Safe zero-copy operations in C#
6 hours ago
- #Performance
- #C#
- #Memory Management
- C# supports low-level, unsafe code with raw pointers for performance and interoperability.
- Bounds-checking in C# can impact performance, but the compiler can eliminate checks in certain scenarios.
- Unsafe code with pointers can be performant but is dangerous due to potential crashes or security vulnerabilities.
- C# introduces `Span<T>` for safe, zero-copy operations, combining a pointer with length in an immutable structure.
- `Span<T>` ensures safety by using ref types, which cannot escape to the heap and must live on the stack.
- Using `Span<T>` or `ReadOnlySpan<T>` eliminates bounds-checking and allows expressive sub-views of arrays.
- Spans enable zero-copy operations, improving performance and memory efficiency in APIs.
- Example: A `Quicksort` implementation with spans is both safe and performant, avoiding buffer overflows.
- .NET runtime now supports zero-copy alternatives for functions like `String.Split`, reducing memory allocations.
- Key takeaways: Prefer spans over arrays in APIs, avoid unsafe code when spans suffice, and use `ReadOnlySpan<T>` where possible.