Sat, 23 Nov 2013 12:25:13 +0100
8028128: Add a type safe alternative for working with counter based data
Reviewed-by: dholmes, egahlin
1 /*
2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "runtime/java.hpp"
30 AdjoiningVirtualSpaces::AdjoiningVirtualSpaces(ReservedSpace rs,
31 size_t min_low_byte_size,
32 size_t min_high_byte_size,
33 size_t alignment) :
34 _reserved_space(rs), _min_low_byte_size(min_low_byte_size),
35 _min_high_byte_size(min_high_byte_size), _low(0), _high(0),
36 _alignment(alignment) {}
38 // The maximum byte sizes are for the initial layout of the
39 // virtual spaces and are not the limit on the maximum bytes sizes.
40 void AdjoiningVirtualSpaces::initialize(size_t max_low_byte_size,
41 size_t init_low_byte_size,
42 size_t init_high_byte_size) {
44 // The reserved spaces for the two parts of the virtual space.
45 ReservedSpace old_rs = _reserved_space.first_part(max_low_byte_size);
46 ReservedSpace young_rs = _reserved_space.last_part(max_low_byte_size);
48 _low = new PSVirtualSpace(old_rs, alignment());
49 if (!_low->expand_by(init_low_byte_size)) {
50 vm_exit_during_initialization("Could not reserve enough space for "
51 "object heap");
52 }
54 _high = new PSVirtualSpaceHighToLow(young_rs, alignment());
55 if (!_high->expand_by(init_high_byte_size)) {
56 vm_exit_during_initialization("Could not reserve enough space for "
57 "object heap");
58 }
59 }
61 bool AdjoiningVirtualSpaces::adjust_boundary_up(size_t change_in_bytes) {
62 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
63 size_t actual_change = low()->expand_into(high(), change_in_bytes);
64 return actual_change != 0;
65 }
67 bool AdjoiningVirtualSpaces::adjust_boundary_down(size_t change_in_bytes) {
68 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
69 size_t actual_change = high()->expand_into(low(), change_in_bytes);
70 return actual_change != 0;
71 }