8327501: Common ForkJoinPool prevents class unloading in some cases

8328366: Thread.setContextClassloader from thread in FJP commonPool task no longer works after JDK-8327501 Backport-of: 53c4714aab2e072ba18631875dcaa3b2d5d22243
openjdk · Aug 12, 2024 · eb103b0 · eb103b0 · openjdk-notifier · Aug 12, 2024
1 parent 27b1e1a
commit eb103b0
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Showing 2 changed files with 9 additions and 3 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
@@ -981,9 +981,7 @@ public final ForkJoinWorkerThread newThread(ForkJoinPool pool) {
             boolean isCommon = (pool.workerNamePrefix == null);
             @SuppressWarnings("removal")
             SecurityManager sm = System.getSecurityManager();
-            if (sm == null)
-                return new ForkJoinWorkerThread(null, pool, true, false);
-            else if (isCommon)
+            if (sm != null && isCommon)
                 return newCommonWithACC(pool);
             else
                 return newRegularWithACC(pool);

diff --git a/test/jdk/java/util/concurrent/tck/ForkJoinPool9Test.java b/test/jdk/java/util/concurrent/tck/ForkJoinPool9Test.java
@@ -79,6 +79,9 @@ public void testCommonPoolThreadContextClassLoader() throws Throwable {
             assertSame(ForkJoinPool.commonPool(), ForkJoinTask.getPool());
             Thread currentThread = Thread.currentThread();
 
+            ClassLoader preexistingContextClassLoader =
+                    currentThread.getContextClassLoader();
+
             Stream.of(systemClassLoader, null).forEach(cl -> {
                 if (randomBoolean())
                     // should always be permitted, without effect
@@ -95,6 +98,11 @@ public void testCommonPoolThreadContextClassLoader() throws Throwable {
                     () -> System.getProperty("foo"),
                     () -> currentThread.setContextClassLoader(
                         classLoaderDistinctFromSystemClassLoader));
+            else {
+                currentThread.setContextClassLoader(classLoaderDistinctFromSystemClassLoader);
+                assertSame(currentThread.getContextClassLoader(), classLoaderDistinctFromSystemClassLoader);
+                currentThread.setContextClassLoader(preexistingContextClassLoader);
+            }
             // TODO ?
 //          if (haveSecurityManager
 //              && Thread.currentThread().getClass().getSimpleName()