What problems can be encountered in a multithreaded environment?

In a multithreaded environment, you may encounter several issues related to concurrent access to shared resources:

• Race conditions: when multiple threads read and write the same data simultaneously without proper synchronization, leading to unpredictable results.
• Deadlocks: a situation where two or more threads block each other forever, waiting for resources to be released.
• Starvation: when one thread constantly gains access to resources while another does not, due to priorities or improper scheduler organization.
• Visibility issues: changes made by one thread may not be visible to others without using volatile or synchronization.
• Performance problems due to excessive synchronization: locks can reduce parallelism and increase delays.

To address these issues, Java provides synchronization mechanisms, volatile, atomic classes from java.util.concurrent.atomic, and high-level constructs from java.util.concurrent.