diff options
Diffstat (limited to 'lib/qobj.h')
| -rw-r--r-- | lib/qobj.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/lib/qobj.h b/lib/qobj.h index 4c326731ed..c24bed4f6a 100644 --- a/lib/qobj.h +++ b/lib/qobj.h @@ -81,7 +81,18 @@ struct qobj_node { #define QOBJ_UNREG(n) \ qobj_unreg(&n->qobj_node) -/* internals - should not be directly used without a good reason*/ +/* internals - should not be directly used without a good reason + * + * note: qobj_get is essentially never safe to use in MT context because + * the object could be deleted by another thread -- and worse, it could be + * of the "wrong" type and deleted. + * + * with qobj_get_typed, the type check is done under lock, which means that + * it can be used as long as another lock prevents the deletion of objects + * of the expected type. + * + * in the long this may need another touch, e.g. built-in per-object locking. + */ void qobj_reg(struct qobj_node *node, struct qobj_nodetype *type); void qobj_unreg(struct qobj_node *node); struct qobj_node *qobj_get(uint64_t id); @@ -109,6 +120,8 @@ void *qobj_get_typed(uint64_t id, struct qobj_nodetype *type); #define QOBJ_ID(ptr) \ ((ptr)->qobj_node.nid) +#define QOBJ_ID_0SAFE(ptr) \ + ({ typeof (ptr) _ptr = (ptr); _ptr ? _ptr->qobj_node.nid : 0ULL; }) void qobj_init(void); void qobj_finish(void); |