jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/collectionSetChooser.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp

Thu, 22 Sep 2011 10:57:37 -0700

author: johnc
date: Thu, 22 Sep 2011 10:57:37 -0700
changeset 3175: 4dfb2df418f2
parent 2717: 371bbc844bf1
child 3185: b9390528617c
permissions: -rw-r--r--

6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

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  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  * published by the Free Software Foundation.
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 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "utilities/growableArray.hpp"
 // We need to sort heap regions by collection desirability.
 class CSetChooserCache VALUE_OBJ_CLASS_SPEC {
 private:
   enum {
     CacheLength = 16
   } PrivateConstants;
   HeapRegion*  _cache[CacheLength];
   int          _occupancy; // number of region in cache
   int          _first; // "first" region in the cache
   // adding CacheLength to deal with negative values
   inline int trim_index(int index) {
     return (index + CacheLength) % CacheLength;
   }
   inline int get_sort_index(int index) {
     return -index-2;
   }
   inline int get_index(int sort_index) {
     return -sort_index-2;
   }
 public:
   CSetChooserCache(void);
   inline int occupancy(void) { return _occupancy; }
   inline bool is_full()      { return _occupancy == CacheLength; }
   inline bool is_empty()     { return _occupancy == 0; }
   void clear(void);
   void insert(HeapRegion *hr);
   HeapRegion *remove_first(void);
   void remove (HeapRegion *hr);
   inline HeapRegion *get_first(void) {
     return _cache[_first];
   }
 #ifndef PRODUCT
   bool verify (void);
   bool region_in_cache(HeapRegion *hr) {
     int sort_index = hr->sort_index();
     if (sort_index < -1) {
       int index = get_index(sort_index);
       guarantee(index < CacheLength, "should be within bounds");
       return _cache[index] == hr;
     } else
       return 0;
   }
 #endif // PRODUCT
 };
 class CollectionSetChooser: public CHeapObj {
   GrowableArray<HeapRegion*> _markedRegions;
   int _curMarkedIndex;
   int _numMarkedRegions;
   CSetChooserCache _cache;
   // True iff last collection pause ran of out new "age 0" regions, and
   // returned an "age 1" region.
   bool _unmarked_age_1_returned_as_new;
   jint _first_par_unreserved_idx;
 public:
   HeapRegion* getNextMarkedRegion(double time_so_far, double avg_prediction);
   CollectionSetChooser();
   void sortMarkedHeapRegions();
   void fillCache();
   bool addRegionToCache(void);
   void addMarkedHeapRegion(HeapRegion *hr);
   // Must be called before calls to getParMarkedHeapRegionChunk.
   // "n_regions" is the number of regions, "chunkSize" the chunk size.
   void prepareForAddMarkedHeapRegionsPar(size_t n_regions, size_t chunkSize);
   // Returns the first index in a contiguous chunk of "n_regions" indexes
   // that the calling thread has reserved.  These must be set by the
   // calling thread using "setMarkedHeapRegion" (to NULL if necessary).
   jint getParMarkedHeapRegionChunk(jint n_regions);
   // Set the marked array entry at index to hr.  Careful to claim the index
   // first if in parallel.
   void setMarkedHeapRegion(jint index, HeapRegion* hr);
   // Atomically increment the number of claimed regions by "inc_by".
   void incNumMarkedHeapRegions(jint inc_by);
   void clearMarkedHeapRegions();
   void updateAfterFullCollection();
   // Ensure that "hr" is not a member of the marked region array or the cache
   void removeRegion(HeapRegion* hr);
   bool unmarked_age_1_returned_as_new() { return _unmarked_age_1_returned_as_new; }
   // Returns true if the used portion of "_markedRegions" is properly
   // sorted, otherwise asserts false.
 #ifndef PRODUCT
   bool verify(void);
   bool regionProperlyOrdered(HeapRegion* r) {
     int si = r->sort_index();
     return (si == -1) ||
       (si > -1 && _markedRegions.at(si) == r) ||
       (si < -1 && _cache.region_in_cache(r));
   }
 #endif
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP

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src/share/vm/gc_implementation/g1/collectionSetChooser.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp