--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/g1/g1RemSet.hpp	Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc.  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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// A G1RemSet provides ways of iterating over pointers into a selected
+// collection set.
+
+class G1CollectedHeap;
+class CardTableModRefBarrierSet;
+class HRInto_G1RemSet;
+class ConcurrentG1Refine;
+
+class G1RemSet {
+protected:
+  G1CollectedHeap* _g1;
+
+  unsigned _conc_refine_traversals;
+  unsigned _conc_refine_cards;
+
+  size_t n_workers();
+
+public:
+  G1RemSet(G1CollectedHeap* g1) :
+    _g1(g1), _conc_refine_traversals(0), _conc_refine_cards(0)
+  {}
+
+  // Invoke "blk->do_oop" on all pointers into the CS in object in regions
+  // outside the CS (having invoked "blk->set_region" to set the "from"
+  // region correctly beforehand.) The "worker_i" param is for the
+  // parallel case where the number of the worker thread calling this
+  // function can be helpful in partitioning the work to be done. It
+  // should be the same as the "i" passed to the calling thread's
+  // work(i) function. In the sequential case this param will be ingored.
+  virtual void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
+                                           int worker_i) = 0;
+
+  // Prepare for and cleanup after an oops_into_collection_set_do
+  // call.  Must call each of these once before and after (in sequential
+  // code) any threads call oops into collection set do.  (This offers an
+  // opportunity to sequential setup and teardown of structures needed by a
+  // parallel iteration over the CS's RS.)
+  virtual void prepare_for_oops_into_collection_set_do() = 0;
+  virtual void cleanup_after_oops_into_collection_set_do() = 0;
+
+  // If "this" is of the given subtype, return "this", else "NULL".
+  virtual HRInto_G1RemSet* as_HRInto_G1RemSet() { return NULL; }
+
+  // Record, if necessary, the fact that *p (where "p" is in region "from")
+  // has changed to its new value.
+  virtual void write_ref(HeapRegion* from, oop* p) = 0;
+  virtual void par_write_ref(HeapRegion* from, oop* p, int tid) = 0;
+
+  // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region
+  // or card, respectively, such that a region or card with a corresponding
+  // 0 bit contains no part of any live object.  Eliminates any remembered
+  // set entries that correspond to dead heap ranges.
+  virtual void scrub(BitMap* region_bm, BitMap* card_bm) = 0;
+  // Like the above, but assumes is called in parallel: "worker_num" is the
+  // parallel thread id of the current thread, and "claim_val" is the
+  // value that should be used to claim heap regions.
+  virtual void scrub_par(BitMap* region_bm, BitMap* card_bm,
+                         int worker_num, int claim_val) = 0;
+
+  // Do any "refinement" activity that might be appropriate to the given
+  // G1RemSet.  If "refinement" has iterateive "passes", do one pass.
+  // If "t" is non-NULL, it is the thread performing the refinement.
+  // Default implementation does nothing.
+  virtual void concurrentRefinementPass(ConcurrentG1Refine* cg1r) {}
+
+  // Refine the card corresponding to "card_ptr".  If "sts" is non-NULL,
+  // join and leave around parts that must be atomic wrt GC.  (NULL means
+  // being done at a safepoint.)
+  virtual void concurrentRefineOneCard(jbyte* card_ptr, int worker_i) {}
+
+  unsigned conc_refine_cards() { return _conc_refine_cards; }
+
+  // Print any relevant summary info.
+  virtual void print_summary_info() {}
+
+  // Prepare remebered set for verification.
+  virtual void prepare_for_verify() {};
+};
+
+
+// The simplest possible G1RemSet: iterates over all objects in non-CS
+// regions, searching for pointers into the CS.
+class StupidG1RemSet: public G1RemSet {
+public:
+  StupidG1RemSet(G1CollectedHeap* g1) : G1RemSet(g1) {}
+
+  void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
+                                   int worker_i);
+
+  void prepare_for_oops_into_collection_set_do() {}
+  void cleanup_after_oops_into_collection_set_do() {}
+
+  // Nothing is necessary in the version below.
+  void write_ref(HeapRegion* from, oop* p) {}
+  void par_write_ref(HeapRegion* from, oop* p, int tid) {}
+
+  void scrub(BitMap* region_bm, BitMap* card_bm) {}
+  void scrub_par(BitMap* region_bm, BitMap* card_bm,
+                 int worker_num, int claim_val) {}
+
+};
+
+// A G1RemSet in which each heap region has a rem set that records the
+// external heap references into it.  Uses a mod ref bs to track updates,
+// so that they can be used to update the individual region remsets.
+
+class HRInto_G1RemSet: public G1RemSet {
+protected:
+  enum SomePrivateConstants {
+    UpdateRStoMergeSync  = 0,
+    MergeRStoDoDirtySync = 1,
+    DoDirtySync          = 2,
+    LastSync             = 3,
+
+    SeqTask              = 0,
+    NumSeqTasks          = 1
+  };
+
+  CardTableModRefBS*             _ct_bs;
+  SubTasksDone*                  _seq_task;
+  G1CollectorPolicy* _g1p;
+
+  ConcurrentG1Refine* _cg1r;
+
+  size_t*             _cards_scanned;
+  size_t              _total_cards_scanned;
+
+  // _par_traversal_in_progress is "true" iff a parallel traversal is in
+  // progress.  If so, then cards added to remembered sets should also have
+  // their references into the collection summarized in "_new_refs".
+  bool _par_traversal_in_progress;
+  void set_par_traversal(bool b);
+  GrowableArray<oop*>** _new_refs;
+
+public:
+  // This is called to reset dual hash tables after the gc pause
+  // is finished and the initial hash table is no longer being
+  // scanned.
+  void cleanupHRRS();
+
+  HRInto_G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs);
+  ~HRInto_G1RemSet();
+
+  void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
+                                   int worker_i);
+
+  void prepare_for_oops_into_collection_set_do();
+  void cleanup_after_oops_into_collection_set_do();
+  void scanRS(OopsInHeapRegionClosure* oc, int worker_i);
+  void scanNewRefsRS(OopsInHeapRegionClosure* oc, int worker_i);
+  void updateRS(int worker_i);
+  HeapRegion* calculateStartRegion(int i);
+
+  HRInto_G1RemSet* as_HRInto_G1RemSet() { return this; }
+
+  CardTableModRefBS* ct_bs() { return _ct_bs; }
+  size_t cardsScanned() { return _total_cards_scanned; }
+
+  // Record, if necessary, the fact that *p (where "p" is in region "from",
+  // which is required to be non-NULL) has changed to a new non-NULL value.
+  inline void write_ref(HeapRegion* from, oop* p);
+  // The "_nv" version is the same; it exists just so that it is not virtual.
+  inline void write_ref_nv(HeapRegion* from, oop* p);
+
+  inline bool self_forwarded(oop obj);
+  inline void par_write_ref(HeapRegion* from, oop* p, int tid);
+
+  void scrub(BitMap* region_bm, BitMap* card_bm);
+  void scrub_par(BitMap* region_bm, BitMap* card_bm,
+                 int worker_num, int claim_val);
+
+  virtual void concurrentRefinementPass(ConcurrentG1Refine* t);
+  virtual void concurrentRefineOneCard(jbyte* card_ptr, int worker_i);
+
+  virtual void print_summary_info();
+  virtual void prepare_for_verify();
+};
+
+#define G1_REM_SET_LOGGING 0
+
+class CountNonCleanMemRegionClosure: public MemRegionClosure {
+  G1CollectedHeap* _g1;
+  int _n;
+  HeapWord* _start_first;
+public:
+  CountNonCleanMemRegionClosure(G1CollectedHeap* g1) :
+    _g1(g1), _n(0), _start_first(NULL)
+  {}
+  void do_MemRegion(MemRegion mr);
+  int n() { return _n; };
+  HeapWord* start_first() { return _start_first; }
+};