forked from kataras/iris
/
interrupt.go
76 lines (67 loc) · 2.03 KB
/
interrupt.go
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package host
import (
"os"
"os/signal"
"sync"
"syscall"
)
// RegisterOnInterrupt registers a global function to call when CTRL+C/CMD+C pressed or a unix kill command received.
func RegisterOnInterrupt(cb func()) {
Interrupt.Register(cb)
}
// Interrupt watches the os.Signals for interruption signals
// and fires the callbacks when those happens.
// A call of its `FireNow` manually will fire and reset the registered interrupt handlers.
var Interrupt = new(interruptListener)
type interruptListener struct {
mu sync.Mutex
once sync.Once
// onInterrupt contains a list of the functions that should be called when CTRL+C/CMD+C or
// a unix kill command received.
onInterrupt []func()
}
// Register registers a global function to call when CTRL+C/CMD+C pressed or a unix kill command received.
func (i *interruptListener) Register(cb func()) {
if cb == nil {
return
}
i.listenOnce()
i.mu.Lock()
i.onInterrupt = append(i.onInterrupt, cb)
i.mu.Unlock()
}
// FireNow can be called more than one times from a Consumer in order to
// execute all interrupt handlers manually.
func (i *interruptListener) FireNow() {
i.mu.Lock()
for _, f := range i.onInterrupt {
f()
}
i.onInterrupt = i.onInterrupt[0:0]
i.mu.Unlock()
}
// listenOnce fires a goroutine which calls the interrupt handlers when CTRL+C/CMD+C and e.t.c.
// If `FireNow` called before then it does nothing when interrupt signal received,
// so it's safe to be used side by side with `FireNow`.
//
// Btw this `listenOnce` is called automatically on first register, it's useless for outsiders.
func (i *interruptListener) listenOnce() {
i.once.Do(func() { go i.notifyAndFire() })
}
func (i *interruptListener) notifyAndFire() {
ch := make(chan os.Signal, 1)
signal.Notify(ch,
// kill -SIGINT XXXX or Ctrl+c
os.Interrupt,
syscall.SIGINT, // register that too, it should be ok
// os.Kill is equivalent with the syscall.SIGKILL
os.Kill,
syscall.SIGKILL, // register that too, it should be ok
// kill -SIGTERM XXXX
syscall.SIGTERM,
)
select {
case <-ch:
i.FireNow()
}
}