ServiceModel.Cancellation library for .Net

Support of CancellationToken for WCF. Allows to propagate notifications from CancellationToken from client to service side.

Supported platforms

.NET Framework 4.5.2 or higher.

Service-side

using CancellationTokenProxy = ServiceModel.Cancellation.CancellationTokenProxy;

[ServiceContract]
[UseCancellation] // enable cancellation support for service
public class DemoService
{
    // accept request with CancellationSourceToken
    [OperationContract]
    public async Task<OperationResult> RunOperationAsync(TimeSpan delay, CancellationTokenProxy token)
    {
        var timer = Stopwatch.StartNew();

        try
        {
            await Task.Delay(delay, token);
        }
        catch (TaskCanceledException ex) when (ex.CancellationToken == token)
        {
        }

        return new OperationResult
        {
            ExecutionTime = timer.Elapsed,
            IsCanceled = token.IsCancellationRequested
        };
    }
}

Client-side

using (var cancellationSource = new CancellationTokenSource())
using (var clientFactory = new ChannelFactory<IDemoService>())
{
    // enable cancellation support for client
    clientFactory.UseCancellation();

    // cancel request after 1 second
    cancellationSource.CancelAfter(TimeSpan.FromSeconds(1));

    var client = clientFactory.CreateChannel();

    // pass CancellationSourceToken to service
    var response = await client.RunOperationAsync(
        TimeSpan.FromSeconds(5),
        cancellationSource.Token);

    Console.WriteLine("ExecutionTime: {0}", response.ExecutionTime);
    Console.WriteLine("IsCanceled: {0}", response.IsCanceled);
}

Todo list to setup your code and environment

Service-side

• each service has to be pre-configured to support cancellation
• your environment has to host entry point (see CancellationContractService)) to accept cancellation requests from client

Client-side

• each client channel has to be pre-configured to support cancellation
• to pass cancellation requests to service CancellationContractClient will be used by default

Examples

• CodeConfiguration demonstrates how to configure ServiceModel.Cancellation from code
• FileConfiguration demonstrates how to configure ServiceModel.Cancellation from application configuration file.

License

This tool is distributed under the MIT license.