1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/modRefBarrierSet.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,104 @@
1.4 +/*
1.5 + * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
1.29 +#define SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
1.30 +
1.31 +#include "memory/barrierSet.hpp"
1.32 +
1.33 +// This kind of "BarrierSet" allows a "CollectedHeap" to detect and
1.34 +// enumerate ref fields that have been modified (since the last
1.35 +// enumeration), using a card table.
1.36 +
1.37 +class OopClosure;
1.38 +class Generation;
1.39 +
1.40 +class ModRefBarrierSet: public BarrierSet {
1.41 +public:
1.42 +
1.43 + ModRefBarrierSet() { _kind = BarrierSet::ModRef; }
1.44 +
1.45 + bool is_a(BarrierSet::Name bsn) {
1.46 + return bsn == BarrierSet::ModRef;
1.47 + }
1.48 +
1.49 + // Barriers only on ref writes.
1.50 + bool has_read_ref_barrier() { return false; }
1.51 + bool has_read_prim_barrier() { return false; }
1.52 + bool has_write_ref_barrier() { return true; }
1.53 + bool has_write_prim_barrier() { return false; }
1.54 +
1.55 + bool read_ref_needs_barrier(void* field) { return false; }
1.56 + bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
1.57 + bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
1.58 + juint val1, juint val2) { return false; }
1.59 +
1.60 + void write_prim_field(oop obj, size_t offset, size_t bytes,
1.61 + juint val1, juint val2) {}
1.62 +
1.63 + void read_ref_field(void* field) {}
1.64 + void read_prim_field(HeapWord* field, size_t bytes) {}
1.65 +protected:
1.66 + virtual void write_ref_field_work(void* field, oop new_val, bool release = false) = 0;
1.67 +public:
1.68 + void write_prim_field(HeapWord* field, size_t bytes,
1.69 + juint val1, juint val2) {}
1.70 +
1.71 + bool has_read_ref_array_opt() { return false; }
1.72 + bool has_read_prim_array_opt() { return false; }
1.73 + bool has_write_prim_array_opt() { return false; }
1.74 +
1.75 + bool has_read_region_opt() { return false; }
1.76 +
1.77 +
1.78 + // These operations should assert false unless the correponding operation
1.79 + // above returns true.
1.80 + void read_ref_array(MemRegion mr) {
1.81 + assert(false, "can't call");
1.82 + }
1.83 + void read_prim_array(MemRegion mr) {
1.84 + assert(false, "can't call");
1.85 + }
1.86 + void write_prim_array(MemRegion mr) {
1.87 + assert(false, "can't call");
1.88 + }
1.89 + void read_region(MemRegion mr) {
1.90 + assert(false, "can't call");
1.91 + }
1.92 +
1.93 + // Causes all refs in "mr" to be assumed to be modified. If "whole_heap"
1.94 + // is true, the caller asserts that the entire heap is being invalidated,
1.95 + // which may admit an optimized implementation for some barriers.
1.96 + virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
1.97 +
1.98 + // The caller guarantees that "mr" contains no references. (Perhaps it's
1.99 + // objects have been moved elsewhere.)
1.100 + virtual void clear(MemRegion mr) = 0;
1.101 +
1.102 + // Pass along the argument to the superclass.
1.103 + ModRefBarrierSet(int max_covered_regions) :
1.104 + BarrierSet(max_covered_regions) {}
1.105 +};
1.106 +
1.107 +#endif // SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
