1 files changed, 27 insertions, 0 deletions
diff --git a/tools/memory-model/litmus-tests/MP+poonceonces.litmus b/tools/memory-model/litmus-tests/MP+poonceonces.litmus
new file mode 100644
index 000000000..ba9c99c6c
--- /dev/null
+++ b/tools/memory-model/litmus-tests/MP+poonceonces.litmus
@@ -0,0 +1,27 @@
+C MP+poonceonces
+
+(*
+ * Result: Sometimes
+ *
+ * Can the counter-intuitive message-passing outcome be prevented with
+ * no ordering at all?
+ *)
+
+{}
+
+P0(int *buf, int *flag) // Producer
+{
+	WRITE_ONCE(*buf, 1);
+	WRITE_ONCE(*flag, 1);
+}
+
+P1(int *buf, int *flag) // Consumer
+{
+	int r0;
+	int r1;
+
+	r0 = READ_ONCE(*flag);
+	r1 = READ_ONCE(*buf);
+}
+
+exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)