protected override async Task<Lease> AcquireLease()
{
var now = DateTimeOffset.UtcNow;
var resource = leasableResources
.Where(l => l.LeaseLastReleased + waitInterval < now)
.OrderBy(l => l.LeaseLastReleased)
.FirstOrDefault(l => !workInProgress.ContainsKey(l));
if (resource == null)
{
return null;
}
var lease = new Lease(resource,
resource.DefaultLeaseDuration);
if (workInProgress.TryAdd(resource, lease))
{
lease.LeasableResource.LeaseLastGranted = now;
return lease;
}
return null;
}
protected override async Task ReleaseLease(Lease lease)
{
lease.NotifyCompleted();
if (!workInProgress.Values.Any(l => l.GetHashCode().Equals(lease.GetHashCode())))
{
Debug.WriteLine("[Distribute] ReleaseLease (failed): " + lease);
return;
}
Lease _;
if (workInProgress.TryRemove(lease.LeasableResource, out _))
{
lease.LeasableResource.LeaseLastReleased = DateTimeOffset.UtcNow;
Debug.WriteLine("[Distribute] ReleaseLease: " + lease);
}
}
protected abstract Task ReleaseLease(Lease lease);