Java多线程并发编程中常见问题实例

原创阳光穿透心脏的1/2处 2024-09-24 14:15 106阅读 0赞

在Java多线程并发编程中，常见的问题有很多，以下是一些实例：

1. 竞态条件（Race Condition）：
```java
class Counter {
    int count = 0;
    
    synchronized void increment() {
        count++;
    }
    
    synchronized int decrement() {
        count--;
        return count;
    }
}

// 两个线程并发访问Counter
Thread thread1 = new Thread(() -> Counter.count = counter.increment()));
Thread thread2 = new Thread(() -> System.out.println(Counter.count) // 可能打印0，取决于同步执行

```
2. 死锁（Deadlock）：
```java
class BankAccount {
    int balance;
    
    synchronized void deposit(int amount) {
        balance += amount;
    }
    
    synchronized void withdraw(int amount) throws InterruptedException {
        if (amount > balance) {
            throw new InterruptedException("Insufficient balance");
        }
        balance -= amount;
    }
}

// 两个线程相互依赖，可能导致死锁
Thread thread1 = new Thread(() -> account.deposit(100)));
Thread thread2 = new Thread(() -> account.withdraw(50)));

```
3. 异步操作（Asynchronous Operations）：
```java
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

class LongRunningTask implements Runnable {
    @Override
    public void run() {
        try {
            // 模拟耗时操作
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Long running task completed");
    }
}

// 使用线程池实现异步任务
ExecutorService executor = Executors.newFixedThreadPool(5);
executor.execute(new LongRunningTask());
executor.shutdown();

```
这些实例涵盖了Java多线程并发编程中的常见问题。理解和解决这些问题对于编写高效、可靠的并发程序至关重要。