1 /* 2 * Copyright (c) 2013, 2020, 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 import java.lang.management.ThreadInfo; 24 import java.lang.management.ThreadMXBean; 25 import java.lang.Thread.State; 26 import java.io.IOException; 27 import java.lang.management.ManagementFactory; 28 import java.util.Random; 29 import java.util.logging.LogManager; 30 import java.util.logging.Logger; 31 import java.util.Map; 32 import jdk.test.lib.RandomFactory; 33 34 /** 35 * @test 36 * @bug 8010939 37 * @summary check for deadlock between findLogger() and drainLoggerRefQueueBounded() 38 * @author jim.gish@oracle.com 39 * @modules java.logging 40 * java.management 41 * @library /test/lib 42 * @build DrainFindDeadlockTest 43 * @run main/othervm DrainFindDeadlockTest 44 * @key randomness 45 */ 46 47 /** 48 * This test is checking for a deadlock between 49 * LogManager$LoggerContext.findLogger() and 50 * LogManager.drainLoggerRefQueueBounded() (which could happen by calling 51 * Logger.getLogger() and LogManager.readConfiguration() in different threads) 52 */ 53 public class DrainFindDeadlockTest { 54 private LogManager mgr = LogManager.getLogManager(); 55 private static final int MAX_ITERATIONS = 100; 56 private static final Random random = RandomFactory.getRandom(); 57 private static int preventLoopElision; 58 59 // Get a ThreadMXBean so we can check for deadlock. N.B. this may 60 // not be supported on all platforms, which means we will have to 61 // resort to the traditional test timeout method. However, if 62 // we have the support we'll get the deadlock details if one 63 // is detected. 64 private static final ThreadMXBean threadMXBean = 65 ManagementFactory.getThreadMXBean(); 66 private final boolean threadMXBeanDeadlockSupported = 67 threadMXBean.isSynchronizerUsageSupported(); 68 main(String... args)69 public static void main(String... args) throws IOException, Exception { 70 new DrainFindDeadlockTest().testForDeadlock(); 71 } 72 randomDelay()73 public static void randomDelay() { 74 int runs = random.nextInt(1000000); 75 int c = 0; 76 77 for (int i=0; i<runs; ++i) { 78 c=c+i; 79 } 80 preventLoopElision = c; 81 } 82 testForDeadlock()83 public void testForDeadlock() throws IOException, Exception { 84 System.out.println("Deadlock detection " 85 + (threadMXBeanDeadlockSupported ? "is" : "is not") + 86 " available."); 87 Thread setup = new Thread(new SetupLogger(), "SetupLogger"); 88 Thread readConfig = new Thread(new ReadConfig(), "ReadConfig"); 89 Thread check = new Thread(new DeadlockChecker(setup, readConfig), 90 "DeadlockChecker"); 91 92 // make the threads daemon threads so they will go away when the 93 // test exits 94 setup.setDaemon(true); 95 readConfig.setDaemon(true); 96 check.setDaemon(true); 97 98 check.start(); setup.start(); readConfig.start(); 99 try { 100 check.join(); 101 } catch (InterruptedException ex) { 102 ex.printStackTrace(); 103 } 104 try { 105 readConfig.join(); 106 setup.join(); 107 } catch (InterruptedException ex) { 108 ex.printStackTrace(); 109 } 110 System.out.println("Test passed"); 111 } 112 113 class SetupLogger implements Runnable { 114 Logger logger = null; 115 116 @Override run()117 public void run() { 118 System.out.println("Running " + Thread.currentThread().getName()); 119 120 try { 121 for (int i=0; i < MAX_ITERATIONS; i++) { 122 logger = Logger.getLogger("DrainFindDeadlockTest"+i); 123 DrainFindDeadlockTest.randomDelay(); 124 } 125 } finally { 126 System.out.println("Completed " + Thread.currentThread().getName()); 127 } 128 } 129 } 130 131 class ReadConfig implements Runnable { 132 @Override run()133 public void run() { 134 System.out.println("Running " + Thread.currentThread().getName()); 135 try { 136 for (int i=0; i < MAX_ITERATIONS; i++) { 137 try { 138 mgr.readConfiguration(); 139 } catch (IOException | SecurityException ex) { 140 throw new RuntimeException("FAILED: test setup problem", ex); 141 } 142 DrainFindDeadlockTest.randomDelay(); 143 } 144 } finally { 145 System.out.println("Completed " + Thread.currentThread().getName()); 146 } 147 } 148 } 149 150 class DeadlockChecker implements Runnable { 151 Thread t1, t2; 152 DeadlockChecker(Thread t1, Thread t2)153 DeadlockChecker(Thread t1, Thread t2) { 154 this.t1 = t1; 155 this.t2 = t2; 156 } 157 checkState(Thread x, Thread y)158 void checkState(Thread x, Thread y) { 159 // System.out.println("checkstate"); 160 boolean isXblocked = x.getState().equals(State.BLOCKED); 161 boolean isYblocked = y.getState().equals(State.BLOCKED); 162 long[] deadlockedThreads = null; 163 164 if (isXblocked && isYblocked) { 165 System.out.println("threads blocked"); 166 // they are both blocked, but this doesn't necessarily mean 167 // they are deadlocked 168 if (threadMXBeanDeadlockSupported) { 169 System.out.println("checking for deadlock"); 170 deadlockedThreads = threadMXBean.findDeadlockedThreads(); 171 } else { 172 System.out.println("Can't check for deadlock"); 173 } 174 if (deadlockedThreads != null) { 175 System.out.println("We detected a deadlock! "); 176 ThreadInfo[] threadInfos = threadMXBean.getThreadInfo( 177 deadlockedThreads, true, true); 178 for (ThreadInfo threadInfo: threadInfos) { 179 System.out.println(threadInfo); 180 } 181 throw new RuntimeException("TEST FAILED: Deadlock detected"); 182 } 183 System.out.println("We may have a deadlock"); 184 Map<Thread, StackTraceElement[]> threadMap = 185 Thread.getAllStackTraces(); 186 dumpStack(threadMap.get(x), x); 187 dumpStack(threadMap.get(y), y); 188 } 189 } 190 dumpStack(StackTraceElement[] aStackElt, Thread aThread)191 private void dumpStack(StackTraceElement[] aStackElt, Thread aThread) { 192 if (aStackElt != null) { 193 System.out.println("Thread:" + aThread.getName() + ": " + 194 aThread.getState()); 195 for (StackTraceElement element: aStackElt) { 196 System.out.println(" " + element); 197 } 198 } 199 } 200 201 @Override run()202 public void run() { 203 System.out.println("Running " + Thread.currentThread().getName()); 204 try { 205 for (int i=0; i < MAX_ITERATIONS*2; i++) { 206 checkState(t1, t2); 207 try { 208 Thread.sleep(10); 209 } catch (InterruptedException ex) { 210 } 211 } 212 } finally { 213 System.out.println("Completed " + Thread.currentThread().getName()); 214 } 215 } 216 } 217 } 218