threadpool

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, and which one would perform better. Option 1 is to use the simple way: THREAD_POOL = Executors

I am pretty new to multithreading, and I am working on a project where I am trying to utilize 4 CPUs in my Java program. I wanted to do something like int numProcessors = Runtime.getRuntime().availableProcessors(); ExecutorService e = Executors.newFixedThreadPool(numProcessors); Will this guarantee that I will have one thread working per CPU? At the time that I create the threads, the system will not be busy, however some time afterwards it will be extremely busy. I thought that the OS will pick the least busy CPU to create the threads, but how does it work if none of them are particularly

There are a huge amount of tasks. Each task is belong to a single group. The requirement is each group of tasks should executed serially just like executed in a single thread and the throughput should be maximized in a multi-core (or multi-cpu) environment. Note: there are also a huge amount of groups that is proportional to the number of tasks. The naive solution is using ThreadPoolExecutor and synchronize (or lock). However, threads would block each other and the throughput is not maximized. Any better idea? Or is there exist a third party library satisfy the requirement? A simple approach

Suppose, I don't set any values explicitly by calling the function: System.Threading.ThreadPool.SetMaxThreads What are the default values? It depends on the .NET framework version, changed in 2.0, 3.0 and 4.0. In 2.0 it was 50 times the number of cores. In 3.0 (aka 2.0 SP1) it was 250 times the number of cores, 4.0 made it dynamic depending on bitness and OS resources. Max I/O completion threads was always 1000 if I remember correctly. In general, it is insanely high and a program should never get close. On a 32-bit machine, the program is pretty likely to bomb with OOM first when all of those

When working with tasks, a rule of thumb appears to be that the thread pool - typically used by e.g. invoking Task.Run() , or Parallel.Invoke() - should be used for relatively short operations. When working with long running operations, we are supposed to use the TaskCreationOptions.LongRunning flag in order to - as far as I understand it - avoid clogging the thread pool queue, i.e. to push work to a newly-created thread. But what exactly is a long running operation? How long is long, in terms of time? Are there other factors besides the expected task duration to be considered when deciding

背景 当系统中的业务存在大量的相同任务（比如发送大量邮件），并且每个任务花费的时间也比较长，前端需要较快 的响应，针对这种需求，我们可以采用消息队列进行异步通知，同时也可以采用线程池+内存队列实现异步通知，处理业务问题。 代码实现 以下采用发送邮件作为demo 邮箱实体类 @Data public class Email implements Serializable { private static final long serialVersionUID = 1L; /** * 自增主键 */ private Long id; /** * 接收人邮箱(多个逗号分开) */ private String receiveEmail; /** * 主题 */ private String subject; /** * 发送内容 */ private String content; /** * 模板 */ private String template; /** * 发送时间 */ private Timestamp sendTime; } 邮件队列 public class MailQueue { //队列大小 static final int QUEUE_MAX_SIZE = 1000; static BlockingQueue<Email> blockingQueue = new