netbird/connection/cond.go
2021-05-01 12:45:37 +02:00

33 lines
645 B
Go

package connection
import "sync"
// A Cond is a condition variable like sync.Cond, but using a channel so we can use select.
type Cond struct {
once sync.Once
C chan struct{}
}
// NewCond creates a new condition variable.
func NewCond() *Cond {
return &Cond{C: make(chan struct{})}
}
// Do runs f if the condition hasn't been signaled yet. Afterwards it will be signaled.
func (c *Cond) Do(f func()) {
c.once.Do(func() {
f()
close(c.C)
})
}
// Signal closes the condition variable channel.
func (c *Cond) Signal() {
c.Do(func() {})
}
// Wait waits for the condition variable channel to close.
func (c *Cond) Wait() {
<-c.C
}