src/share/vm/memory/modRefBarrierSet.hpp

Mon, 29 Apr 2013 16:13:57 -0400

author
hseigel
date
Mon, 29 Apr 2013 16:13:57 -0400
changeset 4987
f258c5828eb8
parent 4037
da91efe96a93
child 6493
3205e78d8193
permissions
-rw-r--r--

8011773: Some tests on Interned String crashed JVM with OOM
Summary: Instead of terminating the VM, throw OutOfMemoryError exceptions.
Reviewed-by: coleenp, dholmes

duke@435 1 /*
coleenp@4037 2 * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #ifndef SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
stefank@2314 26 #define SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
stefank@2314 27
stefank@2314 28 #include "memory/barrierSet.hpp"
stefank@2314 29
duke@435 30 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
duke@435 31 // enumerate ref fields that have been modified (since the last
duke@435 32 // enumeration), using a card table.
duke@435 33
duke@435 34 class OopClosure;
duke@435 35 class Generation;
duke@435 36
duke@435 37 class ModRefBarrierSet: public BarrierSet {
duke@435 38 public:
ysr@777 39
ysr@777 40 ModRefBarrierSet() { _kind = BarrierSet::ModRef; }
ysr@777 41
ysr@777 42 bool is_a(BarrierSet::Name bsn) {
ysr@777 43 return bsn == BarrierSet::ModRef;
ysr@777 44 }
ysr@777 45
duke@435 46 // Barriers only on ref writes.
duke@435 47 bool has_read_ref_barrier() { return false; }
duke@435 48 bool has_read_prim_barrier() { return false; }
duke@435 49 bool has_write_ref_barrier() { return true; }
duke@435 50 bool has_write_prim_barrier() { return false; }
duke@435 51
coleenp@548 52 bool read_ref_needs_barrier(void* field) { return false; }
duke@435 53 bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
duke@435 54 bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
duke@435 55 juint val1, juint val2) { return false; }
duke@435 56
duke@435 57 void write_prim_field(oop obj, size_t offset, size_t bytes,
duke@435 58 juint val1, juint val2) {}
duke@435 59
coleenp@548 60 void read_ref_field(void* field) {}
duke@435 61 void read_prim_field(HeapWord* field, size_t bytes) {}
duke@435 62 protected:
coleenp@548 63 virtual void write_ref_field_work(void* field, oop new_val) = 0;
duke@435 64 public:
duke@435 65 void write_prim_field(HeapWord* field, size_t bytes,
duke@435 66 juint val1, juint val2) {}
duke@435 67
duke@435 68 bool has_read_ref_array_opt() { return false; }
duke@435 69 bool has_read_prim_array_opt() { return false; }
duke@435 70 bool has_write_prim_array_opt() { return false; }
duke@435 71
duke@435 72 bool has_read_region_opt() { return false; }
duke@435 73
duke@435 74
duke@435 75 // These operations should assert false unless the correponding operation
duke@435 76 // above returns true.
duke@435 77 void read_ref_array(MemRegion mr) {
duke@435 78 assert(false, "can't call");
duke@435 79 }
duke@435 80 void read_prim_array(MemRegion mr) {
duke@435 81 assert(false, "can't call");
duke@435 82 }
duke@435 83 void write_prim_array(MemRegion mr) {
duke@435 84 assert(false, "can't call");
duke@435 85 }
duke@435 86 void read_region(MemRegion mr) {
duke@435 87 assert(false, "can't call");
duke@435 88 }
duke@435 89
ysr@777 90 // Causes all refs in "mr" to be assumed to be modified. If "whole_heap"
ysr@777 91 // is true, the caller asserts that the entire heap is being invalidated,
ysr@777 92 // which may admit an optimized implementation for some barriers.
ysr@777 93 virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
duke@435 94
duke@435 95 // The caller guarantees that "mr" contains no references. (Perhaps it's
duke@435 96 // objects have been moved elsewhere.)
duke@435 97 virtual void clear(MemRegion mr) = 0;
duke@435 98
duke@435 99 // Pass along the argument to the superclass.
duke@435 100 ModRefBarrierSet(int max_covered_regions) :
duke@435 101 BarrierSet(max_covered_regions) {}
duke@435 102 };
stefank@2314 103
stefank@2314 104 #endif // SHARE_VM_MEMORY_MODREFBARRIERSET_HPP

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