task-parallel-library

问题 Let's say I have two independent async functions (that I don't control) that create Task objects: Task A(); Task B(); and some other non-async function void X(); How do I construct a single Task chain that executes all of these in sequence and allows further continuations (that will execute after X) to be appended? If I do this: Task Sequential() { return A() .ContinueWith(t => { B(); }) .ContinueWith(t => { X(); }); } that does not work, because B will start a new Task chain. If B takes a

问题 Let's say I have two independent async functions (that I don't control) that create Task objects: Task A(); Task B(); and some other non-async function void X(); How do I construct a single Task chain that executes all of these in sequence and allows further continuations (that will execute after X) to be appended? If I do this: Task Sequential() { return A() .ContinueWith(t => { B(); }) .ContinueWith(t => { X(); }); } that does not work, because B will start a new Task chain. If B takes a

问题 Let's say I have two independent async functions (that I don't control) that create Task objects: Task A(); Task B(); and some other non-async function void X(); How do I construct a single Task chain that executes all of these in sequence and allows further continuations (that will execute after X) to be appended? If I do this: Task Sequential() { return A() .ContinueWith(t => { B(); }) .ContinueWith(t => { X(); }); } that does not work, because B will start a new Task chain. If B takes a

问题 Let's say I have two independent async functions (that I don't control) that create Task objects: Task A(); Task B(); and some other non-async function void X(); How do I construct a single Task chain that executes all of these in sequence and allows further continuations (that will execute after X) to be appended? If I do this: Task Sequential() { return A() .ContinueWith(t => { B(); }) .ContinueWith(t => { X(); }); } that does not work, because B will start a new Task chain. If B takes a

问题 I know it is bad to call Task.Wait in UI thread. It causes a deadlock. Please refer to Constructor invoke async method Await, and UI, and deadlocks! Oh my! Take the following code: public MainPage() { this.InitializeComponent(); step0(); step1(); } private async Task step0() { await Task.Delay(5000); System.Diagnostics.Debug.WriteLine("step 0"); } private async Task step1() { await Task.Delay(3000); System.Diagnostics.Debug.WriteLine("step 1"); } } How can I ensure that "step 0" is always

问题 I'm using TPL dataflow to process items off a queue in an Azure worker role. Should I have a single long running dataflow, or spawn a new flow for every messages I receive? If an error is thrown in a block, that block will stop accepting new messages. That means if there is an exception in a block, the whole dataflow will stop processing. I need to be able to withstand exception from something like invalid queue inputs without locking my dataflow. I see one of two options: I have a start a

问题 I want to set up a TransformBlock that processes its item in parallel. Thus, I'm setting ExecutionDataflowBlockOptions.MaxDegreeOfParallelism to > 1. I don't care about the order of the messages but the documentation says: When you specify a maximum degree of parallelism that is larger than 1, multiple messages are processed simultaneously, and therefore, messages might not be processed in the order in which they are received. The order in which the messages are output from the block will,

问题 The bounty expires tomorrow . Answers to this question are eligible for a +50 reputation bounty. Thomas Weller wants to draw more attention to this question. Given the attached LINQ-Pad snippet. It creates 8 tasks, executes for 500ms and draws a graph on when the threads were actually running. On a 4 core CPU it may look like this: Now, if I add a Thread.Sleep or a Task.Delay within the thread loops, I can visualize the clock of the windows system timer (~15ms): Now, there's also the

问题 The bounty expires tomorrow . Answers to this question are eligible for a +50 reputation bounty. Thomas Weller wants to draw more attention to this question. Given the attached LINQ-Pad snippet. It creates 8 tasks, executes for 500ms and draws a graph on when the threads were actually running. On a 4 core CPU it may look like this: Now, if I add a Thread.Sleep or a Task.Delay within the thread loops, I can visualize the clock of the windows system timer (~15ms): Now, there's also the

问题 I have a base controller with the following abstract method: [HttpDelete] public abstract Task<IHttpActionResult> Delete(int id); In one particular controller, I don't want to implement deletion, so the method looks like this: public override async Task<IHttpActionResult> Delete(int id) { return ResponseMessage(Request.CreateResponse(HttpStatusCode.MethodNotAllowed, new NotSupportedException())); } Although the above code compiles, I get a warning: This async method lacks 'await' operators