1 /*
   2  * Copyright (c) 2005, 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 "classfile/systemDictionary.hpp"
  27 #include "gc/parallel/objectStartArray.hpp"
  28 #include "gc/parallel/parMarkBitMap.inline.hpp"
  29 #include "gc/parallel/parallelScavengeHeap.hpp"
  30 #include "gc/parallel/psCompactionManager.inline.hpp"
  31 #include "gc/parallel/psOldGen.hpp"
  32 #include "gc/parallel/psParallelCompact.inline.hpp"
  33 #include "gc/shared/taskqueue.inline.hpp"
  34 #include "logging/log.hpp"
  35 #include "memory/iterator.inline.hpp"
  36 #include "oops/access.inline.hpp"
  37 #include "oops/compressedOops.inline.hpp"
  38 #include "oops/instanceKlass.inline.hpp"
  39 #include "oops/instanceMirrorKlass.inline.hpp"
  40 #include "oops/objArrayKlass.inline.hpp"
  41 #include "oops/oop.inline.hpp"
  42 
  43 PSOldGen*               ParCompactionManager::_old_gen = NULL;
  44 ParCompactionManager**  ParCompactionManager::_manager_array = NULL;
  45 
  46 ParCompactionManager::OopTaskQueueSet*      ParCompactionManager::_oop_task_queues = NULL;
  47 ParCompactionManager::ObjArrayTaskQueueSet* ParCompactionManager::_objarray_task_queues = NULL;
  48 ParCompactionManager::RegionTaskQueueSet*   ParCompactionManager::_region_task_queues = NULL;
  49 
  50 ObjectStartArray*    ParCompactionManager::_start_array = NULL;
  51 ParMarkBitMap*       ParCompactionManager::_mark_bitmap = NULL;
  52 GrowableArray<size_t >* ParCompactionManager::_shadow_region_array = NULL;
  53 Monitor*                ParCompactionManager::_shadow_region_monitor = NULL;
  54 
  55 ParCompactionManager::ParCompactionManager() {
  56 
  57   ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
  58 
  59   _old_gen = heap->old_gen();
  60   _start_array = old_gen()->start_array();
  61 
  62   marking_stack()->initialize();
  63   _objarray_stack.initialize();
  64   _region_stack.initialize();
  65 
  66   reset_bitmap_query_cache();
  67 }
  68 
  69 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
  70   assert(ParallelScavengeHeap::heap() != NULL,
  71     "Needed for initialization");
  72 
  73   _mark_bitmap = mbm;
  74 
  75   uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
  76 
  77   assert(_manager_array == NULL, "Attempt to initialize twice");
  78   _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
  79 
  80   _oop_task_queues = new OopTaskQueueSet(parallel_gc_threads);
  81   guarantee(_oop_task_queues != NULL, "Could not allocate oop task queues");
  82   _objarray_task_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
  83   guarantee(_objarray_task_queues != NULL, "Could not allocate objarray task queues");
  84   _region_task_queues = new RegionTaskQueueSet(parallel_gc_threads);
  85   guarantee(_region_task_queues != NULL, "Could not allocate region task queues");
  86 
  87   // Create and register the ParCompactionManager(s) for the worker threads.
  88   for(uint i=0; i<parallel_gc_threads; i++) {
  89     _manager_array[i] = new ParCompactionManager();
  90     guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
  91     oop_task_queues()->register_queue(i, _manager_array[i]->marking_stack());
  92     _objarray_task_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
  93     region_task_queues()->register_queue(i, _manager_array[i]->region_stack());
  94   }
  95 
  96   // The VMThread gets its own ParCompactionManager, which is not available
  97   // for work stealing.
  98   _manager_array[parallel_gc_threads] = new ParCompactionManager();
  99   guarantee(_manager_array[parallel_gc_threads] != NULL,
 100     "Could not create ParCompactionManager");
 101   assert(ParallelScavengeHeap::heap()->workers().total_workers() != 0,
 102     "Not initialized?");
 103 
 104   _shadow_region_array = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<size_t >(10, true);
 105 
 106   _shadow_region_monitor = new Monitor(Mutex::barrier, "CompactionManager monitor",
 107                                        Mutex::_allow_vm_block_flag, Monitor::_safepoint_check_never);
 108 }
 109 
 110 void ParCompactionManager::reset_all_bitmap_query_caches() {
 111   uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
 112   for (uint i=0; i<=parallel_gc_threads; i++) {
 113     _manager_array[i]->reset_bitmap_query_cache();
 114   }
 115 }
 116 
 117 
 118 ParCompactionManager*
 119 ParCompactionManager::gc_thread_compaction_manager(uint index) {
 120   assert(index < ParallelGCThreads, "index out of range");
 121   assert(_manager_array != NULL, "Sanity");
 122   return _manager_array[index];
 123 }
 124 
 125 void ParCompactionManager::follow_marking_stacks() {
 126   do {
 127     // Drain the overflow stack first, to allow stealing from the marking stack.
 128     oop obj;
 129     while (marking_stack()->pop_overflow(obj)) {
 130       follow_contents(obj);
 131     }
 132     while (marking_stack()->pop_local(obj)) {
 133       follow_contents(obj);
 134     }
 135 
 136     // Process ObjArrays one at a time to avoid marking stack bloat.
 137     ObjArrayTask task;
 138     if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
 139       follow_array((objArrayOop)task.obj(), task.index());
 140     }
 141   } while (!marking_stacks_empty());
 142 
 143   assert(marking_stacks_empty(), "Sanity");
 144 }
 145 
 146 void ParCompactionManager::drain_region_stacks() {
 147   do {
 148     // Drain overflow stack first so other threads can steal.
 149     size_t region_index;
 150     while (region_stack()->pop_overflow(region_index)) {
 151       PSParallelCompact::fill_and_update_region(this, region_index);
 152     }
 153 
 154     while (region_stack()->pop_local(region_index)) {
 155       PSParallelCompact::fill_and_update_region(this, region_index);
 156     }
 157   } while (!region_stack()->is_empty());
 158 }
 159 
 160 size_t ParCompactionManager::pop_shadow_region_mt_safe(PSParallelCompact::RegionData* region_ptr) {
 161   MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
 162   while (true) {
 163     if (!_shadow_region_array->is_empty()) {
 164       return _shadow_region_array->pop();
 165     }
 166     // Check if the corresponding heap region is available now.
 167     // If so, we don't need to get a shadow region anymore, and
 168     // we return InvalidShadow to indicate such a case.
 169     if (region_ptr->claimed()) {
 170       return InvalidShadow;
 171     }
 172     ml.wait(1);
 173   }
 174 }
 175 
 176 void ParCompactionManager::push_shadow_region_mt_safe(size_t shadow_region) {
 177   MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
 178   _shadow_region_array->push(shadow_region);
 179   ml.notify();
 180 }
 181 
 182 void ParCompactionManager::push_shadow_region(size_t shadow_region) {
 183   _shadow_region_array->push(shadow_region);
 184 }
 185 
 186 void ParCompactionManager::remove_all_shadow_regions() {
 187   _shadow_region_array->clear();
 188 }