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/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package main
func signalSend(s chan<- struct{}) {
select {
case s <- struct{}{}:
default:
}
}
type Signal struct {
enabled AtomicBool
C chan struct{}
}
func NewSignal() (s Signal) {
s.C = make(chan struct{}, 1)
s.Enable()
return
}
func (s *Signal) Close() {
close(s.C)
}
func (s *Signal) Disable() {
s.enabled.Set(false)
s.Clear()
}
func (s *Signal) Enable() {
s.enabled.Set(true)
}
/* Unblock exactly one listener
*/
func (s *Signal) Send() {
if s.enabled.Get() {
select {
case s.C <- struct{}{}:
default:
}
}
}
/* Clear the signal if already fired
*/
func (s Signal) Clear() {
select {
case <-s.C:
default:
}
}
/* Unblocks all listeners (forever)
*/
func (s Signal) Broadcast() {
if s.enabled.Get() {
close(s.C)
}
}
/* Wait for the signal
*/
func (s Signal) Wait() chan struct{} {
return s.C
}
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