#define TALLOC_MAGIC 0xe814ec70
#define TALLOC_FLAG_FREE 0x01
#define TALLOC_FLAG_LOOP 0x02
+#define TALLOC_FLAG_POOL 0x04 /* This is a talloc pool */
+#define TALLOC_FLAG_POOLMEM 0x08 /* This is allocated in a pool */
#define TALLOC_MAGIC_REFERENCE ((const char *)1)
/* by default we abort when given a bad pointer (such as when talloc_free() is called
const char *name;
size_t size;
unsigned flags;
+
+ /*
+ * "pool" has dual use:
+ *
+ * For the talloc pool itself (i.e. TALLOC_FLAG_POOL is set), "pool"
+ * marks the end of the currently allocated area.
+ *
+ * For members of the pool (i.e. TALLOC_FLAG_POOLMEM is set), "pool"
+ * is a pointer to the struct talloc_chunk of the pool that it was
+ * allocated from. This way children can quickly find the pool to chew
+ * from.
+ */
+ void *pool;
};
/* 16 byte alignment seems to keep everyone happy */
return tc? tc->name : NULL;
}
+/*
+ A pool carries an in-pool object count count in the first 16 bytes.
+ bytes. This is done to support talloc_steal() to a parent outside of the
+ pool. The count includes the pool itself, so a talloc_free() on a pool will
+ only destroy the pool if the count has dropped to zero. A talloc_free() of a
+ pool member will reduce the count, and eventually also call free(3) on the
+ pool memory.
+
+ The object count is not put into "struct talloc_chunk" because it is only
+ relevant for talloc pools and the alignment to 16 bytes would increase the
+ memory footprint of each talloc chunk by those 16 bytes.
+*/
+
+#define TALLOC_POOL_HDR_SIZE 16
+
+static unsigned int *talloc_pool_objectcount(struct talloc_chunk *tc)
+{
+ return (unsigned int *)((char *)tc + sizeof(struct talloc_chunk));
+}
+
+/*
+ Allocate from a pool
+*/
+
+static struct talloc_chunk *talloc_alloc_pool(struct talloc_chunk *parent,
+ size_t size)
+{
+ struct talloc_chunk *pool_ctx = NULL;
+ size_t space_left;
+ struct talloc_chunk *result;
+ size_t chunk_size;
+
+ if (parent == NULL) {
+ return NULL;
+ }
+
+ if (parent->flags & TALLOC_FLAG_POOL) {
+ pool_ctx = parent;
+ }
+ else if (parent->flags & TALLOC_FLAG_POOLMEM) {
+ pool_ctx = (struct talloc_chunk *)parent->pool;
+ }
+
+ if (pool_ctx == NULL) {
+ return NULL;
+ }
+
+ space_left = ((char *)pool_ctx + TC_HDR_SIZE + pool_ctx->size)
+ - ((char *)pool_ctx->pool);
+
+ /*
+ * Align size to 16 bytes
+ */
+ chunk_size = ((size + 15) & ~15);
+
+ if (space_left < chunk_size) {
+ return NULL;
+ }
+
+ result = (struct talloc_chunk *)pool_ctx->pool;
+
+#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_UNDEFINED)
+ VALGRIND_MAKE_MEM_UNDEFINED(result, size);
+#endif
+
+ pool_ctx->pool = (void *)((char *)result + chunk_size);
+
+ result->flags = TALLOC_MAGIC | TALLOC_FLAG_POOLMEM;
+ result->pool = pool_ctx;
+
+ *talloc_pool_objectcount(pool_ctx) += 1;
+
+ return result;
+}
+
/*
Allocate a bit of memory as a child of an existing pointer
*/
static inline void *__talloc(const void *context, size_t size)
{
- struct talloc_chunk *tc;
+ struct talloc_chunk *tc = NULL;
if (unlikely(context == NULL)) {
context = null_context;
return NULL;
}
- tc = (struct talloc_chunk *)malloc(TC_HDR_SIZE+size);
- if (unlikely(tc == NULL)) return NULL;
+ if (context != NULL) {
+ tc = talloc_alloc_pool(talloc_chunk_from_ptr(context),
+ TC_HDR_SIZE+size);
+ }
+
+ if (tc == NULL) {
+ tc = (struct talloc_chunk *)malloc(TC_HDR_SIZE+size);
+ if (unlikely(tc == NULL)) return NULL;
+ tc->flags = TALLOC_MAGIC;
+ tc->pool = NULL;
+ }
tc->size = size;
- tc->flags = TALLOC_MAGIC;
tc->destructor = NULL;
tc->child = NULL;
tc->name = NULL;
return TC_PTR_FROM_CHUNK(tc);
}
+/*
+ * Create a talloc pool
+ */
+
+void *talloc_pool(const void *context, size_t size)
+{
+ void *result = __talloc(context, size + TALLOC_POOL_HDR_SIZE);
+ struct talloc_chunk *tc;
+
+ if (unlikely(result == NULL)) {
+ return NULL;
+ }
+
+ tc = talloc_chunk_from_ptr(result);
+
+ tc->flags |= TALLOC_FLAG_POOL;
+ tc->pool = (char *)result + TALLOC_POOL_HDR_SIZE;
+
+ *talloc_pool_objectcount(tc) = 1;
+
+#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_NOACCESS)
+ VALGRIND_MAKE_MEM_NOACCESS(tc->pool, size);
+#endif
+
+ return result;
+}
+
/*
setup a destructor to be called on free of a pointer
the destructor should return 0 on success, or -1 on failure.
}
tc->flags |= TALLOC_FLAG_FREE;
- free(tc);
+
+ if (tc->flags & (TALLOC_FLAG_POOL|TALLOC_FLAG_POOLMEM)) {
+ struct talloc_chunk *pool;
+ unsigned int *pool_object_count;
+
+ pool = (tc->flags & TALLOC_FLAG_POOL)
+ ? tc : (struct talloc_chunk *)tc->pool;
+
+ pool_object_count = talloc_pool_objectcount(pool);
+
+ if (*pool_object_count == 0) {
+ TALLOC_ABORT("Pool object count zero!");
+ }
+
+ *pool_object_count -= 1;
+
+ if (*pool_object_count == 0) {
+ free(pool);
+ }
+ }
+ else {
+ free(tc);
+ }
return 0;
}
talloc_steal(new_parent, child);
}
}
+
+ if ((tc->flags & TALLOC_FLAG_POOL)
+ && (*talloc_pool_objectcount(tc) == 1)) {
+ tc->pool = ((char *)tc + TC_HDR_SIZE + TALLOC_POOL_HDR_SIZE);
+#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_NOACCESS)
+ VALGRIND_MAKE_MEM_NOACCESS(
+ tc->pool, tc->size - TALLOC_POOL_HDR_SIZE);
+#endif
+ }
}
/*
{
struct talloc_chunk *tc;
void *new_ptr;
+ bool malloced = false;
/* size zero is equivalent to free() */
if (unlikely(size == 0)) {
return NULL;
}
+ /* don't shrink if we have less than 1k to gain */
+ if ((size < tc->size) && ((tc->size - size) < 1024)) {
+ tc->size = size;
+ return ptr;
+ }
+
/* by resetting magic we catch users of the old memory */
tc->flags |= TALLOC_FLAG_FREE;
free(tc);
}
#else
- new_ptr = realloc(tc, size + TC_HDR_SIZE);
+ if (tc->flags & TALLOC_FLAG_POOLMEM) {
+
+ new_ptr = talloc_alloc_pool(tc, size + TC_HDR_SIZE);
+ *talloc_pool_objectcount((struct talloc_chunk *)
+ (tc->pool)) -= 1;
+
+ if (new_ptr == NULL) {
+ new_ptr = malloc(TC_HDR_SIZE+size);
+ malloced = true;
+ }
+
+ if (new_ptr) {
+ memcpy(new_ptr, tc, MIN(tc->size,size) + TC_HDR_SIZE);
+ }
+ }
+ else {
+ new_ptr = realloc(tc, size + TC_HDR_SIZE);
+ }
#endif
if (unlikely(!new_ptr)) {
tc->flags &= ~TALLOC_FLAG_FREE;
}
tc = (struct talloc_chunk *)new_ptr;
- tc->flags &= ~TALLOC_FLAG_FREE;
+ tc->flags &= ~TALLOC_FLAG_FREE;
+ if (malloced) {
+ tc->flags &= ~TALLOC_FLAG_POOLMEM;
+ }
if (tc->parent) {
tc->parent->child = tc;
}
return __talloc_strlendup(t, p, strlen(p));
}
-/*
- append to a talloced string
-*/
-char *talloc_append_string(const void *t, char *orig, const char *append)
-{
- char *ret;
- size_t olen = strlen(orig);
- size_t alenz;
-
- if (!append)
- return orig;
-
- alenz = strlen(append) + 1;
-
- ret = talloc_realloc(t, orig, char, olen + alenz);
- if (!ret)
- return NULL;
-
- /* append the string with the trailing \0 */
- memcpy(&ret[olen], append, alenz);
-
- _talloc_set_name_const(ret, ret);
-
- return ret;
-}
-
/*
strndup with a talloc
*/
#endif
char *talloc_vasprintf(const void *t, const char *fmt, va_list ap)
-{
+{
int len;
char *ret;
va_list ap2;
char c;
-
+
/* this call looks strange, but it makes it work on older solaris boxes */
va_copy(ap2, ap);
len = vsnprintf(&c, 1, fmt, ap2);
git.samba.org / samba.git / blobdiff