我有一个执行器服务,它可以同时提交 x 个线程来执行一项长任务。我需要能够停止所有当前正在运行的线程并防止排队任务启动。我正在尝试实现一种方法来处理正在等待同步方法的停止线程,其中可运行对象将字符串列表传递回调用它的接口(interface)。
@Override
public synchronized void FilterResults(List<String> Results) {
//System.out.println("Result found: " + Results.size());
try {
Set<String> hs = new HashSet<>();
hs.addAll(Results);
Results.clear();
Results.addAll(hs);
for (String tempURL : Results) {
//System.out.println("Found url: " + tempURL);
if (!isCompleted(tempURL) && !isQueued(tempURL) && !isRunning(tempURL)) {
System.out.println("Added: " + tempURL + " to queue.");
queueLink(tempURL);
startNewThread(tempURL);
}
}
}catch(Exception e) {
}
return;
}
private synchronized void startNewThread(String seedURL) {
if (!isCompleted(seedURL) && !isRunning(seedURL) ) {
if (completedSize("") + runningSize() > 99) {
Stop();
}
String tempProxy = "";
String tempPort = "";
if (UseProxies) {
String Proxy = grabFreeProxy();
String[] splitProxy = Proxy.split(":");
tempProxy = splitProxy[0]; // 004
tempPort = splitProxy[1]; // 034556
}
//System.out.println("Proxy: " + tempProxy);
//System.out.println("Port: " + tempPort);
execService.submit(new Crawl(seedURL, this, tempProxy, tempPort, UseProxies));
removeFromQueue(url);
}
}
@Override
public Collection<String> Stop() {
try {
execService.shutdown();
if (execService.awaitTermination(45, TimeUnit.SECONDS)) {
System.out.println("task completed");
} else {
execService.shutdownNow();
}
} catch (InterruptedException e) {
}
return PROFILES;
}
The Runnable
public class Crawl implements Runnable{
public void run() {
while(!Thread.currentThread().isInterrupted() && shutdown == false) {
try {
//System.out.println(crawler.queueSize());
Thread.sleep(100);
Crawl(url);
}catch (InterruptedException e) {
Thread.currentThread().interrupt(); // set interrupt flag
}
}
public void crawl(){
try {
submitResults(urls); //Calls FilterResults()
} catch (InterruptedException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
Thread.currentThread().interrupt();
}
crawler.removeUsedProxy(Proxy + ":" + Port);
this.shutdown();
}
}
当我调用关闭方法时,需要 45 秒以上,是否有办法可靠地取消任务而无需长时间等待?随着线程数量的增加,这个数字也会增加,并且由于所有线程都在阻塞等待提交结果,因此可能需要一些时间。如果我手动取消任务,我不在乎结果是否已存储,我只需要能够取消即可。有什么想法吗?
Update I've tried
ExecutorService#shutdownNow
. It has not been reliable when it comes to killing the tasks that are still blocked on thesynchronized
method.
最佳答案
看起来您需要使用 ExecutorService#shutdownNow
如果您不想等待并完成所有工作,您将收到一个包含未执行任务的列表。您可以使用ExecutionService#awaitTermination
(参数不超过 45 秒)如果您想要/需要提供等待任务完成的时间。
关于java - Executors.newFixedThreadPool 如何停止同步方法上的所有 Activity 线程,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51271805/