Atomképességet

Atomképességet, often translated as "atomicity" or "atom-like capability," refers to the property of a computational operation to be executed as a single, indivisible unit. This means that the operation either completes entirely and successfully, or it fails entirely, with no intermediate states observable by other processes or threads. In essence, it is an all-or-nothing guarantee.

The concept of atomicity is crucial in concurrent programming and database systems to ensure data integrity and prevent race conditions. When multiple threads or processes access and modify shared data, an atomic operation guarantees that the sequence of changes it performs will not be interrupted by other operations. This prevents situations where a partial update could leave data in an inconsistent or corrupted state.

For example, consider a simple operation of incrementing a counter. In a non-atomic execution, this might involve three steps: reading the current value, adding one to it, and writing the new value back. If two threads attempt to increment the counter concurrently, they might both read the same initial value, perform the addition, and then write back the same incremented value, resulting in the counter being incremented only once instead of twice. An atomic increment operation ensures that these three steps are treated as a single, uninterruptible unit, guaranteeing the correct outcome.

Atomic operations are often implemented using specialized hardware instructions or operating system primitives. They are fundamental building blocks for more complex synchronization mechanisms like locks and semaphores, which are used to manage access to shared resources in multi-threaded environments.