doorgo/door/write_linux.go

package door

import (
	"log"
	"strings"
	"syscall"
)

// https://go101.org/article/channel-closing.html
func Writer2(handle int, d *Door) {
	log.Println("Writer2")
	defer d.wg.Done()
	for {
		select {
		case <-d.closeChannel:
			// close((*d).writerChannel)
			log.Println("~Writer2")
			return
		default:
		}

		select {
		case <-d.closeChannel:
			// close((*d).writerChannel)
			log.Println("~Writer2")
			return

		case output, ok := <-d.writerChannel:
			if !ok {
				// (*d).writerChannel = nil
				log.Println("closeChannel")
				// close(d.closeChannel)
				d.Disconnected = true
				close(d.writerChannel)
				log.Println("~Writer2")
				return

//				d.closeChannel <- true
//				continue
			} else {
				// log.Println("output")
				if strings.HasSuffix(output, RestorePos) {
					output += Color(d.LastColor...)

				} else {
					d.UpdateLastColor(output, &d.LastColor)
				}
				// log.Println("write output")
				buffer := []byte(output)
				n, err := syscall.Write(handle, buffer)
				if (err != nil) || (n != len(buffer)) {
					// close((*d).writerChannel)
					// (*d).writerChannel = nil
					log.Println("closeChannel")
					// close(d.closeChannel)
					d.Disconnected = true
					close(d.writerChannel)
					log.Println("~Writer2")
					return
//					d.closeChannel <- true
//					continue
				}
			}
		}
	}
}

func Writer(handle int, writerChannel *chan string) {
	for output := range *writerChannel {
		buffer := []byte(output)
		n, err := syscall.Write(handle, buffer)
		if (err != nil) || (n != len(buffer)) {
			close(*writerChannel)
			break
		}
	}
}