alloc: refactor

This commit is contained in:
Matheus
2026-04-01 16:53:16 -03:00
parent 7509d17f1c
commit 4e8f925156
2 changed files with 60 additions and 36 deletions
+2
View File
@@ -230,6 +230,8 @@ int vionet_newdevice(viodevice_t *viodevice) {
char name[10];
snprintf(name, 10, "vionet%d", netdev->id);
netdev->netdev.flags = NETDEV_FLAGS_UP | NETDEV_FLAGS_BROADCAST | NETDEV_FLAGS_RUNNING;
__assert(netdev_register((netdev_t *)netdev, name) == 0);
return 0;
+58 -36
View File
@@ -4,28 +4,37 @@
#include <string.h>
#include <kernel/init.h>
// each allocation has the following structure:
// ptr: data capacity (allocsizes size)
// ptr + sizeof(size_t): current size
// ptr + sizeof(size_t) * 2: data
// ptr + datasize: poison value
#define USE_POISON 0
#define DEBUG 1
#define POISON_VALUE 0xdeadbeefbadc0ffel
#define CACHE_COUNT 14
#define CAPACITY_SIZE(cache) cache->size - sizeof(size_t) * 2 - USE_POISON * sizeof(size_t)
#if DEBUG == 1
typedef struct {
size_t capacity;
size_t current_size;
size_t debug_address;
uint8_t data[];
} alloc_header_t;
#else
typedef struct {
size_t capacity;
size_t current_size;
uint8_t data[];
} alloc_header_t;
#endif
#define CAPACITY_SIZE(cache) cache->size - sizeof(alloc_header_t) - DEBUG * sizeof(size_t);
static size_t allocsizes[CACHE_COUNT] = {32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144};
static scache_t *caches[CACHE_COUNT + 5];
static void initarea(scache_t *cache, void *obj, size_t size) {
size_t *ptr = obj;
*ptr = CAPACITY_SIZE(cache);
*(ptr + 1) = size;
memset(ptr + 2, 0, *ptr);
#if USE_POISON == 1
*((size_t *)((uintptr_t)obj + cache->size - sizeof(size_t))) = POISON_VALUE;
alloc_header_t *hdr = obj;
hdr->capacity = CAPACITY_SIZE(cache);
hdr->current_size = size;
memset(hdr->data, 0, hdr->capacity);
#if DEBUG == 1
*((size_t *)((uintptr_t)obj + cache->size - 1 * sizeof(size_t))) = POISON_VALUE;
#endif
}
@@ -33,61 +42,74 @@ static scache_t *getcachefromsize(size_t size) {
if (unlikely(size <= 1))
return caches[0];
if (unlikely(size > 262144))
return NULL;
size_t i = 64 - __builtin_clzll(size - 1);
return caches[i];
}
void *alloc(size_t size) {
scache_t *cache = getcachefromsize(size);
size_t *ret = slab_allocate(cache);
if (unlikely(cache == NULL))
return NULL;
alloc_header_t *ret = slab_allocate(cache);
if (unlikely(ret == NULL))
return NULL;
initarea(cache, ret, size);
#if USE_POISON == 1
__assert(*ret == CAPACITY_SIZE(cache));
#if DEBUG == 1
__assert(*(size_t *)((uintptr_t)ret + cache->size - sizeof(size_t)) == POISON_VALUE);
ret->debug_address = (size_t)__builtin_return_address(0);
#endif
return ret + 2;
return ret->data;
}
void free(void *ptr) {
slab_free(getcachefromsize(*((size_t *)ptr - 2)), (size_t *)ptr - 2);
alloc_header_t *header = container_of(ptr, alloc_header_t, data);
scache_t *cache = getcachefromsize(header->capacity);
#if DEBUG == 1
__assert(cache);
header->current_size = 0;
__assert(*(size_t *)((uintptr_t)header + cache->size - sizeof(size_t)) == POISON_VALUE);
#endif
slab_free(cache, header);
}
void *realloc(void *ptr, size_t size) {
size_t *start = ptr;
start -= 2;
size_t currentsize = *(start + 1);
if (size <= currentsize) {
*(start + 1) = size;
alloc_header_t *header = container_of(ptr, alloc_header_t, data);
if (size <= header->capacity) {
header->current_size = size;
return ptr;
}
// grow
scache_t *oldcache = getcachefromsize(*start);
scache_t *newcache = getcachefromsize(size);
scache_t *old_cache = getcachefromsize(header->capacity);
scache_t *new_cache = getcachefromsize(size);
// same allocation
if (oldcache == newcache) {
size_t diff = size - currentsize;
memset((void *)((uintptr_t)ptr + currentsize), 0, diff);
*(start + 1) = size;
if (old_cache == new_cache) {
size_t diff = size - header->current_size;
memset((void *)((uintptr_t)ptr + header->current_size), 0, diff);
header->current_size = size;
return ptr;
}
// different allocation
size_t *new = slab_allocate(newcache);
alloc_header_t *new = slab_allocate(new_cache);
if (new == NULL)
return NULL;
initarea(newcache, new, size);
memcpy((new + 2), ptr, currentsize);
slab_free(oldcache, start);
return new + 2;
initarea(new_cache, new, size);
memcpy(new->data, ptr, header->current_size);
slab_free(old_cache, header);
return new->data;
}
void alloc_init() {
for (int i = 0; i < CACHE_COUNT; ++i) {
caches[i + 5] = slab_newcache(allocsizes[i] + sizeof(size_t) * 2 + sizeof(size_t) * USE_POISON, 0, NULL, NULL);
caches[i + 5] = slab_newcache(allocsizes[i] + sizeof(alloc_header_t) + sizeof(size_t) * DEBUG, 0, NULL, NULL);
__assert(caches[i + 5]);
void *p = slab_allocate(caches[i + 5]);
__assert(p);