diff src/share/vm/gc/shared/cardTableModRefBSForCTRS.hpp @ 8747:f149946b84cf

8130931: Refactor CardTableModRefBS[ForCTRS] Summary: Remove friends and push CTRS-specific code down from base to derived Reviewed-by: tschatzl, mgerdin
author kbarrett
date Wed, 22 Jul 2015 00:37:01 -0400
parents
children fe86ccf9132f
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc/shared/cardTableModRefBSForCTRS.hpp	Wed Jul 22 00:37:01 2015 -0400
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2015, Oracle and/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.
+ *
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_SHARED_CARDTABLEMODREFBSFORCTRS_HPP
+#define SHARE_VM_GC_SHARED_CARDTABLEMODREFBSFORCTRS_HPP
+
+#include "gc/shared/cardTableModRefBS.hpp"
+
+class CardTableRS;
+class DirtyCardToOopClosure;
+class OopsInGenClosure;
+
+// A specialization for the CardTableRS gen rem set.
+class CardTableModRefBSForCTRS: public CardTableModRefBS {
+  friend class CardTableRS;
+
+public:
+  CardTableModRefBSForCTRS(MemRegion whole_heap);
+  ~CardTableModRefBSForCTRS();
+
+  virtual void initialize();
+
+  void set_CTRS(CardTableRS* rs) { _rs = rs; }
+
+private:
+  CardTableRS* _rs;
+
+  // *** Support for parallel card scanning.
+
+  // dirty and precleaned are equivalent wrt younger_refs_iter.
+  static bool card_is_dirty_wrt_gen_iter(jbyte cv) {
+    return cv == dirty_card || cv == precleaned_card;
+  }
+
+  // Returns "true" iff the value "cv" will cause the card containing it
+  // to be scanned in the current traversal.  May be overridden by
+  // subtypes.
+  bool card_will_be_scanned(jbyte cv);
+
+  // Returns "true" iff the value "cv" may have represented a dirty card at
+  // some point.
+  bool card_may_have_been_dirty(jbyte cv);
+
+  // Iterate over the portion of the card-table which covers the given
+  // region mr in the given space and apply cl to any dirty sub-regions
+  // of mr. Clears the dirty cards as they are processed.
+  void non_clean_card_iterate_possibly_parallel(Space* sp, MemRegion mr,
+                                                OopsInGenClosure* cl, CardTableRS* ct,
+                                                uint n_threads);
+
+  // Work method used to implement non_clean_card_iterate_possibly_parallel()
+  // above in the parallel case.
+  void non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
+                                            OopsInGenClosure* cl, CardTableRS* ct,
+                                            uint n_threads);
+
+  // This is an array, one element per covered region of the card table.
+  // Each entry is itself an array, with one element per chunk in the
+  // covered region.  Each entry of these arrays is the lowest non-clean
+  // card of the corresponding chunk containing part of an object from the
+  // previous chunk, or else NULL.
+  typedef jbyte*  CardPtr;
+  typedef CardPtr* CardArr;
+  CardArr* _lowest_non_clean;
+  size_t*  _lowest_non_clean_chunk_size;
+  uintptr_t* _lowest_non_clean_base_chunk_index;
+  int* _last_LNC_resizing_collection;
+
+  // Initializes "lowest_non_clean" to point to the array for the region
+  // covering "sp", and "lowest_non_clean_base_chunk_index" to the chunk
+  // index of the corresponding to the first element of that array.
+  // Ensures that these arrays are of sufficient size, allocating if necessary.
+  // May be called by several threads concurrently.
+  void get_LNC_array_for_space(Space* sp,
+                               jbyte**& lowest_non_clean,
+                               uintptr_t& lowest_non_clean_base_chunk_index,
+                               size_t& lowest_non_clean_chunk_size);
+
+  // Returns the number of chunks necessary to cover "mr".
+  size_t chunks_to_cover(MemRegion mr) {
+    return (size_t)(addr_to_chunk_index(mr.last()) -
+                    addr_to_chunk_index(mr.start()) + 1);
+  }
+
+  // Returns the index of the chunk in a stride which
+  // covers the given address.
+  uintptr_t addr_to_chunk_index(const void* addr) {
+    uintptr_t card = (uintptr_t) byte_for(addr);
+    return card / ParGCCardsPerStrideChunk;
+  }
+
+  // Apply cl, which must either itself apply dcto_cl or be dcto_cl,
+  // to the cards in the stride (of n_strides) within the given space.
+  void process_stride(Space* sp,
+                      MemRegion used,
+                      jint stride, int n_strides,
+                      OopsInGenClosure* cl,
+                      CardTableRS* ct,
+                      jbyte** lowest_non_clean,
+                      uintptr_t lowest_non_clean_base_chunk_index,
+                      size_t lowest_non_clean_chunk_size);
+
+  // Makes sure that chunk boundaries are handled appropriately, by
+  // adjusting the min_done of dcto_cl, and by using a special card-table
+  // value to indicate how min_done should be set.
+  void process_chunk_boundaries(Space* sp,
+                                DirtyCardToOopClosure* dcto_cl,
+                                MemRegion chunk_mr,
+                                MemRegion used,
+                                jbyte** lowest_non_clean,
+                                uintptr_t lowest_non_clean_base_chunk_index,
+                                size_t    lowest_non_clean_chunk_size);
+
+};
+
+template<>
+struct BarrierSet::GetName<CardTableModRefBSForCTRS> {
+  static const BarrierSet::Name value = BarrierSet::CardTableForRS;
+};
+
+#endif // include guard
+