32 lines
605 B
Go
32 lines
605 B
Go
// Copyright (C) 2019 Marius Schellenberger
|
|
|
|
package db
|
|
|
|
import "sync/atomic"
|
|
|
|
type countMutex struct {
|
|
mu uint64
|
|
max uint64
|
|
c uint64
|
|
}
|
|
|
|
func (cm *countMutex) Lock() (uint64, uint64, bool) {
|
|
if atomic.CompareAndSwapUint64(&cm.mu, 0, 1) {
|
|
return 0, 0, true
|
|
}
|
|
return atomic.LoadUint64(&cm.max), atomic.LoadUint64(&cm.c), false
|
|
}
|
|
|
|
func (cm *countMutex) Set(max uint64) {
|
|
atomic.StoreUint64(&cm.max, max)
|
|
}
|
|
|
|
func (cm *countMutex) Inc() {
|
|
atomic.AddUint64(&cm.c, 1)
|
|
}
|
|
|
|
func (cm *countMutex) Unlock() {
|
|
atomic.StoreUint64(&cm.max, 0)
|
|
atomic.StoreUint64(&cm.c, 0)
|
|
atomic.StoreUint64(&cm.mu, 0)
|
|
}
|