What data type can be used to store a sequence of elements in programming?

Deadlock is a situation in a multithreaded system where two or more threads permanently block each other, waiting for resources held by each other.

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 can continue because each is waiting for the resource held by the other.

To prevent deadlocks, the following are used:

• ordering resource acquisition (all threads acquire resources in the same order);
• using timeouts when waiting for locks;
• avoiding nested locking.

In Java, this is often related to the use of synchronized blocks or Lock objects.