// Stop the worker process
func (w *Worker) Stop(replyChan chan<- CommandReply) {
//err := syscall.Kill(worker.Pid, syscall.SIGTERM)
proc, err := os.FindProcess(w.Pid)
if nil != err {
w.Logger.Printf("worker.Stop(): Cannot find worker process %d: %s\n", w.Pid, err)
//w.exitChannel <- w.dtoppedCommand(err, state, stalled)
replyChan <- CommandReply{Reply: fmt.Sprintf("[%s] worker process %d already stopped", w.Taskname, w.Pid)}
return
}
// attempt stopping the worker with a SIGTERM first
err = proc.Signal(syscall.SIGTERM)
if err != nil {
if err.Error() == "os: process already finished" {
w.Logger.Println("worker.Stop() SIGTERM sent to already dead process")
} else {
w.Logger.Printf("worker.Stop(): Error sending SIGTERM to worker process %d: %s\n", w.Pid, err)
}
}
var msg string
var cmd Command
var state *os.ProcessState
gracePeriod := time.Duration(w.GracePeriod) * time.Millisecond
// wait until the process returns gracefully from the SIGTERM, or times out + is killed after a grace period
select {
case <-time.After(gracePeriod):
w.Logger.Printf("Grace Period (%s) expired, killing worker process %d", gracePeriod, w.Pid)
err = proc.Kill()
msg = fmt.Sprintf("Worker process %d was still around after %s, killed.", w.Pid, gracePeriod)
if nil != err {
msg = fmt.Sprintf("worker.Stop(): Failed to kill process %d - %s", w.Pid, err.Error())
}
cmd = <-w.exitChannel // coming from waitOnProcess()
cmd.Params["killed"] = true
case cmd = <-w.exitChannel: // wait for the original waitpid() syscall in waitOnProcess() to return
cmd.Params["killed"] = false
err = nil
msg = fmt.Sprintf("Worker process %d terminated gracefully", w.Pid)
if state2, ok := cmd.Params["state"]; ok {
state, ok = state2.(*os.ProcessState)
}
if err2, ok := cmd.Params["error"]; ok {
if err, ok = err2.(error); ok {
msg = fmt.Sprintf("Worker process %d terminated with error: (%T) %#v (%s)", w.Pid, err, err, state.String())
}
}
}
cmd.Params["stalled"] = w.HasStalled()
//w.Logger.Println(msg)
replyChan <- CommandReply{Reply: msg, Error: err}
w.TaskFeedbackChannel <- cmd
}
