APFIVE Lock Ordering and Deadlock
Which potential concurrency problem does the above code illustrate?
public class LockOrdering {
private final Object lockA = new Object();
private final Object lockB = new Object();
public void methodA() {
synchronized(lockA) {
for (int i = 0; i < 100; i++);
synchronized(lockB) {
System.out.println("A");
}
}
}
public void methodB() {
synchronized(lockB) {
for (int i = 0; i < 100; i++);
synchronized(lockA) {
System.out.println("B");
}
}
}
public static void main(String[] args) {
LockOrdering lo = new LockOrdering();
Thread t1 = new Thread(() -> lo.methodA());
Thread t2 = new Thread(() -> lo.methodB());
t1.start();
t2.start();
}
}
A
The use of loops within the synchronized blocks eliminates any concurrency issues.
B
A deadlock may occur because methodA and methodB acquire locks in different orders.
C
The for-loops cause an infinite loop that halts thread progress.
D
A race condition happens due to improper sharing of loop variables.
Question Leaderboard
Not enough data yet to show leaderboard.