/**
* 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;
}
