tabs/kernel/memory.c

145 lines
3.3 KiB
C

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