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envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 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 --- 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