goext/syncext/atomic.go
2022-11-30 23:40:59 +01:00

105 lines
1.7 KiB
Go

package syncext
import (
"context"
"sync/atomic"
"time"
)
type AtomicBool struct {
v int32
waiter chan bool // unbuffered
}
func NewAtomicBool(value bool) *AtomicBool {
if value {
return &AtomicBool{v: 1, waiter: make(chan bool)}
} else {
return &AtomicBool{v: 0, waiter: make(chan bool)}
}
}
func (a *AtomicBool) Get() bool {
return atomic.LoadInt32(&a.v) == 1
}
func (a *AtomicBool) Set(value bool) {
if value {
atomic.StoreInt32(&a.v, 1)
} else {
atomic.StoreInt32(&a.v, 0)
}
select {
case a.waiter <- value:
// message sent
default:
// no receiver on channel
}
}
func (a *AtomicBool) Wait(waitFor bool) {
if a.Get() == waitFor {
return
}
for {
if v, ok := ReadChannelWithTimeout(a.waiter, 128*time.Millisecond); ok {
if v == waitFor {
return
}
} else {
if a.Get() == waitFor {
return
}
}
}
}
func (a *AtomicBool) WaitWithTimeout(timeout time.Duration, waitFor bool) error {
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
return a.WaitWithContext(ctx, waitFor)
}
func (a *AtomicBool) WaitWithContext(ctx context.Context, waitFor bool) error {
if err := ctx.Err(); err != nil {
return err
}
if a.Get() == waitFor {
return nil
}
for {
if err := ctx.Err(); err != nil {
return err
}
timeOut := 128 * time.Millisecond
if dl, ok := ctx.Deadline(); ok {
timeOutMax := dl.Sub(time.Now())
if timeOutMax <= 0 {
timeOut = 0
} else if 0 < timeOutMax && timeOutMax < timeOut {
timeOut = timeOutMax
}
}
if v, ok := ReadChannelWithTimeout(a.waiter, timeOut); ok {
if v == waitFor {
return nil
}
} else {
if err := ctx.Err(); err != nil {
return err
}
if a.Get() == waitFor {
return nil
}
}
}
}