/*
* Copyright (c) 2004, 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 5014783
* @summary Basic unit test of thread states returned by
* Thread.getState().
*
* @author Mandy Chung
*
* @build ThreadStateTest
* @run main ThreadStateTest
*/
import java.util.concurrent.locks.LockSupport;
import java.util.concurrent.Semaphore;
public class ThreadStateTest {
private static boolean testFailed = false;
static class Lock {
private String name;
Lock(String name) {
this.name = name;
}
public String toString() {
return name;
}
}
private static Lock globalLock = new Lock("my lock");
public static void main(String[] argv) {
// Call Thread.getState to force all initialization done
// before test verification begins.
Thread.currentThread().getState();
MyThread myThread = new MyThread("MyThread");
// before myThread starts
checkThreadState(myThread, Thread.State.NEW);
myThread.start();
myThread.waitUntilStarted();
checkThreadState(myThread, Thread.State.RUNNABLE);
synchronized (globalLock) {
myThread.goBlocked();
checkThreadState(myThread, Thread.State.BLOCKED);
}
myThread.goWaiting();
checkThreadState(myThread, Thread.State.WAITING);
myThread.goTimedWaiting();
checkThreadState(myThread, Thread.State.TIMED_WAITING);
/*
*********** park and parkUntil seems not working
* ignore this case for now.
* Bug ID 5062095
***********************************************
myThread.goParked();
checkThreadState(myThread, Thread.State.WAITING);
myThread.goTimedParked();
checkThreadState(myThread, Thread.State.TIMED_WAITING);
*/
myThread.goSleeping();
checkThreadState(myThread, Thread.State.TIMED_WAITING);
myThread.terminate();
checkThreadState(myThread, Thread.State.TERMINATED);
try {
myThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
if (testFailed)
throw new RuntimeException("TEST FAILED.");
System.out.println("Test passed.");
}
private static void checkThreadState(Thread t, Thread.State expected) {
Thread.State state = t.getState();
System.out.println("Checking thread state " + state);
if (state == null) {
throw new RuntimeException(t.getName() + " expected to have " +
expected + " but got null.");
}
if (state != expected) {
throw new RuntimeException(t.getName() + " expected to have " +
expected + " but got " + state);
}
}
private static String getLockName(Object lock) {
if (lock == null) return null;
return lock.getClass().getName() + '@' +
Integer.toHexString(System.identityHashCode(lock));
}
private static void goSleep(long ms) {
try {
Thread.sleep(ms);
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
}
static class MyThread extends Thread {
private ThreadExecutionSynchronizer thrsync = new ThreadExecutionSynchronizer();
MyThread(String name) {
super(name);
}
private final int RUNNABLE = 0;
private final int BLOCKED = 1;
private final int WAITING = 2;
private final int TIMED_WAITING = 3;
private final int PARKED = 4;
private final int TIMED_PARKED = 5;
private final int SLEEPING = 6;
private final int TERMINATE = 7;
private int state = RUNNABLE;
private boolean done = false;
public void run() {
// Signal main thread to continue.
thrsync.signal();
while (!done) {
switch (state) {
case RUNNABLE: {
double sum = 0;
for (int i = 0; i < 1000; i++) {
double r = Math.random();
double x = Math.pow(3, r);
sum += x - r;
}
break;
}
case BLOCKED: {
// signal main thread.
thrsync.signal();
System.out.println(" myThread is going to block.");
synchronized (globalLock) {
// finish blocking
state = RUNNABLE;
}
break;
}
case WAITING: {
synchronized (globalLock) {
// signal main thread.
thrsync.signal();
System.out.println(" myThread is going to wait.");
try {
globalLock.wait();
} catch (InterruptedException e) {
// ignore
}
}
break;
}
case TIMED_WAITING: {
synchronized (globalLock) {
// signal main thread.
thrsync.signal();
System.out.println(" myThread is going to timed wait.");
try {
globalLock.wait(10000);
} catch (InterruptedException e) {
// ignore
}
}
break;
}
case PARKED: {
// signal main thread.
thrsync.signal();
System.out.println(" myThread is going to park.");
LockSupport.park();
// give a chance for the main thread to block
goSleep(10);
break;
}
case TIMED_PARKED: {
// signal main thread.
thrsync.signal();
System.out.println(" myThread is going to timed park.");
long deadline = System.currentTimeMillis() + 10000*1000;
LockSupport.parkUntil(deadline);
// give a chance for the main thread to block
goSleep(10);
break;
}
case SLEEPING: {
// signal main thread.
thrsync.signal();
System.out.println(" myThread is going to sleep.");
try {
Thread.sleep(1000000);
} catch (InterruptedException e) {
// finish sleeping
interrupted();
}
break;
}
case TERMINATE: {
done = true;
// signal main thread.
thrsync.signal();
break;
}
default:
break;
}
}
}
public void waitUntilStarted() {
// wait for MyThread.
thrsync.waitForSignal();
goSleep(10);
}
public void goBlocked() {
System.out.println("Waiting myThread to go blocked.");
setState(BLOCKED);
// wait for MyThread to get blocked
thrsync.waitForSignal();
goSleep(20);
}
public void goWaiting() {
System.out.println("Waiting myThread to go waiting.");
setState(WAITING);
// wait for MyThread to wait on object.
thrsync.waitForSignal();
goSleep(20);
}
public void goTimedWaiting() {
System.out.println("Waiting myThread to go timed waiting.");
setState(TIMED_WAITING);
// wait for MyThread timed wait call.
thrsync.waitForSignal();
goSleep(20);
}
public void goParked() {
System.out.println("Waiting myThread to go parked.");
setState(PARKED);
// wait for MyThread state change to PARKED.
thrsync.waitForSignal();
goSleep(20);
}
public void goTimedParked() {
System.out.println("Waiting myThread to go timed parked.");
setState(TIMED_PARKED);
// wait for MyThread.
thrsync.waitForSignal();
goSleep(20);
}
public void goSleeping() {
System.out.println("Waiting myThread to go sleeping.");
setState(SLEEPING);
// wait for MyThread.
thrsync.waitForSignal();
goSleep(20);
}
public void terminate() {
System.out.println("Waiting myThread to terminate.");
setState(TERMINATE);
// wait for MyThread.
thrsync.waitForSignal();
goSleep(20);
}
private void setState(int newState) {
switch (state) {
case BLOCKED:
while (state == BLOCKED) {
goSleep(20);
}
state = newState;
break;
case WAITING:
case TIMED_WAITING:
state = newState;
synchronized (globalLock) {
globalLock.notify();
}
break;
case PARKED:
case TIMED_PARKED:
state = newState;
LockSupport.unpark(this);
break;
case SLEEPING:
state = newState;
this.interrupt();
break;
default:
state = newState;
break;
}
}
}
static class ThreadExecutionSynchronizer {
private boolean waiting;
private Semaphore semaphore;
public ThreadExecutionSynchronizer() {
semaphore = new Semaphore(1);
waiting = false;
}
// Synchronizes two threads execution points.
// Basically any thread could get scheduled to run and
// it is not possible to know which thread reaches expected
// execution point. So whichever thread reaches a execution
// point first wait for the second thread. When the second thread
// reaches the expected execution point will wake up
// the thread which is waiting here.
void stopOrGo() {
semaphore.acquireUninterruptibly(); // Thread can get blocked.
if (!waiting) {
waiting = true;
// Wait for second thread to enter this method.
while(!semaphore.hasQueuedThreads()) {
try {
Thread.sleep(20);
} catch (InterruptedException xx) {}
}
semaphore.release();
} else {
waiting = false;
semaphore.release();
}
}
// Wrapper function just for code readability.
void waitForSignal() {
stopOrGo();
}
void signal() {
stopOrGo();
}
}
}