src/share/vm/memory/modRefBarrierSet.hpp

Wed, 02 Jul 2008 12:55:16 -0700

author
xdono
date
Wed, 02 Jul 2008 12:55:16 -0700
changeset 631
d1605aabd0a1
parent 548
ba764ed4b6f2
child 791
1ee8caae33af
permissions
-rw-r--r--

6719955: Update copyright year
Summary: Update copyright year for files that have been modified in 2008
Reviewed-by: ohair, tbell

     1 /*
     2  * Copyright 2000-2008 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
    26 // enumerate ref fields that have been modified (since the last
    27 // enumeration), using a card table.
    29 class OopClosure;
    30 class Generation;
    32 class ModRefBarrierSet: public BarrierSet {
    33 public:
    34   // Barriers only on ref writes.
    35   bool has_read_ref_barrier() { return false; }
    36   bool has_read_prim_barrier() { return false; }
    37   bool has_write_ref_barrier() { return true; }
    38   bool has_write_prim_barrier() { return false; }
    40   bool read_ref_needs_barrier(void* field) { return false; }
    41   bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
    42   virtual bool write_ref_needs_barrier(void* field, oop new_val) = 0;
    43   bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
    44                                 juint val1, juint val2) { return false; }
    46   void write_prim_field(oop obj, size_t offset, size_t bytes,
    47                         juint val1, juint val2) {}
    49   void read_ref_field(void* field) {}
    50   void read_prim_field(HeapWord* field, size_t bytes) {}
    51 protected:
    52   virtual void write_ref_field_work(void* field, oop new_val) = 0;
    53 public:
    54   void write_prim_field(HeapWord* field, size_t bytes,
    55                         juint val1, juint val2) {}
    57   bool has_read_ref_array_opt() { return false; }
    58   bool has_read_prim_array_opt() { return false; }
    59   bool has_write_prim_array_opt() { return false; }
    61   bool has_read_region_opt() { return false; }
    64   // These operations should assert false unless the correponding operation
    65   // above returns true.
    66   void read_ref_array(MemRegion mr) {
    67     assert(false, "can't call");
    68   }
    69   void read_prim_array(MemRegion mr) {
    70     assert(false, "can't call");
    71   }
    72   void write_prim_array(MemRegion mr) {
    73     assert(false, "can't call");
    74   }
    75   void read_region(MemRegion mr) {
    76     assert(false, "can't call");
    77   }
    79   // Invoke "cl->do_oop" on (the address of) every possibly-modifed
    80   // reference field in objects in "sp".  If "clear" is "true", the oops
    81   // are no longer considered possibly modified after application of the
    82   // closure.  If' "before_save_marks" is true, oops in objects allocated
    83   // after the last call to "save_marks" on "sp" will not be considered.
    84   virtual void mod_oop_in_space_iterate(Space* sp, OopClosure* cl,
    85                                         bool clear = false,
    86                                         bool before_save_marks = false) = 0;
    88   // Causes all refs in "mr" to be assumed to be modified.
    89   virtual void invalidate(MemRegion mr) = 0;
    91   // The caller guarantees that "mr" contains no references.  (Perhaps it's
    92   // objects have been moved elsewhere.)
    93   virtual void clear(MemRegion mr) = 0;
    95   // Pass along the argument to the superclass.
    96   ModRefBarrierSet(int max_covered_regions) :
    97     BarrierSet(max_covered_regions) {}
    99 #ifndef PRODUCT
   100   // Verifies that the given region contains no modified references.
   101   virtual void verify_clean_region(MemRegion mr) = 0;
   102 #endif
   104 };

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