| /* |
| * Copyright (c) 2003, 2015, 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 4530538 |
| * @summary Basic unit test of ThreadInfo.getStackTrace() and |
| * ThreadInfo.getThreadState() |
| * @author Mandy Chung |
| * |
| * @run build Utils |
| * @run main ThreadStackTrace |
| */ |
| |
| import java.lang.management.*; |
| import java.util.concurrent.Phaser; |
| |
| public class ThreadStackTrace { |
| private static final ThreadMXBean mbean |
| = ManagementFactory.getThreadMXBean(); |
| private static boolean notified = false; |
| private static final Object lockA = new Object(); |
| private static final Object lockB = new Object(); |
| private static volatile boolean testFailed = false; |
| private static final String[] blockedStack = {"run", "test", "A", "B", "C", "D"}; |
| private static final int bsDepth = 6; |
| private static final int methodB = 4; |
| private static final String[] examinerStack = {"run", "examine1", "examine2"}; |
| private static final int esDepth = 3; |
| private static final int methodExamine1= 2; |
| |
| private static void checkNullThreadInfo(Thread t) throws Exception { |
| ThreadInfo ti = mbean.getThreadInfo(t.getId()); |
| if (ti != null) { |
| ThreadInfo info = |
| mbean.getThreadInfo(t.getId(), Integer.MAX_VALUE); |
| System.out.println(INDENT + "TEST FAILED:"); |
| if (info != null) { |
| printStack(t, info.getStackTrace()); |
| System.out.println(INDENT + "Thread state: " + info.getThreadState()); |
| } |
| throw new RuntimeException("TEST FAILED: " + |
| "getThreadInfo() is expected to return null for " + t); |
| } |
| } |
| |
| private static boolean trace = false; |
| public static void main(String args[]) throws Exception { |
| if (args.length > 0 && args[0].equals("trace")) { |
| trace = true; |
| } |
| |
| final Phaser p = new Phaser(2); |
| |
| Examiner examiner = new Examiner("Examiner", p); |
| BlockedThread blocked = new BlockedThread("BlockedThread", p); |
| examiner.setThread(blocked); |
| |
| checkNullThreadInfo(examiner); |
| checkNullThreadInfo(blocked); |
| |
| // Start the threads and check them in Blocked and Waiting states |
| examiner.start(); |
| |
| // #1 - block until examiner begins doing its real work |
| p.arriveAndAwaitAdvance(); |
| |
| System.out.println("Checking stack trace for the examiner thread " + |
| "is waiting to begin."); |
| |
| // The Examiner should be waiting to be notified by the BlockedThread |
| Utils.checkThreadState(examiner, Thread.State.WAITING); |
| |
| // Check that the stack is returned correctly for a new thread |
| checkStack(examiner, examinerStack, esDepth); |
| |
| System.out.println("Now starting the blocked thread"); |
| blocked.start(); |
| |
| try { |
| examiner.join(); |
| blocked.join(); |
| } catch (InterruptedException e) { |
| e.printStackTrace(); |
| System.out.println("Unexpected exception."); |
| testFailed = true; |
| } |
| |
| // Check that the stack is returned correctly for a terminated thread |
| checkNullThreadInfo(examiner); |
| checkNullThreadInfo(blocked); |
| |
| if (testFailed) |
| throw new RuntimeException("TEST FAILED."); |
| |
| System.out.println("Test passed."); |
| } |
| |
| private static String INDENT = " "; |
| private static void printStack(Thread t, StackTraceElement[] stack) { |
| System.out.println(INDENT + t + |
| " stack: (length = " + stack.length + ")"); |
| if (t != null) { |
| for (int j = 0; j < stack.length; j++) { |
| System.out.println(INDENT + stack[j]); |
| } |
| System.out.println(); |
| } |
| } |
| |
| private static void checkStack(Thread t, String[] expectedStack, |
| int depth) throws Exception { |
| ThreadInfo ti = mbean.getThreadInfo(t.getId(), Integer.MAX_VALUE); |
| StackTraceElement[] stack = ti.getStackTrace(); |
| |
| if (trace) { |
| printStack(t, stack); |
| } |
| int frame = stack.length - 1; |
| for (int i = 0; i < depth; i++) { |
| if (! stack[frame].getMethodName().equals(expectedStack[i])) { |
| throw new RuntimeException("TEST FAILED: " + |
| "Expected " + expectedStack[i] + " in frame " + frame + |
| " but got " + stack[frame].getMethodName()); |
| } |
| frame--; |
| } |
| } |
| |
| static class BlockedThread extends Thread { |
| private final Phaser phaser; |
| |
| BlockedThread(String name, Phaser phaser) { |
| super(name); |
| this.phaser = phaser; |
| } |
| |
| private void test() { |
| A(); |
| } |
| private void A() { |
| B(); |
| } |
| private void B() { |
| C(); |
| |
| // #4 - notify the examiner about to block on lockB |
| phaser.arriveAndAwaitAdvance(); |
| |
| synchronized (lockB) {}; |
| } |
| private void C() { |
| D(); |
| } |
| private void D() { |
| // #2 - Notify that examiner about to enter lockA |
| phaser.arriveAndAwaitAdvance(); |
| |
| synchronized (lockA) { |
| notified = false; |
| while (!notified) { |
| try { |
| // #3 - notify the examiner about to release lockA |
| phaser.arriveAndAwaitAdvance(); |
| // Wait and let examiner thread check the mbean |
| lockA.wait(); |
| } catch (InterruptedException e) { |
| e.printStackTrace(); |
| System.out.println("Unexpected exception."); |
| testFailed = true; |
| } |
| } |
| System.out.println("BlockedThread notified"); |
| } |
| } |
| |
| @Override |
| public void run() { |
| test(); |
| } // run() |
| } // BlockedThread |
| |
| static class Examiner extends Thread { |
| private static BlockedThread blockedThread; |
| private final Phaser phaser; |
| |
| Examiner(String name, Phaser phaser) { |
| super(name); |
| this.phaser = phaser; |
| } |
| |
| public void setThread(BlockedThread thread) { |
| blockedThread = thread; |
| } |
| |
| private Thread itself; |
| private void examine1() { |
| synchronized (lockB) { |
| examine2(); |
| try { |
| System.out.println("Checking examiner's its own stack trace"); |
| Utils.checkThreadState(itself, Thread.State.RUNNABLE); |
| checkStack(itself, examinerStack, methodExamine1); |
| |
| // #4 - wait until blockedThread is blocked on lockB |
| phaser.arriveAndAwaitAdvance(); |
| Utils.waitForThreadState(blockedThread, State.BLOCKED); |
| |
| System.out.println("Checking stack trace for " + |
| "BlockedThread - should be blocked on lockB."); |
| Utils.checkThreadState(blockedThread, Thread.State.BLOCKED); |
| checkStack(blockedThread, blockedStack, methodB); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| System.out.println("Unexpected exception."); |
| testFailed = true; |
| } |
| } |
| } |
| |
| private void examine2() { |
| synchronized (lockA) { |
| // #1 - examiner ready to do the real work |
| phaser.arriveAndAwaitAdvance(); |
| try { |
| // #2 - Wait until BlockedThread is about to block on lockA |
| phaser.arriveAndAwaitAdvance(); |
| Utils.waitForThreadState(blockedThread, State.BLOCKED); |
| |
| System.out.println("Checking examiner's its own stack trace"); |
| Utils.checkThreadState(itself, Thread.State.RUNNABLE); |
| checkStack(itself, examinerStack, esDepth); |
| |
| System.out.println("Checking stack trace for " + |
| "BlockedThread - should be blocked on lockA."); |
| Utils.checkThreadState(blockedThread, Thread.State.BLOCKED); |
| checkStack(blockedThread, blockedStack, bsDepth); |
| |
| } catch (Exception e) { |
| e.printStackTrace(); |
| System.out.println("Unexpected exception."); |
| testFailed = true; |
| } |
| } |
| |
| // #3 - release lockA and let BlockedThread to get the lock |
| // and wait on lockA |
| phaser.arriveAndAwaitAdvance(); |
| Utils.waitForThreadState(blockedThread, State.WAITING); |
| |
| synchronized (lockA) { |
| try { |
| System.out.println("Checking stack trace for " + |
| "BlockedThread - should be waiting on lockA."); |
| Utils.checkThreadState(blockedThread, Thread.State.WAITING); |
| checkStack(blockedThread, blockedStack, bsDepth); |
| |
| // Let the blocked thread go |
| notified = true; |
| lockA.notify(); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| System.out.println("Unexpected exception."); |
| testFailed = true; |
| } |
| } |
| // give some time for BlockedThread to proceed |
| Utils.goSleep(50); |
| } // examine2() |
| |
| @Override |
| public void run() { |
| itself = Thread.currentThread(); |
| examine1(); |
| } // run() |
| } // Examiner |
| } |