zane

    class Ticketing {
        Entering: array [1..N] of boolean = {false};
        Number: array [1..N] of integer = {0};
        
        void lock(integer i) {
            Entering[i] = true;
            Number[i] = 1 + max(Number[1], ..., Number[N]);
            Entering[i] = false;
            for (j = 1; j <= N; j++) {
                // Wait until thread j receives its number: