soft-an04/ReversalModel/reversal.pml

#define N 10
#define LENGTH 3
#define R 2

int to_reverse[LENGTH]; // array to reverse
int reversed[LENGTH]; // array where the reverse is stored

mtype = { END };

// ThreadedReverser implementation
proctype ThreadedReverser(int from; int to; chan out) {
    printf("proc[%d]: started\n", _pid);
    
    int k;
    for (k: from .. to) {
        reversed[LENGTH - k - 1] = to_reverse[k];
    }

    printf("proc[%d]: ended\n", _pid);
    
end:
    out!_pid;
}

init {
    chan in = [N] of { mtype };

    // array initialization
    {
        int i;
        for (i in to_reverse) {
            int value;
            select(value: 0 .. R);
            to_reverse[i] = value;
        }
    }

    // ParallelReverser implementation
    int n;
    int s = LENGTH / N;

    pid pids[N];
    
    // fork section
    for (n: 0 .. N) {
        int from = n * s;
        int to;
        if
        :: (n == N - 1) -> to = LENGTH;
        :: else -> to = n * s + s; 
        fi
        pids[n] = run ThreadedReverser(from, to, in);
    }

    // join section
    for (n: 0 .. N) {
        in??eval(pids[n]);

        printf("init: joined process %d\n", pids[n]);
    }    
}

// ltl syntax: https://spinroot.com/spin/Man/ltl.html
ltl test { 
    eventually (false) implies true
//   eventually (a > b) implies len(q) == 0 
}