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 ---