Karutoh/CustomHeapManager
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fixing issues from PR

Browse Source
This commit is contained in:
Gregory Kenneth Bowne 2024-02-14 16:21:16 -08:00
parent 19b2e31119
commit fe9d9e3836
1 changed files with 56 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

99
main.c
View File

@ -68,7 +68,7 @@ struct block *find_first(size_t s)
struct block *fragment_block(struct block *in, size_t s)
{
// Calculate the size of the new block, including the block header
size_t newBlockSize = ALIGN16(s) + BLOCK_SIZE;
size_t newBlockSize = s + BLOCK_SIZE;
// Check if the current block can be split
if (in->size <= newBlockSize)
@ -107,8 +107,9 @@ struct block *find_best_fit(size_t s)
while (current)
{
if (current->free && current->size >= s)
{
if (best_fit && current->size < best_fit->size) // Check for NULL before comparison
{
if (!best_fit || current->size < best_fit->size)
{
best_fit = current;
}
@ -116,6 +117,7 @@ struct block *find_best_fit(size_t s)
current = current->next;
}
return best_fit;
}
}
/// Will find or allocate a memory block.
@ -199,51 +201,62 @@ void *realloc(void *ptr, size_t new_size)
/// @note If all data after the provided memory is free, it will reduce the heap size.
void my_custom_free(void *ptr)
{
if (!ptr)
{
return;
}
if (!ptr)
{
return;
}
struct block *b = (struct block *)((char *)ptr - BLOCK_SIZE);
if (b->free)
{
fprintf(stderr, "Double free detected at block %p.\n", ptr);
abort(); // Terminate the program immediately due to serious error
}
struct block *b = (struct block *)((char *)ptr - BLOCK_SIZE);
if (b->free)
{
fprintf(stderr, "Double free detected at block %p.\n", ptr);
abort(); // Terminate the program immediately due to serious error
}
b->free = 1;
b->free = 1;
// Coalesce free blocks
while (b->prev && b->prev->free)
{
// Merge with previous block
b->prev->size += BLOCK_SIZE + b->size;
b->prev->next = b->next;
b = b->prev;
}
while (b->next && b->next->free)
{
// Merge with next block
b->size += BLOCK_SIZE + b->next->size;
b->next = b->next->next;
}
// Coalesce free blocks
while (b->prev && b->prev->free)
{
// Merge with previous block
b->prev->size += BLOCK_SIZE + b->size;
b->prev->next = b->next;
b = b->prev;
}
// Check if we can shrink the heap
if (b == last)
{
// Update 'last' to the previous block or NULL if there's no previous block
last = b->prev;
if (last)
{
last->next = NULL;
}
else
{
first = NULL;
}
// Reduce the program break to release the memory
sbrk(0 - (b->size + BLOCK_SIZE));
}
// If there is a next block and it's free, merge with it
if (b->next && b->next->free)
{
b->size += BLOCK_SIZE + b->next->size;
b->next = b->next->next;
if (b->next)
{
b->next->prev = b;
}
}
// After merging, update the 'last' pointer if necessary
if (!b->next)
{
last = b;
}
// Check if we can shrink the heap
if (b == last)
{
// Update 'last' to the previous block or NULL if there's no previous block
last = b->prev;
if (last)
{
last->next = NULL;
}
else
{
first = NULL;
}
// Reduce the program break to release the memory
sbrk(0 - (b->size + BLOCK_SIZE));
}
}
int main()