1 /*
  2  * Copyright (c) 2021, 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_SHENANDOAHCONCURRENTGC_HPP
 26 #define SHARE_GC_SHENANDOAH_SHENANDOAHCONCURRENTGC_HPP
 27 
 28 #include "gc/shared/gcCause.hpp"
 29 #include "gc/shenandoah/shenandoahConcurrentMark.hpp"
 30 #include "gc/shenandoah/shenandoahGC.hpp"
 31 #include "gc/shenandoah/shenandoahHeap.hpp"
 32 
 33 class VM_ShenandoahInitMark;
 34 class VM_ShenandoahFinalMarkStartEvac;
 35 class VM_ShenandoahInitUpdateRefs;
 36 class VM_ShenandoahFinalUpdateRefs;
 37 
 38 class ShenandoahConcurrentGC : public ShenandoahGC {
 39   friend class VM_ShenandoahInitMark;
 40   friend class VM_ShenandoahFinalMarkStartEvac;
 41   friend class VM_ShenandoahInitUpdateRefs;
 42   friend class VM_ShenandoahFinalUpdateRefs;
 43   friend class VM_ShenandoahFinalRoots;
 44 
 45 private:
 46   ShenandoahConcurrentMark  _mark;
 47   ShenandoahDegenPoint      _degen_point;
 48 
 49 public:
 50   ShenandoahConcurrentGC();
 51   bool collect(GCCause::Cause cause);
 52   ShenandoahDegenPoint degen_point() const;
 53 
 54   // Cancel ongoing concurrent GC
 55   static void cancel();
 56 private:
 57   // Entry points to STW GC operations, these cause a related safepoint, that then
 58   // call the entry method below
 59   void vmop_entry_init_mark();
 60   void vmop_entry_final_mark();
 61   void vmop_entry_init_updaterefs();
 62   void vmop_entry_final_updaterefs();
 63   void vmop_entry_final_roots();
 64 
 65   // Entry methods to normally STW GC operations. These set up logging, monitoring
 66   // and workers for net VM operation
 67   void entry_init_mark();
 68   void entry_final_mark();
 69   void entry_init_updaterefs();
 70   void entry_final_updaterefs();
 71   void entry_final_roots();
 72 
 73   // Entry methods to normally concurrent GC operations. These set up logging, monitoring
 74   // for concurrent operation.
 75   void entry_reset();
 76   void entry_mark_roots();
 77   void entry_mark();
 78   void entry_thread_roots();
 79   void entry_weak_refs();
 80   void entry_weak_roots();
 81   void entry_class_unloading();
 82   void entry_strong_roots();
 83   void entry_cleanup_early();
 84   void entry_evacuate();
 85   void entry_update_thread_roots();
 86   void entry_updaterefs();
 87   void entry_cleanup_complete();
 88 
 89   // Actual work for the phases
 90   void op_reset();
 91   void op_init_mark();
 92   void op_mark_roots();
 93   void op_mark();
 94   void op_final_mark();
 95   void op_thread_roots();
 96   void op_weak_refs();
 97   void op_weak_roots();
 98   void op_class_unloading();
 99   void op_strong_roots();
100   void op_cleanup_early();
101   void op_evacuate();
102   void op_init_updaterefs();
103   void op_updaterefs();
104   void op_update_thread_roots();
105   void op_final_updaterefs();
106   void op_final_roots();
107   void op_cleanup_complete();
108 
109   // Messages for GC trace events, they have to be immortal for
110   // passing around the logging/tracing systems
111   const char* init_mark_event_message() const;
112   const char* final_mark_event_message() const;
113   const char* conc_mark_event_message() const;
114 
115   // Check GC cancellation and abort concurrent GC
116   bool check_cancellation_and_abort(ShenandoahDegenPoint point);
117 };
118 
119 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCONCURRENTGC_HPP