Misprint in Andrw's Book

[Animesh Saxena]

I just noticed a small mistake in Andrew's book. On page 99 in threading chapter. (Deadlock Example)

public class DeadlockExample {
/**
 * Entry point to the application. Creates 2 threads that will deadlock.
 */
public static void main(String args[]){
DeadlockExample dle = new DeadlockExample();
 
                Object lock1 = "Lock 1";
                Object lock2 = "Lock 2";
 
                Runner thread1 = new Runner(lock1, lock2);
                Runner thread2 = new Runner(lock2, lock1);
 
thread1.start();
thread2.start();
}
 
/**
 * Lock two objects in the order they were specified in the constructor.
 */
static class Runner extends Thread {
private Object lockA;
private Object lockB;
 
public Runner(Object firstLockToGet, Object secondLockToGet) {
this.lockA = firstLockToGet;
this.lockB = secondLockToGet;
}
 
public void run() {
String name = Thread.currentThread().getName();
synchronized(lock1) {
System.out.println(name + ": locked " + lockA);
delay(name);
System.out.println(name + ": trying to get " + lockB);
synchronized(lock2) {
System.out.println(name + ": locked " + lockB);
}
}
}
}
 
/**
 * build in a delay to allow the other thread time to lock the object
 * the delaying thread would like to get.
 */
private static void delay(String name) {
try {
System.out.println(name + ": delaying 1 second");
Thread.currentThread().sleep(1000L);
} catch(InterruptedException ie) {
ie.printStackTrace();
}
}
}

in synchronized code...it should be synchronized(lockA)
similarly synchronized(lockB)
....
if I am wrong please let me know!???

[Barry Gaunt]

Good catch! But it's already on theCorrections Page on the Apress site.
[ April 01, 2006: Message edited by: Barry Gaunt ]