Handling async code

The automation script entry point is synchronous: use void Run(IEngine engine). Do not make the entry point async, and do not move Engine work to a background thread.

Important

The IEngine object, and every object you obtain through it (such as Element objects returned by engine.FindElement, dummies, and their parameters), is not thread-safe. It may only be used from the single thread on which Run(IEngine engine) executes.

This applies even when the work you offload is fully synchronous. Dispatching Engine calls to other threads (for example with Task.Run, Parallel.For, or a manually started Thread) and using the Engine or its objects from more than one thread at a time can corrupt the Automation subsystem's internal state and crash the process (SLAutomation). Keep all interaction with the Engine and its objects on the script's entry point thread.

Note that sending SLNet messages through the Engine object, i.e., using the methods Engine.SendSLNetSingleResponseMessage, Engine.SendSLNetMessages, and Engine.SendSLNetMessage, is thread-safe.

If an external library only exposes an async method, call it synchronously from the entry point thread. Do not pass the Engine object or objects obtained from it into the asynchronous operation.

using System;
using System.Net.Http;
using System.Threading.Tasks;
using Skyline.DataMiner.Automation;

public class Script
{
  public void Run(IEngine engine)
  {
    string url = "https://jsonplaceholder.typicode.com/todos/1"; // Example API
    string result = GetDataSync(url);
    engine.GenerateInformation(result);
  }

  public static string GetDataSync(string url)
  {
    using (HttpClient client = new HttpClient())
    {
      return client.GetStringAsync(url).GetAwaiter().GetResult(); // Synchronous execution
    }
  }
}

Table of Contents

Handling async code

Important