/**
* 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;
}
@Override
public String toString() {
String ret = "CFSM: \n";
for (FSM f : fsms) {
ret += "\t" + f.toString() + "\n\n";
}
return ret.substring(0, ret.length() - 1);
}
/**
* Generate SCM representation of this CFSM, with bad states if this CFSM was augmented with any
* invariants.
*/
public String toScmString(String cfsmName) {
assert unSpecifiedPids == 0;
String ret = "scm " + cfsmName + ":\n\n";
// Channels:
// Add a special channel for handling local events, represented as
// messages on this channel.
LocalEventsChannelId localChId;
if (localEventsChIndex == Integer.MAX_VALUE) {
localChId = new LocalEventsChannelId(this.channelIds.size());
localEventsChIndex = localChId.getScmId();
this.channelIds.add(localChId);
} else {
localChId = (LocalEventsChannelId) this.channelIds.get(localEventsChIndex);
}
ret += "nb_channels = " + channelIds.size() + " ;\n";
ret += "/*\n";
for (int i = 0; i < channelIds.size(); i++) {
ret += "channel " + Integer.toString(i) + " : " + channelIds.get(i).toString() + "\n";
}
ret += "*/\n\n";
// Whether or not any channels are lossy:
// TODO: add lossy field to ChannelId and list all channel ids that
// are lossy here.
// Parameters/Alphabet:
ret += "parameters :\n";
ret += alphabet.toScmParametersString();
ret += "\n";
// FSMS:
for (int pid = 0; pid < numProcesses; pid++) {
FSM f = fsms.get(pid);
ret += "automaton p" + Integer.toString(pid) + " :\n";
ret += f.toScmString(localChId);
ret += "\n";
}
// Bad states:
if (!invs.isEmpty()) {
ret += "\nbad_states:\n";
for (BadState b : getBadStates()) {
ret += b.toScmString() + "\n";
}
}
return ret;
}
/**
* Traverse the graph of FSM f and replace all transitions on e to some state s to transition to a
* new state X, and add a transition from X to s that enqueues event e on channel identified by
* invCid.
*
* @param visited
* @param f1
* @param e1
* @param invCid
*/
private void addSendToEventTx(
FSM f,
DistEventType eToTrace,
DistEventType eTracer1,
DistEventType eTracer2,
Set<FSMState> visited) {
for (FSMState init : f.getInitStates()) {
recurseAddSendToEventTx(f, init, eToTrace, eTracer1, eTracer2, visited);
}
}
/**
* 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);
}
}
}
}
/**
* 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;
}
