1 /*
  2  * Copyright (c) 2021, 2022, Red Hat, Inc. All rights reserved.
  3  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
  4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  5  *
  6  * This code is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 only, as
  8  * published by the Free Software Foundation.
  9  *
 10  * This code is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 13  * version 2 for more details (a copy is included in the LICENSE file that
 14  * accompanied this code).
 15  *
 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
 23  *
 24  */
 25 
 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHMARK_HPP
 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHMARK_HPP
 28 
 29 #include "gc/shared/ageTable.hpp"
 30 #include "gc/shared/stringdedup/stringDedup.hpp"
 31 #include "gc/shared/taskTerminator.hpp"
 32 #include "gc/shenandoah/shenandoahGenerationType.hpp"
 33 #include "gc/shenandoah/shenandoahHeap.hpp"
 34 #include "gc/shenandoah/shenandoahGeneration.hpp"
 35 #include "gc/shenandoah/shenandoahTaskqueue.hpp"
 36 
 37 enum StringDedupMode {
 38   NO_DEDUP,      // Do not do anything for String deduplication
 39   ENQUEUE_DEDUP, // Enqueue candidate Strings for deduplication, if meet age threshold
 40   ALWAYS_DEDUP   // Enqueue Strings for deduplication
 41 };
 42 
 43 class ShenandoahMarkingContext;
 44 class ShenandoahReferenceProcessor;
 45 
 46 // Base class for mark
 47 // Mark class does not maintain states. Instead, mark states are
 48 // maintained by task queues, mark bitmap and SATB buffers (concurrent mark)
 49 class ShenandoahMark: public StackObj {
 50 protected:
 51   ShenandoahGeneration* const _generation;
 52   ShenandoahObjToScanQueueSet* const _task_queues;
 53   ShenandoahObjToScanQueueSet* const _old_gen_task_queues;
 54 
 55 protected:
 56   ShenandoahMark(ShenandoahGeneration* generation);
 57 
 58 public:
 59   template<class T, ShenandoahGenerationType GENERATION>
 60   static inline void mark_through_ref(T* p, ShenandoahObjToScanQueue* q, ShenandoahObjToScanQueue* old_q, ShenandoahMarkingContext* const mark_context, bool weak);
 61 
 62   // Loom support
 63   void start_mark();
 64   void end_mark();
 65 
 66   // Helpers
 67   inline ShenandoahObjToScanQueueSet* task_queues() const;
 68   ShenandoahObjToScanQueueSet* old_task_queues() {
 69     return _old_gen_task_queues;
 70   }
 71 
 72   inline ShenandoahObjToScanQueue* get_queue(uint index) const;
 73   inline ShenandoahObjToScanQueue* get_old_queue(uint index) const;
 74 
 75   inline ShenandoahGeneration* generation() { return _generation; };
 76 
 77 private:
 78 // ---------- Marking loop and tasks
 79 
 80   template <class T, ShenandoahGenerationType GENERATION, StringDedupMode STRING_DEDUP>
 81   inline void do_task(ShenandoahObjToScanQueue* q, T* cl, ShenandoahLiveData* live_data, StringDedup::Requests* const req, ShenandoahMarkTask* task, uint worker_id);
 82 
 83   template <class T>
 84   inline void do_chunked_array_start(ShenandoahObjToScanQueue* q, T* cl, oop array, bool weak);
 85 
 86   template <class T>
 87   inline void do_chunked_array(ShenandoahObjToScanQueue* q, T* cl, oop array, int chunk, int pow, bool weak);
 88 
 89   template <ShenandoahGenerationType GENERATION>
 90   inline void count_liveness(ShenandoahLiveData* live_data, oop obj, uint worker_id);
 91 
 92   template <class T, ShenandoahGenerationType GENERATION, bool CANCELLABLE, StringDedupMode STRING_DEDUP>
 93   void mark_loop_work(T* cl, ShenandoahLiveData* live_data, uint worker_id, TaskTerminator *t, StringDedup::Requests* const req);
 94 
 95   template <ShenandoahGenerationType GENERATION, bool CANCELLABLE, StringDedupMode STRING_DEDUP>
 96   void mark_loop_prework(uint worker_id, TaskTerminator *terminator, ShenandoahReferenceProcessor *rp, StringDedup::Requests* const req, bool update_refs);
 97 
 98   template <ShenandoahGenerationType GENERATION>
 99   static bool in_generation(ShenandoahHeap* const heap, oop obj);
100 
101   static void mark_ref(ShenandoahObjToScanQueue* q,
102                        ShenandoahMarkingContext* const mark_context,
103                        bool weak, oop obj);
104 
105   template <StringDedupMode STRING_DEDUP>
106   inline void dedup_string(oop obj, StringDedup::Requests* const req);
107 protected:
108   template<bool CANCELLABLE, StringDedupMode STRING_DEDUP>
109   void mark_loop(uint worker_id, TaskTerminator* terminator, ShenandoahReferenceProcessor *rp,
110                  ShenandoahGenerationType generation, StringDedup::Requests* const req);
111 
112   void mark_loop(uint worker_id, TaskTerminator* terminator, ShenandoahReferenceProcessor *rp,
113                  ShenandoahGenerationType generation, bool cancellable, StringDedupMode dedup_mode, StringDedup::Requests* const req);
114 };
115 
116 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHMARK_HPP