Reactor-异步/非阻塞

Question

我认为下面的流量链将通过事件循环放置/执行（像JS）。因此，运行下面的代码将首先打印阻塞for循环&然后将执行通量链。

但是，整个通量总是先执行，然后才移动到for循环。[我确实有一些sleep语句正在阻塞。但是有两个doonnext阶段]

AtomicInteger atomicInteger = new AtomicInteger(0);

// reactor
Flux.generate(synchronousSink -> {
            if (atomicInteger.incrementAndGet() < 3) {
                synchronousSink.next(atomicInteger.get());
            } else
                synchronousSink.complete();
    })
    .doOnNext(i -> {
        System.out.println(
                "A - Received " + i + " by " + Thread.currentThread().getName()
        );
        sleep(Duration.ofSeconds(1));
    }).doOnNext(i -> {
        System.out.println(
                "B - Received " + i + " : by " + Thread.currentThread().getName()
        );
        sleep(Duration.ofSeconds(1));
    }).subscribe();


for (int i = 0; i < 5; i++) {
    System.out.println("For " + i + " by " + Thread.currentThread().getName());
    sleep(Duration.ofMillis(500));
}

A - Received 1 by main
B - Received 1 by main
A - Received 2 by main
B - Received 2 by main
For 0 by main
For 1 by main
For 2 by main
For 3 by main
For 4 by main

1. 当我们使用reactor时，通过使用一些调度程序来实现异步/非阻塞行为的唯一方法？
2. 如果我不使用任何调度器，并让代码使用当前线程执行，那么即使对于IO密集型应用程序，使用WebFlux而不是Spring MVC还能有更好的性能差异吗？

Answer 1

1. 线程阻塞不是反应器用法的正确用法。要使其以非阻塞方式工作，您应该使用publishon/subscribeon，然后输出为:

For 0 by main
A - Received 1 by boundedElastic-3
For 1 by main
For 2 by main
B - Received 1 : by boundedElastic-3
For 3 by main
For 4 by main
A - Received 2 by boundedElastic-3

有关publishon与subscribeon的详细信息，请参阅：链接