source: CIVL/examples/concurrency/porCommBug.cvl

#include <comm.cvh>

$gcomm g = $gcomm_create($here, 2);

void p0_f() {
  $comm c = $comm_create($here, g, 0);
  int* m = (int*) $malloc($here, sizeof(int));
  
  *m = 0;
  $comm_enqueue(c, $message_pack(0, 1, 0, &m, sizeof(int*)));
  *m = 1;

  $comm_dequeue(c, 1, 0);
  $free(m);
  $comm_destroy(c);
}

void p1_f() {
  $comm c = $comm_create($here, g, 1);
  $message result = $comm_dequeue(c, 0, 0); 

  int* m;
  $message_unpack(result, &m, sizeof(int*));
  $assert(*m == 1);

  $comm_enqueue(c, $message_pack(1, 0, 0, NULL, 0));
  $comm_destroy(c);
}

int main() {
  $proc p0 = $spawn p0_f();
  $proc p1 = $spawn p1_f();
  $wait(p0);
  $wait(p1);
  $gcomm_destroy(g, NULL);
}