What is deadlock and race condition?

Deadlock — a situation in a multithreaded or distributed system where two or more processes permanently block each other, waiting for resources held by the other. As a result, none of them can continue working.

Example: Thread A holds resource 1 and waits for resource 2, which is held by Thread B, while Thread B waits for resource 1.

Race condition — a situation where the outcome of a program depends on the unpredictable order of execution of operations in parallel threads or processes. This can lead to errors if access to shared data is not synchronized.

Example: Two threads read and modify a shared variable simultaneously without locks, resulting in an incorrect final value.

Both phenomena are related to parallelism and require proper synchronization and design to prevent.