perf: avoid double checking value0 Future.

He-Pin · He-Pin · commit fbd326dc19fb · 2025-01-03T16:47:55.000+08:00
diff --git a/src/library/scala/concurrent/package.scala b/src/library/scala/concurrent/package.scala
@@ -125,6 +125,9 @@ package object concurrent {
 }
 
 package concurrent {
+
+  import scala.util.Try
+
   /**
    * This marker trait is used by [[Await]] to ensure that [[Awaitable.ready]] and [[Awaitable.result]]
    * are not directly called by user code. An implicit instance of this trait is only available when
@@ -170,7 +173,7 @@ package concurrent {
     @throws(classOf[TimeoutException])
     @throws(classOf[InterruptedException])
     final def ready[T](awaitable: Awaitable[T], atMost: Duration): awaitable.type = awaitable match {
-      case f: Future[T] if f.isCompleted => awaitable.ready(atMost)(AwaitPermission)
+      case f: Future[T] if f.isCompleted => awaitable
       case _ => blocking(awaitable.ready(atMost)(AwaitPermission))
     }
 
@@ -197,8 +200,12 @@ package concurrent {
     @throws(classOf[TimeoutException])
     @throws(classOf[InterruptedException])
     final def result[T](awaitable: Awaitable[T], atMost: Duration): T = awaitable match {
-      case f: Future[T] if f.isCompleted => f.result(atMost)(AwaitPermission)
+      case CompletedFuture(result) => result.get
       case _ => blocking(awaitable.result(atMost)(AwaitPermission))
     }
+
+    private final object CompletedFuture {
+      def unapply[T](f: Future[T]): Option[Try[T]] = f.value
+    }
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -125,6 +125,9 @@ package object concurrent {`
`125`	`125`	`}`
`126`	`126`
`127`	`127`	`package concurrent {`
	`128`	`+`
	`129`	`+ import scala.util.Try`
	`130`	`+`
`128`	`131`	`/**`
`129`	`132`	`* This marker trait is used by [[Await]] to ensure that [[Awaitable.ready]] and [[Awaitable.result]]`
`130`	`133`	`* are not directly called by user code. An implicit instance of this trait is only available when`
`@@ -170,7 +173,7 @@ package concurrent {`
`170`	`173`	`@throws(classOf[TimeoutException])`
`171`	`174`	`@throws(classOf[InterruptedException])`
`172`	`175`	`final def ready[T](awaitable: Awaitable[T], atMost: Duration): awaitable.type = awaitable match {`
`173`		`- case f: Future[T] if f.isCompleted => awaitable.ready(atMost)(AwaitPermission)`
	`176`	`+ case f: Future[T] if f.isCompleted => awaitable`
`174`	`177`	`case _ => blocking(awaitable.ready(atMost)(AwaitPermission))`
`175`	`178`	`}`
`176`	`179`
`@@ -197,8 +200,12 @@ package concurrent {`
`197`	`200`	`@throws(classOf[TimeoutException])`
`198`	`201`	`@throws(classOf[InterruptedException])`
`199`	`202`	`final def result[T](awaitable: Awaitable[T], atMost: Duration): T = awaitable match {`
`200`		`- case f: Future[T] if f.isCompleted => f.result(atMost)(AwaitPermission)`
	`203`	`+ case CompletedFuture(result) => result.get`
`201`	`204`	`case _ => blocking(awaitable.result(atMost)(AwaitPermission))`
`202`	`205`	`}`
	`206`	`+`
	`207`	`+ private final object CompletedFuture {`
	`208`	`+ def unapply[T](f: Future[T]): Option[Try[T]] = f.value`
	`209`	`+ }`
`203`	`210`	`}`
`204`	`211`	`}`