1、ArrayBlockingQueue https://blog.csdn.net/qq_23359777/article/details/70146778
2、CopyOnWriteArrayList https://blog.csdn.net/hua631150873/article/details/51306021
Semaphore <used to avoid blocking caused by thread preemption>
If there are three pick-up windows to pick up meals and five people come to eat, then two people must be in a waiting state. Only those who know that the first three people have left the follow-up can pick up the meal. // code example
public static void main() {
ExecutorService service = Executors.newFixedThreadPool(3);
final Semaphore semaphore = new Semaphore(3);
for (int i = 0; i < 5; i++) {
service.submit(new Runnable() {
@Override
public void run() {
try {
semaphore.acquire(); System.out
.println ( "Permits remaining = " + semaphore .availablePermits());
Thread.sleep(1000);
semaphore.release();
} catch (InterruptedException e) {
e.printStackTrace ();
}
}
});
}
}
A round-robin fence allows a group of threads to wait on each other until some common barrier point is reached.
/**
* 循环栅栏 zhalan
*/
public static class CyclicBarrierTest {
private static final int SIZE = 5;
private static CyclicBarrier cyclicBarrier;
public static void main(String[] args) {
cyclicBarrier = new CyclicBarrier(SIZE, new Runnable() {
@Override
public void run() {
System.out .println ( "--> Satisfy the condition <-- " + cyclicBarrier .getParties ());
}
});
for (int i = 0; i < 5; i++) {
new Work().start();
}
}
static class Work extends Thread{
@Override
public void run() {
super.run();
System.out.println(Thread.currentThread().getName() + "等待 CyclicBarrier");
try {
cyclicBarrier.await();System.out.println(Thread.currentThread(). getName
( ) + "Continue to execute" );
} catch (InterruptedException e) {
e.printStackTrace ();
} catch (BrokenBarrierException e) {
e.printStackTrace ();
}
}
}
}
Thread- 3 waits for CyclicBarrier Thread- 2 waits for CyclicBarrier Thread- 1 waits for CyclicBarrier Thread- 4 wait for CyclicBarrier Thread- 5 waiting for CyclicBarrier --> Satisfy the condition <-- 5 Thread- 4 continue to execute Thread- 2 continues execution Thread- 1 continues execution Thread- 3 continues execution Thread- 5 continues execution
latch <allows one or more threads to wait until a condition is met>
/**
* 闭锁
*/
public static class CountDownLatchTest {
private static final int SIZE = 5;
public static void main(String[] args) throws InterruptedException {
CountDownLatch latch = new CountDownLatch(SIZE);
for (int i = 0; i < 5; i++) {
new Work(latch).start();
}
System.out.println ( " Main thread waiting" );
latch.await();
System.out.println ( " Main thread continues to execute" );
}
static class Work extends Thread{
CountDownLatch latch;
Work( CountDownLatch latch){
this.latch = latch;
}
@Override
public void run() {
super.run();
try {
Thread.sleep(1000);
System.out.println(Thread.currentThread().getName() + " 执行操作");
latch.countDown();
} catch (InterruptedException e) {
e.printStackTrace ();
}
}
}
}
main thread waiting Thread- 4 performs the operation Thread- 1 performs the operation Thread- 3 performs the operation Thread- 5 performs the operation Thread- 2 performs the operation The main thread continues to execute