTimes* phase_times, 231 uint worker_id) { 232 if (_process_strong_tasks.try_claim_task(G1RP_PS_CodeCache_oops_do)) { 233 CodeCache::blobs_do(code_closure); 234 } 235 } 236 237 uint G1RootProcessor::n_workers() const { 238 return _srs.n_threads(); 239 } --- EOF ---