What difficulties can arise when two threads simultaneously change the value of a variable?

When the value of a variable is changed simultaneously by two threads, the following issues may arise:

• Race conditions: if both threads read and write the variable's value without synchronization, the final value can be unpredictable.
• Violation of atomicity of operations: operations like increment (x = x + 1) are not atomic, so they can be interrupted by another thread, leading to lost updates.
• Unpredictable behavior and bugs: it is difficult to trace and reproduce errors related to concurrent access.

To address these problems, Android typically uses synchronization mechanisms such as the synchronized keyword, classes from java.util.concurrent (e.g., AtomicInteger), or other approaches to ensure thread safety.