Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

public: static System::Threading::Tasks::Task ^ WhenAll(System::Collections::Generic::IEnumerable<System::Threading::Tasks::Task ^> ^ tasks);

public static System.Threading.Tasks.Task WhenAll(System.Collections.Generic.IEnumerable<System.Threading.Tasks.Task> tasks);

static member WhenAll : seq<System.Threading.Tasks.Task> -> System.Threading.Tasks.Task

Public Shared Function WhenAll (tasks As IEnumerable(Of Task)) As Task

Parameters

Returns

A task that represents the completion of all of the supplied tasks.

Exceptions

Examples

The following example creates a set of tasks that ping the URLs in an array. The tasks are stored in aList<Task> collection that is passed to theWhenAll(IEnumerable<Task>) method. After the call to theWait method ensures that all threads have completed, the example examines theTask.Status property to determine whether any tasks have faulted.

using System;using System.Collections.Generic;using System.Net.NetworkInformation;using System.Threading;using System.Threading.Tasks;public class Example{   public static void Main()   {      int failed = 0;      var tasks = new List<Task>();      String[] urls = { "www.adatum.com", "www.cohovineyard.com",                        "www.cohowinery.com", "www.northwindtraders.com",                        "www.contoso.com" };            foreach (var value in urls) {         var url = value;         tasks.Add(Task.Run( () => { var png = new Ping();                                     try {                                        var reply = png.Send(url);                                        if (!(reply.Status == IPStatus.Success)) {                                           Interlocked.Increment(ref failed);                                           throw new TimeoutException("Unable to reach " + url + ".");                                        }                                     }                                     catch (PingException) {                                        Interlocked.Increment(ref failed);                                        throw;                                     }                                   }));      }      Task t = Task.WhenAll(tasks);      try {         t.Wait();      }      catch {}         if (t.Status == TaskStatus.RanToCompletion)         Console.WriteLine("All ping attempts succeeded.");      else if (t.Status == TaskStatus.Faulted)         Console.WriteLine("{0} ping attempts failed", failed);         }}// The example displays output like the following://       5 ping attempts failed

open Systemopen System.Net.NetworkInformationopen System.Threadingopen System.Threading.Taskslet mutable failed = 0let urls =    [ "www.adatum.com"      "www.cohovineyard.com"      "www.cohowinery.com"      "www.northwindtraders.com"      "www.contoso.com" ]let tasks =    urls    |> List.map (fun url ->        Task.Run(fun () ->            let png = new Ping()            try                let reply = png.Send url                if reply.Status <> IPStatus.Success then                    Interlocked.Increment &failed |> ignore                    raise (TimeoutException $"Unable to reach {url}.")            with :? PingException ->                Interlocked.Increment &failed |> ignore                reraise ()))let t = Task.WhenAll taskstry    t.Wait()with _ ->    ()if t.Status = TaskStatus.RanToCompletion then    printfn "All ping attempts succeeded."elif t.Status = TaskStatus.Faulted then    printfn $"{failed} ping attempts failed"// The example displays output like the following://       5 ping attempts failed

Imports System.Collections.GenericImports System.Net.NetworkInformationImports System.ThreadingImports System.Threading.TasksModule Example   Public Sub Main()      Dim failed As Integer = 0      Dim tasks As New List(Of Task)()      Dim urls() As String = { "www.adatum.com", "www.cohovineyard.com",                              "www.cohowinery.com", "www.northwindtraders.com",                              "www.contoso.com" }            For Each value In urls         Dim url As String = value         tasks.Add(Task.Run( Sub()                                Dim png As New Ping()                                Try                                   Dim reply = png.Send(url)                                   If Not reply.Status = IPStatus.Success Then                                      Interlocked.Increment(failed)                                      Throw New TimeoutException("Unable to reach " + url + ".")                                   End If                                   Catch e As PingException                                      Interlocked.Increment(failed)                                      Throw                                   End Try                             End Sub))      Next      Dim t As Task = Task.WhenAll(tasks)      Try         t.Wait()      Catch      End Try         If t.Status = TaskStatus.RanToCompletion         Console.WriteLine("All ping attempts succeeded.")      ElseIf t.Status = TaskStatus.Faulted         Console.WriteLine("{0} ping attempts failed", failed)            End If   End SubEnd Module' The example displays output like the following:'     5 ping attempts failed

Remarks

The overloads of theWhenAll method that return aTask object are typically called when you are interested in the status of a set of tasks or in the exceptions thrown by a set of tasks.

If any of the supplied tasks completes in a faulted state, the returned task will also complete in aFaulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in theCanceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in theRanToCompletion state.

If the supplied array/enumerable contains no tasks, the returned task will immediately transition to aRanToCompletion state before it's returned to the caller.

Source:

Task.cs

public: static System::Threading::Tasks::Task ^ WhenAll(ReadOnlySpan<System::Threading::Tasks::Task ^> tasks);

public static System.Threading.Tasks.Task WhenAll(scoped ReadOnlySpan<System.Threading.Tasks.Task> tasks);

static member WhenAll : ReadOnlySpan<System.Threading.Tasks.Task> -> System.Threading.Tasks.Task

Public Shared Function WhenAll (tasks As ReadOnlySpan(Of Task)) As Task

Parameters

Returns

A task that represents the completion of all of the supplied tasks.

Exceptions

Remarks

If any of the supplied tasks completes in a faulted state, the returned task will also complete in a Faulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in the Canceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in the RanToCompletion state.

If the supplied span contains no tasks, the returned task will immediately transition to a RanToCompletion state before it's returned to the caller.

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

public: static System::Threading::Tasks::Task ^ WhenAll(... cli::array <System::Threading::Tasks::Task ^> ^ tasks);

public static System.Threading.Tasks.Task WhenAll(params System.Threading.Tasks.Task[] tasks);

static member WhenAll : System.Threading.Tasks.Task[] -> System.Threading.Tasks.Task

Public Shared Function WhenAll (ParamArray tasks As Task()) As Task

Parameters

Returns

A task that represents the completion of all of the supplied tasks.

Exceptions

Examples

The following example creates a set of tasks that ping the URLs in an array. The tasks are stored in aList<Task> collection that is converted to an array and passed to theWhenAll(IEnumerable<Task>) method. After the call to theWait method ensures that all threads have completed, the example examines theTask.Status property to determine whether any tasks have faulted.

using System;using System.Collections.Generic;using System.Net.NetworkInformation;using System.Threading;using System.Threading.Tasks;public class Example{   public static async Task Main()   {      int failed = 0;      var tasks = new List<Task>();      String[] urls = { "www.adatum.com", "www.cohovineyard.com",                        "www.cohowinery.com", "www.northwindtraders.com",                        "www.contoso.com" };            foreach (var value in urls) {         var url = value;         tasks.Add(Task.Run( () => { var png = new Ping();                                     try {                                        var reply = png.Send(url);                                        if (!(reply.Status == IPStatus.Success)) {                                           Interlocked.Increment(ref failed);                                           throw new TimeoutException("Unable to reach " + url + ".");                                        }                                     }                                     catch (PingException) {                                        Interlocked.Increment(ref failed);                                        throw;                                     }                                   }));      }      Task t = Task.WhenAll(tasks.ToArray());      try {         await t;      }      catch {}         if (t.Status == TaskStatus.RanToCompletion)         Console.WriteLine("All ping attempts succeeded.");      else if (t.Status == TaskStatus.Faulted)         Console.WriteLine("{0} ping attempts failed", failed);         }}// The example displays output like the following://       5 ping attempts failed

open Systemopen System.Net.NetworkInformationopen System.Threadingopen System.Threading.Taskslet mutable failed = 0let urls =    [| "www.adatum.com"       "www.cohovineyard.com"       "www.cohowinery.com"       "www.northwindtraders.com"       "www.contoso.com" |]let tasks =    urls    |> Array.map (fun url ->        Task.Run(fun () ->            let png = new Ping()            try                let reply = png.Send url                if reply.Status <> IPStatus.Success then                    Interlocked.Increment &failed |> ignore                    raise (TimeoutException $"Unable to reach {url}.")            with :? PingException ->                Interlocked.Increment &failed |> ignore                reraise ()))let main =    task {        let t = Task.WhenAll tasks        try            do! t        with _ ->            ()        if t.Status = TaskStatus.RanToCompletion then            printfn "All ping attempts succeeded."        elif t.Status = TaskStatus.Faulted then            printfn $"{failed} ping attempts failed"    }main.Wait()// The example displays output like the following://       5 ping attempts failed

Imports System.Collections.GenericImports System.Net.NetworkInformationImports System.ThreadingImports System.Threading.TasksModule Example   Public Sub Main()      Dim failed As Integer = 0      Dim tasks As New List(Of Task)()      Dim urls() As String = { "www.adatum.com", "www.cohovineyard.com",                              "www.cohowinery.com", "www.northwindtraders.com",                              "www.contoso.com" }            For Each value In urls         Dim url As String = value         tasks.Add(Task.Run( Sub()                                Dim png As New Ping()                                Try                                   Dim reply = png.Send(url)                                   If Not reply.Status = IPStatus.Success Then                                      Interlocked.Increment(failed)                                      Throw New TimeoutException("Unable to reach " + url + ".")                                   End If                                   Catch e As PingException                                      Interlocked.Increment(failed)                                      Throw                                   End Try                             End Sub))      Next      Dim t As Task = Task.WhenAll(tasks.ToArray())      Try         t.Wait()      Catch      End Try         If t.Status = TaskStatus.RanToCompletion         Console.WriteLine("All ping attempts succeeded.")      ElseIf t.Status = TaskStatus.Faulted         Console.WriteLine("{0} ping attempts failed", failed)            End If   End SubEnd Module' The example displays output like the following:'     5 ping attempts failed

Remarks

The overloads of theWhenAll method that return aTask object are typically called when you are interested in the status of a set of tasks or in the exceptions thrown by a set of tasks.

If any of the supplied tasks completes in a faulted state, the returned task will also complete in aFaulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in theCanceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in theRanToCompletion state.

If the supplied array/enumerable contains no tasks, the returned task will immediately transition to aRanToCompletion state before it's returned to the caller.

Source:

Task.cs

public:generic <typename TResult> static System::Threading::Tasks::Task<cli::array <TResult> ^> ^ WhenAll(ReadOnlySpan<System::Threading::Tasks::Task<TResult> ^> tasks);

public static System.Threading.Tasks.Task<TResult[]> WhenAll<TResult>(scoped ReadOnlySpan<System.Threading.Tasks.Task<TResult>> tasks);

static member WhenAll : ReadOnlySpan<System.Threading.Tasks.Task<'Result>> -> System.Threading.Tasks.Task<'Result[]>

Public Shared Function WhenAll(Of TResult) (tasks As ReadOnlySpan(Of Task(Of TResult))) As Task(Of TResult())

Type Parameters

Parameters

Returns

A task that represents the completion of all of the supplied tasks.

Exceptions

Remarks

If any of the supplied tasks completes in a faulted state, the returned task will also complete in a Faulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in the Canceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in the RanToCompletion state. The Result of the returned task will be set to an array containing all of the results of the supplied tasks in the same order as they were provided (e.g. if the input tasks array contained t1, t2, t3, the output task's Result will return an TResult[] where arr[0] == t1.Result, arr[1] == t2.Result, and arr[2] == t3.Result).

If the supplied array/enumerable contains no tasks, the returned task will immediately transition to a RanToCompletion state before it's returned to the caller. The returned TResult[] will be an array of 0 elements.

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

public:generic <typename TResult> static System::Threading::Tasks::Task<cli::array <TResult> ^> ^ WhenAll(System::Collections::Generic::IEnumerable<System::Threading::Tasks::Task<TResult> ^> ^ tasks);

public static System.Threading.Tasks.Task<TResult[]> WhenAll<TResult>(System.Collections.Generic.IEnumerable<System.Threading.Tasks.Task<TResult>> tasks);

static member WhenAll : seq<System.Threading.Tasks.Task<'Result>> -> System.Threading.Tasks.Task<'Result[]>

Public Shared Function WhenAll(Of TResult) (tasks As IEnumerable(Of Task(Of TResult))) As Task(Of TResult())

Type Parameters

Parameters

Returns

A task that represents the completion of all of the supplied tasks.

Exceptions

Examples

The following example creates ten tasks, each of which instantiates a random number generator that creates 1,000 random numbers between 1 and 1,000 and computes their mean. TheDelay(Int32) method is used to delay instantiation of the random number generators so that they are not created with identical seed values. The call to theWhenAll method then returns anInt64 array that contains the mean computed by each task. These are then used to calculate the overall mean.

using System;using System.Collections.Generic;using System.Threading.Tasks;public class Example{   public static void Main()   {      var tasks = new List<Task<long>>();      for (int ctr = 1; ctr <= 10; ctr++) {         int delayInterval = 18 * ctr;         tasks.Add(Task.Run(async () => { long total = 0;                                          await Task.Delay(delayInterval);                                          var rnd = new Random();                                          // Generate 1,000 random numbers.                                          for (int n = 1; n <= 1000; n++)                                             total += rnd.Next(0, 1000);                                          return total; } ));      }      var continuation = Task.WhenAll(tasks);      try {         continuation.Wait();      }      catch (AggregateException)      { }         if (continuation.Status == TaskStatus.RanToCompletion) {         long grandTotal = 0;         foreach (var result in continuation.Result) {            grandTotal += result;            Console.WriteLine("Mean: {0:N2}, n = 1,000", result/1000.0);         }            Console.WriteLine("\nMean of Means: {0:N2}, n = 10,000",                           grandTotal/10000);      }      // Display information on faulted tasks.      else {         foreach (var t in tasks) {            Console.WriteLine("Task {0}: {1}", t.Id, t.Status);         }      }   }}// The example displays output like the following://       Mean: 506.34, n = 1,000//       Mean: 504.69, n = 1,000//       Mean: 489.32, n = 1,000//       Mean: 505.96, n = 1,000//       Mean: 515.31, n = 1,000//       Mean: 499.94, n = 1,000//       Mean: 496.92, n = 1,000//       Mean: 508.58, n = 1,000//       Mean: 494.88, n = 1,000//       Mean: 493.53, n = 1,000////       Mean of Means: 501.55, n = 10,000

open Systemopen System.Threading.Taskslet tasks =    [| for i = 1 to 10 do           let delayInterval = 18 * i           task {               let mutable total = 0L               do! Task.Delay delayInterval               let rnd = Random()               for _ = 1 to 1000 do                   total <- total + (rnd.Next(0, 1000) |> int64)               return total           } |]let continuation = Task.WhenAll taskstry    continuation.Wait()with :? AggregateException ->    ()if continuation.Status = TaskStatus.RanToCompletion then    for result in continuation.Result do        printfn $"Mean: {float result / 1000.:N2}, n = 1,000"    let grandTotal = continuation.Result |> Array.sum    printfn $"\nMean of Means: {float grandTotal / 10000.:N2}, n = 10,000"// Display information on faulted tasks.else    for t in tasks do        printfn $"Task {t.Id}: {t.Status}"// The example displays output like the following://       Mean: 506.34, n = 1,000//       Mean: 504.69, n = 1,000//       Mean: 489.32, n = 1,000//       Mean: 505.96, n = 1,000//       Mean: 515.31, n = 1,000//       Mean: 499.94, n = 1,000//       Mean: 496.92, n = 1,000//       Mean: 508.58, n = 1,000//       Mean: 494.88, n = 1,000//       Mean: 493.53, n = 1,000////       Mean of Means: 501.55, n = 10,000

Imports System.Collections.GenericImports System.Threading.TasksModule Example   Public Sub Main()      Dim tasks As New List(Of Task(Of Long))()      For ctr As Integer = 1 To 10         Dim delayInterval As Integer = 18 * ctr         tasks.Add(Task.Run(Async Function()                               Dim total As Long = 0                               Await Task.Delay(delayInterval)                               Dim rnd As New Random()                               ' Generate 1,000 random numbers.                               For n As Integer = 1 To 1000                                  total += rnd.Next(0, 1000)                               Next                               Return total                            End Function))      Next      Dim continuation = Task.WhenAll(tasks)      Try         continuation.Wait()      Catch ae As AggregateException      End Try            If continuation.Status = TaskStatus.RanToCompletion Then         Dim grandTotal As Long = 0         For Each result in continuation.Result            grandTotal += result            Console.WriteLine("Mean: {0:N2}, n = 1,000", result/1000)         Next         Console.WriteLine()         Console.WriteLine("Mean of Means: {0:N2}, n = 10,000",                           grandTotal/10000)      ' Display information on faulted tasks.      Else          For Each t In tasks            Console.WriteLine("Task {0}: {1}", t.Id, t.Status)         Next      End If   End SubEnd Module' The example displays output like the following:'       Mean: 506.34, n = 1,000'       Mean: 504.69, n = 1,000'       Mean: 489.32, n = 1,000'       Mean: 505.96, n = 1,000'       Mean: 515.31, n = 1,000'       Mean: 499.94, n = 1,000'       Mean: 496.92, n = 1,000'       Mean: 508.58, n = 1,000'       Mean: 494.88, n = 1,000'       Mean: 493.53, n = 1,000''       Mean of Means: 501.55, n = 10,000

In this case, the ten individual tasks are stored in aList<T> object.List<T> implements theIEnumerable<T> interface.

Remarks

The call toWhenAll<TResult>(IEnumerable<Task<TResult>>) method does not block the calling thread. However, a call to the returnedResult property does block the calling thread.

If any of the supplied tasks completes in a faulted state, the returned task will also complete in aFaulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in theCanceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in theRanToCompletion state. TheTask<TResult>.Result property of the returned task will be set to an array containing all of the results of the supplied tasks in the same order as they were provided (e.g. if the input tasks array contained t1, t2, t3, the output task'sTask<TResult>.Result property will return anTResult[] wherearr[0] == t1.Result, arr[1] == t2.Result, and arr[2] == t3.Result).

If thetasks argument contains no tasks, the returned task will immediately transition to aRanToCompletion state before it's returned to the caller. The returnedTResult[] will be an array of 0 elements.

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

Source:

Task.cs

public:generic <typename TResult> static System::Threading::Tasks::Task<cli::array <TResult> ^> ^ WhenAll(... cli::array <System::Threading::Tasks::Task<TResult> ^> ^ tasks);

public static System.Threading.Tasks.Task<TResult[]> WhenAll<TResult>(params System.Threading.Tasks.Task<TResult>[] tasks);

static member WhenAll : System.Threading.Tasks.Task<'Result>[] -> System.Threading.Tasks.Task<'Result[]>

Public Shared Function WhenAll(Of TResult) (ParamArray tasks As Task(Of TResult)()) As Task(Of TResult())

Type Parameters

Parameters

Returns

A task that represents the completion of all of the supplied tasks.

Exceptions

Examples

The following example creates ten tasks, each of which instantiates a random number generator that creates 1,000 random numbers between 1 and 1,000 and computes their mean. In this case, the ten individual tasks are stored in aTask<Int64> array. TheDelay(Int32) method is used to delay instantiation of the random number generators so that they are not created with identical seed values. The call to theWhenAll method then returns anInt64 array that contains the mean computed by each task. These are then used to calculate the overall mean.

using System;using System.Collections.Generic;using System.Threading.Tasks;public class Example{   public static void Main()   {      var tasks = new Task<long>[10];      for (int ctr = 1; ctr <= 10; ctr++) {         int delayInterval = 18 * ctr;         tasks[ctr - 1] = Task.Run(async () => { long total = 0;                                                 await Task.Delay(delayInterval);                                                 var rnd = new Random();                                                 // Generate 1,000 random numbers.                                                 for (int n = 1; n <= 1000; n++)                                                    total += rnd.Next(0, 1000);                                                 return total; } );      }      var continuation = Task.WhenAll(tasks);      try {         continuation.Wait();      }      catch (AggregateException)      {}         if (continuation.Status == TaskStatus.RanToCompletion) {         long grandTotal = 0;         foreach (var result in continuation.Result) {            grandTotal += result;            Console.WriteLine("Mean: {0:N2}, n = 1,000", result/1000.0);         }            Console.WriteLine("\nMean of Means: {0:N2}, n = 10,000",                           grandTotal/10000);      }      // Display information on faulted tasks.      else {          foreach (var t in tasks)            Console.WriteLine("Task {0}: {1}", t.Id, t.Status);      }   }}// The example displays output like the following://       Mean: 506.38, n = 1,000//       Mean: 501.01, n = 1,000//       Mean: 505.36, n = 1,000//       Mean: 492.00, n = 1,000//       Mean: 508.36, n = 1,000//       Mean: 503.99, n = 1,000//       Mean: 504.95, n = 1,000//       Mean: 508.58, n = 1,000//       Mean: 490.23, n = 1,000//       Mean: 501.59, n = 1,000////       Mean of Means: 502.00, n = 10,000

open Systemopen System.Threading.Taskslet tasks =    [| for i = 1 to 10 do           let delayInterval = 18 * i           task {               let mutable total = 0L               do! Task.Delay delayInterval               let rnd = Random()               for _ = 1 to 1000 do                   total <- total + (rnd.Next(0, 1000) |> int64)               return total           } |]let continuation = Task.WhenAll taskstry    continuation.Wait()with :? AggregateException ->    ()if continuation.Status = TaskStatus.RanToCompletion then    for result in continuation.Result do        printfn $"Mean: {float result / 1000.:N2}, n = 1,000"    let grandTotal = Array.sum continuation.Result    printfn $"\nMean of Means: {float grandTotal / 10000.:N2}, n = 10,000"// Display information on faulted tasks.else    for t in tasks do        printfn $"Task {t.Id}: {t.Status}"// The example displays output like the following://       Mean: 506.38, n = 1,000//       Mean: 501.01, n = 1,000//       Mean: 505.36, n = 1,000//       Mean: 492.00, n = 1,000//       Mean: 508.36, n = 1,000//       Mean: 503.99, n = 1,000//       Mean: 504.95, n = 1,000//       Mean: 508.58, n = 1,000//       Mean: 490.23, n = 1,000//       Mean: 501.59, n = 1,000////       Mean of Means: 502.00, n = 10,000

Imports System.Collections.GenericImports System.Threading.TasksModule Example   Public Sub Main()      Dim tasks(9) As Task(Of Long)      For ctr As Integer = 1 To 10         Dim delayInterval As Integer = 18 * ctr         tasks(ctr - 1) =Task.Run(Async Function()                                     Dim total As Long = 0                                     Await Task.Delay(delayInterval)                                     Dim rnd As New Random()                                     ' Generate 1,000 random numbers.                                     For n As Integer = 1 To 1000                                        total += rnd.Next(0, 1000)                                     Next                                     Return total                                  End Function)      Next      Dim continuation = Task.WhenAll(tasks)      Try         continuation.Wait()      Catch ae As AggregateException      End Try               If continuation.Status = TaskStatus.RanToCompletion Then         Dim grandTotal As Long = 0         For Each result in continuation.Result            grandTotal += result            Console.WriteLine("Mean: {0:N2}, n = 1,000", result/1000)         Next         Console.WriteLine()         Console.WriteLine("Mean of Means: {0:N2}, n = 10,000",                           grandTotal/10000)      ' Display information on faulted tasks.      Else          For Each t In tasks            Console.WriteLine("Task {0}: {1}", t.Id, t.Status)         Next      End If   End SubEnd Module' The example displays output like the following:'       Mean: 506.38, n = 1,000'       Mean: 501.01, n = 1,000'       Mean: 505.36, n = 1,000'       Mean: 492.00, n = 1,000'       Mean: 508.36, n = 1,000'       Mean: 503.99, n = 1,000'       Mean: 504.95, n = 1,000'       Mean: 508.58, n = 1,000'       Mean: 490.23, n = 1,000'       Mean: 501.59, n = 1,000''       Mean of Means: 502.00, n = 10,000

Remarks

The call toWhenAll<TResult>(Task<TResult>[]) method does not block the calling thread. However, a call to the returnedResult property does block the calling thread.

If any of the supplied tasks completes in a faulted state, the returned task will also complete in aFaulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in theCanceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in theRanToCompletion state. TheResult of the returned task will be set to an array containing all of the results of the supplied tasks in the same order as they were provided (e.g. if the input tasks array contained t1, t2, t3, the output task'sResult will return anTResult[] wherearr[0] == t1.Result, arr[1] == t2.Result, and arr[2] == t3.Result).

If the supplied array/enumerable contains no tasks, the returned task will immediately transition to aRanToCompletion state before it's returned to the caller. The returnedTResult[] will be an array of 0 elements.