Tue, 08 Aug 2017 15:57:29 +0800
merge
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. |
aoqi@0 | 8 | * |
aoqi@0 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 13 | * accompanied this code). |
aoqi@0 | 14 | * |
aoqi@0 | 15 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 18 | * |
aoqi@0 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 20 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 21 | * questions. |
aoqi@0 | 22 | * |
aoqi@0 | 23 | */ |
aoqi@0 | 24 | |
aoqi@0 | 25 | #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_SPACEDECORATOR_HPP |
aoqi@0 | 26 | #define SHARE_VM_GC_IMPLEMENTATION_SHARED_SPACEDECORATOR_HPP |
aoqi@0 | 27 | |
aoqi@0 | 28 | #include "gc_implementation/shared/mutableSpace.hpp" |
aoqi@0 | 29 | #include "memory/space.hpp" |
aoqi@0 | 30 | #include "utilities/globalDefinitions.hpp" |
aoqi@0 | 31 | |
aoqi@0 | 32 | class SpaceDecorator: public AllStatic { |
aoqi@0 | 33 | public: |
aoqi@0 | 34 | // Initialization flags. |
aoqi@0 | 35 | static const bool Clear = true; |
aoqi@0 | 36 | static const bool DontClear = false; |
aoqi@0 | 37 | static const bool Mangle = true; |
aoqi@0 | 38 | static const bool DontMangle = false; |
aoqi@0 | 39 | }; |
aoqi@0 | 40 | |
aoqi@0 | 41 | // Functionality for use with class Space and class MutableSpace. |
aoqi@0 | 42 | // The approach taken with the mangling is to mangle all |
aoqi@0 | 43 | // the space initially and then to mangle areas that have |
aoqi@0 | 44 | // been allocated since the last collection. Mangling is |
aoqi@0 | 45 | // done in the context of a generation and in the context |
aoqi@0 | 46 | // of a space. |
aoqi@0 | 47 | // The space in a generation is mangled when it is first |
aoqi@0 | 48 | // initialized and when the generation grows. The spaces |
aoqi@0 | 49 | // are not necessarily up-to-date when this mangling occurs |
aoqi@0 | 50 | // and the method mangle_region() is used. |
aoqi@0 | 51 | // After allocations have been done in a space, the space generally |
aoqi@0 | 52 | // need to be remangled. Remangling is only done on the |
aoqi@0 | 53 | // recently allocated regions in the space. Typically, that is |
aoqi@0 | 54 | // the region between the new top and the top just before a |
aoqi@0 | 55 | // garbage collection. |
aoqi@0 | 56 | // An exception to the usual mangling in a space is done when the |
aoqi@0 | 57 | // space is used for an extraordinary purpose. Specifically, when |
aoqi@0 | 58 | // to-space is used as scratch space for a mark-sweep-compact |
aoqi@0 | 59 | // collection. |
aoqi@0 | 60 | // Spaces are mangled after a collection. If the generation |
aoqi@0 | 61 | // grows after a collection, the added space is mangled as part of |
aoqi@0 | 62 | // the growth of the generation. No additional mangling is needed when the |
aoqi@0 | 63 | // spaces are resized after an expansion. |
aoqi@0 | 64 | // The class SpaceMangler keeps a pointer to the top of the allocated |
aoqi@0 | 65 | // area and provides the methods for doing the piece meal mangling. |
aoqi@0 | 66 | // Methods for doing sparces and full checking of the mangling are |
aoqi@0 | 67 | // included. The full checking is done if DEBUG_MANGLING is defined. |
aoqi@0 | 68 | // GenSpaceMangler is used with the GenCollectedHeap collectors and |
aoqi@0 | 69 | // MutableSpaceMangler is used with the ParallelScavengeHeap collectors. |
aoqi@0 | 70 | // These subclasses abstract the differences in the types of spaces used |
aoqi@0 | 71 | // by each heap. |
aoqi@0 | 72 | |
aoqi@0 | 73 | class SpaceMangler: public CHeapObj<mtGC> { |
aoqi@0 | 74 | friend class VMStructs; |
aoqi@0 | 75 | |
aoqi@0 | 76 | // High water mark for allocations. Typically, the space above |
aoqi@0 | 77 | // this point have been mangle previously and don't need to be |
aoqi@0 | 78 | // touched again. Space belows this point has been allocated |
aoqi@0 | 79 | // and remangling is needed between the current top and this |
aoqi@0 | 80 | // high water mark. |
aoqi@0 | 81 | HeapWord* _top_for_allocations; |
aoqi@0 | 82 | HeapWord* top_for_allocations() { return _top_for_allocations; } |
aoqi@0 | 83 | |
aoqi@0 | 84 | public: |
aoqi@0 | 85 | |
aoqi@0 | 86 | // Setting _top_for_allocations to NULL at initialization |
aoqi@0 | 87 | // makes it always below top so that mangling done as part |
aoqi@0 | 88 | // of the initialize() call of a space does nothing (as it |
aoqi@0 | 89 | // should since the mangling is done as part of the constructor |
aoqi@0 | 90 | // for the space. |
aoqi@0 | 91 | SpaceMangler() : _top_for_allocations(NULL) {} |
aoqi@0 | 92 | |
aoqi@0 | 93 | // Methods for top and end that delegate to the specific |
aoqi@0 | 94 | // space type. |
aoqi@0 | 95 | virtual HeapWord* top() const = 0; |
aoqi@0 | 96 | virtual HeapWord* end() const = 0; |
aoqi@0 | 97 | |
aoqi@0 | 98 | // Return true if q matches the mangled pattern. |
aoqi@0 | 99 | static bool is_mangled(HeapWord* q) PRODUCT_RETURN0; |
aoqi@0 | 100 | |
aoqi@0 | 101 | // Used to save the an address in a space for later use during mangling. |
aoqi@0 | 102 | void set_top_for_allocations(HeapWord* v); |
aoqi@0 | 103 | |
aoqi@0 | 104 | // Overwrites the unused portion of this space. |
aoqi@0 | 105 | // Mangle only the region not previously mangled [top, top_previously_mangled) |
aoqi@0 | 106 | void mangle_unused_area(); |
aoqi@0 | 107 | // Mangle all the unused region [top, end) |
aoqi@0 | 108 | void mangle_unused_area_complete(); |
aoqi@0 | 109 | // Do some sparse checking on the area that should have been mangled. |
aoqi@0 | 110 | void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN; |
aoqi@0 | 111 | // Do a complete check of the area that should be mangled. |
aoqi@0 | 112 | void check_mangled_unused_area_complete() PRODUCT_RETURN; |
aoqi@0 | 113 | |
aoqi@0 | 114 | // Mangle the MemRegion. This is a non-space specific mangler. It |
aoqi@0 | 115 | // is used during the initial mangling of a space before the space |
aoqi@0 | 116 | // is fully constructed. Also is used when a generation is expanded |
aoqi@0 | 117 | // and possibly before the spaces have been reshaped to to the new |
aoqi@0 | 118 | // size of the generation. |
aoqi@0 | 119 | static void mangle_region(MemRegion mr) PRODUCT_RETURN; |
aoqi@0 | 120 | }; |
aoqi@0 | 121 | |
aoqi@0 | 122 | class ContiguousSpace; |
aoqi@0 | 123 | |
aoqi@0 | 124 | // For use with GenCollectedHeap's |
aoqi@0 | 125 | class GenSpaceMangler: public SpaceMangler { |
aoqi@0 | 126 | ContiguousSpace* _sp; |
aoqi@0 | 127 | |
aoqi@0 | 128 | ContiguousSpace* sp() { return _sp; } |
aoqi@0 | 129 | |
aoqi@0 | 130 | HeapWord* top() const { return _sp->top(); } |
aoqi@0 | 131 | HeapWord* end() const { return _sp->end(); } |
aoqi@0 | 132 | |
aoqi@0 | 133 | public: |
aoqi@0 | 134 | GenSpaceMangler(ContiguousSpace* sp) : SpaceMangler(), _sp(sp) {} |
aoqi@0 | 135 | }; |
aoqi@0 | 136 | |
aoqi@0 | 137 | // For use with ParallelScavengeHeap's. |
aoqi@0 | 138 | class MutableSpaceMangler: public SpaceMangler { |
aoqi@0 | 139 | MutableSpace* _sp; |
aoqi@0 | 140 | |
aoqi@0 | 141 | MutableSpace* sp() { return _sp; } |
aoqi@0 | 142 | |
aoqi@0 | 143 | HeapWord* top() const { return _sp->top(); } |
aoqi@0 | 144 | HeapWord* end() const { return _sp->end(); } |
aoqi@0 | 145 | |
aoqi@0 | 146 | public: |
aoqi@0 | 147 | MutableSpaceMangler(MutableSpace* sp) : SpaceMangler(), _sp(sp) {} |
aoqi@0 | 148 | }; |
aoqi@0 | 149 | |
aoqi@0 | 150 | #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_SPACEDECORATOR_HPP |