Added versions of NRP fault tolerance example.

examples/C/src/leader-election/NRP_FD_NobodyFails.lf

@@ -0,0 +1,36 @@
+/**
+ * This version of NRP_FD simply has the primary (node1) failing after 5 seconds and the backup
+ * (node2) failing at at 15s. The backup detects simultaneous loss of the heartbeat on both networks
+ * and hence assumes that the primary has failed rather than there being a network failure. Switch 1
+ * remains the NRP.
+ *
+ * @author Edward A. Lee
+ * @author Marjan Sirjani
+ */
+target C {
+  coordination: decentralized,
+  timeout: 1000 hours
+}
+import Switch, Node from "NRP_FD.lf"
+
+federated reactor(heartbeat_period: time = 1 s, delay: time = 10 ms) {
+  node1 = new Node(heartbeat_period=heartbeat_period, id=1)
+  node2 = new Node(heartbeat_period=heartbeat_period, id=2)
+
+  switch1 = new Switch(id=1)
+  switch2 = new Switch(id=2)
+  switch3 = new Switch(id=3)
+  switch4 = new Switch(id=4)
+
+  node1.out -> switch1.in1, switch3.in1 after delay
+  switch1.out1, switch3.out1 -> node1.in after delay
+
+  switch1.out2 -> switch2.in2 after delay
+  switch2.out2 -> switch1.in2 after delay
+
+  switch2.out1, switch4.out1 -> node2.in after delay
+  node2.out -> switch2.in1, switch4.in1 after delay
+
+  switch3.out2 -> switch4.in2 after delay
+  switch4.out2 -> switch3.in2 after delay
+}