@@ -141,5 +141,40 @@ void assert_bdrv_graph_readable(void);
*/
void assert_bdrv_graph_writable(void);
+typedef struct GraphLockable { } GraphLockable;
+
+/*
+ * In C, compound literals have the lifetime of an automatic variable.
+ * In C++ it would be different, but then C++ wouldn't need QemuLockable
+ * either...
+ */
+#define GML_OBJ_() (&(GraphLockable) { })
+
+static inline GraphLockable *graph_lockable_auto_lock(GraphLockable *x)
+{
+ bdrv_graph_co_rdlock();
+ return x;
+}
+
+static inline void graph_lockable_auto_unlock(GraphLockable *x)
+{
+ bdrv_graph_co_rdunlock();
+}
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GraphLockable, graph_lockable_auto_unlock)
+
+#define WITH_GRAPH_RDLOCK_GUARD_(var) \
+ for (g_autoptr(GraphLockable) var = graph_lockable_auto_lock(GML_OBJ_()); \
+ var; \
+ graph_lockable_auto_unlock(var), var = NULL)
+
+#define WITH_GRAPH_RDLOCK_GUARD() \
+ WITH_GRAPH_RDLOCK_GUARD_(glue(graph_lockable_auto, __COUNTER__))
+
+#define GRAPH_RDLOCK_GUARD(x) \
+ g_autoptr(GraphLockable) \
+ glue(graph_lockable_auto, __COUNTER__) G_GNUC_UNUSED = \
+ graph_lockable_auto_lock(GML_OBJ_())
+
#endif /* GRAPH_LOCK_H */
Similar to the implementation in lockable.h, implement macros to automatically take and release the rdlock. Create the empty GraphLockable struct only to use it as a type for G_DEFINE_AUTOPTR_CLEANUP_FUNC. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> --- include/block/graph-lock.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)