/* * This file is part of the Jikes RVM project (http://jikesrvm.org). * * This file is licensed to You under the Eclipse Public License (EPL); * You may not use this file except in compliance with the License. You * may obtain a copy of the License at * * http://www.opensource.org/licenses/eclipse-1.0.php * * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. */ class MonitorTest { static boolean verbose = true; // set to true to get messages for each test static boolean allTestPass = true; static volatile boolean startCounting = false; static int globalCount = 0; static String stringObject; public static native void setVerboseOff(); /** * native methods that will call the JNI Monitor functions */ static native int accessMonitorFromNative(Object lockObject); /** * called from native, increment a count protected by a lock on stringObject in native */ static void accessCountUnderNativeLock(int increment) { // lock the same object again to test nested monitor enter synchronized (stringObject) { globalCount += increment; } } static synchronized void setFailFlag() { allTestPass = false; } /** * constructor initializes instance fields */ MonitorTest() { } public static void main(String[] args) { System.loadLibrary("MonitorTest"); if (args.length != 0) { if (args[0].equals("-quiet")) { verbose = false; setVerboseOff(); } } // Create an object to lock on stringObject = new String("Lock me"); // Create 2 threads to contend for the lock and update a count printVerbose("Creating worker threads"); Worker threadOne = new Worker("thread One", stringObject); Worker threadTwo = new Worker("thread Two", stringObject); printVerbose("Starting worker threads"); threadOne.start(); threadTwo.start(); // wait for the threads to come up while (!threadOne.readyFlag || !threadTwo.readyFlag) { } printVerbose("Worker threads running, start counting"); startCounting = true; // wait for the threads to finish while (!threadOne.doneFlag || !threadTwo.doneFlag) { } // check the count, should be 0 if the synchronization is correct printVerbose("Worker threads finish, check count"); // get a copy so the checking can be protected in case some threads are still running int copyCount = globalCount; if (copyCount == 0 && allTestPass) { System.out.println("PASS: MonitorTest"); } else { System.out.println("FAIL: MonitorTest"); printVerbose("Expect globalCount = 0, get " + copyCount); } } static void printVerbose(String str) { if (verbose) System.out.println(str); } }