src/hotspot/share/gc/shenandoah/shenandoahCollectorPolicy.hpp

@@ -1,7 +1,8 @@
  /*
   * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.
+  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.

@@ -26,67 +27,83 @@
  #define SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTORPOLICY_HPP
  
  #include "gc/shared/gcTrace.hpp"
  #include "gc/shenandoah/shenandoahGC.hpp"
  #include "gc/shenandoah/shenandoahSharedVariables.hpp"
+ #include "gc/shenandoah/shenandoahTrace.hpp"
  #include "memory/allocation.hpp"
  #include "utilities/ostream.hpp"
  
- class ShenandoahTracer : public GCTracer, public CHeapObj<mtGC> {
- public:
-   ShenandoahTracer() : GCTracer(Shenandoah) {}
- };
- 
  class ShenandoahCollectorPolicy : public CHeapObj<mtGC> {
  private:
    size_t _success_concurrent_gcs;
+   size_t _abbreviated_concurrent_gcs;
    size_t _success_degenerated_gcs;
+   size_t _abbreviated_degenerated_gcs;
    // Written by control thread, read by mutators
    volatile size_t _success_full_gcs;
+   uint _consecutive_degenerated_gcs;
+   volatile size_t _consecutive_young_gcs;
+   size_t _mixed_gcs;
+   size_t _success_old_gcs;
+   size_t _interrupted_old_gcs;
    size_t _alloc_failure_degenerated;
    size_t _alloc_failure_degenerated_upgrade_to_full;
    size_t _alloc_failure_full;
-   size_t _explicit_concurrent;
-   size_t _explicit_full;
-   size_t _implicit_concurrent;
-   size_t _implicit_full;
-   size_t _degen_points[ShenandoahGC::_DEGENERATED_LIMIT];
+   size_t _collection_cause_counts[GCCause::_last_gc_cause];
+   size_t _degen_point_counts[ShenandoahGC::_DEGENERATED_LIMIT];
  
    ShenandoahSharedFlag _in_shutdown;
- 
    ShenandoahTracer* _tracer;
  
-   size_t _cycle_counter;
  
  public:
    ShenandoahCollectorPolicy();
  
-   // TODO: This is different from gc_end: that one encompasses one VM operation.
-   // These two encompass the entire cycle.
-   void record_cycle_start();
- 
-   void record_success_concurrent();
-   void record_success_degenerated();
+   void record_mixed_cycle();
+   void record_success_old();
+   void record_interrupted_old();
+ 
+   // A collection cycle may be "abbreviated" if Shenandoah finds a sufficient percentage
+   // of regions that contain no live objects (ShenandoahImmediateThreshold). These cycles
+   // end after final mark, skipping the evacuation and reference-updating phases. Such
+   // cycles are very efficient and are worth tracking. Note that both degenerated and
+   // concurrent cycles can be abbreviated.
+   void record_success_concurrent(bool is_young, bool is_abbreviated);
+   void record_success_degenerated(bool is_young, bool is_abbreviated);
    void record_success_full();
    void record_alloc_failure_to_degenerated(ShenandoahGC::ShenandoahDegenPoint point);
    void record_alloc_failure_to_full();
    void record_degenerated_upgrade_to_full();
-   void record_explicit_to_concurrent();
-   void record_explicit_to_full();
-   void record_implicit_to_concurrent();
-   void record_implicit_to_full();
+   void record_collection_cause(GCCause::Cause cause);
  
    void record_shutdown();
    bool is_at_shutdown();
  
    ShenandoahTracer* tracer() {return _tracer;}
  
-   size_t cycle_counter() const;
- 
    void print_gc_stats(outputStream* out) const;
  
    size_t full_gc_count() const {
      return _success_full_gcs + _alloc_failure_degenerated_upgrade_to_full;
    }
+ 
+   // If the heuristics find that the number of consecutive degenerated cycles is above
+   // ShenandoahFullGCThreshold, then they will initiate a Full GC upon an allocation
+   // failure.
+   inline size_t consecutive_degenerated_gc_count() const {
+     return _consecutive_degenerated_gcs;
+   }
+ 
+   static bool is_requested_gc(GCCause::Cause cause);
+   static bool should_run_full_gc(GCCause::Cause cause);
+   static bool should_handle_requested_gc(GCCause::Cause cause);
+ 
+   inline size_t consecutive_young_gc_count() const {
+     return _consecutive_young_gcs;
+   }
+ 
+ private:
+   void update_young(bool is_young);
  };
  
  #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTORPOLICY_HPP