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sharwellsharwell
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Merge pull request #319 from sharwell/task-performance
Improve performance of chained tasks and avoid wrapping exceptions
2 parents dc50e5c + 299b9f6 commit 6976124

14 files changed

+1003
-885
lines changed

‎src/corelib/Core/CoreTaskExtensions.cs‎

Lines changed: 370 additions & 0 deletions
Large diffs are not rendered by default.

‎src/corelib/Core/ParallelExtensionsExtras/TaskExtrasExtensions.cs‎

Lines changed: 0 additions & 214 deletions
Original file line numberDiff line numberDiff line change
@@ -308,219 +308,5 @@ public static TaskStatus WaitForCompletionStatus(this Task task)
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return task.Status;
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}
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#endregion
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#region Then
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/// <summary>Creates a task that represents the completion of a follow-up action when a task completes.</summary>
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/// <param name="task">The task.</param>
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/// <param name="next">The action to run when the task completes.</param>
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/// <returns>The task that represents the completion of both the task and the action.</returns>
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public static Task Then(this Task task, Action next)
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{
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if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<object>();
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task.ContinueWith(delegate
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{
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if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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try
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{
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next();
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tcs.TrySetResult(null);
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}
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a follow-up function when a task completes.</summary>
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/// <param name="task">The task.</param>
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/// <param name="next">The function to run when the task completes.</param>
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/// <returns>The task that represents the completion of both the task and the function.</returns>
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public static Task<TResult> Then<TResult>(this Task task, Func<TResult> next)
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{
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if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<TResult>();
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task.ContinueWith(delegate
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{
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if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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try
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{
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var result = next();
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tcs.TrySetResult(result);
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}
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a follow-up action when a task completes.</summary>
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/// <param name="task">The task.</param>
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/// <param name="next">The action to run when the task completes.</param>
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/// <returns>The task that represents the completion of both the task and the action.</returns>
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public static Task Then<TResult>(this Task<TResult> task, Action<TResult> next)
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{
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if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<object>();
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task.ContinueWith(delegate
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{
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if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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try
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{
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next(task.Result);
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tcs.TrySetResult(null);
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}
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a follow-up function when a task completes.</summary>
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/// <param name="task">The task.</param>
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/// <param name="next">The function to run when the task completes.</param>
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/// <returns>The task that represents the completion of both the task and the function.</returns>
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public static Task<TNewResult> Then<TResult, TNewResult>(this Task<TResult> task, Func<TResult, TNewResult> next)
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{
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if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<TNewResult>();
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task.ContinueWith(delegate
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{
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if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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try
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{
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var result = next(task.Result);
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tcs.TrySetResult(result);
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}
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a second task when a first task completes.</summary>
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/// <param name="task">The first task.</param>
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/// <param name="next">The function that produces the second task.</param>
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/// <returns>The task that represents the completion of both the first and second task.</returns>
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public static Task Then(this Task task, Func<Task> next)
426-
{
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if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<object>();
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task.ContinueWith(delegate
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{
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// When the first task completes, if it faulted or was canceled, bail
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if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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// Otherwise, get the next task. If it's null, bail. If not,
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// when it's done we'll have our result.
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try { next().ContinueWith(t => tcs.TrySetFromTask(t), TaskScheduler.Default); }
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a second task when a first task completes.</summary>
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/// <param name="task">The first task.</param>
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/// <param name="next">The function that produces the second task based on the result of the first task.</param>
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/// <returns>The task that represents the completion of both the first and second task.</returns>
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public static Task Then<T>(this Task<T> task, Func<T, Task> next)
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{
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if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<object>();
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task.ContinueWith(delegate
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{
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// When the first task completes, if it faulted or was canceled, bail
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if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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// Otherwise, get the next task. If it's null, bail. If not,
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// when it's done we'll have our result.
466-
try { next(task.Result).ContinueWith(t => tcs.TrySetFromTask(t), TaskScheduler.Default); }
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a second task when a first task completes.</summary>
474-
/// <param name="task">The first task.</param>
475-
/// <param name="next">The function that produces the second task.</param>
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/// <returns>The task that represents the completion of both the first and second task.</returns>
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public static Task<TResult> Then<TResult>(this Task task, Func<Task<TResult>> next)
478-
{
479-
if (task == null) throw new ArgumentNullException("task");
480-
if (next == null) throw new ArgumentNullException("next");
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482-
var tcs = new TaskCompletionSource<TResult>();
483-
task.ContinueWith(delegate
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{
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// When the first task completes, if it faulted or was canceled, bail
486-
if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
487-
else if (task.IsCanceled) tcs.TrySetCanceled();
488-
else
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{
490-
// Otherwise, get the next task. If it's null, bail. If not,
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// when it's done we'll have our result.
492-
try { next().ContinueWith(t => tcs.TrySetFromTask(t), TaskScheduler.Default); }
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
496-
return tcs.Task;
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}
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/// <summary>Creates a task that represents the completion of a second task when a first task completes.</summary>
500-
/// <param name="task">The first task.</param>
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/// <param name="next">The function that produces the second task based on the result of the first.</param>
502-
/// <returns>The task that represents the completion of both the first and second task.</returns>
503-
public static Task<TNewResult> Then<TResult, TNewResult>(this Task<TResult> task, Func<TResult, Task<TNewResult>> next)
504-
{
505-
if (task == null) throw new ArgumentNullException("task");
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if (next == null) throw new ArgumentNullException("next");
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var tcs = new TaskCompletionSource<TNewResult>();
509-
task.ContinueWith(delegate
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{
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// When the first task completes, if it faulted or was canceled, bail
512-
if (task.IsFaulted) tcs.TrySetException(task.Exception.InnerExceptions);
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else if (task.IsCanceled) tcs.TrySetCanceled();
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else
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{
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// Otherwise, get the next task. If it's null, bail. If not,
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// when it's done we'll have our result.
518-
try { next(task.Result).ContinueWith(t => tcs.TrySetFromTask(t), TaskScheduler.Default); }
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catch (Exception exc) { tcs.TrySetException(exc); }
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}
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}, TaskScheduler.Default);
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return tcs.Task;
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}
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#endregion
525311
}
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}

‎src/corelib/Core/ReadOnlyCollectionPageExtensions.cs‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -91,9 +91,9 @@ public static Task<ReadOnlyCollection<T>> GetAllPagesAsync<T>(this ReadOnlyColle
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9292
// continue with the next page
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currentTask = getNextPage();
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currentTask.ContinueWith(continuation);
94+
currentTask.ContinueWith(continuation, TaskContinuationOptions.ExecuteSynchronously);
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};
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currentTask.ContinueWith(continuation);
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currentTask.ContinueWith(continuation, TaskContinuationOptions.ExecuteSynchronously);
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return taskCompletionSource.Task;

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