Type-safe atomic values for Go
One issue with Go's sync/atomic package is that there is no guarantee from the type system that operations on an integer value will be applied through the sync/atomic functions. This package solves that and introduces two type-safe interfaces for use with integer and non-integer atomic values.
The first interface is for any value:
// Value represents a value that can be atomically loaded or replaced.
type Value[T any] interface {
// Load value atomically.
Load() T
// Store value atomically.
Store(value T)
// Swap the previous value with the new value atomically.
Swap(new T) (old T)
// CompareAndSwap the previous value with new if its value is "old".
CompareAndSwap(old, new T) (swapped bool)
}
The second interface is a Value[T] constrained to the 32 and 64 bit integer types and adds a single Add() method:
// Int expresses atomic operations on signed or unsigned integer values.
type Int[T atomicint] interface {
Value[T]
// Add a value and return the new result.
Add(delta T) (new T)
}
Performance
BenchmarkInt64Add
BenchmarkInt64Add-8 174217112 6.887 ns/op
BenchmarkIntInterfaceAdd
BenchmarkIntInterfaceAdd-8 174129980 6.889 ns/op
BenchmarkStdlibInt64Add
BenchmarkStdlibInt64Add-8 174152660 6.887 ns/op
BenchmarkInterfaceStore
BenchmarkInterfaceStore-8 16015668 76.17 ns/op
BenchmarkValueStore
BenchmarkValueStore-8 16155405 75.03 ns/op
BenchmarkStdlibValueStore
BenchmarkStdlibValueStore-8 16391035 74.85 ns/op
