From 2c034f57d6b4229aaf195fdd6efd016cf694855f Mon Sep 17 00:00:00 2001
From: Doug Lea <dl@openjdk.org>
Date: Mon, 26 May 2025 22:37:42 +0000
Subject: [PATCH] 8357146: ForkJoinPool:schedule(*) does not throw
 RejectedExecutionException when pool is shutdown

Reviewed-by: alanb
---
 .../java/util/concurrent/ForkJoinPool.java    | 22 +++++++++++++------
 .../concurrent/tck/ForkJoinPool20Test.java    | 18 +++++++++++++++
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java b/src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java
index eac0f5bdc18..a7821921bc9 100644
--- a/src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java
+++ b/src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java
@@ -3452,9 +3452,9 @@ public class ForkJoinPool extends AbstractExecutorService
             String name = poolName + "-delayScheduler";
             if (workerNamePrefix == null)
                 asyncCommonPool();  // override common parallelism zero
-            lockRunState();
+            long isShutdown = lockRunState() & SHUTDOWN;
             try {
-                if ((ds = delayScheduler) == null) {
+                if (isShutdown == 0L && (ds = delayScheduler) == null) {
                     ds = delayScheduler = new DelayScheduler(this, name);
                     start = true;
                 }
@@ -3462,12 +3462,20 @@ public class ForkJoinPool extends AbstractExecutorService
                 unlockRunState();
             }
             if (start) { // start outside of lock
-                // exceptions on start passed to (external) callers
                 SharedThreadContainer ctr;
-                if ((ctr = container) != null)
-                    ctr.start(ds);
-                else
-                    ds.start();
+                try {
+                    if ((ctr = container) != null)
+                        ctr.start(ds);
+                    else
+                        ds.start();
+                } catch (RuntimeException | Error ex) { // back out
+                    lockRunState();
+                    ds = delayScheduler = null;
+                    unlockRunState();
+                    tryTerminate(false, false);
+                    if (ex instanceof Error)
+                        throw ex;
+                }
             }
         }
         return ds;
diff --git a/test/jdk/java/util/concurrent/tck/ForkJoinPool20Test.java b/test/jdk/java/util/concurrent/tck/ForkJoinPool20Test.java
index 9b60bbae484..9e26ec11d72 100644
--- a/test/jdk/java/util/concurrent/tck/ForkJoinPool20Test.java
+++ b/test/jdk/java/util/concurrent/tck/ForkJoinPool20Test.java
@@ -644,4 +644,22 @@ public class ForkJoinPool20Test extends JSR166TestCase {
         }
     }
 
+    /**
+     * schedule throws RejectedExecutionException if shutdown before
+     * first delayed task is submitted
+     */
+    public void testInitialScheduleAfterShutdown() throws InterruptedException {
+        Runnable r = new NoOpRunnable();
+        boolean rje = false;
+        try (final ForkJoinPool p = new ForkJoinPool(1)) {
+            p.shutdown();
+            assertTrue(p.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
+            try {
+                p.schedule(r, 1, MILLISECONDS);
+            } catch (RejectedExecutionException ok) {
+                rje = true;
+            }
+        }
+        assertTrue(rje);
+    }
 }