我想弄清楚如何跟踪我的应用程序生成的所有线程。最初,我以为我已经使用 CyclicBarrier 解决了这个问题,但是我看到线程在我的 await 调用之后执行。
下面是工作伪代码:
public class ThreadTesterRunner {
public static void main(String[] args) throws InterruptedException {
final CyclicBarrier cb = new CyclicBarrier(1);
ThreadRunner tr = new ThreadRunner(cb);
Thread t = new Thread(tr, "Thread Runner");
t.start();
boolean process = true;
// wait until all threads process, then print reports
while (process){
if(tr.getIsFinished()){
System.out.println("Print metrics");
process = false;
}
Thread.sleep(1000);
}
}
}
class ThreadRunner implements Runnable {
static int timeOutTime = 2;
private ExecutorService executorService = Executors.newFixedThreadPool(10);
private final CyclicBarrier barrier;
private boolean isFinished=false;
public ThreadRunner(CyclicBarrier cb) {
this.barrier = cb;
}
public void run(){
try {
boolean stillLoop = true; int i = 0;
while (stillLoop){
int size;
Future<Integer> future = null;
try {
future = executorService.submit(new Reader()); // sleeps
size = future.get();
} catch (InterruptedException | ExecutionException ex) {
// handle Errs
}
if(i == 3){
stillLoop = false;
this.barrier.await();
this.isFinished=true;
}
//System.out.println("i = "+i+" Size is: "+size+"\r");
i++;
}
} catch (InterruptedException | BrokenBarrierException e1) {
e1.printStackTrace();
}
}
public boolean getIsFinished(){
return this.isFinished;
}
}
class Reader implements Callable {
private ExecutorService executorService = Executors.newFixedThreadPool(1);
@Override
public Object call() throws Exception {
System.out.println("Reading...");
Thread.sleep(2000);
executorService.submit(new Writer());
return 1000;
}
}
class Writer implements Callable {
@Override
public Void call() throws Exception {
Thread.sleep(4000);
System.out.println("Wrote");
return null;
}
}
谁能建议一种在所有线程运行后只打印“打印指标”的方法?
最佳答案
您似乎没有做任何事情来协调您的 Reader
和 Writer
线程,而这正是您要等待的线程。如果您将同步屏障传递给这些线程,以便它们可以在完成时注册并发出信号,那么它就可以正常工作。
这是为此重写的版本,使用 Phaser
而不是 CyclicBarrier
。请注意,每个 Reader
和 Writer
在构造时注册自己,并在执行完成时通知同步屏障:
public class ThreadTesterRunner {
public static void main(String[] args) throws InterruptedException {
final Phaser cb = new Phaser();
ThreadRunner tr = new ThreadRunner(cb);
Thread t = new Thread(tr, "Thread Runner");
t.start();
boolean process = true;
// wait until all threads process, then print reports
while (process){
if(tr.getIsFinished()){
System.out.println("Print metrics");
process = false;
}
//else {
// System.out.println("Waiting: registered=" + cb.getRegisteredParties() + ", arrived=" + cb.getArrivedParties() + ", unarrived=" + cb.getUnarrivedParties());
//}
Thread.sleep(1000);
}
}
}
class ThreadRunner implements Runnable {
static int timeOutTime = 2;
private ExecutorService executorService = Executors.newFixedThreadPool(10);
private final Phaser barrier;
private boolean isFinished=false;
public ThreadRunner(Phaser phaser) {
this.barrier = phaser;
}
public void run(){
try {
boolean stillLoop = true; int i = 0;
while (stillLoop){
int size;
Future<Integer> future = null;
try {
future = executorService.submit(new Reader(this.barrier)); // sleeps
size = future.get();
} catch (InterruptedException | ExecutionException ex) {
// handle Errs
}
if(i == 3){
stillLoop = false;
this.barrier.awaitAdvance(0);
this.isFinished=true;
}
//System.out.println("i = "+i+" Size is: "+size+"\r");
i++;
}
} catch (Exception e1) {
e1.printStackTrace();
}
}
public boolean getIsFinished(){
return this.isFinished;
}
}
class Reader implements Callable {
private Phaser barrier;
private ExecutorService executorService = Executors.newFixedThreadPool(1);
public Reader(Phaser phase) {
phase.register();
this.barrier = phase;
}
@Override
public Object call() throws Exception {
System.out.println("Reading...");
Thread.sleep(2000);
executorService.submit(new Writer(this.barrier));
this.barrier.arrive();
return 1000;
}
}
class Writer implements Callable {
private Phaser barrier;
public Writer(Phaser phase) {
phase.register();
this.barrier = phase;
}
@Override
public Void call() throws Exception {
Thread.sleep(4000);
System.out.println("Wrote");
this.barrier.arrive();
return null;
}
}
关于java - 跟踪执行线程,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23165042/