From 21935fbde6ee26a6694b7887da92e9174541c62c Mon Sep 17 00:00:00 2001
From: Michiel Meeuwissen <michiel.meeuwissen@gmail.com>
Date: Fri, 1 Nov 2024 12:00:20 +0100
Subject: [PATCH] Common pool cannot be shut down.

---
 .../java/nl/vpro/util/ThreadPoolShutdowner.java    | 14 ++++++++++----
 .../src/main/java/nl/vpro/util/ThreadPools.java    |  5 ++---
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPoolShutdowner.java b/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPoolShutdowner.java
index ff3578b26..a2b6d0e16 100644
--- a/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPoolShutdowner.java
+++ b/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPoolShutdowner.java
@@ -1,22 +1,28 @@
 package nl.vpro.util;
 
 import lombok.extern.log4j.Log4j2;
-import org.junit.platform.launcher.TestExecutionListener;
-import org.junit.platform.launcher.TestPlan;
 
 import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.platform.launcher.TestExecutionListener;
+import org.junit.platform.launcher.TestPlan;
 
 /**
  * A junit TestExecutionListener that just makes sure that all ThreadPools are shutdown after the tests.
+ * Also, it calls {@link ForkJoinPool#awaitQuiescence(long, TimeUnit)} (100s) on {@link ForkJoinPool#commonPool()}
  */
 @Log4j2
 public class ThreadPoolShutdowner implements TestExecutionListener {
 
     @Override
     public void testPlanExecutionFinished(TestPlan testPlan) {
+
         ThreadPools.shutdown();
-        log.info("Shutting down ForkJoinPool.commonPool() too");
-        ForkJoinPool.commonPool().shutdown();
+        log.info("Waiting for ForkJoinPool.commonPool() too");
+        // commonPool cannot be shut down. But you can wait for tasks
+        boolean b = ForkJoinPool.commonPool().awaitQuiescence(100, TimeUnit.SECONDS);
+
     }
 
 }
diff --git a/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPools.java b/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPools.java
index a0521d4aa..da44bc7e9 100644
--- a/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPools.java
+++ b/vpro-shared-util/src/main/java/nl/vpro/util/ThreadPools.java
@@ -94,13 +94,12 @@ public Thread newThread(@NonNull Runnable r) {
                 false,
                 Thread.NORM_PRIORITY));
 
-
-	public static void shutdown() {
+    public static void shutdown() {
         log.info("Shutting down thread pools");
         copyExecutor.shutdown();
         startUpExecutor.shutdown();
         backgroundExecutor.shutdown();
         longBackgroundExecutor.shutdown();
-	}
+    }
 }