async Task <TValue> CreateValue(IPendingValue <TValue> pendingValue)
{
ExceptionDispatchInfo dispatchInfo;
do
{
try
{
var value = await pendingValue.CreateValue().ConfigureAwait(false);
SetResult(value);
return(value);
}
catch (Exception ex)
{
dispatchInfo = ExceptionDispatchInfo.Capture(ex.GetBaseException());
}
}while (TryTake(out pendingValue));
SetException(dispatchInfo);
dispatchInfo.Throw();
throw dispatchInfo.SourceException;
}
public Task <TValue> GetValue(Func <IPendingValue <TValue> > pendingValueFactory)
{
Interlocked.Increment(ref _usage);
lock (this)
{
if (HasValue)
{
return(_value.Task);
}
IPendingValue <TValue> pendingValue = pendingValueFactory();
if (_createValue == null)
{
_createValue = CreateValue(pendingValue);
}
else
{
(_pending ??= new Queue <IPendingValue <TValue> >(1)).Enqueue(pendingValue);
}
return(pendingValue.Value);
}
}
/// <summary>
/// Creates a node value factory, with the inital pending value
/// </summary>
/// <param name="initialPendingValue">The value that brought the node to the cache</param>
/// <param name="timeoutInMilliseconds">The timeout to wait for additional factories before faulting</param>
public NodeValueFactory(IPendingValue <TValue> initialPendingValue, int timeoutInMilliseconds)
{
_timeout = timeoutInMilliseconds;
_pendingCollection = new BlockingCollection <IPendingValue <TValue> >();
_value = TaskUtil.GetTask <TValue>();
_pendingCollection.Add(initialPendingValue);
}
public void Add(IPendingValue <TValue> pendingValue)
{
if (_value.Task.Status != TaskStatus.WaitingForActivation)
{
pendingValue.SetValue(_value.Task);
}
else
{
_pendingCollection.Add(pendingValue);
}
}
bool TryTake(out IPendingValue <TValue> pendingValue)
{
lock (this)
{
if (_pending != null && _pending.Count > 0)
{
pendingValue = _pending.Dequeue();
return(true);
}
}
pendingValue = default;
return(false);
}
public Task <TValue> GetValue(IPendingValue <TValue> pendingValue)
{
_nodeValueFactory.Add(pendingValue);
return(_nodeValueFactory.Value);
}
public Task <TValue> GetValue(IPendingValue <TValue> pendingValue)
{
return(_value);
}
