Does the use of functional programming allow avoiding issues related to thread contention?

The use of functional programming (FP) can significantly reduce issues related to thread contention, but it is not always possible to completely avoid them.

Main reasons:

• In FP, data is usually immutable, which eliminates shared mutable state that can be changed by multiple threads simultaneously. This reduces the need for locks and synchronization.
• The absence of side effects and pure functions simplify parallel execution of code.

However:

• If the program still has shared mutable state (for example, interaction with external resources, input-output, global variables), thread contention issues can arise.
• Some operations, such as database or filesystem interactions, require synchronization regardless of the programming style.

Thus, FP helps reduce risks and simplifies writing thread-safe code, but does not guarantee complete elimination of thread contention problems.