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/referenceProcessor.hpp" 44 #include "memory/allocation.inline.hpp" 45 #include "memory/universe.hpp" 46 #include "runtime/mutex.hpp" 47 #include "services/management.hpp" 48 #include "utilities/macros.hpp" 49 50 G1RootProcessor::G1RootProcessor(G1CollectedHeap* g1h, uint n_workers) : 51 _g1h(g1h), 52 _process_strong_tasks(G1RP_PS_NumElements), 53 _srs(n_workers) {} 54 55 void G1RootProcessor::evacuate_roots(G1ParScanThreadState* pss, uint worker_id) { 56 G1GCPhaseTimes* phase_times = _g1h->phase_times(); 57 58 G1EvacPhaseTimesTracker timer(phase_times, pss, G1GCPhaseTimes::ExtRootScan, worker_id); 59 60 G1EvacuationRootClosures* closures = pss->closures(); 61 process_java_roots(closures, phase_times, worker_id); 62 63 process_vm_roots(closures, phase_times, worker_id); 64 65 { 66 // Now the CM ref_processor roots. 67 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CMRefRoots, worker_id); 68 if (_process_strong_tasks.try_claim_task(G1RP_PS_refProcessor_oops_do)) { 69 // We need to treat the discovered reference lists of the 70 // concurrent mark ref processor as roots and keep entries 71 // (which are added by the marking threads) on them live 72 // until they can be processed at the end of marking. 73 _g1h->ref_processor_cm()->weak_oops_do(closures->strong_oops()); 74 } 75 } 76 77 _process_strong_tasks.all_tasks_completed(n_workers()); 78 } 79 80 // Adaptor to pass the closures to the strong roots in the VM. 81 class StrongRootsClosures : public G1RootClosures { 82 OopClosure* _roots; 83 CLDClosure* _clds; 84 CodeBlobClosure* _blobs; 85 public: 86 StrongRootsClosures(OopClosure* roots, CLDClosure* clds, CodeBlobClosure* blobs) : 87 _roots(roots), _clds(clds), _blobs(blobs) {} 88 89 OopClosure* weak_oops() { return NULL; } 90 OopClosure* strong_oops() { return _roots; } 91 92 CLDClosure* weak_clds() { return NULL; } 93 CLDClosure* strong_clds() { return _clds; } 94 95 CodeBlobClosure* strong_codeblobs() { return _blobs; } 96 }; 97 98 void G1RootProcessor::process_strong_roots(OopClosure* oops, 99 CLDClosure* clds, 100 CodeBlobClosure* blobs) { 101 StrongRootsClosures closures(oops, clds, blobs); 102 103 process_java_roots(&closures, NULL, 0); 104 process_vm_roots(&closures, NULL, 0); 105 106 _process_strong_tasks.all_tasks_completed(n_workers()); 107 } 108 109 // Adaptor to pass the closures to all the roots in the VM. 110 class AllRootsClosures : public G1RootClosures { 111 OopClosure* _roots; 112 CLDClosure* _clds; 113 public: 114 AllRootsClosures(OopClosure* roots, CLDClosure* clds) : 115 _roots(roots), _clds(clds) {} 116 117 OopClosure* weak_oops() { return _roots; } 118 OopClosure* strong_oops() { return _roots; } 119 120 // By returning the same CLDClosure for both weak and strong CLDs we ensure 121 // that a single walk of the CLDG will invoke the closure on all CLDs i the 122 // system. 123 CLDClosure* weak_clds() { return _clds; } 124 CLDClosure* strong_clds() { return _clds; } 125 126 // We don't want to visit code blobs more than once, so we return NULL for the 127 // strong case and walk the entire code cache as a separate step. 128 CodeBlobClosure* strong_codeblobs() { return NULL; } 129 }; 130 131 void G1RootProcessor::process_all_roots(OopClosure* oops, 132 CLDClosure* clds, 133 CodeBlobClosure* blobs) { 134 AllRootsClosures closures(oops, clds); 135 136 process_java_roots(&closures, NULL, 0); 137 process_vm_roots(&closures, NULL, 0); 138 139 process_code_cache_roots(blobs, NULL, 0); 140 141 _process_strong_tasks.all_tasks_completed(n_workers()); 142 } 143 144 void G1RootProcessor::process_java_roots(G1RootClosures* closures, 145 G1GCPhaseTimes* phase_times, 146 uint worker_id) { 147 // We need to make make sure that the "strong" nmethods are processed first 148 // using the strong closure. Only after that we process the weakly reachable 149 // nmethods. 150 // We need to strictly separate the strong and weak nmethod processing because 151 // any processing claims that nmethod, i.e. will not be iterated again. 152 // Which means if an nmethod is processed first and claimed, the strong processing 153 // will not happen, and the oops reachable by that nmethod will not be marked 154 // properly. 155 // 156 // That is why we process strong nmethods first, synchronize all threads via a 157 // barrier, and only then allow weak processing. To minimize the wait time at 158 // that barrier we do the strong nmethod processing first, and immediately after- 159 // wards indicate that that thread is done. Hopefully other root processing after 160 // nmethod processing is enough so there is no need to wait. 161 // 162 // This is only required in the concurrent start pause with class unloading enabled. 163 { 164 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ThreadRoots, worker_id); 165 bool is_par = n_workers() > 1; 166 Threads::possibly_parallel_oops_do(is_par, 167 closures->strong_oops(), 168 closures->strong_codeblobs()); 169 } 170 171 { 172 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CLDGRoots, worker_id); 173 if (_process_strong_tasks.try_claim_task(G1RP_PS_ClassLoaderDataGraph_oops_do)) { 174 ClassLoaderDataGraph::roots_cld_do(closures->strong_clds(), closures->weak_clds()); 175 } 176 } 177 } 178 179 void G1RootProcessor::process_vm_roots(G1RootClosures* closures, 180 G1GCPhaseTimes* phase_times, 181 uint worker_id) { 182 OopClosure* strong_roots = closures->strong_oops(); 183 184 { 185 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::UniverseRoots, worker_id); 186 if (_process_strong_tasks.try_claim_task(G1RP_PS_Universe_oops_do)) { 187 Universe::oops_do(strong_roots); 188 } 189 } 190 191 { 192 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JNIRoots, worker_id); 193 if (_process_strong_tasks.try_claim_task(G1RP_PS_JNIHandles_oops_do)) { 194 JNIHandles::oops_do(strong_roots); 195 } 196 } 197 198 { 199 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ObjectSynchronizerRoots, worker_id); 200 if (_process_strong_tasks.try_claim_task(G1RP_PS_ObjectSynchronizer_oops_do)) { 201 ObjectSynchronizer::oops_do(strong_roots); 202 } 203 } 204 205 { 206 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ManagementRoots, worker_id); 207 if (_process_strong_tasks.try_claim_task(G1RP_PS_Management_oops_do)) { 208 Management::oops_do(strong_roots); 209 } 210 } 211 212 { 213 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JVMTIRoots, worker_id); 214 if (_process_strong_tasks.try_claim_task(G1RP_PS_jvmti_oops_do)) { 215 JvmtiExport::oops_do(strong_roots); 216 } 217 } 218 219 #if INCLUDE_AOT 220 if (UseAOT) { 221 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::AOTCodeRoots, worker_id); 222 if (_process_strong_tasks.try_claim_task(G1RP_PS_aot_oops_do)) { 223 AOTLoader::oops_do(strong_roots); 224 } 225 } 226 #endif 227 228 { 229 G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::VMGlobalRoots, worker_id); 230 if (_process_strong_tasks.try_claim_task(G1RP_PS_VMGlobal_oops_do)) { 231 OopStorageSet::vm_global()->oops_do(strong_roots); 232 } 233 } 234 } 235 236 void G1RootProcessor::process_code_cache_roots(CodeBlobClosure* code_closure, 237 G1GCPhaseTimes* phase_times, 238 uint worker_id) { 239 if (_process_strong_tasks.try_claim_task(G1RP_PS_CodeCache_oops_do)) { 240 CodeCache::blobs_do(code_closure); 241 } 242 } 243 244 uint G1RootProcessor::n_workers() const { 245 return _srs.n_threads(); 246 } --- EOF ---