astobj2: Support using a separate object for locking.

Create ao2_alloc_with_lockobj function to support shared locking.

Change-Id: Iba687eb9843922be7e481e23a32c0700ecf88a80

1 files changed, 73 insertions, 2 deletions

diff --git a/main/astobj2.c b/main/astobj2.c
index 5c92f263f..604e6a1ae 100644
--- a/main/astobj2.c
+++ b/main/astobj2.c
@@ -108,6 +108,17 @@ struct astobj2_rwlock {
 	void *user_data[0];
 };
 
+struct ao2_lockobj_priv {
+	void *lock;
+};
+
+/* AstObj2 with locking provided by a separate object. */
+struct astobj2_lockobj {
+	struct ao2_lockobj_priv lockobj;
+	struct __priv_data priv_data;
+	void *user_data[0];
+};
+
 #ifdef AO2_DEBUG
 struct ao2_stats ao2;
 #endif
@@ -118,6 +129,9 @@ struct ao2_stats ao2;
 #define INTERNAL_OBJ_RWLOCK(user_data) \
 	((struct astobj2_rwlock *) (((char *) (user_data)) - sizeof(struct astobj2_rwlock)))
 
+#define INTERNAL_OBJ_LOCKOBJ(user_data) \
+	((struct astobj2_lockobj *) (((char *) (user_data)) - sizeof(struct astobj2_lockobj)))
+
 #define INTERNAL_OBJ(user_data) \
 	(struct astobj2 *) ((char *) user_data - sizeof(struct astobj2))
 
@@ -187,6 +201,7 @@ int __ao2_lock(void *user_data, enum ao2_lock_req lock_how, const char *file, co
 	struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
 	struct astobj2_lock *obj_mutex;
 	struct astobj2_rwlock *obj_rwlock;
+	struct astobj2_lockobj *obj_lockobj;
 	int res = 0;
 
 	if (obj == NULL) {
@@ -231,6 +246,10 @@ int __ao2_lock(void *user_data, enum ao2_lock_req lock_how, const char *file, co
 	case AO2_ALLOC_OPT_LOCK_NOLOCK:
 		/* The ao2 object has no lock. */
 		break;
+	case AO2_ALLOC_OPT_LOCK_OBJ:
+		obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
+		res = __ao2_lock(obj_lockobj->lockobj.lock, lock_how, file, func, line, var);
+		break;
 	default:
 		ast_log(__LOG_ERROR, file, line, func, "Invalid lock option on ao2 object %p\n",
 			user_data);
@@ -245,6 +264,7 @@ int __ao2_unlock(void *user_data, const char *file, const char *func, int line,
 	struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
 	struct astobj2_lock *obj_mutex;
 	struct astobj2_rwlock *obj_rwlock;
+	struct astobj2_lockobj *obj_lockobj;
 	int res = 0;
 	int current_value;
 
@@ -281,6 +301,10 @@ int __ao2_unlock(void *user_data, const char *file, const char *func, int line,
 	case AO2_ALLOC_OPT_LOCK_NOLOCK:
 		/* The ao2 object has no lock. */
 		break;
+	case AO2_ALLOC_OPT_LOCK_OBJ:
+		obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
+		res = __ao2_unlock(obj_lockobj->lockobj.lock, file, func, line, var);
+		break;
 	default:
 		ast_log(__LOG_ERROR, file, line, func, "Invalid lock option on ao2 object %p\n",
 			user_data);
@@ -295,6 +319,7 @@ int __ao2_trylock(void *user_data, enum ao2_lock_req lock_how, const char *file,
 	struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
 	struct astobj2_lock *obj_mutex;
 	struct astobj2_rwlock *obj_rwlock;
+	struct astobj2_lockobj *obj_lockobj;
 	int res = 0;
 
 	if (obj == NULL) {
@@ -339,6 +364,10 @@ int __ao2_trylock(void *user_data, enum ao2_lock_req lock_how, const char *file,
 	case AO2_ALLOC_OPT_LOCK_NOLOCK:
 		/* The ao2 object has no lock. */
 		return 0;
+	case AO2_ALLOC_OPT_LOCK_OBJ:
+		obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
+		res = __ao2_trylock(obj_lockobj->lockobj.lock, lock_how, file, func, line, var);
+		break;
 	default:
 		ast_log(__LOG_ERROR, file, line, func, "Invalid lock option on ao2 object %p\n",
 			user_data);
@@ -370,6 +399,7 @@ enum ao2_lock_req __adjust_lock(void *user_data, enum ao2_lock_req lock_how, int
 {
 	struct astobj2 *obj = INTERNAL_OBJ(user_data);
 	struct astobj2_rwlock *obj_rwlock;
+	struct astobj2_lockobj *obj_lockobj;
 	enum ao2_lock_req orig_lock;
 
 	switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
@@ -400,6 +430,10 @@ enum ao2_lock_req __adjust_lock(void *user_data, enum ao2_lock_req lock_how, int
 			break;
 		}
 		break;
+	case AO2_ALLOC_OPT_LOCK_OBJ:
+		obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
+		orig_lock = __adjust_lock(obj_lockobj->lockobj.lock, lock_how, keep_stronger);
+		break;
 	default:
 		ast_log(LOG_ERROR, "Invalid lock option on ao2 object %p\n", user_data);
 		/* Fall through */
@@ -441,6 +475,7 @@ int __ao2_ref(void *user_data, int delta,
 	struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
 	struct astobj2_lock *obj_mutex;
 	struct astobj2_rwlock *obj_rwlock;
+	struct astobj2_lockobj *obj_lockobj;
 	int current_value;
 	int ret;
 	void *weakproxy = NULL;
@@ -552,6 +587,12 @@ int __ao2_ref(void *user_data, int delta,
 	case AO2_ALLOC_OPT_LOCK_NOLOCK:
 		ast_free(obj);
 		break;
+	case AO2_ALLOC_OPT_LOCK_OBJ:
+		obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
+		ao2_t_ref(obj_lockobj->lockobj.lock, -1, "release lockobj");
+
+		ast_free(obj_lockobj);
+		break;
 	default:
 		ast_log(__LOG_ERROR, file, line, func,
 			"Invalid lock option on ao2 object %p\n", user_data);
@@ -581,13 +622,14 @@ void __ao2_cleanup(void *obj)
 	}
 }
 
-void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned int options,
-	const char *tag, const char *file, int line, const char *func)
+static void *internal_ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned int options,
+	void *lockobj, const char *tag, const char *file, int line, const char *func)
 {
 	/* allocation */
 	struct astobj2 *obj;
 	struct astobj2_lock *obj_mutex;
 	struct astobj2_rwlock *obj_rwlock;
+	struct astobj2_lockobj *obj_lockobj;
 
 	switch (options & AO2_ALLOC_OPT_LOCK_MASK) {
 	case AO2_ALLOC_OPT_LOCK_MUTEX:
@@ -614,6 +656,22 @@ void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned in
 			return NULL;
 		}
 		break;
+	case AO2_ALLOC_OPT_LOCK_OBJ:
+		lockobj = ao2_t_bump(lockobj, "set lockobj");
+		if (!lockobj) {
+			ast_log(__LOG_ERROR, file, line, func, "AO2_ALLOC_OPT_LOCK_OBJ requires a non-NULL lockobj.\n");
+			return NULL;
+		}
+
+		obj_lockobj = __ast_calloc(1, sizeof(*obj_lockobj) + data_size, file, line, func);
+		if (obj_lockobj == NULL) {
+			ao2_t_ref(lockobj, -1, "release lockobj for failed alloc");
+			return NULL;
+		}
+
+		obj_lockobj->lockobj.lock = lockobj;
+		obj = (struct astobj2 *) &obj_lockobj->priv_data;
+		break;
 	default:
 		/* Invalid option value. */
 		ast_log(__LOG_DEBUG, file, line, func, "Invalid lock option requested\n");
@@ -643,6 +701,19 @@ void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned in
 	return EXTERNAL_OBJ(obj);
 }
 
+void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned int options,
+	const char *tag, const char *file, int line, const char *func)
+{
+	return internal_ao2_alloc(data_size, destructor_fn, options, NULL, tag, file, line, func);
+}
+
+void *__ao2_alloc_with_lockobj(size_t data_size, ao2_destructor_fn destructor_fn, void *lockobj,
+	const char *tag, const char *file, int line, const char *func)
+{
+	return internal_ao2_alloc(data_size, destructor_fn, AO2_ALLOC_OPT_LOCK_OBJ, lockobj,
+		tag, file, line, func);
+}
+
 unsigned int ao2_options_get(void *obj)
 {
 	struct astobj2 *orig_obj;