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package atomics
import (
"sync/atomic"
"time"
"unsafe"
)
// Time provides user-friendly means of performing atomic operations on time.Time types.
type Time struct{ ptr unsafe.Pointer }
// NewTime will return a new Time instance initialized with zero value.
func NewTime() *Time {
var v time.Time
return &Time{
ptr: unsafe.Pointer(&v),
}
}
// Store will atomically store time.Time value in address contained within v.
func (v *Time) Store(val time.Time) {
atomic.StorePointer(&v.ptr, unsafe.Pointer(&val))
}
// Load will atomically load time.Time value at address contained within v.
func (v *Time) Load() time.Time {
return *(*time.Time)(atomic.LoadPointer(&v.ptr))
}
// CAS performs a compare-and-swap for a(n) time.Time value at address contained within v.
func (v *Time) CAS(cmp, swp time.Time) bool {
for {
// Load current value at address
ptr := atomic.LoadPointer(&v.ptr)
cur := *(*time.Time)(ptr)
// Perform comparison against current
if !(cur.Equal(cmp)) {
return false
}
// Attempt to replace pointer
if atomic.CompareAndSwapPointer(
&v.ptr,
ptr,
unsafe.Pointer(&swp),
) {
return true
}
}
}
// Swap atomically stores new time.Time value into address contained within v, and returns previous value.
func (v *Time) Swap(swp time.Time) time.Time {
ptr := unsafe.Pointer(&swp)
ptr = atomic.SwapPointer(&v.ptr, ptr)
return *(*time.Time)(ptr)
}
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