1 /*
   2  * Copyright (c) 2018, 2019, Red Hat, Inc. 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_SHENANDOAH_SHENANDOAHTRAVERSALGC_HPP
  26 #define SHARE_GC_SHENANDOAH_SHENANDOAHTRAVERSALGC_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "gc/shenandoah/shenandoahHeap.hpp"
  30 #include "gc/shenandoah/shenandoahHeapRegionSet.hpp"
  31 #include "gc/shenandoah/shenandoahTaskqueue.hpp"
  32 #include "runtime/thread.hpp"
  33 
  34 class ShenandoahTraversalGC : public CHeapObj<mtGC> {
  35 private:
  36   ShenandoahHeap* const _heap;
  37   ShenandoahObjToScanQueueSet* const _task_queues;
  38   ShenandoahHeapRegionSet _traversal_set;
  39 
  40 public:
  41   ShenandoahTraversalGC(ShenandoahHeap* heap, size_t num_regions);
  42   ~ShenandoahTraversalGC();
  43 
  44   ShenandoahHeapRegionSet* traversal_set() { return &_traversal_set; }
  45 
  46   void reset();
  47   void prepare();
  48   void init_traversal_collection();
  49   void concurrent_traversal_collection();
  50   void final_traversal_collection();
  51 
  52   template <class T, bool STRING_DEDUP, bool DEGEN, bool ATOMIC_UPDATE>
  53   inline void process_oop(T* p, Thread* thread, ShenandoahObjToScanQueue* queue, ShenandoahMarkingContext* const mark_context);
  54 
  55   bool check_and_handle_cancelled_gc(ShenandoahTaskTerminator* terminator, bool sts_yield);
  56 
  57   ShenandoahObjToScanQueueSet* task_queues();
  58 
  59   void main_loop(uint worker_id, ShenandoahTaskTerminator* terminator, bool sts_yield);
  60 
  61 private:
  62   void prepare_regions();
  63 
  64   template <class T>
  65   void main_loop_work(T* cl, jushort* live_data, uint worker_id, ShenandoahTaskTerminator* terminator, bool sts_yield);
  66 
  67   void preclean_weak_refs();
  68   void weak_refs_work();
  69   void weak_refs_work_doit();
  70 
  71   void fixup_roots();
  72   void verify_roots_after_gc();
  73 };
  74 
  75 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHTRAVERSALGC_HPP