81 lines
2.2 KiB
C
81 lines
2.2 KiB
C
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#ifndef __slab_H
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#define __slab_H
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/*
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* Copyright (c) 2008 Picture Elements, Inc.
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* Stephen Williams (steve@icarus.com)
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*
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* This source code is free software; you can redistribute it
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* and/or modify it in source code form under the terms of the GNU
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* General Public License as published by the Free Software
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* Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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template <size_t SLAB_SIZE, size_t CHUNK_COUNT> class slab_t {
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union item_cell_u {
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item_cell_u*next;
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char space[SLAB_SIZE];
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};
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public:
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slab_t();
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void* alloc_slab();
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void free_slab(void*);
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unsigned long pool;
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private:
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item_cell_u*heap_;
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item_cell_u initial_chunk_[CHUNK_COUNT];
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};
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template <size_t SLAB_SIZE, size_t CHUNK_COUNT>
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slab_t<SLAB_SIZE,CHUNK_COUNT>::slab_t()
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{
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pool = CHUNK_COUNT;
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heap_ = initial_chunk_;
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for (unsigned idx = 0 ; idx < CHUNK_COUNT-1 ; idx += 1)
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initial_chunk_[idx].next = initial_chunk_+idx+1;
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initial_chunk_[CHUNK_COUNT-1].next = 0;
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}
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template <size_t SLAB_SIZE, size_t CHUNK_COUNT>
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inline void* slab_t<SLAB_SIZE,CHUNK_COUNT>::alloc_slab()
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{
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if (heap_ == 0) {
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item_cell_u*chunk = new item_cell_u[CHUNK_COUNT];
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for (unsigned idx = 0 ; idx < CHUNK_COUNT ; idx += 1) {
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chunk[idx].next = heap_;
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heap_ = chunk+idx;
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}
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pool += CHUNK_COUNT;
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}
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item_cell_u*cur = heap_;
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heap_ = heap_->next;
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return cur;
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}
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template <size_t SLAB_SIZE, size_t CHUNK_COUNT>
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inline void slab_t<SLAB_SIZE,CHUNK_COUNT>::free_slab(void*ptr)
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{
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item_cell_u*cur = reinterpret_cast<item_cell_u*> (ptr);
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cur->next = heap_;
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heap_ = cur;
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}
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#endif
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