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-rw-r--r--tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus34
1 files changed, 34 insertions, 0 deletions
diff --git a/tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus b/tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus
new file mode 100644
index 000000000..97731b4bb
--- /dev/null
+++ b/tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus
@@ -0,0 +1,34 @@
+C MP+onceassign+derefonce
+
+(*
+ * Result: Never
+ *
+ * This litmus test demonstrates that rcu_assign_pointer() and
+ * rcu_dereference() suffice to ensure that an RCU reader will not see
+ * pre-initialization garbage when it traverses an RCU-protected data
+ * structure containing a newly inserted element.
+ *)
+
+{
+y=z;
+z=0;
+}
+
+P0(int *x, int **y)
+{
+ WRITE_ONCE(*x, 1);
+ rcu_assign_pointer(*y, x);
+}
+
+P1(int *x, int **y)
+{
+ int *r0;
+ int r1;
+
+ rcu_read_lock();
+ r0 = rcu_dereference(*y);
+ r1 = READ_ONCE(*r0);
+ rcu_read_unlock();
+}
+
+exists (1:r0=x /\ 1:r1=0)