55 lines
1.0 KiB
C
55 lines
1.0 KiB
C
#include <assert.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <stdio.h>
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#include "logger.h"
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#define NUM_VALUES 0xFFFFFFFF
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#define PAGE_SIZE 0xFFFF
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#define NUM_PAGES (NUM_VALUES / PAGE_SIZE)
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#define SIZE (8*sizeof(uint64_t))
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uint64_t** pbm_init(void)
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{
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uint64_t** retv = calloc(NUM_PAGES, sizeof(void*));
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if (!retv) {
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log_fatal("pbm", "unable to allocate memory for base page table");
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}
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return retv;
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}
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static int bm_check(uint64_t *bm, uint32_t v)
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{
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return bm[v/SIZE] & (1<< (v % SIZE));
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}
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static void bm_set(uint64_t *bm, uint32_t v)
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{
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bm[v/SIZE] |= (1 << (v % SIZE));
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}
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int pbm_check(uint64_t **b, uint32_t v)
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{
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uint32_t top = v >> 16;
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uint32_t bottom = v & PAGE_SIZE;
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return b[top] && bm_check(b[top], bottom);
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}
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void pbm_set(uint64_t **b, uint32_t v)
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{
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uint32_t top = v >> 16;
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uint32_t bottom = v & PAGE_SIZE;
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if (!b[top]) {
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uint64_t *bm = malloc(PAGE_SIZE);
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if (!bm) {
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log_fatal("bpm", "unable to allocate memory for new bitmap page");
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}
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memset(bm, 0, PAGE_SIZE);
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b[top] = bm;
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}
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bm_set(b[top], bottom);
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}
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