8306647: Implementation of Structured Concurrency (Preview)

8306572: Implementation of Scoped Values (Preview)

Co-authored-by: Alan Bateman <alanb@openjdk.org>
Co-authored-by: Andrew Haley <aph@openjdk.org>
Reviewed-by: psandoz, dfuchs, mchung

src/java.base/share/classes/java/util/concurrent/StructureViolationException.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.util.concurrent;
+
+import jdk.internal.javac.PreviewFeature;
+
+/**
+ * Thrown when a structure violation is detected.
+ *
+ * @see StructuredTaskScope#close()
+ *
+ * @since 21
+ */
+@PreviewFeature(feature = PreviewFeature.Feature.STRUCTURED_CONCURRENCY)
+public final class StructureViolationException extends RuntimeException {
+    @java.io.Serial
+    private static final long serialVersionUID = -7705327650798235468L;
+
+    /**
+     * Constructs a {@code StructureViolationException} with no detail message.
+     */
+    public StructureViolationException() {
+        super();
+    }
+
+    /**
+     * Constructs a {@code StructureViolationException} with the specified
+     * detail message.
+     *
+     * @param  message the detail message, can be null
+     */
+    public StructureViolationException(String message) {
+        super(message);
+    }
+}

src/java.base/share/classes/java/util/concurrent/ThreadPerTaskExecutor.java

@@ -54,7 +54,7 @@ class ThreadPerTaskExecutor extends ThreadContainer implements ExecutorService {
             MethodHandles.Lookup l = MethodHandles.lookup();
             STATE = l.findVarHandle(ThreadPerTaskExecutor.class, "state", int.class);
         } catch (Exception e) {
-            throw new InternalError(e);
+            throw new ExceptionInInitializerError(e);
         }
     }