Tue, 07 Oct 2008 11:01:35 -0700
Merge
duke@435 | 1 | /* |
duke@435 | 2 | * Copyright 2003 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | |
duke@435 | 26 | // Contains two virtual spaces that each can individually span |
duke@435 | 27 | // most of the reserved region but committed parts of which |
duke@435 | 28 | // cannot overlap. |
duke@435 | 29 | // |
duke@435 | 30 | // +-------+ <--- high_boundary for H |
duke@435 | 31 | // | | |
duke@435 | 32 | // | H | |
duke@435 | 33 | // | | |
duke@435 | 34 | // | | |
duke@435 | 35 | // | | |
duke@435 | 36 | // --------- <--- low for H |
duke@435 | 37 | // | | |
duke@435 | 38 | // ========= <--- low_boundary for H, high_boundary for L |
duke@435 | 39 | // | | |
duke@435 | 40 | // | | |
duke@435 | 41 | // | | |
duke@435 | 42 | // --------- <--- high for L |
duke@435 | 43 | // | | |
duke@435 | 44 | // | L | |
duke@435 | 45 | // | | |
duke@435 | 46 | // | | |
duke@435 | 47 | // | | |
duke@435 | 48 | // +-------+ <--- low_boundary for L |
duke@435 | 49 | // |
duke@435 | 50 | // Each virtual space in the AdjoiningVirtualSpaces grows and shrink |
duke@435 | 51 | // within its reserved region (between the low_boundary and the |
duke@435 | 52 | // boundary) independently. If L want to grow above its high_boundary, |
duke@435 | 53 | // then the high_boundary of L and the low_boundary of H must be |
duke@435 | 54 | // moved up consistently. AdjoiningVirtualSpaces provide the |
duke@435 | 55 | // interfaces for moving the this boundary. |
duke@435 | 56 | |
duke@435 | 57 | class AdjoiningVirtualSpaces { |
duke@435 | 58 | // space at the high end and the low end, respectively |
duke@435 | 59 | PSVirtualSpace* _high; |
duke@435 | 60 | PSVirtualSpace* _low; |
duke@435 | 61 | |
duke@435 | 62 | // The reserved space spanned by the two spaces. |
duke@435 | 63 | ReservedSpace _reserved_space; |
duke@435 | 64 | |
duke@435 | 65 | // The minimum byte size for the low space. It will not |
duke@435 | 66 | // be shrunk below this value. |
duke@435 | 67 | size_t _min_low_byte_size; |
duke@435 | 68 | // Same for the high space |
duke@435 | 69 | size_t _min_high_byte_size; |
duke@435 | 70 | |
duke@435 | 71 | const size_t _alignment; |
duke@435 | 72 | |
duke@435 | 73 | public: |
duke@435 | 74 | // Allocates two virtual spaces that will be located at the |
duke@435 | 75 | // high and low ends. Does no initialization. |
duke@435 | 76 | AdjoiningVirtualSpaces(ReservedSpace rs, |
duke@435 | 77 | size_t min_low_byte_size, |
duke@435 | 78 | size_t min_high_byte_size, |
duke@435 | 79 | size_t alignment); |
duke@435 | 80 | |
duke@435 | 81 | // accessors |
duke@435 | 82 | PSVirtualSpace* high() { return _high; } |
duke@435 | 83 | PSVirtualSpace* low() { return _low; } |
duke@435 | 84 | ReservedSpace reserved_space() { return _reserved_space; } |
duke@435 | 85 | size_t min_low_byte_size() { return _min_low_byte_size; } |
duke@435 | 86 | size_t min_high_byte_size() { return _min_high_byte_size; } |
duke@435 | 87 | size_t alignment() const { return _alignment; } |
duke@435 | 88 | |
duke@435 | 89 | // move boundary between the two spaces up |
duke@435 | 90 | bool adjust_boundary_up(size_t size_in_bytes); |
duke@435 | 91 | // and down |
duke@435 | 92 | bool adjust_boundary_down(size_t size_in_bytes); |
duke@435 | 93 | |
duke@435 | 94 | // Maximum byte size for the high space. |
duke@435 | 95 | size_t high_byte_size_limit() { |
duke@435 | 96 | return _reserved_space.size() - _min_low_byte_size; |
duke@435 | 97 | } |
duke@435 | 98 | // Maximum byte size for the low space. |
duke@435 | 99 | size_t low_byte_size_limit() { |
duke@435 | 100 | return _reserved_space.size() - _min_high_byte_size; |
duke@435 | 101 | } |
duke@435 | 102 | |
duke@435 | 103 | // Sets the boundaries for the virtual spaces and commits and |
duke@435 | 104 | // initial size; |
duke@435 | 105 | void initialize(size_t max_low_byte_size, |
duke@435 | 106 | size_t init_low_byte_size, |
duke@435 | 107 | size_t init_high_byte_size); |
duke@435 | 108 | }; |