Concurrency Quote by Brian Goetz
““Immutable objects are simple. They can only be in one state, which is carefully controlled by the constructor. One of the most difficult elements of program design is reasoning about the possible states of complex objects. Reasoning about the state of immutable objects, on the other hand, is trivial. Immutable objects are also safer. Passing a mutable object to untrusted code, or otherwise publishing it where untrusted code could find it, is dangerous — the untrusted code might modify its state, or, worse, retain a reference to it and modify its state later from another thread. On the other hand, immutable objects cannot be subverted in this manner by malicious or buggy code, so they are safe to share and publish freely without the need to make defensive copies.””
About This Quote
Source Book: Java Concurrency in Practice, 2006
Immutable objects simplify reasoning about program state, making code safer and easier to share without defensive copying.
In simple terms: Immutability makes code safer and simpler.
Key Takeaway
Prefer immutable structures for reliability.
Themes
software engineering
concurrency
security
Mood
technical
pragmatic
Type
educational
explanatory
When to use this quote
- API design
- multithreaded programming
- secure coding
- library development
Key Concepts
immutability
state management
Questions to Reflect On
- When is mutability necessary?
- How to balance performance and safety?
A Different Perspective
Immutability may reduce flexibility in certain designs.
