1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/modRefBarrierSet.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,104 @@
1.4 +/*
1.5 + * Copyright 2000-2002 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// This kind of "BarrierSet" allows a "CollectedHeap" to detect and
1.29 +// enumerate ref fields that have been modified (since the last
1.30 +// enumeration), using a card table.
1.31 +
1.32 +class OopClosure;
1.33 +class Generation;
1.34 +
1.35 +class ModRefBarrierSet: public BarrierSet {
1.36 +public:
1.37 + // Barriers only on ref writes.
1.38 + bool has_read_ref_barrier() { return false; }
1.39 + bool has_read_prim_barrier() { return false; }
1.40 + bool has_write_ref_barrier() { return true; }
1.41 + bool has_write_prim_barrier() { return false; }
1.42 +
1.43 + bool read_ref_needs_barrier(oop* field) { return false; }
1.44 + bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
1.45 + virtual bool write_ref_needs_barrier(oop* field, oop new_val) = 0;
1.46 + bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
1.47 + juint val1, juint val2) { return false; }
1.48 +
1.49 + void write_prim_field(oop obj, size_t offset, size_t bytes,
1.50 + juint val1, juint val2) {}
1.51 +
1.52 + void read_ref_field(oop* field) {}
1.53 + void read_prim_field(HeapWord* field, size_t bytes) {}
1.54 +protected:
1.55 + virtual void write_ref_field_work(oop* field, oop new_val) = 0;
1.56 +public:
1.57 + void write_prim_field(HeapWord* field, size_t bytes,
1.58 + juint val1, juint val2) {}
1.59 +
1.60 + bool has_read_ref_array_opt() { return false; }
1.61 + bool has_read_prim_array_opt() { return false; }
1.62 + bool has_write_prim_array_opt() { return false; }
1.63 +
1.64 + bool has_read_region_opt() { return false; }
1.65 +
1.66 +
1.67 + // These operations should assert false unless the correponding operation
1.68 + // above returns true.
1.69 + void read_ref_array(MemRegion mr) {
1.70 + assert(false, "can't call");
1.71 + }
1.72 + void read_prim_array(MemRegion mr) {
1.73 + assert(false, "can't call");
1.74 + }
1.75 + void write_prim_array(MemRegion mr) {
1.76 + assert(false, "can't call");
1.77 + }
1.78 + void read_region(MemRegion mr) {
1.79 + assert(false, "can't call");
1.80 + }
1.81 +
1.82 + // Invoke "cl->do_oop" on (the address of) every possibly-modifed
1.83 + // reference field in objects in "sp". If "clear" is "true", the oops
1.84 + // are no longer considered possibly modified after application of the
1.85 + // closure. If' "before_save_marks" is true, oops in objects allocated
1.86 + // after the last call to "save_marks" on "sp" will not be considered.
1.87 + virtual void mod_oop_in_space_iterate(Space* sp, OopClosure* cl,
1.88 + bool clear = false,
1.89 + bool before_save_marks = false) = 0;
1.90 +
1.91 + // Causes all refs in "mr" to be assumed to be modified.
1.92 + virtual void invalidate(MemRegion mr) = 0;
1.93 +
1.94 + // The caller guarantees that "mr" contains no references. (Perhaps it's
1.95 + // objects have been moved elsewhere.)
1.96 + virtual void clear(MemRegion mr) = 0;
1.97 +
1.98 + // Pass along the argument to the superclass.
1.99 + ModRefBarrierSet(int max_covered_regions) :
1.100 + BarrierSet(max_covered_regions) {}
1.101 +
1.102 +#ifndef PRODUCT
1.103 + // Verifies that the given region contains no modified references.
1.104 + virtual void verify_clean_region(MemRegion mr) = 0;
1.105 +#endif
1.106 +
1.107 +};
