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src/share/vm/gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp@4dfb2df418f2 (annotated)
src/share/vm/gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp
Thu, 22 Sep 2011 10:57:37 -0700
- author
- johnc
- date
- Thu, 22 Sep 2011 10:57:37 -0700
- changeset 3175
- 4dfb2df418f2
- parent 2314
- f95d63e2154a
- child 6876
- 710a3c8b516e
- permissions
- -rw-r--r--
6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp
| duke@435 | 1 | /* |
| stefank@2314 | 2 | * Copyright (c) 2003, 2010, Oracle and/or its affiliates. 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 | * |
| trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
| trims@1907 | 21 | * questions. |
| duke@435 | 22 | * |
| duke@435 | 23 | */ |
| duke@435 | 24 | |
| stefank@2314 | 25 | #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGVIRTUALSPACES_HPP |
| stefank@2314 | 26 | #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGVIRTUALSPACES_HPP |
| stefank@2314 | 27 | |
| stefank@2314 | 28 | #include "gc_implementation/parallelScavenge/psVirtualspace.hpp" |
| stefank@2314 | 29 | |
| duke@435 | 30 | |
| duke@435 | 31 | // Contains two virtual spaces that each can individually span |
| duke@435 | 32 | // most of the reserved region but committed parts of which |
| duke@435 | 33 | // cannot overlap. |
| duke@435 | 34 | // |
| duke@435 | 35 | // +-------+ <--- high_boundary for H |
| duke@435 | 36 | // | | |
| duke@435 | 37 | // | H | |
| duke@435 | 38 | // | | |
| duke@435 | 39 | // | | |
| duke@435 | 40 | // | | |
| duke@435 | 41 | // --------- <--- low for H |
| duke@435 | 42 | // | | |
| duke@435 | 43 | // ========= <--- low_boundary for H, high_boundary for L |
| duke@435 | 44 | // | | |
| duke@435 | 45 | // | | |
| duke@435 | 46 | // | | |
| duke@435 | 47 | // --------- <--- high for L |
| duke@435 | 48 | // | | |
| duke@435 | 49 | // | L | |
| duke@435 | 50 | // | | |
| duke@435 | 51 | // | | |
| duke@435 | 52 | // | | |
| duke@435 | 53 | // +-------+ <--- low_boundary for L |
| duke@435 | 54 | // |
| duke@435 | 55 | // Each virtual space in the AdjoiningVirtualSpaces grows and shrink |
| duke@435 | 56 | // within its reserved region (between the low_boundary and the |
| duke@435 | 57 | // boundary) independently. If L want to grow above its high_boundary, |
| duke@435 | 58 | // then the high_boundary of L and the low_boundary of H must be |
| duke@435 | 59 | // moved up consistently. AdjoiningVirtualSpaces provide the |
| duke@435 | 60 | // interfaces for moving the this boundary. |
| duke@435 | 61 | |
| duke@435 | 62 | class AdjoiningVirtualSpaces { |
| duke@435 | 63 | // space at the high end and the low end, respectively |
| duke@435 | 64 | PSVirtualSpace* _high; |
| duke@435 | 65 | PSVirtualSpace* _low; |
| duke@435 | 66 | |
| duke@435 | 67 | // The reserved space spanned by the two spaces. |
| duke@435 | 68 | ReservedSpace _reserved_space; |
| duke@435 | 69 | |
| duke@435 | 70 | // The minimum byte size for the low space. It will not |
| duke@435 | 71 | // be shrunk below this value. |
| duke@435 | 72 | size_t _min_low_byte_size; |
| duke@435 | 73 | // Same for the high space |
| duke@435 | 74 | size_t _min_high_byte_size; |
| duke@435 | 75 | |
| duke@435 | 76 | const size_t _alignment; |
| duke@435 | 77 | |
| duke@435 | 78 | public: |
| duke@435 | 79 | // Allocates two virtual spaces that will be located at the |
| duke@435 | 80 | // high and low ends. Does no initialization. |
| duke@435 | 81 | AdjoiningVirtualSpaces(ReservedSpace rs, |
| duke@435 | 82 | size_t min_low_byte_size, |
| duke@435 | 83 | size_t min_high_byte_size, |
| duke@435 | 84 | size_t alignment); |
| duke@435 | 85 | |
| duke@435 | 86 | // accessors |
| duke@435 | 87 | PSVirtualSpace* high() { return _high; } |
| duke@435 | 88 | PSVirtualSpace* low() { return _low; } |
| duke@435 | 89 | ReservedSpace reserved_space() { return _reserved_space; } |
| duke@435 | 90 | size_t min_low_byte_size() { return _min_low_byte_size; } |
| duke@435 | 91 | size_t min_high_byte_size() { return _min_high_byte_size; } |
| duke@435 | 92 | size_t alignment() const { return _alignment; } |
| duke@435 | 93 | |
| duke@435 | 94 | // move boundary between the two spaces up |
| duke@435 | 95 | bool adjust_boundary_up(size_t size_in_bytes); |
| duke@435 | 96 | // and down |
| duke@435 | 97 | bool adjust_boundary_down(size_t size_in_bytes); |
| duke@435 | 98 | |
| duke@435 | 99 | // Maximum byte size for the high space. |
| duke@435 | 100 | size_t high_byte_size_limit() { |
| duke@435 | 101 | return _reserved_space.size() - _min_low_byte_size; |
| duke@435 | 102 | } |
| duke@435 | 103 | // Maximum byte size for the low space. |
| duke@435 | 104 | size_t low_byte_size_limit() { |
| duke@435 | 105 | return _reserved_space.size() - _min_high_byte_size; |
| duke@435 | 106 | } |
| duke@435 | 107 | |
| duke@435 | 108 | // Sets the boundaries for the virtual spaces and commits and |
| duke@435 | 109 | // initial size; |
| duke@435 | 110 | void initialize(size_t max_low_byte_size, |
| duke@435 | 111 | size_t init_low_byte_size, |
| duke@435 | 112 | size_t init_high_byte_size); |
| duke@435 | 113 | }; |
| stefank@2314 | 114 | |
| stefank@2314 | 115 | #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_ADJOININGVIRTUALSPACES_HPP |
