IReliableConcurrentQueue<T>.Count Property
Definition
Important
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Gets the number of values in the IReliableConcurrentQueue<T>.
public long Count { get; }member this.Count : int64Public ReadOnly Property Count As LongProperty Value
The number of values in the IReliableConcurrentQueue<T>.
Exceptions
The replica is currently not readable.
The IReliableConcurrentQueue<T> was closed by the runtime.
Examples
This example shows how to monitor the queue's count infinitely, until the cancellation token is canceled.
protected override async Task RunAsync(CancellationToken cancellationToken)
{
var concurrentQueue = await this.StateManager.GetOrAddAsync<IReliableConcurrentQueue<long>>(new Uri("fabric:/concurrentQueue"));
// Assumption: values are being enqueued/dequeued in another place (e.g. the communication listener).
var observer = Task.Run(
async () =>
{
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
try
{
Console.WriteLine("Count: " + concurrentQueue.Count);
}
catch (FabricNotReadableException e)
{
// Retry until the queue is readable or a different exception is thrown.
Console.WriteLine("Queue is not readable, retrying the observation: " + e);
}
catch (FabricObjectClosedException e)
{
// Gracefully exit as this is happening due to replica close.
Console.WriteLine("Replica is closing, stopping observer: " + e);
return;
}
await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken);
}
},
cancellationToken);
}
Remarks
This count represents the number of values currently visible to TryDequeueAsync(ITransaction, CancellationToken, Nullable<TimeSpan>). Uncommitted Enqueues will not increase the count, however uncommitted Dequeues will decrease the count.
Note that this API does not take a transaction parameter. Since the effects of TryDequeueAsync(ITransaction, CancellationToken, Nullable<TimeSpan>) are not isolated from other transactions, the count also cannot be isolated from other transactions.
