8295278: Add parallel class loading tests

Reviewed-by: vlivanov, ccheung

test/hotspot/jtreg/runtime/ParallelLoad/CallLoadClass/CallLoadClassTest.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8295278
+ * @summary Call unlocked version loadClass directly, with another thread calling forName
+ *          One class goes through the ClassLoader path and the other goes through JVM path
+ * @library /test/lib
+ * @compile test-classes/A.java ../share/ThreadPrint.java
+ * @run main/othervm CallLoadClassTest
+ */
+
+import jdk.test.lib.classloader.ClassUnloadCommon;
+import java.util.concurrent.Semaphore;
+
+public class CallLoadClassTest {
+
+    private static Semaphore mainSync = null;
+
+    private static class MyLoader extends ClassLoader {
+
+        ClassLoader parent;
+        int count;
+
+        MyLoader(ClassLoader parent) {
+            this.parent = parent;
+            this.count = 0;
+        }
+
+        public synchronized Class<?> loadClass(String name) throws ClassNotFoundException {
+            Class<?> loadedClass = findLoadedClass(name);
+            if (name.equals("A") && loadedClass == null) {
+                ThreadPrint.println("Loading A");
+                if (count == 0) {
+                    count++;
+                    ThreadPrint.println("Waiting for A");
+                    try {
+                        mainSync.release(); // Let t2 start
+                        wait();  // let the other thread load A instead.
+                    } catch (InterruptedException ie) {
+                    }
+                } else {
+                    notify(); // notify any waiting threads.
+                }
+                byte[] classfile = ClassUnloadCommon.getClassData("A");
+                return defineClass(name, classfile, 0, classfile.length);
+            } else {
+                return parent.loadClass(name);
+            }
+        }
+    }
+
+    private static ClassLoadingThread[] threads = new ClassLoadingThread[2];
+    private static boolean success = true;
+
+    private static boolean report_success() {
+        for (int i = 0; i < 2; i++) {
+          try {
+            threads[i].join();
+            if (!threads[i].report_success()) success = false;
+          } catch (InterruptedException e) {}
+        }
+        return success;
+    }
+
+    public static void main(java.lang.String[] unused) {
+        mainSync = new Semaphore(0);
+
+        // t1 does loadClass directly, t2 does class.ForName()
+        ClassLoader appLoader = CallLoadClassTest.class.getClassLoader();
+        MyLoader ldr = new MyLoader(appLoader);
+        for (int i = 0; i < 2; i++) {
+            threads[i] = new ClassLoadingThread(ldr, i, mainSync);
+            threads[i].setName("Loading Thread #" + (i + 1));
+            threads[i].start();
+            System.out.println("Thread " + (i + 1) + " was started...");
+        }
+        if (report_success()) {
+           System.out.println("PASSED");
+        } else {
+            throw new RuntimeException("FAILED");
+        }
+    }
+}

test/hotspot/jtreg/runtime/ParallelLoad/CallLoadClass/ClassLoadingThread.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ * 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.
+ */
+
+import java.util.concurrent.Semaphore;
+
+class ClassLoadingThread extends Thread {
+
+    private ClassLoader ldr = null;
+    private int which;
+    private Semaphore syncOrder;
+
+    public ClassLoadingThread(ClassLoader loader, int i, Semaphore sem) {
+        ldr = loader;
+        which = i;
+        syncOrder = sem;
+    }
+
+    private boolean success = true;
+    public boolean report_success() { return success; }
+
+    public void callForName() {
+        try {
+            ThreadPrint.println("Starting forName thread ...");
+            // Initiate class loading using specified type
+            Class<?> a = Class.forName("A", true, ldr);
+            Object obj = a.getConstructor().newInstance();
+        } catch (Throwable e) {
+            ThreadPrint.println("Exception is caught: " + e);
+            e.printStackTrace();
+            success = false;
+        }
+    }
+
+    public void callLoadClass() {
+        try {
+            ThreadPrint.println("Starting loadClass thread ...");
+            Class<?> a = ldr.loadClass("A");
+            Object obj = a.getConstructor().newInstance();
+            success = false; // Should have thrown LinkageError
+        } catch (Throwable e) {
+            // If you call loadClass directly, this will result in LinkageError
+            ThreadPrint.println("Exception is caught: " + e);
+            e.printStackTrace();
+            success = (e instanceof LinkageError);
+        }
+    }
+
+    public void run() {
+       if (which == 0) {
+           callLoadClass();
+       } else {
+           try {
+               syncOrder.acquire();  // wait until loadClass is waiting.
+           } catch (InterruptedException idc) {}
+           callForName();
+       }
+    }
+}

test/hotspot/jtreg/runtime/ParallelLoad/CallLoadClass/test-classes/A.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ * 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.
+ */
+
+// This doesn't have to do anything
+public class A {
+  static { System.out.println("A called"); }
+  public A() { System.out.println("A.<init> called"); }
+}
+

test/hotspot/jtreg/runtime/ParallelLoad/ParallelCircularity/ParallelCircularityTest.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 4699981 8295278
+ * @summary This is a testcase for JDK-4699981. When 2 threads are loading the same class with
+ *           the same classloader, and somehow one of the 2 threads releases the
+ *           synchronization lock on the classloader, the JVM code
+ *           throws ClassCircularityError, mistakenly.
+ * @library /test/lib
+ * @compile test-classes/Base.java test-classes/Derived.java test-classes/Support.java
+ * @run main/othervm ParallelCircularityTest
+ */
+
+import java.net.URL;
+import java.net.URLClassLoader;
+
+public class ParallelCircularityTest {
+
+    private Object lock = new Object();
+
+    private void test() throws Exception {
+       URL location = getClass().getProtectionDomain().getCodeSource().getLocation();
+       URLLoader loader = new URLLoader(new URL[] {location}, getClass().getClassLoader().getParent());
+
+       Class cls = loader.loadClass("Support");
+
+       Thread t1 = new Thread(new Run1(cls));
+       t1.start();
+
+       Thread.sleep(1000);
+
+       // Load Derived, will trigger a loadClassInternal for Base
+       loader.loadClass("Derived");
+    }
+
+    public static void main(String[] args) throws Exception {
+        ParallelCircularityTest pct = new ParallelCircularityTest();
+        pct.test();
+    }
+
+    public class URLLoader extends URLClassLoader {
+       private boolean m_firstTime = true;
+
+       public URLLoader(URL[] urls, ClassLoader parent) {
+          super(urls, parent);
+       }
+
+       public Class loadClass(String name) throws ClassNotFoundException {
+          if (name.equals("Base")) {
+             if (m_firstTime) {
+                m_firstTime = false;
+
+                // Notify the other thread
+                synchronized (lock) {
+                   lock.notifyAll();
+                }
+
+                // Wait on the classloader to have the JVM throw ClassCircularityError
+                try {
+                   synchronized (this) {
+                      wait(5000);
+                   }
+                }
+                catch (InterruptedException ignored) { }
+             }
+          }
+          return super.loadClass(name);
+       }
+    }
+
+    public class Run1 implements Runnable {
+       private Class cls;
+
+       public Run1(Class cls) {
+          this.cls = cls;
+       }
+
+       public void run() {
+          synchronized (lock) {
+             try {
+                lock.wait();
+             }
+             catch (InterruptedException ignored) {}
+          }
+
+          // Trigger loadClassInternal for Base
+          try {
+             cls.newInstance();
+          } catch (Throwable x) {
+             x.printStackTrace();
+          }
+       }
+    }
+}

test/hotspot/jtreg/runtime/ParallelLoad/ParallelCircularity/test-classes/Base.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ * 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.
+ */
+
+public class Base {}

test/hotspot/jtreg/runtime/ParallelLoad/ParallelCircularity/test-classes/Derived.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ * 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.
+ */
+
+public class Derived extends Base {}