diff src/share/vm/memory/cardTableRS.hpp @ 0:a61af66fc99e jdk7-b24

Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children 73e96e5c30df
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/cardTableRS.hpp	Sat Dec 01 00:00:00 2007 +0000
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+/*
+ * Copyright 2001-2006 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.
+ *
+ */
+
+class Space;
+class OopsInGenClosure;
+class DirtyCardToOopClosure;
+
+// This kind of "GenRemSet" uses a card table both as shared data structure
+// for a mod ref barrier set and for the rem set information.
+
+class CardTableRS: public GenRemSet {
+  friend class VMStructs;
+  // Below are private classes used in impl.
+  friend class VerifyCTSpaceClosure;
+  friend class ClearNoncleanCardWrapper;
+
+  static jbyte clean_card_val() {
+    return CardTableModRefBS::clean_card;
+  }
+
+  static bool
+  card_is_dirty_wrt_gen_iter(jbyte cv) {
+    return CardTableModRefBS::card_is_dirty_wrt_gen_iter(cv);
+  }
+
+  CardTableModRefBSForCTRS _ct_bs;
+
+  virtual void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl);
+
+  void verify_space(Space* s, HeapWord* gen_start);
+
+  enum ExtendedCardValue {
+    youngergen_card   = CardTableModRefBS::CT_MR_BS_last_reserved + 1,
+    // These are for parallel collection.
+    // There are three P (parallel) youngergen card values.  In general, this
+    // needs to be more than the number of generations (including the perm
+    // gen) that might have younger_refs_do invoked on them separately.  So
+    // if we add more gens, we have to add more values.
+    youngergenP1_card  = CardTableModRefBS::CT_MR_BS_last_reserved + 2,
+    youngergenP2_card  = CardTableModRefBS::CT_MR_BS_last_reserved + 3,
+    youngergenP3_card  = CardTableModRefBS::CT_MR_BS_last_reserved + 4,
+    cur_youngergen_and_prev_nonclean_card =
+      CardTableModRefBS::CT_MR_BS_last_reserved + 5
+  };
+
+  // An array that contains, for each generation, the card table value last
+  // used as the current value for a younger_refs_do iteration of that
+  // portion of the table.  (The perm gen is index 0; other gens are at
+  // their level plus 1.  They youngest gen is in the table, but will
+  // always have the value "clean_card".)
+  jbyte* _last_cur_val_in_gen;
+
+  jbyte _cur_youngergen_card_val;
+
+  jbyte cur_youngergen_card_val() {
+    return _cur_youngergen_card_val;
+  }
+  void set_cur_youngergen_card_val(jbyte v) {
+    _cur_youngergen_card_val = v;
+  }
+  bool is_prev_youngergen_card_val(jbyte v) {
+    return
+      youngergen_card <= v &&
+      v < cur_youngergen_and_prev_nonclean_card &&
+      v != _cur_youngergen_card_val;
+  }
+  // Return a youngergen_card_value that is not currently in use.
+  jbyte find_unused_youngergenP_card_value();
+
+public:
+  CardTableRS(MemRegion whole_heap, int max_covered_regions);
+
+  // *** GenRemSet functions.
+  GenRemSet::Name rs_kind() { return GenRemSet::CardTable; }
+
+  CardTableRS* as_CardTableRS() { return this; }
+
+  CardTableModRefBS* ct_bs() { return &_ct_bs; }
+
+  // Override.
+  void prepare_for_younger_refs_iterate(bool parallel);
+
+  // Card table entries are cleared before application; "blk" is
+  // responsible for dirtying if the oop is still older-to-younger after
+  // closure application.
+  void younger_refs_iterate(Generation* g, OopsInGenClosure* blk);
+
+  void inline_write_ref_field_gc(oop* field, oop new_val) {
+    jbyte* byte = _ct_bs.byte_for(field);
+    *byte = youngergen_card;
+  }
+  void write_ref_field_gc_work(oop* field, oop new_val) {
+    inline_write_ref_field_gc(field, new_val);
+  }
+
+  // Override.  Might want to devirtualize this in the same fashion as
+  // above.  Ensures that the value of the card for field says that it's
+  // a younger card in the current collection.
+  virtual void write_ref_field_gc_par(oop* field, oop new_val);
+
+  void resize_covered_region(MemRegion new_region);
+
+  bool is_aligned(HeapWord* addr) {
+    return _ct_bs.is_card_aligned(addr);
+  }
+
+  void verify();
+  void verify_empty(MemRegion mr);
+
+  void clear(MemRegion mr) { _ct_bs.clear(mr); }
+  void clear_into_younger(Generation* gen, bool clear_perm);
+
+  void invalidate(MemRegion mr) { _ct_bs.invalidate(mr); }
+  void invalidate_or_clear(Generation* gen, bool younger, bool perm);
+
+  static uintx ct_max_alignment_constraint() {
+    return CardTableModRefBS::ct_max_alignment_constraint();
+  }
+
+  jbyte* byte_for(void* p)     { return _ct_bs.byte_for(p); }
+  jbyte* byte_after(void* p)   { return _ct_bs.byte_after(p); }
+  HeapWord* addr_for(jbyte* p) { return _ct_bs.addr_for(p); }
+
+  bool is_prev_nonclean_card_val(jbyte v) {
+    return
+      youngergen_card <= v &&
+      v <= cur_youngergen_and_prev_nonclean_card &&
+      v != _cur_youngergen_card_val;
+  }
+
+  static bool youngergen_may_have_been_dirty(jbyte cv) {
+    return cv == CardTableRS::cur_youngergen_and_prev_nonclean_card;
+  }
+
+};