You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
ntool/nstd/chan.go

64 lines
1.5 KiB
Go

package nstd
import (
"context"
"fmt"
"io"
"os"
"os/signal"
"syscall"
)
// WaitCloseSignals for some huang program.
func WaitCloseSignals(closer io.Closer) error {
signals := make(chan os.Signal, 1)
signal.Notify(signals, os.Interrupt, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGINT)
<-signals
return closer.Close()
}
// Go is a basic promise implementation: it wraps calls a function in a goroutine
// and returns a channel which will later return the function's return value.
func Go(f func() error) error {
ch := make(chan error)
go func() {
ch <- f()
}()
return <-ch
}
// SignalHandler returns an actor, i.e. an execute and interrupt func, that
// terminates with SignalError when the process receives one of the provided
// signals, or the parent context is canceled.
//
// from https://github.com/oklog/run/blob/master/actors.go
func SignalHandler(ctx context.Context, signals ...os.Signal) (execute func() error, interrupt func(error)) {
ctx, cancel := context.WithCancel(ctx)
return func() error {
c := make(chan os.Signal, 1)
signal.Notify(c, signals...)
defer signal.Stop(c)
select {
case sig := <-c:
return SignalError{Signal: sig}
case <-ctx.Done():
return ctx.Err()
}
}, func(error) {
cancel()
}
}
// SignalError is returned by the signal handler's execute function
// when it terminates due to a received signal.
type SignalError struct {
Signal os.Signal
}
// Error implements the error interface.
func (e SignalError) Error() string {
return fmt.Sprintf("received signal %s", e.Signal)
}