threadpool | 易学教程

谈一谈linux下线程池

阅读更多关于谈一谈linux下线程池

什么是线程池：　　　　首先，顾名思义，就是把一堆开辟好的线程放在一个池子里统一管理，就是一个线程池。　　其次，为什么要用线程池，难道来一个请求给它申请一个线程，请求处理完了释放线程不行么？也行，但是如果创建线程和销毁线程的时间比线程处理请求的时间长，而且请求很多的情况下，我们的CPU资源都浪费在了创建和销毁线程上了，所以这种方法的效率比较低，于是，我们可以将若干已经创建完成的线程放在一起统一管理，如果来了一个请求，我们从线程池中取出一个线程来处理，处理完了放回池内等待下一个任务，线程池的好处是避免了繁琐的创建和结束线程的时间，有效的利用了CPU资源。　　按照我的理解，线程池的作用和双缓冲的作用类似，可以完成任务处理的“鱼贯”动作。　　最后，如何才能创建一个线程池的模型呢，一般需要以下三个参与者：　　　　1、线程池结构，它负责管理多个线程并提供任务队列的接口　　　　2、工作线程，它们负责处理任务　　　　3、任务队列，存放待处理的任务　　有了三个参与者，下一个问题就是怎么使线程池安全有序的工作，可以使用POSIX中的信号量、互斥锁和条件变量等同步手段。有了这些认识，我们就可以创建自己的线程池代码示例如下： #include <stdlib.h> #include <pthread.h> #include <unistd.h> #include <assert.h>

C# Task详解 https://www.cnblogs.com/zhaoshujie/p/11082753.html

阅读更多关于 C# Task详解 https://www.cnblogs.com/zhaoshujie/p/11082753.html

C# Task详解 https://www.cnblogs.com/zhaoshujie/p/11082753.html 1、Task的优势　　ThreadPool相比Thread来说具备了很多优势，但是ThreadPool却又存在一些使用上的不方便。比如：　　◆ ThreadPool不支持线程的取消、完成、失败通知等交互性操作；　　◆ ThreadPool不支持线程执行的先后次序；　　以往，如果开发者要实现上述功能，需要完成很多额外的工作，现在，FCL中提供了一个功能更强大的概念：Task。Task在线程池的基础上进行了优化，并提供了更多的API。在FCL4.0中，如果我们要编写多线程程序，Task显然已经优于传统的方式。　　以下是一个简单的任务示例： using System; using System.Threading; using System.Threading.Tasks; namespace ConsoleApp1 { class Program { static void Main(string[] args) { Task t = new Task(() => { Console.WriteLine("任务开始工作……"); //模拟工作过程 Thread.Sleep(5000); }); t.Start(); t.ContinueWith((task

如何写个死循环，既不独占线程，又不阻塞UI线程？

阅读更多关于如何写个死循环，既不独占线程，又不阻塞UI线程？

如果死循环独占线程，500个死循环要占用500个线程，如果死循环不独占线程，500个死循环，用200个线程也行，用20个线程也行，无非是执行的慢点这样可以把同步操作改写为异步，并且节省线程占用出个题：写个Socket服务端，接收数据不准用BeginReceive和ReceiveAsync，只能用Receive，Socket客户端10000个，线程池最大不准超过1000，如何实现？代码： using System; using System.Text; using System.Threading; using System.Threading.Tasks; using System.Windows.Forms; using Utils; /* * * 如何写个死循环，既不独占线程，又不阻塞UI线程 * * * */ namespace test { public partial class Form1 : Form { private int _n = 0 ; private System.Windows.Forms.Timer _timer = null ; private bool _run1 = false ; private bool _run2 = false ; public Form1() { InitializeComponent(); _timer =

Multithread Spring-boot controller method

阅读更多关于 Multithread Spring-boot controller method

问题 So my application (spring-boot) runs really slow as it uses Selenium to scrap data, processes it and displays in the home page. I came across multithreading and I think it can be useful to my application to allow it to run faster, however the tutorials seem to display in the setting of a normal java application with a main. How can I multithread this single method in my controller? The methods get.. are all selenium methods. I'm looking to run these 4 lines of code simultaneously @Autowired

Progress Bar Does not Render Until Job is Complete

阅读更多关于 Progress Bar Does not Render Until Job is Complete

问题 I am trying to make a progress bar for copying large files. However, currently the Dialog window goes black until the process is finished. I now understand I probably have to learn how to use treads and pass the data back into the GUI. But I still don't understand why the window fails to render completely. I'd understand if the window was unresponsive because the moveFilesWithProgress function is running. But within that function I am updating the progress bar value. I even tried adding QtGui

Boost asio thread_pool join does not wait for tasks to be finished

阅读更多关于 Boost asio thread_pool join does not wait for tasks to be finished

问题 Consider the functions #include <iostream> #include <boost/bind.hpp> #include <boost/asio.hpp> void foo(const uint64_t begin, uint64_t *result) { uint64_t prev[] = {begin, 0}; for (uint64_t i = 0; i < 1000000000; ++i) { const auto tmp = (prev[0] + prev[1]) % 1000; prev[1] = prev[0]; prev[0] = tmp; } *result = prev[0]; } void batch(boost::asio::thread_pool &pool, const uint64_t a[]) { uint64_t r[] = {0, 0}; boost::asio::post(pool, boost::bind(foo, a[0], &r[0])); boost::asio::post(pool, boost:

Setting limit on post queue size with Boost Asio?

阅读更多关于 Setting limit on post queue size with Boost Asio?

问题 I'm using boost::asio::io_service as a basic thread pool. Some threads get added to io_service, the main thread starts posting handlers, the worker threads start running the handlers, and everything finishes. So far, so good; I get a nice speedup over single-threaded code. However, the main thread has millions of things to post. And it just keeps on posting them, much faster than the worker threads can handle them. I don't hit RAM limits, but it's still kind of silly to be enqueuing so many

What happens to the ThreadPoolExecutor when thread dies in Java

阅读更多关于 What happens to the ThreadPoolExecutor when thread dies in Java

问题 I have created a thread which in turn creates a ThreadPoolExecutor and submits some long running tasks to it. At some point, the original thread dies due to unhandled exception/error. What should happen to the executor (it's local to that dead thread, no external references to it)? Should it be GCed or not? EDIT: this question was formulated incorrectly from the beginning, but I will leave it as Gray provided some good details of how TPE work. 回答1: Threads are so called GC roots. This means

threadpool c++ implementation questions

阅读更多关于 threadpool c++ implementation questions

问题 here and here , we can see similar threadpool implementations. my question is about function to add the task to threadpool, these are add and enqueue in projects above respectively. because these look very similar I'm posting a piece of one here (from second project) auto ThreadPool::enqueue(F&& f, Args&&... args) -> std::future<typename std::result_of<F(Args...)>::type> { using return_type = typename std::result_of<F(Args...)>::type; auto task = std::make_shared< std::packaged_task<return

threadpool c++ implementation questions

阅读更多关于 threadpool c++ implementation questions

订阅 threadpool