Callbacks are not being executed for already completed completion stages.

[Mateusz Warowny]

Callbacks attached to already completed CompletionStages returned by CompletableFuture#completedStage() static factory method should be called just after being attached, but they are not. The issue doesn't occur when #completedFuture is being used instead.

Example:

public class CompletionStageTest
{
  public static void main(String[] args) {
    CompletableFuture<String> future1 = new CompletableFuture<>();
    future1.thenAccept(System.out::println);
    future1.complete("Future 1");
    
    CompletionStage<String> future2 = CompletableFuture.completedFuture("Future 2");
    future2.thenAccept(System.out::println);
    
    CompletionStage<String> future3 = CompletableFuture.completedStage("Future 3");
    future3.thenAccept(System.out::println);
  }
}

The last callback printing "Future 3" is not executed but it should be.

[Bob Hanson]

fix is pushed. Several Java 9 methods added to CompletableFuture

…

On Thu, Feb 4, 2021 at 8:06 AM Mateusz Warowny ***@***.***> wrote: Callbacks attached to already completed CompletionStages returned by CompletableFuture#completedStage() static factory method should be called just after being attached, but they are not. The issue doesn't occur when #completedFuture is being used instead. Example: public class CompletionStageTest { public static void main(String[] args) { CompletableFuture<String> future1 = new CompletableFuture<>(); future1.thenAccept(System.out::println); future1.complete("Future 1"); CompletionStage<String> future2 = CompletableFuture.completedFuture("Future 2"); future2.thenAccept(System.out::println); CompletionStage<String> future3 = CompletableFuture.completedStage("Future 3"); future3.thenAccept(System.out::println); } } The last callback printing "Future 3" is not executed but it should be. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#208>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEHNCW7NKKHVHHWD6TE7HE3S5KSVFANCNFSM4XC4LZ7A> .

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