1 /*
   2  * Copyright (c) 2015, 2018, 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/classLoaderData.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
  31 #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"
  32 #include "gc/shenandoah/shenandoahHeap.hpp"
  33 #include "gc/shenandoah/shenandoahHeuristics.hpp"
  34 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
  35 #include "gc/shenandoah/shenandoahStringDedup.hpp"
  36 #include "gc/shenandoah/shenandoahTimingTracker.hpp"
  37 #include "gc/shenandoah/shenandoahVMOperations.hpp"
  38 #include "gc/shared/weakProcessor.hpp"
  39 #include "memory/allocation.inline.hpp"
  40 #include "memory/iterator.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "runtime/thread.hpp"
  43 #include "services/management.hpp"
  44 
  45 ShenandoahSerialRoot::ShenandoahSerialRoot(ShenandoahSerialRoot::OopsDo oops_do, ShenandoahPhaseTimings::GCParPhases phase) :
  46   _claimed(false), _oops_do(oops_do), _phase(phase) {
  47 }
  48 
  49 void ShenandoahSerialRoot::oops_do(OopClosure* cl, uint worker_id) {
  50   if (!_claimed && Atomic::cmpxchg(true, &_claimed, false) == false) {
  51     ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  52     ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);
  53     _oops_do(cl);
  54   }
  55 }
  56 
  57 ShenandoahSerialRoots::ShenandoahSerialRoots() :
  58   _universe_root(&ShenandoahSerialRoots::universe_oops_do, ShenandoahPhaseTimings::UniverseRoots),
  59   _object_synchronizer_root(&ObjectSynchronizer::oops_do, ShenandoahPhaseTimings::ObjectSynchronizerRoots),
  60   _management_root(&Management::oops_do, ShenandoahPhaseTimings::ManagementRoots),
  61   _system_dictionary_root(&SystemDictionary::oops_do, ShenandoahPhaseTimings::SystemDictionaryRoots),
  62   _jvmti_root(&JvmtiExport::oops_do, ShenandoahPhaseTimings::JVMTIRoots) {
  63 }
  64 
  65 void ShenandoahSerialRoots::oops_do(OopClosure* cl, uint worker_id) {
  66   _universe_root.oops_do(cl, worker_id);
  67   _object_synchronizer_root.oops_do(cl, worker_id);
  68   _management_root.oops_do(cl, worker_id);
  69   _system_dictionary_root.oops_do(cl, worker_id);
  70   _jvmti_root.oops_do(cl, worker_id);
  71 }
  72 
  73 ShenandoahJNIHandleRoots::ShenandoahJNIHandleRoots() :
  74   ShenandoahSerialRoot(&JNIHandles::oops_do, ShenandoahPhaseTimings::JNIRoots) {
  75 }
  76 
  77 ShenandoahThreadRoots::ShenandoahThreadRoots(bool is_par) : _is_par(is_par) {
  78   Threads::change_thread_claim_parity();
  79 }
  80 
  81 void ShenandoahThreadRoots::oops_do(OopClosure* oops_cl, CodeBlobClosure* code_cl, uint worker_id) {
  82   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  83   ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
  84   ResourceMark rm;
  85   Threads::possibly_parallel_oops_do(_is_par, oops_cl, code_cl);
  86 }
  87 
  88 void ShenandoahThreadRoots::threads_do(ThreadClosure* tc, uint worker_id) {
  89   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  90   ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
  91   ResourceMark rm;
  92   Threads::possibly_parallel_threads_do(_is_par, tc);
  93 }
  94 
  95 ShenandoahThreadRoots::~ShenandoahThreadRoots() {
  96   Threads::assert_all_threads_claimed();
  97 }
  98 
  99 ShenandoahWeakRoots::ShenandoahWeakRoots(uint n_workers) :
 100   _par_state_string(StringTable::weak_storage()),
 101   _claimed(false) {
 102 }
 103 
 104 ShenandoahWeakRoots::~ShenandoahWeakRoots() {
 105 }
 106 
 107 ShenandoahStringDedupRoots::ShenandoahStringDedupRoots() {
 108   if (ShenandoahStringDedup::is_enabled()) {
 109     StringDedup::gc_prologue(false);
 110   }
 111 }
 112 
 113 ShenandoahStringDedupRoots::~ShenandoahStringDedupRoots() {
 114   if (ShenandoahStringDedup::is_enabled()) {
 115     StringDedup::gc_epilogue();
 116   }
 117 }
 118 
 119 void ShenandoahStringDedupRoots::oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {
 120   if (ShenandoahStringDedup::is_enabled()) {
 121     ShenandoahStringDedup::parallel_oops_do(is_alive, keep_alive, worker_id);
 122   }
 123 }
 124 
 125 ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahPhaseTimings::Phase phase) :
 126   _heap(ShenandoahHeap::heap()),
 127   _phase(phase) {
 128   assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
 129   _heap->phase_timings()->record_workers_start(_phase);
 130 }
 131 
 132 ShenandoahRootProcessor::~ShenandoahRootProcessor() {
 133   assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
 134   _heap->phase_timings()->record_workers_end(_phase);
 135 }
 136 
 137 ShenandoahRootEvacuator::ShenandoahRootEvacuator(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
 138   ShenandoahRootProcessor(phase),
 139   _thread_roots(n_workers > 1),
 140   _weak_roots(n_workers) {
 141 }
 142 
 143 void ShenandoahRootEvacuator::roots_do(uint worker_id, OopClosure* oops) {
 144   MarkingCodeBlobClosure blobsCl(oops, CodeBlobToOopClosure::FixRelocations);
 145   CLDToOopClosure clds(oops);
 146   CLDToOopClosure* weak_clds = ShenandoahHeap::heap()->unload_classes() ? NULL : &clds;
 147 
 148   AlwaysTrueClosure always_true;
 149 
 150   _serial_roots.oops_do(oops, worker_id);
 151   _jni_roots.oops_do(oops, worker_id);
 152 
 153   _thread_roots.oops_do(oops, NULL, worker_id);
 154   _cld_roots.cld_do(&clds, worker_id);
 155   _code_roots.code_blobs_do(&blobsCl, worker_id);
 156 
 157   _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, worker_id);
 158   _dedup_roots.oops_do(&always_true, oops, worker_id);
 159 }
 160 
 161 ShenandoahRootUpdater::ShenandoahRootUpdater(uint n_workers, ShenandoahPhaseTimings::Phase phase, bool update_code_cache) :
 162   ShenandoahRootProcessor(phase),
 163   _thread_roots(n_workers > 1),
 164   _weak_roots(n_workers),
 165   _update_code_cache(update_code_cache) {
 166 }
 167 
 168 ShenandoahRootAdjuster::ShenandoahRootAdjuster(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
 169   ShenandoahRootProcessor(phase),
 170   _thread_roots(n_workers > 1),
 171   _weak_roots(n_workers) {
 172   assert(ShenandoahHeap::heap()->is_full_gc_in_progress(), "Full GC only");
 173 }
 174 
 175 void ShenandoahRootAdjuster::roots_do(uint worker_id, OopClosure* oops) {
 176   CodeBlobToOopClosure adjust_code_closure(oops, CodeBlobToOopClosure::FixRelocations);
 177   CLDToOopClosure adjust_cld_closure(oops);
 178   AlwaysTrueClosure always_true;
 179 
 180   _serial_roots.oops_do(oops, worker_id);
 181   _jni_roots.oops_do(oops, worker_id);
 182 
 183   _thread_roots.oops_do(oops, NULL, worker_id);
 184   _cld_roots.cld_do(&adjust_cld_closure, worker_id);
 185   _code_roots.code_blobs_do(&adjust_code_closure, worker_id);
 186 
 187   _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, worker_id);
 188   _dedup_roots.oops_do(&always_true, oops, worker_id);
 189 }
 190 
 191  ShenandoahHeapIterationRootScanner::ShenandoahHeapIterationRootScanner() :
 192    ShenandoahRootProcessor(ShenandoahPhaseTimings::_num_phases),
 193    _thread_roots(false /*is par*/) {
 194  }
 195 
 196  void ShenandoahHeapIterationRootScanner::roots_do(OopClosure* oops) {
 197    assert(Thread::current()->is_VM_thread(), "Only by VM thread");
 198    // Must use _claim_none to avoid interfering with concurrent CLDG iteration
 199    CLDToOopClosure clds(oops, false);
 200    MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);
 201    ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);
 202    ResourceMark rm;
 203 
 204    _serial_roots.oops_do(oops, 0);
 205    _jni_roots.oops_do(oops, 0);
 206    _cld_roots.cld_do(&clds, 0);
 207    _thread_roots.threads_do(&tc_cl, 0);
 208    _code_roots.code_blobs_do(&code, 0);
 209  }
 210 
 211  void ShenandoahHeapIterationRootScanner::strong_roots_do(OopClosure* oops) {
 212    assert(Thread::current()->is_VM_thread(), "Only by VM thread");
 213    // Must use _claim_none to avoid interfering with concurrent CLDG iteration
 214    CLDToOopClosure clds(oops, false);
 215    MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);
 216    ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);
 217    ResourceMark rm;
 218 
 219    _serial_roots.oops_do(oops, 0);
 220    _jni_roots.oops_do(oops, 0);
 221    _cld_roots.always_strong_cld_do(&clds, 0);
 222    _thread_roots.threads_do(&tc_cl, 0);
 223  }