tehsquidge/SquidgeOS
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

adding prev to HeapHeader to allow backwards coalescing.

Browse source
This commit is contained in:
Liam Kerr 2026-02-09 15:33:11 +00:00
parent 8226764dea
commit de312ee5fa
2 changed files with 41 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

57
src/kernel/memory.c
View file

@ -52,6 +52,7 @@ void *kmalloc(size_t size) {
header->size = PAGE_SIZE - sizeof(HeapHeader);
header->is_free = 1;
header->next = NULL;
header->prev = NULL;
heap_free_list = header;
}
@ -73,6 +74,10 @@ void *kmalloc(size_t size) {
header->size = PAGE_SIZE - sizeof(HeapHeader);
header->is_free = 1;
header->next = heap_free_list;
header->prev = NULL;
if(heap_free_list) {
heap_free_list->prev = header;
}
heap_free_list = header;
current = header;
}
@ -94,8 +99,12 @@ void *kmalloc(size_t size) {
}
new_header->size = current->size - size - sizeof(HeapHeader);
new_header->is_free = 1;
new_header->next = current->next;
new_header->next = current->next;
new_header->prev = current;
if(current->next) {
current->next->prev = new_header;
}
current->size = size;
current->next = new_header;
}
@ -112,22 +121,27 @@ void kfree(void *ptr) {
}
header->is_free = 1;
HeapHeader *temp = heap_free_list;
while (temp != NULL) {
if (temp->is_free) {
kcoalesce(temp);
}
temp = temp->next;
}
kcoalesce(header);
}
void kcoalesce(HeapHeader *header) {
if(!header || !header->next || !header->is_free) return;
uintptr_t current_end = (uintptr_t)header + sizeof(HeapHeader) + header->size;
if (current_end == (uintptr_t)header->next && header->next->is_free) {
header->size += sizeof(HeapHeader) + header->next->size;
header->next = header->next->next;
kcoalesce(header);
if(!header || !header->is_free) return;
//merge backward
while (header->prev && header->prev->is_free) {
header = header->prev;
}
//merge forward
while (header->next && header->next->is_free){
uintptr_t current_end = (uintptr_t)header + sizeof(HeapHeader) + header->size;
if (current_end == (uintptr_t)header->next) {
header->size += sizeof(HeapHeader) + header->next->size;
header->next = header->next->next;
if(header->next) {
header->next->prev = header;
}
} else {
break;
}
}
}
@ -164,13 +178,13 @@ void test_memory_alignment() {
void test_memory_stress() {
kprintf("Starting Stress Test...\n");
heap_stats();
void *ptrs[50] = {0}; // Track allocated pointers
void *ptrs[100] = {0}; // Track allocated pointers
uint32_t seed = 0xACE2026; // Example seed
for (int i = 0; i < 100; i++) {
for (int i = 0; i < 1000; i++) {
kprintf("Iteration %d\n", i);
// 1. Randomly allocate or free
int idx = i % 50;
int idx = (seed >> 16) % 50;
if (ptrs[idx] == NULL) {
size_t size = (seed % 256) + 1;
ptrs[idx] = kmalloc(size);
@ -183,7 +197,16 @@ void test_memory_stress() {
seed = (seed * 1103515245 + 12345) & 0x7fffffff;
}
kprintf("Stress Test Finished. Check heap_stats() for sanity.\n");
kprintf("HeadHeader size: %d bytes\n", sizeof(HeapHeader));
heap_stats();
kprintf("Cleaning up remaining allocations...\n");
for (int i = 0; i < 100; i++) {
if (ptrs[i] != NULL) {
kfree(ptrs[i]);
ptrs[i] = NULL;
}
}
heap_stats();
}
void heap_stats() {