[svn-commits] rizzo: branch rizzo/astobj2 r47334 -
/team/rizzo/astobj2/main/astobj2.c
svn-commits at lists.digium.com
svn-commits at lists.digium.com
Wed Nov 8 11:21:19 MST 2006
Author: rizzo
Date: Wed Nov 8 12:21:19 2006
New Revision: 47334
URL: http://svn.digium.com/view/asterisk?rev=47334&view=rev
Log:
put ref/unref in the right places,
include safety checks to make sure we pass proper objects
to the various astobj2 functions.
Modified:
team/rizzo/astobj2/main/astobj2.c
Modified: team/rizzo/astobj2/main/astobj2.c
URL: http://svn.digium.com/view/asterisk/team/rizzo/astobj2/main/astobj2.c?rev=47334&r1=47333&r2=47334&view=diff
==============================================================================
--- team/rizzo/astobj2/main/astobj2.c (original)
+++ team/rizzo/astobj2/main/astobj2.c Wed Nov 8 12:21:19 2006
@@ -35,12 +35,16 @@
* the flags and a pointer to a destructor.
* The refcount is used to decide when it is time to
* invoke the destructor.
+ * The magic number is used for consistency check.
*/
struct __priv_data {
ast_mutex_t lock;
int ref_counter;
ao2_destructor_fn destructor_fn;
+ uint32_t magic; /* magic number */
};
+
+#define AO2_MAGIC 0xa570b123
/*!
* What an astobj2 object looks like: fixed-size private data
@@ -57,7 +61,18 @@
* From a pointer _p to a user-defined object,
* return the pointer to the astobj2 structure
*/
-#define INTERNAL_OBJ(_p) ((struct astobj2 *)( (_p) == NULL ? NULL : (char *)(_p) - sizeof(struct astobj2) ))
+static struct astobj2 *INTERNAL_OBJ(void *user_data)
+{
+ struct astobj2 *p;
+
+ assert (user_data != NULL);
+ p = (struct astobj2 *)((char *)(user_data) - sizeof(struct astobj2));
+ if (AO2_MAGIC != (p->priv_data.magic ^ (uint32_t)p) ) {
+ ast_verbose("----!!!!!--------- bad magic number 0x%x for %p\n", p->priv_data.magic, p);
+ p = NULL;
+ }
+ return p;
+}
/*
* From a pointer _p to an astobj2 object,
@@ -67,12 +82,18 @@
int ao2_lock(void *user_data)
{
- return ast_mutex_lock( &INTERNAL_OBJ(user_data)->priv_data.lock );
+ struct astobj2 *p = INTERNAL_OBJ(user_data);
+ if (p == NULL)
+ return -1;
+ return ast_mutex_lock( &p->priv_data.lock );
}
int ao2_unlock(void *user_data)
{
- return ast_mutex_unlock( &INTERNAL_OBJ(user_data)->priv_data.lock );
+ struct astobj2 *p = INTERNAL_OBJ(user_data);
+ if (p == NULL)
+ return -1;
+ return ast_mutex_unlock( &p->priv_data.lock );
}
/*
@@ -83,12 +104,13 @@
#if 0
ast_log(LOG_NOTICE, "Reference counter changed by %i\n", delta);
#endif
- struct astobj2 *obj = INTERNAL_OBJ(user_data);
-
int current_value;
int ret;
-
- assert(user_data != NULL);
+ struct astobj2 *obj = INTERNAL_OBJ(user_data);
+
+ if (obj == NULL)
+ return -1;
+
/* if delta is 0, just return the refcount */
if (delta == 0)
return (obj->priv_data.ref_counter);
@@ -96,6 +118,7 @@
/* we modify with an atomic operation the reference counter */
ret = ast_atomic_fetchadd_int( &obj->priv_data.ref_counter, delta );
current_value = ret + delta;
+ // ast_log(LOG_NOTICE, "refcount %d on object %p\n", current_value, user_data);
/* this case must never happen */
if (current_value < 0) {
ast_log(LOG_ERROR, "refcount %d on object %p\n", current_value, user_data);
@@ -140,6 +163,7 @@
/* init */
ast_mutex_init(&obj->priv_data.lock);
+ obj->priv_data.magic = AO2_MAGIC ^ (uint32_t)(obj);
obj->priv_data.ref_counter = 1;
obj->priv_data.destructor_fn = destructor_fn; /* can be NULL */
ast_atomic_fetchadd_int(&ao2_total_objects, 1);
@@ -242,8 +266,12 @@
{
int i;
/* create a new list entry */
- struct bucket_list *p = ast_calloc(1, sizeof(struct bucket_list));
-
+ struct bucket_list *p;
+ struct astobj2 *obj = INTERNAL_OBJ(user_data);
+
+ if (obj == NULL)
+ return NULL;
+ p = ast_calloc(1, sizeof(struct bucket_list));
if (p == NULL) /* alloc failure, die */
return NULL;
/* apply the hash function */
@@ -253,7 +281,7 @@
i %= c->n_buckets;
p->next = NULL;
- p->astobj = INTERNAL_OBJ(user_data);
+ p->astobj = obj;
p->version = ast_atomic_fetchadd_int(&c->version, 1);
if (c->buckets[i].head == NULL)
c->buckets[i].head = p;
@@ -281,11 +309,10 @@
*/
void *ao2_unlink(ao2_container *c, void *user_data)
{
- // ast_verbose("unlinking %p from container\n", user_data);
+ ast_verbose("unlinking %p from container\n", user_data);
+ if (INTERNAL_OBJ(user_data) == NULL) /* safety check on the argument */
+ return NULL;
ao2_callback(c, OBJ_SINGLE | OBJ_UNLINK | OBJ_POINTER, match_by_addr, user_data);
- /* the container has changed its content, so we update the version */
- ast_atomic_fetchadd_int(&c->version, 1);
- ao2_ref(user_data, -1);
return NULL;
}
@@ -345,6 +372,7 @@
while (cur) {
int match = cb_fn(EXTERNAL_OBJ(cur->astobj), arg, flags) & (CMP_MATCH | CMP_STOP);
+ // ast_verbose("match on %p returns %d\n", arg, match);
/* we found the object, performing operations according flags */
if (match == 0) { /* no match, no stop, continue */
@@ -356,8 +384,11 @@
break;
}
/* we have a match (CMP_MATCH) here */
- if (flags & OBJ_DATA) /* if must return the object, record the value */
+ if (flags & OBJ_DATA) { /* if must return the object, record the value */
+ /* it is important to handle this case before the unlink */
ret = EXTERNAL_OBJ(cur->astobj);
+ ao2_ref(ret, 1);
+ }
if (flags & OBJ_UNLINK) { /* must unlink */
struct bucket_list *x = cur;
@@ -369,9 +400,12 @@
prev->next = cur->next;
if (c->buckets[i].tail == cur) /* update tail if needed */
c->buckets[i].tail = prev;
+ ao2_ref(EXTERNAL_OBJ(cur->astobj), -1);
cur = cur->next ; /* prepare for next cycle */
free(x); /* free the link record */
+ /* update number of elements and version */
ast_atomic_fetchadd_int(&c->elements, -1);
+ ast_atomic_fetchadd_int(&c->version, 1);
} else { /* prepare for next cycle */
prev = cur;
cur = cur->next;
@@ -384,18 +418,15 @@
}
if (flags & OBJ_DATA) {
#if 0 /* XXX to be completed */
- /* here build a list of object pointers and increase
- * the reference counter for each reference created
+ /*
+ * This is the multiple-return case. We need to link
+ * the object in a list. The refcount is already increased.
*/
#endif
}
}
}
ao2_unlock(c);
-
- /* increase the reference counter, unlock the container and return */
- if ( ret != NULL )
- ao2_ref(ret, 1);
return ret;
}
@@ -568,6 +599,9 @@
ast_cli(fd, "testing callbacks again\n");
ao2_callback(c1, 0, print_cb, (void*)fd);
+ { int a;
+ ao2_ref(&a, -1);
+ }
ast_cli(fd, "destroy container\n");
ao2_ref(c1, -1); /* destroy container */
ast_verbose("at the end have %d objects\n",
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