task-parallel-library

问题 I have 1 method that I want to run in 10 different parallel threads, all will be independent there are no dependency on each other, my problem is that if I have 100 items to process and would like to process 10 at a time then how do in run 10 at a time. I have created a sample code where I am using Parallel.ForEach but what do I need to set so it should run 10 threads at a time and suppose any of the the running task have completed then it should automatically take new one, so all 10 threads

问题 I have 1 method that I want to run in 10 different parallel threads, all will be independent there are no dependency on each other, my problem is that if I have 100 items to process and would like to process 10 at a time then how do in run 10 at a time. I have created a sample code where I am using Parallel.ForEach but what do I need to set so it should run 10 threads at a time and suppose any of the the running task have completed then it should automatically take new one, so all 10 threads

问题 I've been studying Tasks in .net 4.0 and their cancellation. I like the fact that TPL tries to deal with cancellation correctly in cooperative manner. However, what should one do in situation where a call inside a task is blocking and takes a long time? For examle IO/Network. Obviously cancelling writes would be dangerous. But those are examples. Example: How would I cancel this? DownloadFile can take a long time. Task.Factory.StartNew(() => WebClient client = new WebClient(); client

问题 I've been studying Tasks in .net 4.0 and their cancellation. I like the fact that TPL tries to deal with cancellation correctly in cooperative manner. However, what should one do in situation where a call inside a task is blocking and takes a long time? For examle IO/Network. Obviously cancelling writes would be dangerous. But those are examples. Example: How would I cancel this? DownloadFile can take a long time. Task.Factory.StartNew(() => WebClient client = new WebClient(); client

问题 I found Difference between […]Async and Begin[…] .net asynchronous APIs question but this answer confused me a little bit. Talking about these patterns, Stephen said: Most *Async methods (with corresponding *Completed events) are using the Event-Based Asynchronous Pattern. The older (but still perfectly valid) Begin* and End* is a pattern called the Asynchronous Programming Model. The Socket class is an exception to this rule; its *Async methods do not have any corresponding events; it's

问题 This question already has answers here : How to tell a lambda function to capture a copy instead of a reference in C#? (4 answers) Closed 1 year ago . I have created a console app which print the number in a for loop using C# Task.Run() method. If you look at the code, I am initializing the Employee object in the loop and pass the number in the method, though it prints the same number. Code: class Program { static void Main(string[] args) { for (int i = 1; i <= 500; i++) { Task.Run(() => new

问题 I have 2 loops(nested), trying to do a simple parallelisation pseudocode : for item1 in data1 (~100 million row) for item2 in data2 (~100 rows) result = process(item1,item2) // couple of if conditions hashset.add(result) // while adding, incase of a duplicate i also decide wihch one to retain process(item1,item2) to be precise has 4 if conditions bases on values in item1 and item2.(time taken is less than 50ms) data1 size is Nx17 data2 size is Nx17 result size is 1x17 (result is joined into a

问题 I have a simple tpl data flow which basically does some tasks. I noticed when there is an exception in any of the datablocks, it wasn't getting caught in the initial parent block caller. I have added some manual code to check for exception but doesn't seem the right approach. if (readBlock.Completion.Exception != null || saveBlockJoinedProcess.Completion.Exception != null || processBlock1.Completion.Exception != null || processBlock2.Completion.Exception != null) { throw readBlock.Completion

问题 When awaiting a Task I would like to have an easy way to ignore specific types of exceptions, like OperationCanceledException or TimeoutException or whatever. I got the idea of writing an extension method that could wrap my Task , and suppress the Exception type I would give it as argument. So I wrote this one: public static async Task Ignore<TException>(this Task task) where TException : Exception { try { await task; } catch (Exception ex) { if (ex is TException) return; throw; } } I can use

问题 So I am attempting to process records from a datatable one row at a time. I am new to multi-threaded environments and I was asked to use Parallel.Foreach Loop. I wanted to know how local variables are treated in a Parallel execution mode. Following is my code. Parallel.ForEach(dtReportData.Tables[0].AsEnumerable(), drow => { string strType = drow["type"]; //Based on this type, I am executing logic from a switch case. }); Now. I want to know if I can declare and assign value to the variable