Explain what a guaranteed deadlock in multithreaded programming means.

A guaranteed deadlock in multithreaded programming is a situation where two or more threads permanently block each other, waiting for resources held by each other. As a result, none of the threads can continue working.

Example: Thread A has acquired resource 1 and is waiting for resource 2, while Thread B has acquired resource 2 and is waiting for resource 1. Neither thread will release its resource, and the program will hang.

To avoid deadlocks, approaches such as:

• Acquiring resources in a specific order
• Using timeouts when waiting for locks
• Avoiding nested locks

are used.

In Java, this is especially important when working with synchronized blocks or Lock objects.