166 lines
4.2 KiB
C
166 lines
4.2 KiB
C
#ifndef LINKED_LIST_C
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#define LINKED_LIST_C
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#include <stddef.h>
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#include "terminal.c"
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#define MEMORY_START 0x200000
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//#define MEMORY_END 0x300000
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//size_t total_memory = MEMORY_END - MEMORY_START;
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typedef struct page_tag {
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size_t size;
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struct page_tag *prev;
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struct page_tag *next;
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} page_tag;
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page_tag *start = (void *) MEMORY_START;;
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page_tag *__searchPage(void *data) {
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page_tag *curr_page = start;
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while (curr_page + (sizeof(page_tag)) != data) {
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curr_page = curr_page->next;
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}
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return curr_page;
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}
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void *alloc(size_t size) {
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page_tag *curr_page = start;
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while (curr_page->next != NULL) {
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page_tag *new_page = ((void *) curr_page) + sizeof(page_tag) + curr_page->size;
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if ((void *) new_page + sizeof(page_tag) + size <= (void *) curr_page->next) {
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new_page->size = size;
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curr_page->next->prev = new_page;
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new_page->next = curr_page->next;
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curr_page->next = new_page;
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new_page->prev = curr_page;
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return new_page + 1;
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}
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curr_page = curr_page->next;
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}
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page_tag *new_page = ((void *) curr_page) + sizeof(page_tag) + curr_page->size;
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new_page->size = size;
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curr_page->next = new_page;
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new_page->prev = curr_page;
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new_page->next = NULL;
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return new_page + 1;
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}
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void free(void *data) {
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page_tag *data_tag = data - sizeof(page_tag);
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data_tag->prev->next = data_tag->next;
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data_tag->next->prev = data_tag->prev;
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}
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void print_memory() {
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terminal_write("==== MEM DUMP ====\n", 19);
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page_tag *curr_page = start;
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int i = 0;
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while (curr_page != NULL) {
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terminal_writeint(i, 10);
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terminal_write(": [", 3);
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terminal_writeint((int) curr_page, 16);
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terminal_write(" ", 1);
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terminal_writeint(sizeof(page_tag), 10);
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terminal_write("] [", 3);
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terminal_writeint((int) (curr_page + 1), 16);
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terminal_write(" ", 1);
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terminal_writeint(curr_page->size, 10);
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terminal_writestring("]\n");
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// printf("%d: [%p (%zu)] [%p (%zu)]\n",
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// i,
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// curr_page, sizeof(page_tag),
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// curr_page + 1, curr_page->size);
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void *empty_start = (void *) curr_page + sizeof(page_tag) + curr_page->size;
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if (empty_start + sizeof(page_tag) < (void *) curr_page->next) {
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terminal_writestring("empty_page (");
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terminal_writeint(sizeof(page_tag), 10);
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terminal_writestring(", ");
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terminal_writeint(
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(void *) curr_page->next -
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(empty_start + sizeof(page_tag)), 10);
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terminal_writestring(")\n");
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// printf("empty_page (%ld, %ld)\n",
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// sizeof(page_tag),
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// (void *) curr_page->next -
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// (empty_start + sizeof(page_tag)));
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} else if (empty_start < (void *) curr_page->next) {
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terminal_writestring("not enough room (");
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terminal_writeint((void *) curr_page->next - empty_start, 10);
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terminal_writestring(")\n");
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// printf("not enough room (%ld)\n",
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// (void *) curr_page->next - empty_start);
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}
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curr_page = curr_page->next;
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i++;
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}
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terminal_write("------------------\n\n", 20);
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}
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//
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//void test_allocs() {
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// void *ptr0 = __alloc(64);
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// void *ptr1 = __alloc(64);
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// void *ptr4 = __alloc(64);
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// print();
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//
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// printf("Free nr 2 -> %p\n", ptr1);
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// __free(ptr1);
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// print();
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//
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// printf("Alloc 32 bytes\n");
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// void *ptr2 = __alloc(32);
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// print();
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//
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// printf("Alloc 32 bytes\n");
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// __alloc(32);
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// print();
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//
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// printf("Alloc 8 bytes\n");
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// void *ptr3 = __alloc(8);
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// print();
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//
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// __free(ptr2);
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// print();
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// __free(ptr4);
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// print();
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// __free(ptr3);
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// print();
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//
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// __free(ptr0);
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// print();
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//
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// printf("#########\nTry almost fill\n");
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// __alloc(160);
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// print();
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// __alloc(50);
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// print();
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//
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//
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//}
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//
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//int main() {
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// start = malloc(sizeof(size_t) * 1000);
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// start->next = NULL;
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// start->prev = NULL;
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// test_allocs();
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//}
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#endif // LINKED_LIST_C
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