source: CIVL/examples/concurrency/diningBad.cvl@ c1012e4

/* Dining philosophers, standard version, which deadlocks.
 *
 *              civl verify -inputB=4 diningBad.cvl
 * or (if you want to find the minimal counterexample)
 *              civl verify -inputB=4 diningBad.cvl -min
 */
#include <civlc.cvh>

$input int B = 4; // upper bound on number of philosophers
$input int n;     // number of philosophers
$assume(2<=n && n<=B);

int forks[n]; // Each fork will be on the table (0) or in a hand (1).

void dine(int id) {
  int left = id;
  int right = (id + 1) % n;

  while (1) {
    $when (forks[left] == 0) forks[left] = 1;
    $when (forks[right] == 0) forks[right] = 1;
    forks[right] = 0;
    forks[left] = 0;
  }
}

void main() { 
  elaborate(n);
  $for(int i: 0 .. n-1)
    forks[i] = 0;
  $parfor(int i: 0 .. n-1)
    dine(i);
}