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