public void OrderingOfEventsExample()
{
// ^ ^ time ↑
// | |
// evt p3 * |
// | |
// rcv p2 *---+ +---* q2 rcv
// | \ / |
// | \/ |
// | /\ |
// | / \ |
// rcv p1 *---+ +---* q1 snd
// | |
Stamp seed = new Stamp();
(Stamp, Stamp)fork = seed.Fork();
Process p = new Process("p", fork.Item1);
Process q = new Process("q", fork.Item2);
Message msgp1 = p.Send("p1");
Stamp p1 = p.CurrentStamp;
Console.WriteLine($"p1:{p1} after send");
Message msgq1 = q.Send("q1");
Stamp q1 = q.CurrentStamp;
Console.WriteLine($"q1:{q1} after send");
Stamp p2 = p.Receive(msgq1);
Console.WriteLine($"p2:{p2} after receive");
Stamp q2 = q.Receive(msgp1);
Console.WriteLine($"q1:{q1} after receive");
Stamp p3 = p.Increment();
Console.WriteLine($"p3:{p3} after event");
p1.Leq(p2).Should().BeTrue();
p1.Leq(p3).Should().BeTrue();
p2.Leq(p3).Should().BeTrue();
q1.Leq(q2).Should().BeTrue();
p1.Leq(q2).Should().BeTrue(); // send occurs before receive
q1.Leq(p2).Should().BeTrue(); // send occurs before receive
p1.Concurrent(q1).Should().BeTrue();
p2.Concurrent(q2).Should().BeTrue();
p3.Concurrent(q2).Should().BeTrue();
// Stamp implements IComparable<Stamp> so a collection of stamps
// can be partially ordered using Sort methods. Note this is a
// partial order (not total order) as CompareTo returns 0
// for equal and concurrent stamps.
var arr = new[] { q2, q1, p3, p2, p1 };
Array.Sort(arr);
arr.Should().ContainInOrder(p1, p2, p3);
arr.Should().ContainInOrder(q1, q2);
arr.Should().ContainInOrder(p1, q2);
arr.Should().ContainInOrder(q1, p2, p3);
}
