0N/A/*
2362N/A * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
0N/A * published by the Free Software Foundation.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
2362N/A * or visit www.oracle.com if you need additional information or have any
2362N/A * questions.
0N/A */
0N/A
0N/A/* @test
0N/A @bug 4905777
0N/A @summary PrintStream.println(Object) oversynchronized, can deadlock
0N/A*/
0N/A
0N/Aimport java.io.PrintStream;
0N/A
0N/Apublic class OversynchronizedTest extends Thread {
0N/A private static TestObj testObj = new TestObj("This is a test.");
0N/A private static int loopNum = 100;
0N/A
0N/A public void run() {
0N/A for(int i=0; i<loopNum; i++) {
0N/A testObj.test();
0N/A
0N/A //passing an object to System.out.println might cause deadlock
0N/A //if the object has a synchronized toString() method.
0N/A //using System.out.println(testObj.toString()) won't have a problem
0N/A System.out.println(testObj);
0N/A }
0N/A }
0N/A
0N/A public static void main(String args[]) throws Exception {
0N/A // should no NullPointerException
0N/A System.out.println((Object)null);
0N/A
0N/A // over synch test
0N/A int num = 5;
0N/A
0N/A OversynchronizedTest[] t = new OversynchronizedTest[num];
0N/A for(int i=0; i<num; i++) {
0N/A t[i] = new OversynchronizedTest();
0N/A t[i].start();
0N/A }
0N/A
0N/A for(int i=0; i <num; i++) {
0N/A t[i].join();
0N/A }
0N/A
0N/A System.out.println("Test completed.");
0N/A }
0N/A}
0N/A
0N/Aclass TestObj {
0N/A String mStr;
0N/A
0N/A TestObj(String str) {
0N/A mStr = str;
0N/A }
0N/A
0N/A synchronized void test() {
0N/A try {
0N/A long t = Math.round(Math.random()*10);
0N/A Thread.currentThread().sleep(t);
0N/A } catch (InterruptedException e) {
0N/A // jtreg timeout?
0N/A // Only jtreg will interrupt this thread so it knows what to do:
0N/A e.printStackTrace();
0N/A }
0N/A
0N/A //the following line might cause hang if there is System.out.println(testObj)
0N/A //called by other threads.
0N/A System.out.println("In test().");
0N/A }
0N/A
0N/A synchronized public String toString() {
0N/A System.out.println("Calling toString\n");
0N/A return mStr;
0N/A }
0N/A}