src/hotspot/share/gc/parallel/psCardTable.hpp
changeset 49164 7e958a8ebcd3
parent 48961 120b61d50f85
child 49194 ece10494786c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/parallel/psCardTable.hpp	Mon Feb 26 09:34:12 2018 +0100
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2001, 2018, 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_PARALLEL_PSCARDTABLE_HPP
+#define SHARE_VM_GC_PARALLEL_PSCARDTABLE_HPP
+
+#include "gc/shared/cardTable.hpp"
+#include "oops/oop.hpp"
+
+class MutableSpace;
+class ObjectStartArray;
+class PSPromotionManager;
+class GCTaskQueue;
+
+class PSCardTable: public CardTable {
+ private:
+  // Support methods for resizing the card table.
+  // resize_commit_uncommit() returns true if the pages were committed or
+  // uncommitted
+  bool resize_commit_uncommit(int changed_region, MemRegion new_region);
+  void resize_update_card_table_entries(int changed_region,
+                                        MemRegion new_region);
+  void resize_update_committed_table(int changed_region, MemRegion new_region);
+  void resize_update_covered_table(int changed_region, MemRegion new_region);
+
+  void verify_all_young_refs_precise_helper(MemRegion mr);
+
+  enum ExtendedCardValue {
+    youngergen_card   = CT_MR_BS_last_reserved + 1,
+    verify_card       = CT_MR_BS_last_reserved + 5
+  };
+
+ public:
+  PSCardTable(MemRegion whole_heap) : CardTable(whole_heap, /* scanned_concurrently */ false) {}
+
+  static jbyte youngergen_card_val() { return youngergen_card; }
+  static jbyte verify_card_val()     { return verify_card; }
+
+  // Scavenge support
+  void scavenge_contents_parallel(ObjectStartArray* start_array,
+                                  MutableSpace* sp,
+                                  HeapWord* space_top,
+                                  PSPromotionManager* pm,
+                                  uint stripe_number,
+                                  uint stripe_total);
+
+  bool addr_is_marked_imprecise(void *addr);
+  bool addr_is_marked_precise(void *addr);
+
+  void set_card_newgen(void* addr)   { jbyte* p = byte_for(addr); *p = verify_card; }
+
+  // Testers for entries
+  static bool card_is_dirty(int value)      { return value == dirty_card; }
+  static bool card_is_newgen(int value)     { return value == youngergen_card; }
+  static bool card_is_clean(int value)      { return value == clean_card; }
+  static bool card_is_verify(int value)     { return value == verify_card; }
+
+  // Card marking
+  void inline_write_ref_field_gc(void* field, oop new_val) {
+    jbyte* byte = byte_for(field);
+    *byte = youngergen_card;
+  }
+
+  // ReduceInitialCardMarks support
+  bool is_in_young(oop obj) const;
+
+  // Adaptive size policy support
+  // Allows adjustment of the base and size of the covered regions
+  void resize_covered_region(MemRegion new_region);
+  // Finds the covered region to resize based on the start address
+  // of the covered regions.
+  void resize_covered_region_by_start(MemRegion new_region);
+  // Finds the covered region to resize based on the end address
+  // of the covered regions.
+  void resize_covered_region_by_end(int changed_region, MemRegion new_region);
+  // Finds the lowest start address of a covered region that is
+  // previous (i.e., lower index) to the covered region with index "ind".
+  HeapWord* lowest_prev_committed_start(int ind) const;
+
+#ifdef ASSERT
+  bool is_valid_card_address(jbyte* addr) {
+    return (addr >= _byte_map) && (addr < _byte_map + _byte_map_size);
+  }
+#endif // ASSERT
+
+  // Verification
+  void verify_all_young_refs_imprecise();
+  void verify_all_young_refs_precise();
+};
+
+#endif // SHARE_VM_GC_PARALLEL_PSCARDTABLE