77 lines
2.8 KiB
C
77 lines
2.8 KiB
C
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/*-
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* Copyright (c) 1998 Matthew Dillon. All Rights Reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* The radix bitmap structure is ported from FreeBSD and is only used
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* in swap system at the time.
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*/
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#ifndef _KERNEL_UTIL_RADIX_BITMAP_H
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#define _KERNEL_UTIL_RADIX_BITMAP_H
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#include <SupportDefs.h>
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typedef uint32 swap_addr_t;
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typedef uint32 bitmap_t;
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typedef struct radix_node {
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union {
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bitmap_t bitmap; // bitmap for the slots if we are a leaf
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int32 available; // available slots under us if we are not a leaf
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} u;
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int32 big_hint; // the biggest continuous slots under us
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} radix_node;
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// Bitmap which uses radix tree for hinting.
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// The radix tree is stored in an array.
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typedef struct radix_bitmap {
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swap_addr_t free_slots; // # of free slots
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swap_addr_t radix; // coverage radix
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swap_addr_t skip; // starting skip
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radix_node *root; // root of radix tree, actually it is an array
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swap_addr_t root_size; // size of the array(# of nodes in the tree)
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} radix_bitmap;
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#define BITMAP_RADIX (sizeof(swap_addr_t) * 8)
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#define NODE_RADIX 16
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#define SWAP_SLOT_NONE ((swap_addr_t)-1)
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extern radix_bitmap *radix_bitmap_create(uint32 slots);
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extern swap_addr_t radix_bitmap_alloc(radix_bitmap *bmp, uint32 count);
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extern void radix_bitmap_dealloc(radix_bitmap *bmp, swap_addr_t slotIndex,
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uint32 count);
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extern void radix_bitmap_destroy(radix_bitmap *bmp);
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#endif // _KERNEL_UTIL_RADIX_BITMAP_H
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