How would I run an async TaskT method synchronously

2025-01-26 (Last Modified: 2025-01-26)

Asynchronous programming has go a cornerstone of contemporary exertion improvement, permitting for responsive and businesslike dealing with of clip-consuming operations. Successful C, the async and await key phrases simplify asynchronous programming, however typically you mightiness discovery your self needing to tally an async Project<T> methodology synchronously. This tin happen successful bequest codification, UI case handlers, oregon throughout investigating. Knowing however to span the spread betwixt asynchronous and synchronous execution is important for immoderate C developer. This article explores respective approaches to moving async duties synchronously, outlining the advantages and drawbacks of all technique, and offering applicable examples to usher you done the procedure.

Knowing the Asynchronous Exemplary

Earlier diving into the options, it’s important to realize wherefore asynchronous programming is generous and the challenges of moving asynchronous codification synchronously. Asynchronous operations let your exertion to stay responsive piece ready for agelong-moving duties similar web requests oregon record I/O. Alternatively of blocking the chief thread, these duties are offloaded, liberating ahead assets and stopping UI freezes. Nevertheless, definite contexts necessitate synchronous execution, creating a demand for bridging methods.

1 communal script is inside UI case handlers, wherever straight awaiting an asynchronous project tin pb to surprising behaviour. Different illustration is bequest codification that hasn’t been up to date to activity asynchronous patterns.

Utilizing .Consequence and .GetAwaiter().GetResult()

The about simple strategies for moving an async Project<T> synchronously are .Consequence and .GetAwaiter().GetResult(). Piece seemingly elemental, these approaches person possible pitfalls, particularly regarding deadlocks. .Consequence volition artifact the calling thread till the project completes, which tin beryllium problematic successful UI contexts oregon once dealing with nested asynchronous calls.

.GetAwaiter().GetResult(), piece somewhat much verbose, behaves likewise. Some strategies volition propulsion immoderate exceptions raised by the asynchronous project straight, dissimilar .Delay() which wraps exceptions successful an AggregateException. See this illustration:

// Illustration utilizing .Consequence var consequence = MyAsyncMethod().Consequence; // Illustration utilizing .GetAwaiter().GetResult() var consequence = MyAsyncMethod().GetAwaiter().GetResult();

Leveraging Project.Tally() for CPU-Certain Duties

For CPU-certain asynchronous operations, Project.Tally() tin beryllium a utile implement. This methodology offloads the asynchronous project to a thread excavation thread, permitting it to tally successful parallel with out blocking the chief thread. This attack is peculiarly appropriate for agelong-moving computations that would other frost the UI. Nevertheless, it’s crucial to line that Project.Tally() isn’t perfect for I/O-certain operations, arsenic it introduces pointless overhead.

Present’s an illustration of utilizing Project.Tally():

var consequence = Project.Tally(() => MyAsyncMethod()).Consequence;

AsyncContext: A Much Sturdy Resolution

Libraries similar Nito.AsyncEx message much blase options for managing asynchronous contexts. The AsyncContext people offers a devoted synchronization discourse that permits asynchronous codification to beryllium tally synchronously with out the hazard of deadlocks. This is peculiarly invaluable successful analyzable functions oregon libraries wherever managing asynchronous operations tin beryllium difficult.

Illustration utilizing AsyncContext (requires Nito.AsyncEx room):

// Assuming AsyncContext is initialized var consequence = AsyncContext.Tally(() => MyAsyncMethod());

Selecting the Correct Attack

The champion attack relies upon connected the circumstantial discourse and the quality of the asynchronous project. For elemental eventualities and non-UI contexts, .GetAwaiter().GetResult() is frequently adequate. Project.Tally() is appropriate for CPU-sure duties, piece AsyncContext offers a much sturdy resolution for analyzable functions and libraries. It is important to realize the implications of all technique and take the 1 that champion matches your wants. Avoiding deadlocks and sustaining exertion responsiveness ought to beryllium capital concerns.

Prioritize .GetAwaiter().GetResult() for elemental eventualities.
Usage Project.Tally() judiciously for CPU-sure operations.

Analyse the discourse of your asynchronous cognition.
See the possible for deadlocks.
Take the due technique primarily based connected the project’s quality and exertion discourse.

For much accusation connected asynchronous programming champion practices, mention to the Microsoft documentation connected asynchronous programming.

[Infographic depicting the antithetic approaches and their usage circumstances]

Selecting the correct scheme for dealing with async Project<T> strategies synchronously is indispensable for sturdy and responsive C functions. By knowing the nuances of all attack, you tin brand knowledgeable selections that forestall deadlocks and keep a creaseless person education. Research assets similar Stephen Cleary’s weblog station connected asynchronous champion practices and applicable Stack Overflow discussions for deeper insights.

Larn MuchBy cautiously contemplating the discourse of your asynchronous operations and selecting the due synchronization methodology, you tin compose businesslike and dependable C codification that seamlessly integrates asynchronous duties into synchronous workflows. Retrieve to prioritize impasse avoidance and exertion responsiveness successful your determination-making procedure. Present, geared up with a deeper knowing of these methods, you tin confidently sort out the challenges of moving asynchronous codification synchronously successful your C tasks.

FAQ

Q: What’s the chief hazard of moving async codification synchronously?

A: The capital hazard is deadlocks, peculiarly successful UI threads oregon nested asynchronous calls. Blocking the chief thread tin frost the exertion and pb to surprising behaviour.

Question & Answer :
I americium studying astir async/await, and ran into a occupation wherever I demand to call an async methodology synchronously. However tin I bash that?

Async methodology:

national async Project<Clients> GetCustomers() { instrument await Work.GetCustomersAsync(); }

Average utilization:

national async void GetCustomers() { customerList = await GetCustomers(); }

I’ve tried utilizing the pursuing:

Project<Buyer> project = GetCustomers(); project.Delay() Project<Buyer> project = GetCustomers(); project.RunSynchronously(); Project<Buyer> project = GetCustomers(); piece(project.Position != TaskStatus.RanToCompletion)

I besides tried a proposition from present, nevertheless it doesn’t activity once the dispatcher is successful a suspended government.

national static void WaitWithPumping(this Project project) { if (project == null) propulsion fresh ArgumentNullException(“project”); var nestedFrame = fresh DispatcherFrame(); project.ContinueWith(_ => nestedFrame.Proceed = mendacious); Dispatcher.PushFrame(nestedFrame); project.Delay(); }

Present is the objection and stack hint from calling RunSynchronously:

Scheme.InvalidOperationException

Communication: RunSynchronously whitethorn not beryllium known as connected a project unbound to a delegate.

InnerException: null

Origin: mscorlib

StackTrace:

astatine Scheme.Threading.Duties.Project.InternalRunSynchronously(TaskScheduler scheduler) astatine Scheme.Threading.Duties.Project.RunSynchronously() astatine MyApplication.CustomControls.Controls.MyCustomControl.CreateAvailablePanelList() successful C:\Paperwork and Settings\...\MyApplication.CustomControls\Controls\MyCustomControl.xaml.cs:formation 638 astatine MyApplication.CustomControls.Controls.MyCustomControl.get_AvailablePanels() successful C:\Paperwork and Settings\...\MyApplication.CustomControls\Controls\MyCustomControl.xaml.cs:formation 233 astatine MyApplication.CustomControls.Controls.MyCustomControl.<CreateOpenPanelList>b__36(DesktopPanel sheet) successful C:\Paperwork and Settings\...\MyApplication.CustomControls\Controls\MyCustomControl.xaml.cs:formation 597 astatine Scheme.Collections.Generic.Database`1.ForEach(Act`1 act) astatine MyApplication.CustomControls.Controls.MyCustomControl.<CreateOpenPanelList>d__3b.MoveNext() successful C:\Paperwork and Settings\...\MyApplication.CustomControls\Controls\MyCustomControl.xaml.cs:formation 625 astatine Scheme.Runtime.CompilerServices.TaskAwaiter.<>c__DisplayClass7.<TrySetContinuationForAwait>b__1(Entity government) astatine Scheme.Home windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Entity args, Int32 numArgs) astatine Sclerosis.Inner.Threading.ExceptionFilterHelper.TryCatchWhen(Entity origin, Delegate methodology, Entity args, Int32 numArgs, Delegate catchHandler) astatine Scheme.Home windows.Threading.DispatcherOperation.InvokeImpl() astatine Scheme.Home windows.Threading.DispatcherOperation.InvokeInSecurityContext(Entity government) astatine Scheme.Threading.ExecutionContext.runTryCode(Entity userData) astatine Scheme.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode codification, CleanupCode backoutCode, Entity userData) astatine Scheme.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Entity government) astatine Scheme.Threading.ExecutionContext.Tally(ExecutionContext executionContext, ContextCallback callback, Entity government, Boolean ignoreSyncCtx) astatine Scheme.Threading.ExecutionContext.Tally(ExecutionContext executionContext, ContextCallback callback, Entity government) astatine Scheme.Home windows.Threading.DispatcherOperation.Invoke() astatine Scheme.Home windows.Threading.Dispatcher.ProcessQueue() astatine Scheme.Home windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& dealt with) astatine Sclerosis.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& dealt with) astatine Sclerosis.Win32.HwndSubclass.DispatcherCallbackOperation(Entity o) astatine Scheme.Home windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Entity args, Int32 numArgs) astatine Sclerosis.Inner.Threading.ExceptionFilterHelper.TryCatchWhen(Entity origin, Delegate technique, Entity args, Int32 numArgs, Delegate catchHandler) astatine Scheme.Home windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority precedence, TimeSpan timeout, Delegate technique, Entity args, Int32 numArgs) astatine Sclerosis.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) astatine Sclerosis.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) astatine Scheme.Home windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame framework) astatine Scheme.Home windows.Threading.Dispatcher.PushFrame(DispatcherFrame framework) astatine Scheme.Home windows.Threading.Dispatcher.Tally() astatine Scheme.Home windows.Exertion.RunDispatcher(Entity disregard) astatine Scheme.Home windows.Exertion.RunInternal(Framework framework) astatine Scheme.Home windows.Exertion.Tally(Framework framework) astatine Scheme.Home windows.Exertion.Tally() astatine MyApplication.App.Chief() successful C:\Paperwork and Settings\...\MyApplication\obj\Debug\App.g.cs:formation 50 astatine Scheme.AppDomain._nExecuteAssembly(RuntimeAssembly meeting, Drawstring[] args) astatine Scheme.AppDomain.ExecuteAssembly(Drawstring assemblyFile, Grounds assemblySecurity, Drawstring[] args) astatine Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() astatine Scheme.Threading.ThreadHelper.ThreadStart_Context(Entity government) astatine Scheme.Threading.ExecutionContext.Tally(ExecutionContext executionContext, ContextCallback callback, Entity government, Boolean ignoreSyncCtx) astatine Scheme.Threading.ExecutionContext.Tally(ExecutionContext executionContext, ContextCallback callback, Entity government) astatine Scheme.Threading.ThreadHelper.ThreadStart()

Present’s a workaround I recovered that plant for each circumstances (together with suspended dispatchers). It’s not my codification and I’m inactive running to full realize it, however it does activity.

It tin beryllium referred to as utilizing:

customerList = AsyncHelpers.RunSync<Database<Buyer>>(() => GetCustomers());

Codification is from present

national static people AsyncHelpers { /// <abstract> /// Synchronously execute's an async Project technique which has a void instrument worth. /// </abstract> /// <param sanction="project">The Project methodology to execute.</param> national static void RunSync(Func<Project> project) { var oldContext = SynchronizationContext.Actual; var syncContext = fresh ExclusiveSynchronizationContext(); SynchronizationContext.SetSynchronizationContext(syncContext); syncContext.Station(async _ => { attempt { await project(); } drawback (Objection e) { syncContext.InnerException = e; propulsion; } eventually { syncContext.EndMessageLoop(); } }, null); syncContext.BeginMessageLoop(); SynchronizationContext.SetSynchronizationContext(oldContext); } /// <abstract> /// Synchronously execute's an async Project<T> methodology which has a T instrument kind. /// </abstract> /// <typeparam sanction="T">Instrument Kind</typeparam> /// <param sanction="project">The Project<T> methodology to execute.</param> /// <returns>The consequence of awaiting the fixed Project<T>.</returns> national static T RunSync<T>(Func<Project<T>> project) { var oldContext = SynchronizationContext.Actual; var syncContext = fresh ExclusiveSynchronizationContext(); SynchronizationContext.SetSynchronizationContext(syncContext); T consequence; syncContext.Station(async _ => { attempt { consequence = await project(); } drawback (Objection e) { syncContext.InnerException = e; propulsion; } eventually { syncContext.EndMessageLoop(); } }, null); syncContext.BeginMessageLoop(); SynchronizationContext.SetSynchronizationContext(oldContext); instrument consequence; } backstage people ExclusiveSynchronizationContext : SynchronizationContext { backstage readonly AutoResetEvent workItemsWaiting = fresh AutoResetEvent(mendacious); backstage readonly Queue<Tuple<SendOrPostCallback, entity>> gadgets = fresh Queue<Tuple<SendOrPostCallback, entity>>(); backstage bool completed; national Objection InnerException { acquire; fit; } national override void Direct(SendOrPostCallback d, entity government) { propulsion fresh NotSupportedException("We can not direct to our aforesaid thread"); } national override void Station(SendOrPostCallback d, entity government) { fastener (gadgets) { objects.Enqueue(Tuple.Make(d, government)); } workItemsWaiting.Fit(); } national void EndMessageLoop() { Station(_ => achieved = actual, null); } national void BeginMessageLoop() { piece (!executed) { Tuple<SendOrPostCallback, entity> project = null; fastener (objects) { if (objects.Number > zero) { project = gadgets.Dequeue(); } } if (project != null) { project.Item1(project.Item2); if (InnerException != null) // the technique threw an exeption { propulsion fresh AggregateException("AsyncHelpers.Tally technique threw an objection.", InnerException); } } other { workItemsWaiting.WaitOne(); } } } national override SynchronizationContext CreateCopy() { instrument this; } } }