如何從期貨＃awaitAll的結果中獲得一些（x）？

Question

全部。

我寫了下面簡單的代碼來測試scala.actors._：

// java version "1.7.0_02" 
// Scala code runner version 2.9.1.final 
// Windows 7 Ultimate sp1 64-bit 
import scala.actors._ 
import scala.collection.mutable.ArrayBuffer 

object FutureResults extends App { 
    val t1 = System.currentTimeMillis 
    val (timeout, results) = (1000, new ArrayBuffer[Future[_]]) 
    for (i <- 0 until 3) results += new FutureResultsActor !! "execute" 
    val options = Futures awaitAll (timeout, results:_*) 

    val t2 = System.currentTimeMillis 
    println("spent: %,d ms" format t2 - t1) 
    options foreach println 
    results foreach { i => println("isSet: %b" format i.isSet) } 

    Thread sleep timeout 

    val t3 = System.currentTimeMillis 
    println("spent: %,d ms" format t3 - t1) 
    options foreach println 
    results foreach { i => println("isSet: %b" format i.isSet) } 
} 

class FutureResultsActor extends Actor { 
    start 
    override def act = react { case "execute" => Futures future "done" } 
} 

這將產生：

spent: 1,092 ms 
None 
None 
None 
isSet: false 
isSet: false 
isSet: false 

spent: 2,137 ms 
None 
None 
None 
isSet: false 
isSet: false 
isSet: false 

期貨Scaladoc的＃awaitAll說：

The result of a future that resolved during the time span is its value wrapped in Some. 
The result of a future that did not resolve during the time span is None. 

是超時值太小？好吧，我將該值更改爲5000毫秒，然後重試：

spent: 5,070 ms 
None 
None 
None 
isSet: false 
isSet: false 
isSet: false 

spent: 10,093 ms 
None 
None 
None 
isSet: false 
isSet: false 
isSet: false 

全部爲無。爲什麼？...

如何從期貨＃awaitAll的結果中獲得一些（x）？

有沒有不正確的代碼？

Answer 1

事實上，他們都超時。非常悲劇！原因是：你沒有發送演員的回覆，或者至少沒有正確回覆。我真的不知道什麼是「期貨未來」是，但是......我的理解是正確的方式從內部的演員是像這樣回覆：

class FutureResultsActor extends Actor { 
    start 
    override def act = react { case "execute" => reply("done") } // Use reply()! 
} 

做這讓我這樣的結果：

spent: 150 ms 
Some(done) 
Some(done) 
Some(done) 
isSet: true 
isSet: true 
isSet: true 
spent: 1,165 ms 
Some(done) 
Some(done) 
Some(done) 
isSet: true 
isSet: true 
isSet: true