From a87afd222afa3505216af0741be34357588cb640 Mon Sep 17 00:00:00 2001
From: Julien Viet <julien@julienviet.com>
Date: Tue, 5 Nov 2024 09:20:22 +0100
Subject: [PATCH] Future.await should interrupt the current thread when the
 worker executor is closed.

Motivation:

Future.await incorrectly performs a no-op when the worker executor is closed (returns a null latch), which reports a failure that might not exist.

Changes:

When the worker executor returns null, throw an interrupted exception.
---
 src/main/java/io/vertx/core/Future.java       |  5 +++-
 .../vertx/core/VirtualThreadContextTest.java  | 27 +++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/main/java/io/vertx/core/Future.java b/src/main/java/io/vertx/core/Future.java
index 575d14efe00..824026ab536 100644
--- a/src/main/java/io/vertx/core/Future.java
+++ b/src/main/java/io/vertx/core/Future.java
@@ -683,9 +683,12 @@ static <T> T await(Future<T> future) {
     }
     if (future.succeeded()) {
       return future.result();
-    } else {
+    } else if (future.failed()) {
       Utils.throwAsUnchecked(future.cause());
       return null;
+    } else {
+      Utils.throwAsUnchecked(new InterruptedException("Context closed"));
+      return null;
     }
   }
 
diff --git a/src/test/java/io/vertx/core/VirtualThreadContextTest.java b/src/test/java/io/vertx/core/VirtualThreadContextTest.java
index b8bed95272c..21739711756 100644
--- a/src/test/java/io/vertx/core/VirtualThreadContextTest.java
+++ b/src/test/java/io/vertx/core/VirtualThreadContextTest.java
@@ -349,4 +349,31 @@ public void testContextCloseContextSerialization() throws Exception {
     }
     f.toCompletionStage().toCompletableFuture().get(20, TimeUnit.SECONDS);
   }
+
+  @Test
+  public void testAwaitWhenClosed() throws Exception {
+    Assume.assumeTrue(isVirtualThreadAvailable());
+    ContextInternal ctx = vertx.createVirtualThreadContext();
+    CountDownLatch latch = new CountDownLatch(1);
+    ctx.runOnContext(v -> {
+      latch.countDown();
+      try {
+        new CountDownLatch(1).await();
+        fail();
+      } catch (InterruptedException expected) {
+        assertFalse(Thread.currentThread().isInterrupted());
+      }
+      try {
+        Promise.promise().future().await();
+        fail();
+      } catch (Exception e) {
+        assertEquals(InterruptedException.class, e.getClass());
+        testComplete();
+      }
+    });
+    awaitLatch(latch);
+    // Interrupts virtual thread
+    ctx.close();
+    await();
+  }
 }