Mercurial > hg > truffle
diff src/share/vm/gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
---|---|
date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c18cbe5936b8 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,108 @@ +/* + * Copyright 2003 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + + +// Contains two virtual spaces that each can individually span +// most of the reserved region but committed parts of which +// cannot overlap. +// +// +-------+ <--- high_boundary for H +// | | +// | H | +// | | +// | | +// | | +// --------- <--- low for H +// | | +// ========= <--- low_boundary for H, high_boundary for L +// | | +// | | +// | | +// --------- <--- high for L +// | | +// | L | +// | | +// | | +// | | +// +-------+ <--- low_boundary for L +// +// Each virtual space in the AdjoiningVirtualSpaces grows and shrink +// within its reserved region (between the low_boundary and the +// boundary) independently. If L want to grow above its high_boundary, +// then the high_boundary of L and the low_boundary of H must be +// moved up consistently. AdjoiningVirtualSpaces provide the +// interfaces for moving the this boundary. + +class AdjoiningVirtualSpaces { + // space at the high end and the low end, respectively + PSVirtualSpace* _high; + PSVirtualSpace* _low; + + // The reserved space spanned by the two spaces. + ReservedSpace _reserved_space; + + // The minimum byte size for the low space. It will not + // be shrunk below this value. + size_t _min_low_byte_size; + // Same for the high space + size_t _min_high_byte_size; + + const size_t _alignment; + + public: + // Allocates two virtual spaces that will be located at the + // high and low ends. Does no initialization. + AdjoiningVirtualSpaces(ReservedSpace rs, + size_t min_low_byte_size, + size_t min_high_byte_size, + size_t alignment); + + // accessors + PSVirtualSpace* high() { return _high; } + PSVirtualSpace* low() { return _low; } + ReservedSpace reserved_space() { return _reserved_space; } + size_t min_low_byte_size() { return _min_low_byte_size; } + size_t min_high_byte_size() { return _min_high_byte_size; } + size_t alignment() const { return _alignment; } + + // move boundary between the two spaces up + bool adjust_boundary_up(size_t size_in_bytes); + // and down + bool adjust_boundary_down(size_t size_in_bytes); + + // Maximum byte size for the high space. + size_t high_byte_size_limit() { + return _reserved_space.size() - _min_low_byte_size; + } + // Maximum byte size for the low space. + size_t low_byte_size_limit() { + return _reserved_space.size() - _min_high_byte_size; + } + + // Sets the boundaries for the virtual spaces and commits and + // initial size; + void initialize(size_t max_low_byte_size, + size_t init_low_byte_size, + size_t init_high_byte_size); +};