1 /*
  2  * Copyright (c) 2005, 2019, 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 #ifndef SHARE_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP
 26 #define SHARE_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP
 27 
 28 #include "gc/parallel/psParallelCompact.hpp"
 29 #include "gc/shared/taskqueue.hpp"
 30 #include "memory/allocation.hpp"
 31 #include "utilities/stack.hpp"
 32 
 33 class MutableSpace;
 34 class PSOldGen;
 35 class ParCompactionManager;
 36 class ObjectStartArray;
 37 class ParallelCompactData;
 38 class ParMarkBitMap;
 39 
 40 class ParCompactionManager : public CHeapObj<mtGC> {
 41   friend class ParallelTaskTerminator;
 42   friend class ParMarkBitMap;
 43   friend class PSParallelCompact;
 44   friend class CompactionWithStealingTask;
 45   friend class UpdateAndFillClosure;
 46   friend class RefProcTaskExecutor;
 47   friend class PCRefProcTask;
 48   friend class MarkFromRootsTask;
 49   friend class UpdateDensePrefixAndCompactionTask;
 50 
 51  public:
 52 
 53 // ------------------------  Don't putback if not needed
 54   // Actions that the compaction manager should take.
 55   enum Action {
 56     Update,
 57     Copy,
 58     UpdateAndCopy,
 59     CopyAndUpdate,
 60     NotValid
 61   };
 62 // ------------------------  End don't putback if not needed
 63 
 64  private:
 65   // 32-bit:  4K * 8 = 32KiB; 64-bit:  8K * 16 = 128KiB
 66   #define QUEUE_SIZE (1 << NOT_LP64(12) LP64_ONLY(13))
 67   typedef OverflowTaskQueue<ObjArrayTask, mtGC, QUEUE_SIZE> ObjArrayTaskQueue;
 68   typedef GenericTaskQueueSet<ObjArrayTaskQueue, mtGC>      ObjArrayTaskQueueSet;
 69   #undef QUEUE_SIZE
 70 
 71   static ParCompactionManager** _manager_array;
 72   static OopTaskQueueSet*       _stack_array;
 73   static ObjArrayTaskQueueSet*  _objarray_queues;
 74   static ObjectStartArray*      _start_array;
 75   static RegionTaskQueueSet*    _region_array;
 76   static PSOldGen*              _old_gen;
 77 
 78 private:
 79   OverflowTaskQueue<oop, mtGC>        _marking_stack;
 80   ObjArrayTaskQueue             _objarray_stack;
 81   size_t                        _next_shadow_region;
 82 
 83   // Is there a way to reuse the _marking_stack for the
 84   // saving empty regions?  For now just create a different
 85   // type of TaskQueue.
 86   RegionTaskQueue              _region_stack;
 87 
 88   static ParMarkBitMap* _mark_bitmap;
 89 
 90   // Contains currently free shadow regions. We use it in
 91   // a LIFO fashion for better data locality and utilization.
 92   static GrowableArray<size_t>* _shadow_region_array;
 93 
 94   // Provides mutual exclusive access of _shadow_region_array.
 95   // See pop/push_shadow_region_mt_safe() below
 96   static Monitor*               _shadow_region_monitor;
 97 
 98   Action _action;
 99 
100   HeapWord* _last_query_beg;
101   oop _last_query_obj;
102   size_t _last_query_ret;
103 
104   static PSOldGen* old_gen()             { return _old_gen; }
105   static ObjectStartArray* start_array() { return _start_array; }
106   static OopTaskQueueSet* stack_array()  { return _stack_array; }
107 
108   static void initialize(ParMarkBitMap* mbm);
109 
110  protected:
111   // Array of tasks.  Needed by the ParallelTaskTerminator.
112   static RegionTaskQueueSet* region_array()      { return _region_array; }
113   OverflowTaskQueue<oop, mtGC>*  marking_stack()       { return &_marking_stack; }
114 
115   // Pushes onto the marking stack.  If the marking stack is full,
116   // pushes onto the overflow stack.
117   void stack_push(oop obj);
118   // Do not implement an equivalent stack_pop.  Deal with the
119   // marking stack and overflow stack directly.
120 
121  public:
122   static const size_t InvalidShadow = ~0;
123   static size_t  pop_shadow_region_mt_safe(PSParallelCompact::RegionData* region_ptr);
124   static void    push_shadow_region_mt_safe(size_t shadow_region);
125   static void    push_shadow_region(size_t shadow_region);
126   static void    remove_all_shadow_regions();
127 
128   inline size_t  next_shadow_region() { return _next_shadow_region; }
129   inline void    set_next_shadow_region(size_t record) { _next_shadow_region = record; }
130   inline size_t  move_next_shadow_region_by(size_t workers) {
131     _next_shadow_region += workers;
132     return next_shadow_region();
133   }
134 
135   void reset_bitmap_query_cache() {
136     _last_query_beg = NULL;
137     _last_query_obj = NULL;
138     _last_query_ret = 0;
139   }
140 
141   Action action() { return _action; }
142   void set_action(Action v) { _action = v; }
143 
144   // Bitmap query support, cache last query and result
145   HeapWord* last_query_begin() { return _last_query_beg; }
146   oop last_query_object() { return _last_query_obj; }
147   size_t last_query_return() { return _last_query_ret; }
148 
149   void set_last_query_begin(HeapWord *new_beg) { _last_query_beg = new_beg; }
150   void set_last_query_object(oop new_obj) { _last_query_obj = new_obj; }
151   void set_last_query_return(size_t new_ret) { _last_query_ret = new_ret; }
152 
153   static void reset_all_bitmap_query_caches();
154 
155   RegionTaskQueue* region_stack()                { return &_region_stack; }
156 
157   inline static ParCompactionManager* manager_array(uint index);
158 
159   ParCompactionManager();
160 
161   // Pushes onto the region stack at the given index.  If the
162   // region stack is full,
163   // pushes onto the region overflow stack.
164   static void verify_region_list_empty(uint stack_index);
165   ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }
166 
167   // void drain_stacks();
168 
169   bool should_update();
170   bool should_copy();
171 
172   // Save for later processing.  Must not fail.
173   inline void push(oop obj);
174   inline void push_objarray(oop objarray, size_t index);
175   inline void push_region(size_t index);
176 
177   // Check mark and maybe push on marking stack.
178   template <typename T> inline void mark_and_push(T* p);
179 
180   inline void follow_klass(Klass* klass);
181 
182   void follow_class_loader(ClassLoaderData* klass);
183 
184   // Access function for compaction managers
185   static ParCompactionManager* gc_thread_compaction_manager(uint index);
186 
187   static bool steal(int queue_num, oop& t);
188   static bool steal_objarray(int queue_num, ObjArrayTask& t);
189   static bool steal(int queue_num, size_t& region);
190 
191   // Process tasks remaining on any marking stack
192   void follow_marking_stacks();
193   inline bool marking_stacks_empty() const;
194 
195   // Process tasks remaining on any stack
196   void drain_region_stacks();
197 
198   void follow_contents(oop obj);
199   void follow_array(objArrayOop array, int index);
200 
201   void update_contents(oop obj);
202 
203   class FollowStackClosure: public VoidClosure {
204    private:
205     ParCompactionManager* _compaction_manager;
206    public:
207     FollowStackClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
208     virtual void do_void();
209   };
210 };
211 
212 inline ParCompactionManager* ParCompactionManager::manager_array(uint index) {
213   assert(_manager_array != NULL, "access of NULL manager_array");
214   assert(index <= ParallelGCThreads, "out of range manager_array access");
215   return _manager_array[index];
216 }
217 
218 bool ParCompactionManager::marking_stacks_empty() const {
219   return _marking_stack.is_empty() && _objarray_stack.is_empty();
220 }
221 
222 #endif // SHARE_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP