// 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 }