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/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGGENERATIONS_HPP
#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGGENERATIONS_HPP
#include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp"
#include "gc_implementation/parallelScavenge/asPSOldGen.hpp"
#include "gc_implementation/parallelScavenge/asPSYoungGen.hpp"
#include "gc_implementation/parallelScavenge/psPermGen.hpp"
// Contains two generations that both use an AdjoiningVirtualSpaces.
// The two generations are adjacent in the reserved space for the
// heap. Each generation has a virtual space and shrinking and
// expanding of the generations can still be down with that
// virtual space as was previously done. If expanding of reserved
// size of a generation is required, the adjacent generation
// must be shrunk. Adjusting the boundary between the generations
// is called for in this class.
class AdjoiningGenerations : public CHeapObj {
friend class VMStructs;
private:
// The young generation and old generation, respectively
PSYoungGen* _young_gen;
PSOldGen* _old_gen;
// The spaces used by the two generations.
AdjoiningVirtualSpaces _virtual_spaces;
// Move boundary up to expand old gen. Checks are made to
// determine if the move can be done with specified limits.
void request_old_gen_expansion(size_t desired_change_in_bytes);
// Move boundary down to expand young gen.
bool request_young_gen_expansion(size_t desired_change_in_bytes);
public:
AdjoiningGenerations(ReservedSpace rs,
size_t init_low_byte_size,
size_t min_low_byte_size,
size_t max_low_byte_size,
size_t init_high_byte_size,
size_t min_high_byte_size,
size_t max_high_bytes_size,
size_t alignment);
// Accessors
PSYoungGen* young_gen() { return _young_gen; }
PSOldGen* old_gen() { return _old_gen; }
AdjoiningVirtualSpaces* virtual_spaces() { return &_virtual_spaces; }
// Additional space is needed in the old generation. Check
// the available space and attempt to move the boundary if more space
// is needed. The growth is not guaranteed to occur.
void adjust_boundary_for_old_gen_needs(size_t desired_change_in_bytes);
// Similary for a growth of the young generation.
void adjust_boundary_for_young_gen_needs(size_t eden_size, size_t survivor_size);
// Return the total byte size of the reserved space
// for the adjoining generations.
size_t reserved_byte_size();
};
#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGGENERATIONS_HPP
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