Glossary · Automation software engineering and architecture
Garbage collection
Also known as: GC, Automatic memory management
German: Automatische Speicherbereinigung
In programming, garbage collection is a form of automatic memory management in which the runtime system identifies memory that is no longer reachable by the program and reclaims it, so developers do not free memory explicitly. It is used for example in Java, C#, Python and Go.
- Software engineering
In one sentence
Garbage collection automatically reclaims memory the program can no longer reach, so developers need not free it explicitly.
Example
An HMI application written in C# shows short freezes every few minutes; profiling reveals garbage collection pauses caused by many temporary objects created per screen update.
How it applies
- Engineering: Garbage collection prevents many memory errors, such as Dangling pointer defects and most leaks, and speeds up development. It is common in HMI, MES, edge and tool software.
- Real-time behavior: Collection pauses can delay execution unpredictably and increase Execution jitter. Hard real-time control therefore usually runs in languages and runtimes without garbage collection, or with specialized real-time collectors and allocation rules.
- Documentation: For applications where responsiveness matters, document the runtime version and relevant memory settings, and describe symptoms of memory pressure in service documentation.
Garbage collection vs. manual memory management
With manual management, as in C, the program frees memory itself, which is predictable but error-prone. Garbage collection trades some predictability for safety. Languages such as Rust use compile-time ownership rules as a third approach, achieving memory safety without a garbage collector.