1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/adjoiningGenerations.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,77 @@
1.4 +/*
1.5 + * Copyright 2003 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +
1.29 +// Contains two generations that both use an AdjoiningVirtualSpaces.
1.30 +// The two generations are adjacent in the reserved space for the
1.31 +// heap. Each generation has a virtual space and shrinking and
1.32 +// expanding of the generations can still be down with that
1.33 +// virtual space as was previously done. If expanding of reserved
1.34 +// size of a generation is required, the adjacent generation
1.35 +// must be shrunk. Adjusting the boundary between the generations
1.36 +// is called for in this class.
1.37 +
1.38 +class AdjoiningGenerations : public CHeapObj {
1.39 + friend class VMStructs;
1.40 + private:
1.41 + // The young generation and old generation, respectively
1.42 + PSYoungGen* _young_gen;
1.43 + PSOldGen* _old_gen;
1.44 +
1.45 + // The spaces used by the two generations.
1.46 + AdjoiningVirtualSpaces _virtual_spaces;
1.47 +
1.48 + // Move boundary up to expand old gen. Checks are made to
1.49 + // determine if the move can be done with specified limits.
1.50 + void request_old_gen_expansion(size_t desired_change_in_bytes);
1.51 + // Move boundary down to expand young gen.
1.52 + bool request_young_gen_expansion(size_t desired_change_in_bytes);
1.53 +
1.54 + public:
1.55 + AdjoiningGenerations(ReservedSpace rs,
1.56 + size_t init_low_byte_size,
1.57 + size_t min_low_byte_size,
1.58 + size_t max_low_byte_size,
1.59 + size_t init_high_byte_size,
1.60 + size_t min_high_byte_size,
1.61 + size_t max_high_bytes_size,
1.62 + size_t alignment);
1.63 +
1.64 + // Accessors
1.65 + PSYoungGen* young_gen() { return _young_gen; }
1.66 + PSOldGen* old_gen() { return _old_gen; }
1.67 +
1.68 + AdjoiningVirtualSpaces* virtual_spaces() { return &_virtual_spaces; }
1.69 +
1.70 + // Additional space is needed in the old generation. Check
1.71 + // the available space and attempt to move the boundary if more space
1.72 + // is needed. The growth is not guaranteed to occur.
1.73 + void adjust_boundary_for_old_gen_needs(size_t desired_change_in_bytes);
1.74 + // Similary for a growth of the young generation.
1.75 + void adjust_boundary_for_young_gen_needs(size_t eden_size, size_t survivor_size);
1.76 +
1.77 + // Return the total byte size of the reserved space
1.78 + // for the adjoining generations.
1.79 + size_t reserved_byte_size();
1.80 +};
