/// <summary>
/// Periodically purge expired resources from _availableResources
/// </summary>
private async void SetupPeriodicPurge()
{
if (_resourcesExpireAfter != null)
{
using (var purgeCancellationTokenSource = new CancellationTokenSource())
{
var purgeCancellationToken = purgeCancellationTokenSource.Token;
#pragma warning disable 4014
Task.Run(async() =>
#pragma warning restore 4014
{
while (!purgeCancellationToken.IsCancellationRequested)
{
// Run the clean-up 10X as often as resources will expire. This will ensure that we
// keep the number of resources that have expired in the queue to a minimum.
const int frequency = 10;
await Task.Delay(new TimeSpan(_resourcesExpireAfter.Value.Ticks / frequency), purgeCancellationToken).ConfigureAwait(false);
var purgeMessage = new PurgeExpiredResourcesMessage();
_messageHandler.Post(purgeMessage);
}
}, purgeCancellationToken);
try
{
await _messageHandler.Completion.ConfigureAwait(false);
}
finally
{
purgeCancellationTokenSource.Cancel();
}
}
}
}
private void HandlePurgeExpiredResource(PurgeExpiredResourcesMessage purgeExpiredResourcesMessage)
{
var nonExpiredResources = new List <TimestampedResource>();
while (_availableResources.Count > 0)
{
var timestampedResource = _availableResources.Dequeue();
if (IsResourceExpired(timestampedResource))
{
DisposeResource(timestampedResource.Resource);
}
else
{
nonExpiredResources.Add(timestampedResource);
}
}
foreach (var timestampedResource in nonExpiredResources)
{
_availableResources.Enqueue(timestampedResource);
}
_messageHandler.Post(new EnsureAvailableResourcesMessage());
}
