[176] | 1 | /* -*- C++ -*- */ |
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| 2 | |
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| 3 | /* |
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| 4 | |
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| 5 | Heap Layers: An Extensible Memory Allocation Infrastructure |
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| 6 | |
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| 7 | Copyright (C) 2000-2003 by Emery Berger |
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| 8 | http://www.cs.umass.edu/~emery |
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| 9 | emery@cs.umass.edu |
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| 10 | |
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| 11 | This program is free software; you can redistribute it and/or modify |
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| 12 | it under the terms of the GNU General Public License as published by |
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| 13 | the Free Software Foundation; either version 2 of the License, or |
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| 14 | (at your option) any later version. |
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| 15 | |
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| 16 | This program is distributed in the hope that it will be useful, |
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| 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 19 | GNU General Public License for more details. |
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| 20 | |
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| 21 | You should have received a copy of the GNU General Public License |
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| 22 | along with this program; if not, write to the Free Software |
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| 23 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 24 | |
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| 25 | */ |
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| 26 | |
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| 27 | #ifndef _SIZEHEAP_H_ |
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| 28 | #define _SIZEHEAP_H_ |
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| 29 | |
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| 30 | /** |
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| 31 | * @file sizeheap.h |
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| 32 | * @brief Contains UseSizeHeap and SizeHeap. |
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| 33 | */ |
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| 34 | |
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| 35 | #include <assert.h> |
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| 36 | |
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| 37 | #include "addheap.h" |
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| 38 | |
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| 39 | #if 1 |
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| 40 | |
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| 41 | /** |
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| 42 | * @class UseSizeHeap |
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| 43 | * @brief Adds a getSize method to access the size of an allocated object. |
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| 44 | * @see SizeHeap |
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| 45 | */ |
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| 46 | |
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| 47 | namespace HL { |
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| 48 | |
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| 49 | template <class Super> |
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| 50 | class UseSizeHeap : public Super { |
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| 51 | public: |
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| 52 | |
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| 53 | inline UseSizeHeap (void) {} |
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| 54 | |
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| 55 | inline static size_t getSize (const void * ptr) { |
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| 56 | return ((freeObject *) ptr - 1)->sz; |
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| 57 | } |
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| 58 | |
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| 59 | protected: |
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| 60 | union freeObject { |
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| 61 | size_t sz; |
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| 62 | double _dummy; // for alignment. |
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| 63 | }; |
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| 64 | }; |
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| 65 | |
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| 66 | /** |
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| 67 | * @class SizeHeap |
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| 68 | * @brief Allocates extra room for the size of an object. |
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| 69 | */ |
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| 70 | |
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| 71 | template <class SuperHeap> |
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| 72 | class SizeHeap : public UseSizeHeap<SuperHeap> { |
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| 73 | typedef typename UseSizeHeap<SuperHeap>::freeObject freeObject; |
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| 74 | public: |
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| 75 | inline SizeHeap (void) {} |
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| 76 | inline void * malloc (const size_t sz) { |
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| 77 | // Add room for a size field. |
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| 78 | freeObject * ptr = (freeObject *) |
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| 79 | SuperHeap::malloc (sz + sizeof(freeObject)); |
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| 80 | // Store the requested size. |
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| 81 | ptr->sz = sz; |
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| 82 | return (void *) (ptr + 1); |
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| 83 | } |
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| 84 | inline void free (void * ptr) { |
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| 85 | SuperHeap::free ((freeObject *) ptr - 1); |
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| 86 | } |
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| 87 | }; |
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| 88 | |
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| 89 | }; |
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| 90 | |
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| 91 | #else |
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| 92 | |
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| 93 | template <class Super> |
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| 94 | class SizeHeap : public Super { |
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| 95 | public: |
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| 96 | |
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| 97 | inline void * malloc (size_t sz) { |
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| 98 | // Add room for a size field. |
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| 99 | assert (sizeof(size_t) <= sizeof(double)); |
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| 100 | void * ptr = Super::malloc (sz + sizeof(double)); |
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| 101 | // Store the requested size. |
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| 102 | *((size_t *) ptr) = sz; |
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| 103 | return (void *) ((double *) ptr + 1); |
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| 104 | } |
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| 105 | |
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| 106 | inline void free (void * ptr) { |
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| 107 | void * origPtr = (void *) ((double *) ptr - 1); |
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| 108 | Super::free (origPtr); |
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| 109 | } |
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| 110 | |
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| 111 | inline static size_t getSize (void * ptr) { |
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| 112 | return *((size_t *) ((double *) ptr - 1)); |
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| 113 | } |
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| 114 | }; |
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| 115 | |
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| 116 | |
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| 117 | |
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| 118 | template <class Super> |
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| 119 | class UseSizeHeap : public Super { |
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| 120 | public: |
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| 121 | |
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| 122 | inline static size_t getSize (void * ptr) { |
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| 123 | return *((size_t *) ((double *) ptr - 1)); |
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| 124 | } |
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| 125 | }; |
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| 126 | |
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| 127 | #endif |
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| 128 | |
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| 129 | #endif |
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