How can mutual process blocking be avoided or eliminated in a system?

Mutual exclusion (deadlock) occurs when two or more processes are permanently waiting for resources held by each other. To avoid or eliminate deadlock, the following approaches are used:

1. Avoid cyclic dependencies: always request resources in the same order to prevent waiting cycles.
2. Use timeouts: attempt to acquire a resource with a timeout to avoid waiting indefinitely, and release already acquired resources if unsuccessful.
3. Avoid hold and wait: processes should request all necessary resources at once or release already held resources if they cannot obtain all at once.
4. Apply detection and recovery algorithms: periodically check the system for deadlock and, upon detection, interrupt or roll back one of the processes.

In Java, for example, you can use tryLock with a timeout from java.util.concurrent.locks.Lock to prevent mutual locking:

Lock lock1 = new ReentrantLock();
Lock lock2 = new ReentrantLock();

if(lock1.tryLock(1000, TimeUnit.MILLISECONDS)) {
    try {
        if(lock2.tryLock(1000, TimeUnit.MILLISECONDS)) {
            try {
                // critical section
            } finally {
                lock2.unlock();
            }
        }
    } finally {
        lock1.unlock();
    }
}

This approach helps avoid infinite waiting and deadlock.