multithreading - Scala:唤醒 sleep 线程

Question

在scala中，我如何告诉线程: sleep t秒钟，或直到收到消息？也就是说，最多只能睡t秒钟，但是如果t尚未结束，您会醒来，并且您会收到一条特定的消息。

Answer 1

或者，您可以使用条件变量。

val monitor = new AnyRef
var messageReceived: Boolean = false

// The waiting thread...

def waitUntilMessageReceived(timeout: Int): Boolean = {
    monitor synchronized {
        // The time-out handling here is simplified for the purpose
        // of exhibition. The "wait" may wake up spuriously for no
        // apparent reason. So in practice, this would be more complicated,
        // actually.
        while (!messageReceived) monitor.wait(timeout * 1000L)
        messageReceived
    }
}

// The thread, which sends the message...

def sendMessage: Unit = monitor synchronized {
    messageReceived = true
    monitor.notifyAll
}