qom: add child properties (composition) (v3)

Child properties express a relationship of composition.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2011-12-12 14:29:31 -06:00
parent dc45c21f39
commit 3de1c3e82d
2 changed files with 46 additions and 0 deletions

View File

@ -1174,6 +1174,32 @@ DeviceState *qdev_get_root(void)
return qdev_root;
}
static void qdev_get_child_property(DeviceState *dev, Visitor *v, void *opaque,
const char *name, Error **errp)
{
DeviceState *child = opaque;
gchar *path;
path = qdev_get_canonical_path(child);
visit_type_str(v, &path, name, errp);
g_free(path);
}
void qdev_property_add_child(DeviceState *dev, const char *name,
DeviceState *child, Error **errp)
{
gchar *type;
type = g_strdup_printf("child<%s>", child->info->name);
qdev_property_add(dev, name, type, qdev_get_child_property,
NULL, NULL, child, errp);
qdev_ref(child);
g_free(type);
}
static gchar *qdev_get_path_in(DeviceState *parent, DeviceState *dev)
{
DeviceProperty *prop;

View File

@ -527,4 +527,24 @@ gchar *qdev_get_canonical_path(DeviceState *dev);
*/
DeviceState *qdev_resolve_path(const char *path, bool *ambiguous);
/**
* @qdev_property_add_child - Add a child property to a device
*
* Child properties form the composition tree. All devices need to be a child
* of another device. Devices can only be a child of one device.
*
* There is no way for a child to determine what its parent is. It is not
* a bidirectional relationship. This is by design.
*
* @dev - the device to add a property to
*
* @name - the name of the property
*
* @child - the child device
*
* @errp - if an error occurs, a pointer to an area to store the area
*/
void qdev_property_add_child(DeviceState *dev, const char *name,
DeviceState *child, Error **errp);
#endif