threadpoolexecutor | 易学教程

ThreadPoolExecutor : Tasks are getting queued up and not submitted

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问题 We have a scenario where tasks submitted to ThreadPoolExecutor are long running. When the thread pool is started we start it with core pool size = 5, max pool size = 20 and queue size of 10. In our application around 10 tasks get submitted. Most of the time these tasks run for few mins/hrs and then complete. However there was a situation when all of the 5 tasks got hanged on I/O. As a result my core pool size reached it max, but my Threadpoolexecutor queue was not full. So the additional 5

Perform requests with Retrofit inside custom Runnable

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问题 I am migrating from Volley to a custom implementation using Retrofit , but I'm trying to add to my implementation some of the Volley features that I liked, for example RequestQueue.cancel(String tag) If the Request has the requested tag, then it's canceled by setting a boolean value, mCanceled , to true. The run method checks this value and returns if it's true. To be able to reproduce this with Retrofit I should be able to use my custom class implementing Runnable instead of the default one,

How to stop next thread from running in a ScheduledThreadPoolExecutor

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问题 I have a ScheduledThreadPoolExecutor which has one thread and runs for every 30 seconds. Now, if the current executing thread throws some exception, then I need to make sure that the next thread do not run and the the ScheduledThreadPoolExecutor is down. How do I achieve this? 回答1: As a clean way, you can simply use a static accessed class to set/check the execution availability. import java.util.concurrent.atomic.AtomicBoolean; class ThreadManager { private static AtomicBoolean shouldStop =

How to can I run adb screenrecord on a Android Device from Java and end the screenrecording?

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问题 How to can I run adb shell screenrecord on a Android Device from Java and end the screenrecording ? Currently I have to specify the --time-limit to end the recording. If I try to capture the video prior to it ending it fails. Is there a way to tell adb to stop recording? Is there a way to configure the thread to send a CTRL-C to the shell command? This is to be run on unrooted phones. Code videoExecutor.submit(() -> { //Start recording video String recordVideo = "screenrecord --time-limit " +

How to can I run adb screenrecord on a Android Device from Java and end the screenrecording?

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Testing PriorityBlockingQueue in ThreadPoolExecutor

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问题 I realized my ThreadPoolExecutor with PriorityBlockingQueue like in this example: https://stackoverflow.com/a/12722648/2206775 and wrote a test: PriorityExecutor executorService = (PriorityExecutor) PriorityExecutor.newFixedThreadPool(16); executorService.submit(new Runnable() { @Override public void run() { try { Thread.sleep(1000); Thread.sleep(1000); System.out.println("1"); } catch (InterruptedException e) { e.printStackTrace(); } } }, 1); executorService.submit(new Runnable() { @Override

Unable to get CallableThread in RejectionHandler

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问题 I have thread pool, which will take Callable worker thread with a RejectionHandler . I need to get this Callable task in RejectionHandler but unable to get it. In this below example, I need uniqueId of Callable task for which RejectionHandler executed. In RejecitonHandler , the Runnable is casted FutureTask where I expect that it should be casted to Callable worker thread. Please help me in getting Callable Worker thread instance in RejectionHandler . import java.util.Random; import java.util

Avoiding RejectedExecutionException in Android 4.4 when app uses list

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问题 In Android 4.4 there seems to be a change in the code that causes list icons to be loaded using AsyncTasks. The result is that many of my users on Android 4.4 get RejectedExecutionException since the queue size limit is exceeded. A clever user at Code Google discovered this, and explained it in this way: ResolverActivity will throw RejectedExecutionException on Android 4.4. I viewed the code of latest ResolverActivity and noticed that in ResolveListAdapter.bindView method it is using new

Impossible to make a cached thread pool with a size limit?

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问题 It seems to be impossible to make a cached thread pool with a limit to the number of threads that it can create. Here is how static Executors.newCachedThreadPool is implemented in the standard Java library: public static ExecutorService newCachedThreadPool() { return new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>()); } So, using that template to go on to create a fixed sized cached thread pool: new ThreadPoolExecutor(0, 3, 60L, TimeUnit

ThreadPoolExecutor源码详解

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 我之前一篇文章谈到了ThreadPoolExecutor的作用（ http://my.oschina.net/xionghui/blog/494004 ），这篇文章介绍下它的原理，并根据原理分析下它的实现源码。我们先来查看一下ThreadPoolExecutor API，看看它能实现什么功能，然后看看它是怎么实现这些功能的。 ThreadPoolExecutor API ThreadPoolExecutor API比较长，这里列出几个关键点：核心和最大池大小：如果运行的线程少于 corePoolSize，则创建新线程来处理请求（即一个Runnable实例），即使其它线程是空闲的。如果运行的线程多于 corePoolSize 而少于 maximumPoolSize，则仅当队列满时才创建新线程。保持活动时间：如果池中当前有多于 corePoolSize 的线程，则这些多出的线程在空闲时间超过 keepAliveTime 时将会终止。排队：如果运行的线程等于或多于 corePoolSize，则 Executor 始终首选将请求加入队列BlockingQueue，而不添加新的线程。被拒绝的任务：当 Executor 已经关闭，或者队列已满且线程数量达到 maximumPoolSize时（即线程池饱和了）