34 lines
788 B
Go
34 lines
788 B
Go
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package signal
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import (
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"sync"
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)
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// Signal lets goroutines signal that some event has occurred. Other goroutines can wait for the signal.
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type Signal struct {
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ch chan struct{}
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once sync.Once
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}
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// New wraps a channel and turns it into a signal for a one-time event.
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func New(ch chan struct{}) *Signal {
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return &Signal{
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ch: ch,
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once: sync.Once{},
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}
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}
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// Notify alerts any goroutines waiting on this signal that the event has occurred.
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// After the first call to Notify(), future calls are no-op.
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func (s *Signal) Notify() {
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s.once.Do(func() {
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close(s.ch)
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})
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}
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// Wait returns a channel which will be written to when Notify() is called for the first time.
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// This channel will never be written to a second time.
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func (s *Signal) Wait() <-chan struct{} {
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return s.ch
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}
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