ooni-probe-cli/internal/engine/atomicx/atomicx.go

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// Package atomicx contains atomic int64/float64 that work also on 32 bit
// platforms. The main reason for rolling out this package is to avoid potential
// crashes when using 32 bit devices where we are atomically accessing a 64 bit
// variable that is not aligned. The solution to this issue is rather crude: use
// a normal variable and protect it using a normal mutex. While this could be
// disappointing in general, it seems fine to be done in our context where
// we mainly use atomic semantics for counting.
package atomicx
import (
"sync"
)
// Int64 is an int64 with atomic semantics.
type Int64 struct {
mu sync.Mutex
v int64
}
// NewInt64 creates a new int64 with atomic semantics.
func NewInt64() *Int64 {
return new(Int64)
}
// Add behaves like atomic.AddInt64
func (i64 *Int64) Add(delta int64) (newvalue int64) {
i64.mu.Lock()
i64.v += delta
newvalue = i64.v
i64.mu.Unlock()
return
}
// Load behaves like atomic.LoadInt64
func (i64 *Int64) Load() (v int64) {
i64.mu.Lock()
v = i64.v
i64.mu.Unlock()
return
}
// Float64 is an float64 with atomic semantics.
type Float64 struct {
mu sync.Mutex
v float64
}
// NewFloat64 creates a new float64 with atomic semantics.
func NewFloat64() *Float64 {
return new(Float64)
}
// Add behaves like AtomicInt64.Add but for float64
func (f64 *Float64) Add(delta float64) (newvalue float64) {
f64.mu.Lock()
f64.v += delta
newvalue = f64.v
f64.mu.Unlock()
return
}
// Load behaves like LoadInt64.Load buf for float64
func (f64 *Float64) Load() (v float64) {
f64.mu.Lock()
v = f64.v
f64.mu.Unlock()
return
}