threadpool

问题 I wonder where is the verge after which a thread pool should be used. How many new threads per second can I create without using a thread pool still avoiding noticeable performance penalty? Are there any observable open-source thread-pool implementations? 回答1: You should always use a thread pool. Not just for performance, but for the ease of use the java.util.concurrent package gives you. With Java 5 and later, thread pooling is built in. Instead of thinking in terms of 'threads', use the

问题 I want to create a fixed-size thread pool that admits no task into its queue. In other words, if the thread pool is currently in use, the incoming task should be rejected outright. Based on the documentation, one way to do this, in my opinion, would be to create a dummy Queue object which refuses to admit a task. What is the idiomatic way to accomplish this in Java? 回答1: You can use a SynchronousQueue in your ThreadPoolExector which is a queue which holds no objects. The cached thread pool

问题 Why the default value for CreationOptions of a Task created using Task.Run is DenyChildAttach rather than None ? Has it anything to do with making work with the new async and await in C# 5.0 simpler (by preventing you from escaping current scheduler of current context I guess)? 回答1: Stephen Toub explains this well in his blog post on the subject. Parent and child tasks are somewhat common when using Task s in a parallel fashion. Note that when a parent Task has a child, the parent's

问题 I want to make a practice with module ThreadPool,to add 2 for every element in range(1,100). from multiprocessing.pool import ThreadPool array=range(1,100) class test(): def myadd(self,x): return(x+2) do=ThreadPool(5) do.map(test.myadd,array) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "D:\Python34\lib\multiprocessing\pool.py", line 255, in map return self._map_async(func, iterable, mapstar, chunksize).get() File "D:\Python34\lib\multiprocessing\pool.py", line

问题 I created a mutable list called tickets that contains type Ticket. I also have a bookSeat function that imitates booking a seat.Since F# list type is immutable, my bookSeat function always returns a new, modified, copy of tickets list. open System open System.Threading type Ticket = {seat:int; customer:string} let mutable tickets = [for n in 1..10 -> {Ticket.seat = n; Ticket.customer = ""}] let bookSeat _ = Console.WriteLine("Enter seat number: ") let seatNo = int(Console.ReadLine()) Console

问题 In continuation with my problem here, I created a test app that uses ThreadPool threads to send emails. Here's the code I am using. protected void btnSend_Click(object sender, EventArgs e) { EmailInfo em = new EmailInfo { Body = "Test", FromEmail = "test@test.com", Subject = "Test Email", To = "test@test.com" }; //txtNumEmails is a textbox where I can enter number of emails to send for (int i = 0; i < Convert.ToInt32(this.txtNumEmails.Text); i++) { bool bResult = ThreadPool.QueueUserWorkItem

问题 This is a continuation of Prevent IIS from killing a Task before it ends My question: Given public static Task StartNew(Action act) { IISNotifier notif = new IISNotifier(); -> HostingEnvironment.RegisterObject(this); notif.Started(); return Task.Factory.StartNew(() => { act.Invoke(); notif.Finished(); -> HostingEnvironment.UnregisterObject(this); }); } Invoked by return new LogResult(id, IISTaskFactory.StartNew(() => DoLogInAzure(account, id, exception, request)) ); Example implementation

问题 I have previously used Jetty 8.1.14 as embedded web server in my application. Now I am trying to upgrade to version 9.2.10. With Jetty 8, it was possible to specify the Host Address and Port using the setters in the "SelectChannelConnector" or "SslSelectChannelConnector", and also the ThreadPool as a constructor argument in the "Server" class. Now, it seems one can only specify one or the other in the "Server" class. There are only constructor variants for the address and/or port, or the

问题 I create a thread using Thread t = new Thread(); t.start(); You start a thread using t.start(); Now how long the thread will be alive? To what state it will go after X (the answer of above question) seconds? Thread t = new Thread(); t.start(); public void run(){ System.out.println("Threads"); } What will happen if the thread has run() method? 回答1: A thread created and started exactly as you describe will be alive only for as long as the empty Thread.run() method takes to do nothing and return

问题 We are currently enhancing an ASP.NET app that performs quotes on a number of products. At present the existing quote engine is basically a big stored procedure (2-3 secs per call) followed by a small amount of business logic that runs after the procedure call. We are looking into multi-threading the call to each product in order to speed up a set of quotes. Our current approach is to encapsulate each product quote work in a ThreadPool thread. This seems to perform much better, but I'm a