summaryrefslogtreecommitdiffstats
path: root/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus
diff options
context:
space:
mode:
Diffstat (limited to 'tools/memory-model/litmus-tests/SB+fencembonceonces.litmus')
-rw-r--r--tools/memory-model/litmus-tests/SB+fencembonceonces.litmus32
1 files changed, 32 insertions, 0 deletions
diff --git a/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus b/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus
new file mode 100644
index 000000000..ed5fff18d
--- /dev/null
+++ b/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus
@@ -0,0 +1,32 @@
+C SB+fencembonceonces
+
+(*
+ * Result: Never
+ *
+ * This litmus test demonstrates that full memory barriers suffice to
+ * order the store-buffering pattern, where each process writes to the
+ * variable that the preceding process reads. (Locking and RCU can also
+ * suffice, but not much else.)
+ *)
+
+{}
+
+P0(int *x, int *y)
+{
+ int r0;
+
+ WRITE_ONCE(*x, 1);
+ smp_mb();
+ r0 = READ_ONCE(*y);
+}
+
+P1(int *x, int *y)
+{
+ int r0;
+
+ WRITE_ONCE(*y, 1);
+ smp_mb();
+ r0 = READ_ONCE(*x);
+}
+
+exists (0:r0=0 /\ 1:r0=0)