@Test
public void createFromQueues() {
// Create config [[e],[]]
DistEventType sendE = DistEventType.SendEvent("e", cid1);
chStates.get(0).enqueue(sendE);
mc = ImmutableMultiChState.fromChannelStates(chStates);
// Create config [[],[]]
mc2 = ImmutableMultiChState.fromChannelIds(cids);
assertTrue(mc != mc2);
assertTrue(!mc.equals(mc2));
// Add e to [[],[]] at cid1 (index 0)
// This should result in [[],[e]] and equal the first mc above.
mc3 = mc2.getNextChState(sendE);
assertTrue(mc == mc3);
assertTrue(mc.equals(mc3));
assertTrue(mc.hashCode() == mc3.hashCode());
// Apply e again, resulting in: [[e,e],[]]
mc4 = mc3.getNextChState(sendE);
assertTrue(mc != mc4);
assertTrue(mc2 != mc4);
assertTrue(mc3 != mc4);
// Consume e, resulting in: [[e],[]]
DistEventType recvE = DistEventType.RecvEvent("e", cid1);
mc4 = mc4.getNextChState(recvE);
assertTrue(mc4 == mc3);
// Execute a local etype at pid 0, which should not change the state
DistEventType localE = DistEventType.LocalEvent("e", 1);
mc4 = mc4.getNextChState(localE);
assertTrue(mc4 == mc3);
}
/**
* Augment this CFSM with an "eventually happens e" invariant for model checking. This procedure
* is slightly different from binary invariants. In particular, we do not trace an 'initial' event
* and instead just trace the event e.
*/
private void augmentWithInvTracing(EventuallyHappens inv) {
DistEventType e1 = inv.getEvent();
assert alphabet.contains(e1);
assert e1.getPid() < fsms.size();
assert !invs.contains(invs);
invs.add(inv);
int scmId = this.channelIds.size();
if (firstSyntheticChIndex > scmId) {
firstSyntheticChIndex = scmId;
}
// Create and add a new invariant-specific channel.
ChannelId invCid = new InvChannelId(inv, scmId);
this.channelIds.add(invCid);
// Update the FSM corresponding to e1.
Set<FSMState> visited = Util.newSet();
FSM f1 = this.fsms.get(e1.getPid());
DistEventType e1Tracer1 = DistEventType.SynthSendEvent(e1, invCid, true);
DistEventType e1Tracer2 = DistEventType.SynthSendEvent(e1, invCid, false);
addSendToEventTx(f1, e1, e1Tracer1, e1Tracer2, visited);
this.alphabet.add(e1Tracer1);
this.alphabet.add(e1Tracer2);
inv.setFirstSynthTracers(e1Tracer1, e1Tracer2);
inv.setSecondSynthTracers(null, null);
}
/**
* Adds a new FSM instance to the CFSM. Once all the FSMs have been added, the CFSM is considered
* initialized.
*
* @param fsm
*/
public void addFSM(FSM fsm) {
assert unSpecifiedPids > 0;
assert fsm != null;
int pid = fsm.getPid();
if (CSightMain.assertsOn) {
// Must be a valid pid (in the right range).
assert (pid >= 0 && pid < numProcesses);
// Only allow to set the FSM for a pid once.
assert (fsms.get(pid) == null);
// Check that the FSM alphabet conforms to the expected number of
// processes.
int ppid;
for (DistEventType e : fsm.getAlphabet()) {
if (e.isCommEvent()) {
ppid = e.getChannelId().getDstPid();
assert ppid >= 0 && ppid < numProcesses;
ppid = e.getChannelId().getSrcPid();
assert ppid >= 0 && ppid < numProcesses;
} else {
ppid = e.getPid();
assert ppid >= 0 && ppid < numProcesses;
}
}
}
fsms.set(pid, fsm);
alphabet.addAll(fsm.getAlphabet());
unSpecifiedPids -= 1;
}
/**
* Recursive call to perform DFA exploration of FSM f. Helper to addSendToEventTx
*
* @param visited
*/
private void recurseAddSendToEventTx(
FSM f,
FSMState parent,
DistEventType eToTrace,
DistEventType eTracer1,
DistEventType eTracer2,
Set<FSMState> visited) {
if (visited.contains(parent)) {
return;
}
visited.add(parent);
// If there is a transition on to-trace event, then perform the
// re-writing.
if (parent.getTransitioningEvents().contains(eToTrace)) {
for (FSMState child : parent.getNextStates(eToTrace)) {
f.addSyntheticState(parent, child, eToTrace, eTracer1, eTracer2);
if (!visited.contains(child)) {
// If we haven't visited the child yet, then recurse to it.
recurseAddSendToEventTx(f, child, eToTrace, eTracer1, eTracer2, visited);
}
}
}
for (DistEventType e : parent.getTransitioningEvents()) {
// Now handle all the non-to-trace events. Note, however, that these
// have been re-written above with eTracer1 events, so this is what
// we check for.
if (!e.equals(eTracer1)) {
for (FSMState nextF : parent.getNextStates(e)) {
if (visited.contains(nextF)) {
continue;
}
recurseAddSendToEventTx(f, nextF, eToTrace, eTracer1, eTracer2, visited);
}
}
}
}
@Before
public void setUp() throws Exception {
super.setUp();
cids = Util.newList(2);
// Two process system.
cid1 = new ChannelId(0, 1, 0);
cid2 = new ChannelId(1, 0, 1);
cids.add(cid1);
cids.add(cid2);
Pmc = ImmutableMultiChState.fromChannelIds(cids);
List<ObsFSMState> P = Util.newList();
ObsFSMState p0 = ObsFSMState.namedObsFSMState(0, "p", false, true);
ObsFSMState p1 = ObsFSMState.namedObsFSMState(1, "q", false, true);
P.add(p0);
P.add(p1);
obsFSMState1 = ObsMultFSMState.getMultiFSMState(P);
s1 = ObsFifoSysState.getFifoSysState(obsFSMState1, Pmc);
List<ObsFSMState> P2 = Util.newList();
P2.add(p0);
ObsFSMState p2 = ObsFSMState.namedObsFSMState(1, "r", false, true);
P2.add(p2);
obsFSMState2 = ObsMultFSMState.getMultiFSMState(P2);
// Get a third instance that is different from the first two.
s2 = ObsFifoSysState.getFifoSysState(obsFSMState2, Pmc);
e1 = DistEventType.LocalEvent("e", 0);
ObsDistEventType obsE = new ObsDistEventType(e1, 0);
s1.addTransition(obsE, s2);
g1 = fromOneObs(2, s1);
g2 = fromOneObs(2, s2);
}
/**
* Generates a Promela representation of this CFSM, to be used with SPIN. The never claim is not
* specified here and it is appended to the CFSM elsewhere.
*/
public String toPromelaString(List<BinaryInvariant> invariants, int chanCapacity) {
assert unSpecifiedPids == 0;
String ret = "/* Spin-promela Multiple invariants */\n\n";
// Message types:
//
// mtype is global and can only be declared once.
// There is also limit of 255 for the size of mtype.
// This outputs a set of event types for the CFSM.
ret += "/* Message types: */\n";
ret += "mtype = { ";
Set<String> eventTypes = Util.newSet();
for (DistEventType e : alphabet) {
eventTypes.add(e.getPromelaEType());
}
ret += StringUtils.join(eventTypes, ", ");
ret += " };\n"; // End mtype declaration.
ret += "\n\n";
// Define the channels:
ret += "/* Channels: */\n\n";
// Specifying channels as an array to work with inlines.
ret +=
String.format("chan channel[%d] = [%d] of { mtype };\n", channelIds.size(), chanCapacity);
// The following block defines EMPTYCHANNELCHECK as a conditional that
// checks if all the channels are empty. This is used in the never claim
// to make sure our channels are empty before terminating.
String emptyChannelCheck = "";
for (int i = 0; i < channelIds.size(); i++) {
ret += "/* Channel " + channelIds.get(i).toString() + " */\n";
if (i != 0) {
emptyChannelCheck += " && ";
}
emptyChannelCheck += "empty(channel[" + i + "])";
}
ret += String.format("#define EMPTYCHANNELCHECK (%s)\n", emptyChannelCheck);
ret += "\n\n";
// Tracks if the current states of each of the FSM are terminal.
ret += "bit terminal[" + numProcesses + "];\n";
// ENDSTATECHECK is the conditional used by the never claim to
// check the terminal states in all CFSMs. The never claim has this to
// ensure that the processes are in a proper terminal state when the
// never claim is done.
String endStateCheck = "";
for (int pid = 0; pid < numProcesses; pid++) {
// Set up the terminal check conditional.
if (pid != 0) {
endStateCheck += " && ";
}
endStateCheck += "terminal[" + pid + "]";
}
ret += String.format("#define ENDSTATECHECK (%s)\n", endStateCheck);
// Event type definitions for type tracking
// OTHEREVENTs are used for other transitions so we do not accidentally
// trigger an "a NFby b". This can happen when a == b. This invariant
// can be accepted if a transition happens that does not call
// setRecentEvent. OTHEREVENT does not match any event we are interested
// in tracking so it is safe to use during these transitions.
ret += "#define OTHEREVENT (0)\n";
// Event types we're actively tracking.
ret += "#define LOCAL (1)\n";
ret += "#define SEND (2)\n";
ret += "#define RECV (3)\n";
// Custom datatype to assist in tracking recent event.
ret += "typedef myEvent {\n";
// The type of event: LOCAL, SEND or RECV
ret += " byte type;\n";
// id is the process id if the type is LOCAL and the channel id if the
// type is SEND or RECV.
ret += " byte id;\n";
// The event itself. These are the previously defined mtypes.
ret += " mtype event;\n";
ret += "};\n";
// Declaration of event tracker.
ret += "myEvent recentEvent;\n";
// Custom inline function to update most recent event.
ret += "inline setRecentEvent(event_type, owner_id, event_message) {\n";
ret += " d_step{\n";
ret += " recentEvent.type = event_type;\n";
ret += " recentEvent.id = owner_id;\n";
ret += " recentEvent.event = event_message;\n";
ret += " };\n";
ret += "}\n";
// Each of the FSMs in the CFSM:
for (int pid = 0; pid < numProcesses; pid++) {
String labelPrefix = "state" + Integer.toString(pid);
FSM f = fsms.get(pid);
ret += "active proctype p" + Integer.toString(pid) + "(){\n";
ret += f.toPromelaString(invariants, labelPrefix);
ret += "}\n\n";
}
ret += "\n\n";
for (BinaryInvariant inv : invariants) {
ret += "/* " + inv.toString() + "*/\n";
ret += inv.promelaNeverClaim();
ret += "\n\n";
}
return ret;
}