--- a/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp	Wed Apr 18 07:21:15 2012 -0400
+++ b/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp	Wed Apr 18 13:39:55 2012 -0400
@@ -28,77 +28,42 @@
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "utilities/growableArray.hpp"
 
-class CSetChooserCache VALUE_OBJ_CLASS_SPEC {
-private:
-  enum {
-    CacheLength = 16
-  } PrivateConstants;
-
-  HeapRegion*  _cache[CacheLength];
-  int          _occupancy; // number of regions in cache
-  int          _first;     // (index of) "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);
-  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;
+  GrowableArray<HeapRegion*> _regions;
+
+  // Unfortunately, GrowableArray uses ints for length and indexes. To
+  // avoid excessive casting in the rest of the class the following
+  // wrapper methods are provided that use uints.
+
+  uint regions_length()          { return (uint) _regions.length(); }
+  HeapRegion* regions_at(uint i) { return _regions.at((int) i);     }
+  void regions_at_put(uint i, HeapRegion* hr) {
+    _regions.at_put((int) i, hr);
+  }
+  void regions_at_put_grow(uint i, HeapRegion* hr) {
+    _regions.at_put_grow((int) i, hr);
+  }
+  void regions_trunc_to(uint i)  { _regions.trunc_to((uint) i); }
 
   // The index of the next candidate old region to be considered for
   // addition to the CSet.
-  int _curr_index;
+  uint _curr_index;
 
   // The number of candidate old regions added to the CSet chooser.
-  int _length;
+  uint _length;
 
-  CSetChooserCache _cache;
-  jint _first_par_unreserved_idx;
+  // Keeps track of the start of the next array chunk to be claimed by
+  // parallel GC workers.
+  uint _first_par_unreserved_idx;
 
   // If a region has more live bytes than this threshold, it will not
   // be added to the CSet chooser and will not be a candidate for
   // collection.
-  size_t _regionLiveThresholdBytes;
+  size_t _region_live_threshold_bytes;
 
   // The sum of reclaimable bytes over all the regions in the CSet chooser.
-  size_t _remainingReclaimableBytes;
+  size_t _remaining_reclaimable_bytes;
 
 public:
 
@@ -107,9 +72,9 @@
   HeapRegion* peek() {
     HeapRegion* res = NULL;
     if (_curr_index < _length) {
-      res = _markedRegions.at(_curr_index);
+      res = regions_at(_curr_index);
       assert(res != NULL,
-             err_msg("Unexpected NULL hr in _markedRegions at index %d",
+             err_msg("Unexpected NULL hr in _regions at index %u",
                      _curr_index));
     }
     return res;
@@ -121,90 +86,71 @@
   void remove_and_move_to_next(HeapRegion* hr) {
     assert(hr != NULL, "pre-condition");
     assert(_curr_index < _length, "pre-condition");
-    assert(_markedRegions.at(_curr_index) == hr, "pre-condition");
-    hr->set_sort_index(-1);
-    _markedRegions.at_put(_curr_index, NULL);
-    assert(hr->reclaimable_bytes() <= _remainingReclaimableBytes,
+    assert(regions_at(_curr_index) == hr, "pre-condition");
+    regions_at_put(_curr_index, NULL);
+    assert(hr->reclaimable_bytes() <= _remaining_reclaimable_bytes,
            err_msg("remaining reclaimable bytes inconsistent "
                    "from region: "SIZE_FORMAT" remaining: "SIZE_FORMAT,
-                   hr->reclaimable_bytes(), _remainingReclaimableBytes));
-    _remainingReclaimableBytes -= hr->reclaimable_bytes();
+                   hr->reclaimable_bytes(), _remaining_reclaimable_bytes));
+    _remaining_reclaimable_bytes -= hr->reclaimable_bytes();
     _curr_index += 1;
   }
 
   CollectionSetChooser();
 
-  void sortMarkedHeapRegions();
-  void fillCache();
+  void sort_regions();
 
   // Determine whether to add the given region to the CSet chooser or
   // not. Currently, we skip humongous regions (we never add them to
   // the CSet, we only reclaim them during cleanup) and regions whose
   // live bytes are over the threshold.
-  bool shouldAdd(HeapRegion* hr) {
+  bool should_add(HeapRegion* hr) {
     assert(hr->is_marked(), "pre-condition");
     assert(!hr->is_young(), "should never consider young regions");
     return !hr->isHumongous() &&
-            hr->live_bytes() < _regionLiveThresholdBytes;
+            hr->live_bytes() < _region_live_threshold_bytes;
   }
 
   // Calculate the minimum number of old regions we'll add to the CSet
   // during a mixed GC.
-  uint calcMinOldCSetLength();
+  uint calc_min_old_cset_length();
 
   // Calculate the maximum number of old regions we'll add to the CSet
   // during a mixed GC.
-  uint calcMaxOldCSetLength();
+  uint calc_max_old_cset_length();
 
   // Serial version.
-  void addMarkedHeapRegion(HeapRegion *hr);
+  void add_region(HeapRegion *hr);
 
-  // Must be called before calls to getParMarkedHeapRegionChunk.
-  // "n_regions" is the number of regions, "chunkSize" the chunk size.
-  void prepareForAddMarkedHeapRegionsPar(uint n_regions, uint chunkSize);
-  // Returns the first index in a contiguous chunk of "n_regions" indexes
+  // Must be called before calls to claim_array_chunk().
+  // n_regions is the number of regions, chunk_size the chunk size.
+  void prepare_for_par_region_addition(uint n_regions, uint chunk_size);
+  // Returns the first index in a contiguous chunk of chunk_size 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);
+  // calling thread using set_region() (to NULL if necessary).
+  uint claim_array_chunk(uint chunk_size);
   // Set the marked array entry at index to hr.  Careful to claim the index
   // first if in parallel.
-  void setMarkedHeapRegion(jint index, HeapRegion* hr);
+  void set_region(uint index, HeapRegion* hr);
   // Atomically increment the number of added regions by region_num
   // and the amount of reclaimable bytes by reclaimable_bytes.
-  void updateTotals(jint region_num, size_t reclaimable_bytes);
+  void update_totals(uint region_num, size_t reclaimable_bytes);
 
-  void clearMarkedHeapRegions();
+  void clear();
 
   // Return the number of candidate regions that remain to be collected.
-  uint remainingRegions() { return (uint) (_length - _curr_index); }
+  uint remaining_regions() { return _length - _curr_index; }
 
   // Determine whether the CSet chooser has more candidate regions or not.
-  bool isEmpty() { return remainingRegions() == 0; }
+  bool is_empty() { return remaining_regions() == 0; }
 
   // Return the reclaimable bytes that remain to be collected on
   // all the candidate regions in the CSet chooser.
-  size_t remainingReclaimableBytes () { return _remainingReclaimableBytes; }
+  size_t remaining_reclaimable_bytes() { return _remaining_reclaimable_bytes; }
 
-  // Returns true if the used portion of "_markedRegions" is properly
+  // Returns true if the used portion of "_regions" is properly
   // sorted, otherwise asserts false.
-#ifndef PRODUCT
-  bool verify(void);
-  bool regionProperlyOrdered(HeapRegion* r) {
-    int si = r->sort_index();
-    if (si > -1) {
-      guarantee(_curr_index <= si && si < _length,
-                err_msg("curr: %d sort index: %d: length: %d",
-                        _curr_index, si, _length));
-      guarantee(_markedRegions.at(si) == r,
-                err_msg("sort index: %d at: "PTR_FORMAT" r: "PTR_FORMAT,
-                        si, _markedRegions.at(si), r));
-    } else {
-      guarantee(si == -1, err_msg("sort index: %d", si));
-    }
-    return true;
-  }
-#endif
-
+  void verify() PRODUCT_RETURN;
 };
 
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP