threadpool

Multiprocessing pool 'apply_async' only seems to call function once

由 断了今生、忘了曾经 提交于 2019-12-21 02:01:31
问题 I've been following the docs to try to understand multiprocessing pools. I came up with this: import time from multiprocessing import Pool def f(a): print 'f(' + str(a) + ')' return True t = time.time() pool = Pool(processes=10) result = pool.apply_async(f, (1,)) print result.get() pool.close() print ' [i] Time elapsed ' + str(time.time() - t) I'm trying to use 10 processes to evaluate the function f(a) . I've put a print statement in f . This is the output I'm getting: $ python pooltest.py f

Optimal way of creating a fixed size thread pool in Java using the Executors service

由 谁都会走 提交于 2019-12-21 01:19:35
问题 I am using the Executors framework in Java to create thread pools for a multi-threaded application, and I have a question related to performance. I have an application which can work in realtime or non-realtime mode. In case it's realtime, I'm simply using the following: THREAD_POOL = Executors.newCachedThreadPool(); But in case it's not realtime, I want the ability to control the size of my thread pool. To do this, I'm thinking about 2 options, but I don't really understand the difference,

Is the max thread limit actually a non-relevant issue for Python / Linux?

由 百般思念 提交于 2019-12-20 11:56:09
问题 The current Python application that I'm working on has a need to utilize 1000+ threads (Pythons threading module). Not that any single thread is working at max cpu cycles, this is just a web server load test app I'm creating. I.E. emulate 200 firefox clients all longing into web server and downloading small web components, basically emulating humans that operate in seconds as opposed to microseconds. So, I was reading through the various topics such as "how many threads does python support on

Why doesn't Ruby have a ThreadPool built-in?

由 送分小仙女□ 提交于 2019-12-20 10:25:22
问题 I have a program that creates 10000 threads at once, and runs 8 at the same time. But ruby doesn't have a ThreadPool built-in as Java. Is there a good reason? 回答1: Most likely the reason is because ruby doesn't have "real" threads. It has what are called Green threads. The ruby interpreter takes care of scheduling execution threads without using any underlying OS threads. This effectively makes Ruby single threaded. 回答2: probably because it's easy to roll your own using the standard library

Java Threadpool vs. new Thread in high request scenario

由 ε祈祈猫儿з 提交于 2019-12-20 10:08:28
问题 I have some old java code for a REST service that uses a separate thread for every incoming request. I.e. the main loop would loop on socket.accept() and hand off the socket to a Runnable which then would start up its own background thread and invoke run on itself. This worked admiringly well for a while until recently i noticed that the lag of accept to processing the request would get unacceptable under high load. When i say admiringly well, i mean that it was handling 100-200 requests a

How do you get list of running threads in C#?

由 限于喜欢 提交于 2019-12-20 09:24:39
问题 I create dynamic threads in C# and I need to get the status of those running threads. List<string>[] list; list = dbConnect.Select(); for (int i = 0; i < list[0].Count; i++) { Thread th = new Thread(() =>{ sendMessage(list[0]['1']); //calling callback function }); th.Name = "SID"+i; th.Start(); } for (int i = 0; i < list[0].Count; i++) { // here how can i get list of running thread here. } How can you get list of running threads? 回答1: Create a List<Thread> and store each new thread in your

Types of Thread Pools in java [closed]

由 牧云@^-^@ 提交于 2019-12-20 09:13:32
问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 6 years ago . What are the types of thread pools in java. I need to implement a robust multi-threaded application which uses heavy computation, which thread pool should I use? 回答1: There are various thread pools in java: Single Thread Executor : A thread pool with only one thread. So all the

如何在动态链接库dll/so中导出自定义的模板类template class

由 爱⌒轻易说出口 提交于 2019-12-20 08:32:07
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 本文首发于个人博客 https://kezunlin.me/post/4ec4ae49/ ，欢迎阅读最新内容！ how to implement a template class with c++ and export in dll/so <!--more--> Guide questions 模板类必须在header中实现，而不能在cpp中实现，否则作为dll调用进行链接的时候回出错。 common solutions(Recommend) implement template functions in header. ThreadPool.h class SHARED_EXPORT ThreadPool { public: static ThreadPool* Instance(size_t max_thread_pool_size); ~ThreadPool(); // Add new work item to the pool. template<class F> inline void Enqueue(F f) { io_service_.post(f);//sync, return immediately } void Free(); private: static std::shared_ptr

terminate called after throwing an instance of 'std::system_error' threadpool

由 ☆樱花仙子☆ 提交于 2019-12-20 06:34:14
问题 When I run my code : nb workers = 12 I'm i : 0 HELLO I'm func1 BYE I'm func2 terminate called after throwing an instance of 'std::system_error' what(): Invalid argument Aborted (core dumped) terminate called after throwing an instance of 'std::system_error'l what(): Invalid argument #ifndef CPP_PLAZZA_EXAMPLE_H #define CPP_PLAZZA_EXAMPLE_H #include <thread> #include <vector> #include <list> #include <memory> #include <functional> #include <mutex> #include <condition_variable> #include <atomic

NLog FileTarget wrapped with BufferingTargetWrapper fails to write log if there is a delay

由 戏子无情 提交于 2019-12-20 04:07:42
问题 I may have stumbled across an issue with NLog, but thought I would check here first for an answer: To recreate the issue I cloned the NLog source so I could add a delay to cause the problem. Once open in visual studio, I added a console application that references the NLog source projects and makes some very simple log calls. The NLog.config is as follows: <nlog> <targets> <target name="buffer" type="BufferingWrapper"> <target name="logfile" type="File" fileName="log.txt"/> </target> <
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