synchronous-programming.md

title	description
Synchronous programming with MSAL.NET	MSAL.NET is based on Task-based Asynchronous Pattern (TAP). This page provides links to guidance about how to use async methods in a synchronous way. This has no one solution that fits all. So various best practices are recommended.

Synchronous programming with MSAL.NET

It is strongly recommended to use async programming practices for better performance and responsive apps. However, some legacy apps cannot use asynchronous programming.

MSAL.NET is based on Task-based Asynchronous Pattern (TAP). This page provides links to guidance about how to use async methods in a synchronous way. This has no one solution that fits all. So various best practices are recommended.

Asynchronous programming

If you are not familiar with asynchronous programming, check out Asynchronous programming with async and await.

You can also check out the Advanced Programming in C# course on LinkedIn.

Calling Asynchronous methods from synchronous code

There are several ways to run asynchronous code from a synchronous code. Various links are listed here.

Task.RunSynchronously

var getAcctsTasks = PCA.RemoveAsync(acct);
// there is no timeout for RunSynchronously
if (!getAcctsTasks.IsCompleted)
{
   getAcctsTasks.RunSynchronously();
}

Wait for a task to complete with Task.Wait

// wait can optionally have timeout, and cancellation token (not shown)
int timeoutMilliSec = 3000;
PCA.RemoveAsync(acct).Wait(timeoutMilliSec);

Wait to get result with Task.Result

var authResult = PCA.AcquireTokenSilent(Scopes, acct).ExecuteAsync().Result;
return authResult;

If you need to run multiple tasks at a time prior to wrapping them, it may be useful to take a look at Consuming the Task-based Asynchronous Pattern.

Watch out for exceptions and deadlocks

Here is how to catch exceptions and prevent deadlocks with .ConfigureAwait(false).

try
{
    Console.WriteLine("Pre AcquireTokenInteractive");
    // Run with wait command
    // create the builder
    var builder = PCA.AcquireTokenInteractive(Scopes);

    // run it interactively.
    // make sure to have ConfigureAwait(false) to avoid any potential deadlocks
    var authResult = builder.ExecuteAsync()
                .ConfigureAwait(false)
                .GetAwaiter()
                .GetResult();
    Console.WriteLine("Post AcquireTokenInteractive - Got the token");

    return result;
}
catch (MsalClientException ex)
{
    // catch MSAL exception
    Console.WriteLine(ex.Message);
}
catch (Exception ex)
{
    Console.WriteLine(ex.Message);
}