# error The slab allocator requires that your system have the mmap() system call.
#endif
-#define SLAB_DEBUG 1
-#define SLAB_RESERVE 1024
+#if !defined(SLAB_DEBUG)
+# define SLAB_DEBUG 1
+#endif
+
+#if !defined(SLAB_RESERVE)
+# define SLAB_RESERVE 0
+#endif
+
+#if !defined(MAX_SLAB_FREE)
+# define MAX_SLAB_FREE 1024
+#endif
#if SLAB_DEBUG
-#define ALLOC_MAGIC 0x1acf
-#define FREE_MAGIC 0xfc1d
+#define ALLOC_MAGIC 0x1a
+#define FREE_MAGIC 0xcf
struct alloc_header {
- unsigned int file_id : 8;
unsigned int size : 24;
+ unsigned int magic : 8;
+ unsigned int file_id : 8;
unsigned int line : 16;
- unsigned int magic : 16;
};
static const char *file_ids[256];
#define SLAB_MIN (2 * sizeof(void*))
#define SLAB_GRAIN sizeof(void*)
#define SLAB_ALIGN SLAB_GRAIN
-#define SMALL_CUTOFF 580
+#define SMALL_CUTOFF 576
/* Element size < SMALL_CUTOFF -> use small slabs.
* Larger elements are allocated directly using mmap(). The largest
* regularly allocated struct in srvx 1.x is smaller than
assert(!slab->prev || slab == slab->prev->next);
sset->child = slab;
sset->nslabs++;
- /* log_module(MAIN_LOG, LOG_DEBUG, "Allocated new %u-slab %p.", sset->size, slab); */
}
slab = sset->child;
<= (slab_pagesize() - sizeof(*slab) - sset->size));
slab->free = *item;
if (++slab->used == sset->items_per_slab) {
- /* log_module(MAIN_LOG, LOG_DEBUG, "%u-slab %p is empty.", sset->size, item); */
if (sset->child != slab) {
/* Unlink slab and reinsert before sset->child. */
if (slab->prev)
static void
slab_unalloc(void *ptr, size_t size)
{
- void **item;
struct slab *slab, *new_next;
- item = ptr;
assert(size < SMALL_CUTOFF);
slab = (struct slab*)((((unsigned long)ptr | (slab_pagesize() - 1)) + 1) - sizeof(*slab));
- *item = slab->free;
- memset(item + 1, 0xde, size - sizeof(*item));
- slab->free = item;
+ *(void**)ptr = slab->free;
+ slab->free = ptr;
slab->parent->nallocs--;
if (slab->used-- == slab->parent->items_per_slab
slab->parent->child = slab;
assert(!slab->next || slab == slab->next->prev);
assert(!slab->prev || slab == slab->prev->next);
- /* log_module(MAIN_LOG, LOG_DEBUG, "%u-slab %p became partial.", slab->parent->size, slab); */
} else if (!slab->used) {
- /* log_module(MAIN_LOG, LOG_DEBUG, "%u-slab %p became full.", slab->parent->size, slab); */
/* Unlink slab from its parent. */
slab->parent->nslabs--;
if (slab->prev)
}
#if SLAB_RESERVE
- if (!free_slab_count) {
- /* Make sure we have enough free slab pages. */
- while (free_slab_count < SLAB_RESERVE) {
- struct slab *tslab;
- item = slab_map(slab_pagesize());
- tslab = (struct slab*)((char*)item + slab_pagesize() - sizeof(*slab));
- tslab->base = item;
- tslab->prev = free_slab_tail;
- free_slab_tail = tslab;
- if (!free_slab_head)
- free_slab_head = tslab;
- free_slab_count++;
- slab_count++;
- }
+ /* Make sure we have enough free slab pages. */
+ while (free_slab_count < SLAB_RESERVE) {
+ struct slab *tslab;
+ void *item;
+
+ item = slab_map(slab_pagesize());
+ tslab = (struct slab*)((char*)item + slab_pagesize() - sizeof(*slab));
+ tslab->base = item;
+ tslab->prev = free_slab_tail;
+ free_slab_tail = tslab;
+ if (!free_slab_head)
+ free_slab_head = tslab;
+ else
+ tslab->prev->next = tslab;
+ free_slab_count++;
+ slab_count++;
}
+#endif
- /* Unmap old slab, so accesses to stale pointers will fault. */
- munmap(slab->base, slab_pagesize());
- slab_count--;
-#else
/* Link to list of free slabs. */
slab->parent = NULL;
- slab->prev = free_slab_tail;
slab->next = NULL;
+ slab->prev = free_slab_tail;
free_slab_tail = slab;
- if (!free_slab_head)
+ if (free_slab_head)
+ slab->prev->next = slab;
+ else
free_slab_head = slab;
free_slab_count++;
+
+#if MAX_SLAB_FREE >= 0
+ /* Unlink and unmap old slabs, so accesses to stale-enough
+ * pointers will fault. */
+ while (free_slab_count > MAX_SLAB_FREE) {
+ struct slab *tslab;
+
+ tslab = free_slab_tail;
+ free_slab_tail = tslab->prev;
+ if (tslab->prev)
+ tslab->prev->next = NULL;
+ else
+ free_slab_head = NULL;
+ free_slab_count--;
+ slab_count--;
+ munmap(slab->base, slab_pagesize());
+ }
#endif
}
+ (void)size;
}
void *
slab_free(const char *file, unsigned int line, void *ptr)
{
alloc_header_t *hdr;
- size_t real;
+ size_t user, real;
if (!ptr)
return;
hdr->file_id = get_file_id(file);
hdr->line = line;
hdr->magic = FREE_MAGIC;
- real = hdr->size + sizeof(*hdr);
+ user = hdr->size;
#else
- real = *hdr + sizeof(*hdr);
+ user = *hdr;
(void)file; (void)line;
#endif
- real = (real + SLAB_GRAIN - 1) & ~(SLAB_GRAIN - 1);
+ real = (user + sizeof(*hdr) + SLAB_GRAIN - 1) & ~(SLAB_GRAIN - 1);
if (real < SMALL_CUTOFF) {
+ memset(hdr + 1, 0xde, real - sizeof(*hdr));
slab_unalloc(hdr, real);
slab_alloc_count--;
- slab_alloc_size -= real - sizeof(*hdr);
+ slab_alloc_size -= user;
} else {
munmap(hdr, slab_round_up(real));
big_alloc_count--;
- big_alloc_size -= real - sizeof(*hdr);
+ big_alloc_size -= user;
}
}
+/* Undefine the verify macro in case we're not debugging. */
+#undef verify
void
verify(const void *ptr)
{
projects / srvx.git / blobdiff