75 lines
2.9 KiB
Java
75 lines
2.9 KiB
Java
/*
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* Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
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* Copyright (c) 2021, BELLSOFT. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* LoadLibraryDeadlock class triggers the deadlock between the two
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* lock objects - ZipFile object and ClassLoader.loadedLibraryNames hashmap.
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* Thread #2 loads a signed jar which leads to acquiring the lock objects in
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* natural order (ZipFile then HashMap) - loading a signed jar may involve
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* Providers initialization. Providers may load native libraries.
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* Thread #1 acquires the locks in reverse order, first entering loadLibrary
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* called from Class1, then acquiring ZipFile during the search for a class
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* triggered from JNI.
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*/
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import java.lang.*;
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public class LoadLibraryDeadlock {
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public static void main(String[] args) {
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Thread t1 = new Thread() {
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public void run() {
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try {
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// an instance of unsigned class that loads a native library
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Class<?> c1 = Class.forName("Class1");
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Object o = c1.newInstance();
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} catch (ClassNotFoundException |
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InstantiationException |
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IllegalAccessException e) {
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System.out.println("Class Class1 not found.");
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throw new RuntimeException(e);
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}
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}
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};
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Thread t2 = new Thread() {
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public void run() {
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try {
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// load a class from a signed jar, which locks the JarFile
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Class<?> c2 = Class.forName("p.Class2");
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System.out.println("Signed jar loaded.");
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} catch (ClassNotFoundException e) {
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System.out.println("Class Class2 not found.");
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throw new RuntimeException(e);
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}
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}
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};
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t2.start();
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t1.start();
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try {
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t1.join();
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t2.join();
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} catch (InterruptedException ignore) {
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}
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}
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}
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