1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,115 @@
1.4 +/*
1.5 + * Copyright (c) 2003, 2010, 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_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGVIRTUALSPACES_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGVIRTUALSPACES_HPP
1.30 +
1.31 +#include "gc_implementation/parallelScavenge/psVirtualspace.hpp"
1.32 +
1.33 +
1.34 +// Contains two virtual spaces that each can individually span
1.35 +// most of the reserved region but committed parts of which
1.36 +// cannot overlap.
1.37 +//
1.38 +// +-------+ <--- high_boundary for H
1.39 +// | |
1.40 +// | H |
1.41 +// | |
1.42 +// | |
1.43 +// | |
1.44 +// --------- <--- low for H
1.45 +// | |
1.46 +// ========= <--- low_boundary for H, high_boundary for L
1.47 +// | |
1.48 +// | |
1.49 +// | |
1.50 +// --------- <--- high for L
1.51 +// | |
1.52 +// | L |
1.53 +// | |
1.54 +// | |
1.55 +// | |
1.56 +// +-------+ <--- low_boundary for L
1.57 +//
1.58 +// Each virtual space in the AdjoiningVirtualSpaces grows and shrink
1.59 +// within its reserved region (between the low_boundary and the
1.60 +// boundary) independently. If L want to grow above its high_boundary,
1.61 +// then the high_boundary of L and the low_boundary of H must be
1.62 +// moved up consistently. AdjoiningVirtualSpaces provide the
1.63 +// interfaces for moving the this boundary.
1.64 +
1.65 +class AdjoiningVirtualSpaces {
1.66 + // space at the high end and the low end, respectively
1.67 + PSVirtualSpace* _high;
1.68 + PSVirtualSpace* _low;
1.69 +
1.70 + // The reserved space spanned by the two spaces.
1.71 + ReservedSpace _reserved_space;
1.72 +
1.73 + // The minimum byte size for the low space. It will not
1.74 + // be shrunk below this value.
1.75 + size_t _min_low_byte_size;
1.76 + // Same for the high space
1.77 + size_t _min_high_byte_size;
1.78 +
1.79 + const size_t _alignment;
1.80 +
1.81 + public:
1.82 + // Allocates two virtual spaces that will be located at the
1.83 + // high and low ends. Does no initialization.
1.84 + AdjoiningVirtualSpaces(ReservedSpace rs,
1.85 + size_t min_low_byte_size,
1.86 + size_t min_high_byte_size,
1.87 + size_t alignment);
1.88 +
1.89 + // accessors
1.90 + PSVirtualSpace* high() { return _high; }
1.91 + PSVirtualSpace* low() { return _low; }
1.92 + ReservedSpace reserved_space() { return _reserved_space; }
1.93 + size_t min_low_byte_size() { return _min_low_byte_size; }
1.94 + size_t min_high_byte_size() { return _min_high_byte_size; }
1.95 + size_t alignment() const { return _alignment; }
1.96 +
1.97 + // move boundary between the two spaces up
1.98 + bool adjust_boundary_up(size_t size_in_bytes);
1.99 + // and down
1.100 + bool adjust_boundary_down(size_t size_in_bytes);
1.101 +
1.102 + // Maximum byte size for the high space.
1.103 + size_t high_byte_size_limit() {
1.104 + return _reserved_space.size() - _min_low_byte_size;
1.105 + }
1.106 + // Maximum byte size for the low space.
1.107 + size_t low_byte_size_limit() {
1.108 + return _reserved_space.size() - _min_high_byte_size;
1.109 + }
1.110 +
1.111 + // Sets the boundaries for the virtual spaces and commits and
1.112 + // initial size;
1.113 + void initialize(size_t max_low_byte_size,
1.114 + size_t init_low_byte_size,
1.115 + size_t init_high_byte_size);
1.116 +};
1.117 +
1.118 +#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGVIRTUALSPACES_HPP
