1 /* 2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test 26 * @bug 8140450 27 * @library /lib/testlibrary 28 * @build jdk.testlibrary.* 29 * @summary Test if the getCallerClass method returns empty optional 30 * @run main CallerFromMain exec 31 */ 32 33 import jdk.testlibrary.ProcessTools; 34 import jdk.testlibrary.OutputAnalyzer; 35 36 public class CallerFromMain { 37 38 private static final StackWalker sw = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE); 39 public static void main(String[] args) throws Exception { 40 if (args.length > 0) { 41 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(true, "CallerFromMain"); 42 OutputAnalyzer output = ProcessTools.executeProcess(pb); 43 System.out.println(output.getOutput()); 44 output.shouldHaveExitValue(0); 45 return; 46 } 47 48 // StackWalker::getCallerClass 49 // CallerFromMain::main 50 // no caller 51 try { 52 Class<?> c = sw.getCallerClass(); 53 throw new RuntimeException("UOE not thrown. Caller: " + c); 54 } catch (IllegalCallerException e) {} 55 56 // StackWalker::getCallerClass 57 // Runnable::run 58 // Thread::run 59 Thread t1 = new Thread(new Runnable() { 60 @Override 61 public void run() { 62 Class<?> c = sw.getCallerClass(); 63 System.out.println("Call from Thread.run: " + c); 64 assertThreadClassAsCaller(c); 65 } 66 }); 67 t1.setDaemon(true); 68 t1.start(); 69 70 // StackWalker::getCallerClass 71 // CallerFromMain::doit 72 // Thread::run 73 Thread t2 = new Thread(CallerFromMain::doit); 74 t2.setDaemon(true); 75 t2.start(); 76 77 // StackWalker::getCallerClass 78 // MyRunnable::run 79 // Thread::run 80 Thread t3 = new Thread(new MyRunnable()); 81 t3.setDaemon(true); 82 t3.start(); 83 84 // StackWalker::getCallerClass 85 // Runnable::run 86 // MyThread::run 87 Thread t4 = new MyThread(new Runnable() { 88 @Override 89 public void run() { 90 Class<?> c = sw.getCallerClass(); 91 System.out.println("Call from MyThread.run: " + c); 92 if (c != MyThread.class) { 93 throw new RuntimeException("Expected MyThread.class but got " + c); 94 } 95 } 96 }); 97 t4.setDaemon(true); 98 t4.start(); 99 100 t1.join(); 101 t2.join(); 102 t3.join(); 103 t4.join(); 104 } 105 106 static class MyThread extends Thread { 107 final Runnable runnable; 108 MyThread(Runnable runnable) { 109 super("MyThread"); 110 this.runnable = runnable; 111 } 112 public void run() { 113 runnable.run(); 114 } 115 } 116 117 static class MyRunnable implements Runnable { 118 @Override 119 public void run() { 120 Class<?> c = sw.getCallerClass(); 121 System.out.println("Call from Thread::run: " + c); 122 assertThreadClassAsCaller(c); 123 } 124 } 125 126 static void doit() { 127 Class<?> c = sw.getCallerClass(); 128 System.out.println("Call from CallerFromMain.doit: " + c); 129 assertThreadClassAsCaller(c); 130 } 131 132 static void assertThreadClassAsCaller(Class<?> caller) { 133 if (caller != Thread.class) { 134 throw new RuntimeException("Expected Thread.class but got " + caller); 135 } 136 } 137 }