The Rust bindings for QObject will only share a complete object and treat it as immutable from that point on. With that constraint, it is trivial to make QObjects thread-safe just by making reference count operations atomic. Do the same when the C code adds or removes references.
Signed-off-by: Paolo Bonzini <[email protected]> --- include/qobject/qobject.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/qobject/qobject.h b/include/qobject/qobject.h index a6244d0ce00..02f4c6a6eb2 100644 --- a/include/qobject/qobject.h +++ b/include/qobject/qobject.h @@ -32,6 +32,7 @@ #ifndef QOBJECT_H #define QOBJECT_H +#include "qemu/atomic.h" #include "qapi/qapi-builtin-types.h" /* Not for use outside include/qobject/ */ @@ -73,7 +74,7 @@ QEMU_BUILD_BUG_MSG(QTYPE__MAX != 7, static inline void qobject_ref_impl(QObject *obj) { if (obj) { - obj->base.refcnt++; + qatomic_inc(&obj->base.refcnt); } } @@ -95,7 +96,7 @@ void qobject_destroy(QObject *obj); static inline void qobject_unref_impl(QObject *obj) { assert(!obj || obj->base.refcnt); - if (obj && --obj->base.refcnt == 0) { + if (obj && qatomic_fetch_dec(&obj->base.refcnt) == 1) { qobject_destroy(obj); } } -- 2.51.0
