Compare commits
2 Commits
main
...
gbowne1-ma
Author | SHA1 | Date | |
---|---|---|---|
b34189b028 | |||
bb185366a6 |
50
main.c
50
main.c
@ -2,6 +2,7 @@
|
||||
#include <stdio.h>
|
||||
#include <unistd.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
|
||||
#define ALIGN16(s) (((s) + 15) & ~0x0F)
|
||||
#define BLOCK_SIZE sizeof(struct block)
|
||||
@ -30,11 +31,14 @@ struct block *extend_heap(size_t s)
|
||||
|
||||
struct block *b = (struct block *)sbrk(0); // Get the current break
|
||||
|
||||
// Add the size of the block header to the requested size
|
||||
s += BLOCK_SIZE;
|
||||
|
||||
if (sbrk(s) == (void *)-1) // Extend the break by s bytes
|
||||
// Attempt to extend the break by s bytes
|
||||
void *new_break = sbrk(BLOCK_SIZE + s);
|
||||
if (new_break == (void *)-1)
|
||||
{
|
||||
// Handle the error, e.g., by setting an error code or printing an error message
|
||||
fprintf(stderr, "Failed to extend heap by %zu bytes.\n", s);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
b->size = s;
|
||||
b->prev = last;
|
||||
@ -82,13 +86,13 @@ struct block *fragment_block(struct block *in, size_t s)
|
||||
|
||||
// Create the new block in the remainder space
|
||||
struct block *newBlock = (struct block *)((char *)(in + 1) + s);
|
||||
newBlock->size = remainderSize;
|
||||
newBlock->size = remainderSize; // Subtract the size of the block header
|
||||
newBlock->prev = in;
|
||||
newBlock->next = in->next;
|
||||
newBlock->free = 1; // Set the new block as free
|
||||
|
||||
// Update the current block to reflect the reduced size
|
||||
in->size = newBlockSize;
|
||||
in->size = newBlockSize; // Subtract the size of the block header
|
||||
in->next = newBlock;
|
||||
|
||||
// Insert the new block into the linked list of blocks
|
||||
@ -108,16 +112,14 @@ struct block *find_best_fit(size_t s)
|
||||
{
|
||||
if (current->free && current->size >= s)
|
||||
{
|
||||
if (best_fit && current->size < best_fit->size) // Check for NULL before comparison
|
||||
{
|
||||
if (best_fit == NULL || current->size < best_fit->size)
|
||||
{
|
||||
best_fit = current;
|
||||
}
|
||||
}
|
||||
current = current->next;
|
||||
}
|
||||
return best_fit;
|
||||
}
|
||||
return best_fit; // This return statement is now outside the while loop
|
||||
}
|
||||
|
||||
/// Will find or allocate a memory block.
|
||||
@ -199,7 +201,7 @@ void *realloc(void *ptr, size_t new_size)
|
||||
/// Will flag the provided memory as free and will defragment other blocks adjacent to it.
|
||||
/// @param [in] ptr The memory to flag as free.
|
||||
/// @note If all data after the provided memory is free, it will reduce the heap size.
|
||||
void my_custom_free(void *ptr)
|
||||
void free(void *ptr)
|
||||
{
|
||||
if (!ptr)
|
||||
{
|
||||
@ -231,7 +233,7 @@ void my_custom_free(void *ptr)
|
||||
b->next = b->next->next;
|
||||
if (b->next)
|
||||
{
|
||||
b->next->prev = b;
|
||||
b->next->prev = b; // Update the prev pointer of the next block
|
||||
}
|
||||
}
|
||||
|
||||
@ -259,22 +261,36 @@ void my_custom_free(void *ptr)
|
||||
}
|
||||
}
|
||||
|
||||
size_t get_heap_size()
|
||||
{
|
||||
size_t total_size = 0;
|
||||
struct block *current = first;
|
||||
|
||||
while (current != NULL)
|
||||
{
|
||||
total_size += current->size;
|
||||
current = current->next;
|
||||
}
|
||||
|
||||
return total_size;
|
||||
}
|
||||
|
||||
int main()
|
||||
{
|
||||
int *a = (int *)malloc(sizeof(int));
|
||||
int *b = (int *)malloc(sizeof(int));
|
||||
int *c = (int *)malloc(sizeof(int)); // Allocate memory for c
|
||||
|
||||
*a = 5;
|
||||
*b = 12;
|
||||
|
||||
printf("Test 1: %i\n", *a);
|
||||
printf("Test 2: %i\n", *b);
|
||||
printf("Heap Size: %zu Bytes\n", get_heap_size());
|
||||
printf("Heap Size: %zu Bytes\n", get_heap_size()); // Assuming get_heap_size is implemented
|
||||
|
||||
free(a);
|
||||
free(b);
|
||||
|
||||
int *c = (int *)malloc(sizeof(int));
|
||||
free(a); // Free memory for a
|
||||
free(b); // Free memory for b
|
||||
free(c); // Free memory for c
|
||||
|
||||
return 0;
|
||||
}
|
Loading…
Reference in New Issue
Block a user