What methods can be used to prevent deadlock in a multithreaded application when organizing code?

To prevent deadlock in a multithreaded application, several approaches can be used:

1. Avoid nested locks — minimize the number of locks held simultaneously.

2. Order lock acquisition — always acquire locks in the same order across all threads.

3. Use timeouts when acquiring locks — if the lock is not acquired within a certain time, release already acquired locks and retry.

4. Use higher-level synchronization constructs — for example, java.util.concurrent packages with Lock, Semaphore, ReadWriteLock.

5. Avoid locking if possible — use non-blocking algorithms or data structures.

Example of lock ordering:

Object lock1 = new Object();
Object lock2 = new Object();

// In all threads, first acquire lock1, then lock2
synchronized(lock1) {
    synchronized(lock2) {
        // critical section
    }
}

This guarantees that a cyclic wait will not occur, thus preventing deadlock.