130 lines
3.1 KiB
C
130 lines
3.1 KiB
C
#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#define CHECK_FERROR(f) { if (ferror(f)) {fprintf(stderr, "IO Error"); exit(1);} }
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#include "mmap.h"
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struct MMap* mmap_init(){
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struct MMap *mmap = malloc(sizeof(struct MMap));
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mmap->size = 4096*100;
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mmap->memory = malloc(mmap->size);
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mmap->count = 0;
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mmap->support = malloc(sizeof(struct PageInfo));
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mmap->support->data = malloc(4096);
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mmap->free_list = createLinkedList();
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// insert 100 pages in the free list
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for (int i = 0; i < 100; i++) {
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struct PageInfo *page = malloc(sizeof(struct PageInfo));
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page->data = mmap->memory + i*4096;
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page->key = i;
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insertFirst(mmap->free_list, i, page);
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}
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mmap->alloc_list = createLinkedList();
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mmap->swap = fopen("/tmp/myswap", "wb+");
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int tmp = -1;
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for (int i = 0; i < 100*sizeof(int); i+=sizeof(int)) {
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fwrite(&tmp, sizeof(int), 1, mmap->swap);
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}
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char tmp2 = '\0';
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for (int i = 0; i < 100*4096; i++) {
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fwrite(&tmp2, 1, 1, mmap->swap);
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}
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return mmap;
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}
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void mmap_clean(struct MMap *mmap) {
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free(mmap->memory);
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fclose(mmap->swap);
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free(mmap);
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remove("/tmp/myswap");
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}
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struct PageInfo* page_alloc(struct MMap *mmap) {
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struct PageInfo *page = NULL;
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page = page_free(mmap);
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if(page!=NULL) {
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insertFirst(mmap->alloc_list, page->key, page);
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mmap->count++;
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}
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return page;
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}
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struct PageInfo* page_free(struct MMap *mmap) {
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struct PageInfo *page = NULL;
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struct node *node = deleteFirst(mmap->free_list);
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if (node != NULL) {
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page = node->data;
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}
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return page;
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}
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int check_page_free_list(struct MMap *mmap) {
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return length(mmap->free_list);
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}
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int check_page_alloc(struct MMap *mmap) {
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return length(mmap->alloc_list);
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}
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int move_to_swap(struct MMap *mmap, struct PageInfo *page) {
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int key = -1;
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fseek(mmap->swap, 0, SEEK_SET);
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CHECK_FERROR(mmap->swap);
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for (int i = 0; i < 100*sizeof(int); i+=sizeof(int)) {
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fread(&key, sizeof(int), 1, mmap->swap);
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CHECK_FERROR(mmap->swap);
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if (key == -1) {
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fseek(mmap->swap, i, SEEK_SET);
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CHECK_FERROR(mmap->swap);
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fwrite(&page->key, sizeof(int), 1, mmap->swap);
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CHECK_FERROR(mmap->swap);
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fseek(mmap->swap, 100*sizeof(int) + (i/sizeof(int))*4096, SEEK_SET);
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CHECK_FERROR(mmap->swap);
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fwrite(page->data, 4096, 1, mmap->swap);
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CHECK_FERROR(mmap->swap);
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return 0;
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}
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}
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return -1;
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}
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struct PageInfo* read_from_swap(struct MMap* mmap, struct PageInfo *page) {
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int key = -1;
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fseek(mmap->swap, 0, SEEK_SET);
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CHECK_FERROR(mmap->swap);
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for (int i = 0; i < 100*sizeof(int); i+=sizeof(int)) {
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int ret = fread(&key, sizeof(int), 1, mmap->swap);
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CHECK_FERROR(mmap->swap);
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if (key != page->key)
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continue;
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fseek(mmap->swap, 100*sizeof(int) + (i/sizeof(int))*4096, SEEK_SET);
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CHECK_FERROR(mmap->swap);
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fread(page->data, 4096, 1, mmap->swap);
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CHECK_FERROR(mmap->swap);
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fseek(mmap->swap, i, SEEK_SET);
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CHECK_FERROR(mmap->swap);
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int tmp = -1;
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fwrite(&tmp, sizeof(int), 1, mmap->swap);
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CHECK_FERROR(mmap->swap);
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return page;
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}
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return NULL;
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}
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