1 /*
   2  * Copyright (c) 2015, 2019, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "precompiled.hpp"
  25 
  26 #include "classfile/classLoaderDataGraph.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "gc/shenandoah/shenandoahRootProcessor.hpp"
  31 #include "gc/shenandoah/shenandoahHeap.hpp"
  32 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
  33 #include "gc/shenandoah/shenandoahStringDedup.hpp"
  34 #include "gc/shenandoah/shenandoahTimingTracker.hpp"
  35 #include "gc/shenandoah/shenandoahUtils.hpp"
  36 #include "gc/shenandoah/shenandoahVMOperations.hpp"
  37 #include "gc/shared/weakProcessor.inline.hpp"
  38 #include "memory/allocation.inline.hpp"
  39 #include "memory/iterator.hpp"
  40 #include "memory/resourceArea.hpp"
  41 #include "runtime/thread.hpp"
  42 #include "services/management.hpp"
  43 
  44 struct PhaseMap {
  45   WeakProcessorPhases::Phase            _weak_processor_phase;
  46   ShenandoahPhaseTimings::GCParPhases   _shenandoah_phase;
  47 };
  48 
  49 static const struct PhaseMap phase_mapping[] = {
  50 #if INCLUDE_JVMTI
  51   {WeakProcessorPhases::jvmti,       ShenandoahPhaseTimings::JVMTIWeakRoots},
  52 #endif
  53 #if INCLUDE_JFR
  54   {WeakProcessorPhases::jfr,         ShenandoahPhaseTimings::JFRWeakRoots},
  55 #endif
  56   {WeakProcessorPhases::jni,         ShenandoahPhaseTimings::JNIWeakRoots},
  57   {WeakProcessorPhases::stringtable, ShenandoahPhaseTimings::StringTableRoots},
  58   {WeakProcessorPhases::vm,          ShenandoahPhaseTimings::VMWeakRoots}
  59 };
  60 
  61 STATIC_ASSERT(sizeof(phase_mapping) / sizeof(PhaseMap) == WeakProcessorPhases::phase_count);
  62 
  63 ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahHeap* heap, uint n_workers,
  64                                                  ShenandoahPhaseTimings::Phase phase) :
  65   _process_strong_tasks(new SubTasksDone(SHENANDOAH_RP_PS_NumElements)),
  66   _srs(n_workers),
  67   _par_state_string(StringTable::weak_storage()),
  68   _phase(phase),
  69   _coderoots_all_iterator(ShenandoahCodeRoots::iterator()),
  70   _weak_processor_timings(n_workers),
  71   _weak_processor_task(&_weak_processor_timings, n_workers),
  72   _processed_weak_roots(false) {
  73   heap->phase_timings()->record_workers_start(_phase);
  74 
  75   if (ShenandoahStringDedup::is_enabled()) {
  76     StringDedup::gc_prologue(false);
  77   }
  78 }
  79 
  80 ShenandoahRootProcessor::~ShenandoahRootProcessor() {
  81   delete _process_strong_tasks;
  82   if (ShenandoahStringDedup::is_enabled()) {
  83     StringDedup::gc_epilogue();
  84   }
  85 
  86   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  87 
  88   if (_processed_weak_roots) {
  89     assert(_weak_processor_timings.max_threads() == n_workers(), "Must match");
  90     for (uint index = 0; index < WeakProcessorPhases::phase_count; index ++) {
  91       weak_processor_timing_to_shenandoah_timing(phase_mapping[index]._weak_processor_phase,
  92                                                  phase_mapping[index]._shenandoah_phase,
  93                                                  worker_times);
  94     }
  95   }
  96 
  97   ShenandoahHeap::heap()->phase_timings()->record_workers_end(_phase);
  98 }
  99 
 100 void ShenandoahRootProcessor::weak_processor_timing_to_shenandoah_timing(const WeakProcessorPhases::Phase wpp,
 101                                                                          const ShenandoahPhaseTimings::GCParPhases spp,
 102                                                                          ShenandoahWorkerTimings* worker_times) const {
 103   if (WeakProcessorPhases::is_serial(wpp)) {
 104     worker_times->record_time_secs(spp, 0, _weak_processor_timings.phase_time_sec(wpp));
 105   } else {
 106     for (uint index = 0; index < _weak_processor_timings.max_threads(); index ++) {
 107       worker_times->record_time_secs(spp, index, _weak_processor_timings.worker_time_sec(index, wpp));
 108     }
 109   }
 110 }
 111 
 112 void ShenandoahRootProcessor::process_all_roots_slow(OopClosure* oops) {
 113   CLDToOopClosure clds(oops, ClassLoaderData::_claim_strong);
 114   CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
 115 
 116   CodeCache::blobs_do(&blobs);
 117   ClassLoaderDataGraph::cld_do(&clds);
 118   Universe::oops_do(oops);
 119   Management::oops_do(oops);
 120   JvmtiExport::oops_do(oops);
 121   JNIHandles::oops_do(oops);
 122   ObjectSynchronizer::oops_do(oops);
 123   SystemDictionary::oops_do(oops);
 124 
 125   // Do thread roots the last. This allows verification code to find
 126   // any broken objects from those special roots first, not the accidental
 127   // dangling reference from the thread root.
 128   Threads::possibly_parallel_oops_do(false, oops, &blobs);
 129 }
 130 
 131 void ShenandoahRootProcessor::process_strong_roots(OopClosure* oops,
 132                                                    CLDClosure* clds,
 133                                                    CodeBlobClosure* blobs,
 134                                                    ThreadClosure* thread_cl,
 135                                                    uint worker_id) {
 136 
 137   process_java_roots(oops, clds, NULL, blobs, thread_cl, worker_id);
 138   process_vm_roots(oops, worker_id);
 139 
 140   _process_strong_tasks->all_tasks_completed(n_workers());
 141 }
 142 
 143 void ShenandoahRootProcessor::process_all_roots(OopClosure* oops,
 144                                                 CLDClosure* clds,
 145                                                 CodeBlobClosure* blobs,
 146                                                 ThreadClosure* thread_cl,
 147                                                 uint worker_id) {
 148 
 149   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
 150   process_java_roots(oops, clds, clds, blobs, thread_cl, worker_id);
 151   process_vm_roots(oops, worker_id);
 152 
 153   if (blobs != NULL) {
 154     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::CodeCacheRoots, worker_id);
 155     _coderoots_all_iterator.possibly_parallel_blobs_do(blobs);
 156   }
 157 
 158   _process_strong_tasks->all_tasks_completed(n_workers());
 159 
 160 }
 161 
 162 class ShenandoahParallelOopsDoThreadClosure : public ThreadClosure {
 163 private:
 164   OopClosure* _f;
 165   CodeBlobClosure* _cf;
 166   ThreadClosure* _thread_cl;
 167 public:
 168   ShenandoahParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf, ThreadClosure* thread_cl) :
 169     _f(f), _cf(cf), _thread_cl(thread_cl) {}
 170 
 171   void do_thread(Thread* t) {
 172     if (_thread_cl != NULL) {
 173       _thread_cl->do_thread(t);
 174     }
 175     t->oops_do(_f, _cf);
 176   }
 177 };
 178 
 179 void ShenandoahRootProcessor::process_java_roots(OopClosure* strong_roots,
 180                                                  CLDClosure* strong_clds,
 181                                                  CLDClosure* weak_clds,
 182                                                  CodeBlobClosure* strong_code,
 183                                                  ThreadClosure* thread_cl,
 184                                                  uint worker_id)
 185 {
 186   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
 187   // Iterating over the CLDG and the Threads are done early to allow us to
 188   // first process the strong CLDs and nmethods and then, after a barrier,
 189   // let the thread process the weak CLDs and nmethods.
 190   {
 191     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::CLDGRoots, worker_id);
 192     _cld_iterator.root_cld_do(strong_clds, weak_clds);
 193   }
 194 
 195   {
 196     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
 197     bool is_par = n_workers() > 1;
 198     ResourceMark rm;
 199     ShenandoahParallelOopsDoThreadClosure cl(strong_roots, strong_code, thread_cl);
 200     Threads::possibly_parallel_threads_do(is_par, &cl);
 201   }
 202 }
 203 
 204 void ShenandoahRootProcessor::process_vm_roots(OopClosure* strong_roots,
 205                                                uint worker_id) {
 206   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
 207   if (_process_strong_tasks->try_claim_task(SHENANDOAH_RP_PS_Universe_oops_do)) {
 208     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::UniverseRoots, worker_id);
 209     Universe::oops_do(strong_roots);
 210   }
 211 
 212   if (_process_strong_tasks->try_claim_task(SHENANDOAH_RP_PS_JNIHandles_oops_do)) {
 213     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::JNIRoots, worker_id);
 214     JNIHandles::oops_do(strong_roots);
 215   }
 216   if (_process_strong_tasks->try_claim_task(SHENANDOAH_RP_PS_Management_oops_do)) {
 217     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ManagementRoots, worker_id);
 218     Management::oops_do(strong_roots);
 219   }
 220   if (_process_strong_tasks->try_claim_task(SHENANDOAH_RP_PS_jvmti_oops_do)) {
 221     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::JVMTIRoots, worker_id);
 222     JvmtiExport::oops_do(strong_roots);
 223   }
 224   if (_process_strong_tasks->try_claim_task(SHENANDOAH_RP_PS_SystemDictionary_oops_do)) {
 225     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::SystemDictionaryRoots, worker_id);
 226     SystemDictionary::oops_do(strong_roots);
 227   }
 228 
 229   {
 230     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ObjectSynchronizerRoots, worker_id);
 231     if (_process_strong_tasks->try_claim_task(SHENANDOAH_RP_PS_ObjectSynchronizer_oops_do)) {
 232       ObjectSynchronizer::oops_do(strong_roots);
 233     }
 234   }
 235 }
 236 
 237 uint ShenandoahRootProcessor::n_workers() const {
 238   return _srs.n_threads();
 239 }
 240 
 241 ShenandoahRootEvacuator::ShenandoahRootEvacuator(ShenandoahHeap* heap, uint n_workers, ShenandoahPhaseTimings::Phase phase) :
 242   _evacuation_tasks(new SubTasksDone(SHENANDOAH_EVAC_NumElements)),
 243   _srs(n_workers),
 244   _phase(phase),
 245   _coderoots_cset_iterator(ShenandoahCodeRoots::cset_iterator()),
 246   _par_state_string(StringTable::weak_storage())
 247 
 248 {
 249   heap->phase_timings()->record_workers_start(_phase);
 250   if (ShenandoahStringDedup::is_enabled()) {
 251     StringDedup::gc_prologue(false);
 252   }
 253 }
 254 
 255 ShenandoahRootEvacuator::~ShenandoahRootEvacuator() {
 256   delete _evacuation_tasks;
 257   if (ShenandoahStringDedup::is_enabled()) {
 258     StringDedup::gc_epilogue();
 259   }
 260   ShenandoahHeap::heap()->phase_timings()->record_workers_end(_phase);
 261 }
 262 
 263 void ShenandoahRootEvacuator::process_evacuate_roots(OopClosure* oops,
 264                                                      CodeBlobClosure* blobs,
 265                                                      uint worker_id) {
 266 
 267   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
 268   {
 269     bool is_par = n_workers() > 1;
 270     ResourceMark rm;
 271     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
 272 
 273     Threads::possibly_parallel_oops_do(is_par, oops, NULL);
 274   }
 275 
 276   if (blobs != NULL) {
 277     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::CodeCacheRoots, worker_id);
 278     _coderoots_cset_iterator.possibly_parallel_blobs_do(blobs);
 279   }
 280 
 281   if (ShenandoahStringDedup::is_enabled()) {
 282     ShenandoahForwardedIsAliveClosure is_alive;
 283     ShenandoahStringDedup::parallel_oops_do(&is_alive, oops, worker_id);
 284   }
 285 
 286   if (_evacuation_tasks->try_claim_task(SHENANDOAH_EVAC_Universe_oops_do)) {
 287     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::UniverseRoots, worker_id);
 288     Universe::oops_do(oops);
 289   }
 290 
 291   if (_evacuation_tasks->try_claim_task(SHENANDOAH_EVAC_Management_oops_do)) {
 292     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ManagementRoots, worker_id);
 293     Management::oops_do(oops);
 294   }
 295 
 296   if (_evacuation_tasks->try_claim_task(SHENANDOAH_EVAC_jvmti_oops_do)) {
 297     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::JVMTIRoots, worker_id);
 298     JvmtiExport::oops_do(oops);
 299     ShenandoahForwardedIsAliveClosure is_alive;
 300     JvmtiExport::weak_oops_do(&is_alive, oops);
 301   }
 302 
 303   if (_evacuation_tasks->try_claim_task(SHENANDOAH_EVAC_SystemDictionary_oops_do)) {
 304     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::SystemDictionaryRoots, worker_id);
 305     SystemDictionary::oops_do(oops);
 306   }
 307 
 308   if (_evacuation_tasks->try_claim_task(SHENANDOAH_EVAC_ObjectSynchronizer_oops_do)) {
 309     ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ObjectSynchronizerRoots, worker_id);
 310     ObjectSynchronizer::oops_do(oops);
 311   }
 312 
 313 }
 314 
 315 uint ShenandoahRootEvacuator::n_workers() const {
 316   return _srs.n_threads();
 317 }
 318 
 319 // Implemenation of ParallelCLDRootIterator
 320 ParallelCLDRootIterator::ParallelCLDRootIterator() {
 321   assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
 322   ClassLoaderDataGraph::clear_claimed_marks();
 323 }
 324 
 325 void ParallelCLDRootIterator::root_cld_do(CLDClosure* strong, CLDClosure* weak) {
 326     ClassLoaderDataGraph::roots_cld_do(strong, weak);
 327 }