first pass at using gaio for non-blocking net reads

go.sum

@@ -0,0 +1,2 @@
+github.com/xtaci/gaio v1.2.9 h1:EuVc7Q2JDzIY2mk5mjtq4K5BgTuO+kj5LXzCwjOK+mo=
+github.com/xtaci/gaio v1.2.9/go.mod h1:rJMerwiLCLnKa14YTM/sRggTPrnBZrlCg9U3DnV5VBE=

main.go

@@ -1,13 +1,11 @@
 package main
 
 import (
-	"bufio"
 	"flag"
-	"io"
 	"log"
 	"net"
-	"os/exec"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -38,108 +36,190 @@ func main() {
 			log.Panicln(err)
 		}
 
-		log.Println("new client", conn.RemoteAddr())
+		log.Println("new client: ", conn.RemoteAddr())
-
-		// set up io channel for this connection
-		chIO := make(chan gaio.OpResult)
 
 		// submit the first async write IO request
-		err = (chIO, conn, welcomeHandler())
+		err = w.Write(nil, conn, welcomeHandler())
 		if err != nil {
-            log.Printf("err sending welcomeHandler: %v\n", err)
+			log.Printf("err sending welcomeHandler: %v\n", err)
 			return
 		}
 		// hand off channel to menuHandler
-		menuHandler(chIO, conn, *w)
+		//		menuHandler(w, conn)
+		wg := new(sync.WaitGroup)
+
+		// chan to terminate watcher goroutine when necessary
+		WatcherControl := make(chan string)
+
+		// watcher.WaitIO goroutine
+		wg.Add(1)
+		go func(WatcherControl *chan string) {
+			log.Println("starting menu watchercontrol")
+			defer wg.Done()
+		ControlLoop:
+			for {
+				log.Println("checking watcher waitio")
+				select {
+				case msg := <-*WatcherControl:
+					if msg == "stop" {
+						log.Println("closing menu watchercontrol")
+						break ControlLoop
+					}
+				default:
+					log.Println("menu watchercontrol waiting for IO")
+					inBuf := make([]byte, 256)
+					err := w.ReadTimeout(nil, conn, inBuf, time.Now().Add(time.Second))
+					if err != nil {
+						log.Printf("err on watcher readtimeout in menu: %v\n", err)
+						continue
+					}
+					results, err := w.WaitIO()
+					if err != nil {
+						log.Println("watcher wait err: ", err)
+						continue
+					}
+
+					log.Println("menu received IO!")
+					for _, res := range results {
+						if res.Operation == gaio.OpRead && res.Size > 0 {
+							log.Println("menu receive: ", strings.TrimSpace(string(res.Buffer[:res.Size-2])))
+							switch string(strings.TrimSpace(string(res.Buffer[:res.Size-2]))) {
+							case "welcome":
+								if err := w.Write(nil, conn, welcomeHandler()); err != nil {
+									log.Printf("error sending welcomeHandler from cmd `welcome`: %v", err)
+								}
+							case "adventure":
+								// start the door and wait
+								log.Printf("starting door handler...")
+								/*
+									if err := doorHandler(&c); err != nil {
+										log.Printf("error from cmd `adventure`: %v", err)
+									}
+									log.Printf("returning from door")
+									n, err := c.Write([]byte("\n\n> "))
+									if err != nil {
+										log.Printf("error writing to connection: %v", err)
+									} else {
+										log.Printf("wrote %d byte prompt to connection", n)
+									}
+								*/
+							case "exit":
+								/*
+									if err := exitHandler(); err != nil {
+										log.Printf("error sending exitHandler from cmd `exit`: %v", err)
+									}
+								*/
+							default:
+								err := w.Write(nil, conn, []byte("huh?\n\n> "))
+								if err != nil {
+									log.Printf("error writing to connection: %v", err)
+								}
+							}
+						} else {
+							log.Println("watcher confirming write:", string(res.Buffer))
+						}
+					}
+				}
+				time.Sleep(time.Second)
+			}
+			log.Println("watcher controlloop closed!")
+		}(&WatcherControl)
+		log.Println("main thread waiting on wg")
+		wg.Wait()
+		log.Printf("Goodbye %s!", conn.RemoteAddr())
 	}
 }
 
-func menuHandler(chIO chan gaio.OpResult, c net.Conn, w gaio.Watcher) {
+func menuHandler(w *gaio.Watcher, c net.Conn) {
-	log.Printf("Connection received: %s", c.RemoteAddr())
-
-	// watcher.WaitIO goroutine
-	go func() {
-		for {
-			results, err := w.WaitIO()
-			if err != nil {
-				log.Println(err)
-				return
-			}
-
-			for _, res := range results {
-				chIO <- res
-			}
-		}
-	}()
-
-	// send welcome banner
-	if err := welcomeHandler(&c); err != nil {
-		log.Printf("error sending welcomeHandler on initial connect: %v", err)
-	}
-
 	wg := new(sync.WaitGroup)
 
+	// chan to terminate watcher goroutine when necessary
+	WatcherControl := make(chan string)
+
+	// watcher.WaitIO goroutine
 	wg.Add(1)
-	go func() {
+	go func(WatcherControl *chan string) {
+		log.Println("starting menu watchercontrol")
 		defer wg.Done()
-		scanner := bufio.NewScanner(c)
+	ControlLoop:
-		scanner.Split(bufio.ScanLines)
+		for {
-
+			log.Println("checking watcher waitio")
-		for scanner.Scan() {
+			select {
-			line := scanner.Bytes()
+			case msg := <-*WatcherControl:
-
+				if msg == "stop" {
-			log.Printf("Menu received line: %v (%v)", line, string(line))
+					log.Println("closing menu watchercontrol")
-			switch string(line) {
+					break ControlLoop
-			case "welcome":
-				if err := welcomeHandler(&c); err != nil {
-					log.Printf("error sending welcomeHandler from cmd `welcome`: %v", err)
-				}
-			case "adventure":
-				// start the door and wait
-				log.Printf("starting door handler...")
-				if err := doorHandler(&c); err != nil {
-					log.Printf("error from cmd `adventure`: %v", err)
-				}
-				log.Printf("returning from door")
-				n, err := c.Write([]byte("\n\n> "))
-				if err != nil {
-					log.Printf("error writing to connection: %v", err)
-				} else {
-					log.Printf("wrote %d byte prompt to connection", n)
-				}
-			case "exit":
-				if err := exitHandler(c); err != nil {
-					log.Printf("error sending exitHandler from cmd `exit`: %v", err)
 				}
 			default:
-				n, err := c.Write([]byte("huh?\n\n> "))
+				log.Println("menu watchercontrol waiting for IO")
+				results, err := w.WaitIO()
 				if err != nil {
-					log.Printf("error writing to connection: %v", err)
+					log.Println(err)
-				} else {
+					return
-					log.Printf("wrote %d bytes to connection", n)
+				}
+
+				log.Println("menu received IO!")
+				for _, res := range results {
+					if res.Operation == gaio.OpRead {
+						log.Println("menu receive: ", string(res.Buffer))
+						switch string(res.Buffer) {
+						case "":
+							// noop
+						case "welcome":
+							if err := w.Write(nil, c, welcomeHandler()); err != nil {
+								log.Printf("error sending welcomeHandler from cmd `welcome`: %v", err)
+							}
+						case "adventure":
+							// start the door and wait
+							log.Printf("starting door handler...")
+							/*
+								if err := doorHandler(&c); err != nil {
+									log.Printf("error from cmd `adventure`: %v", err)
+								}
+								log.Printf("returning from door")
+								n, err := c.Write([]byte("\n\n> "))
+								if err != nil {
+									log.Printf("error writing to connection: %v", err)
+								} else {
+									log.Printf("wrote %d byte prompt to connection", n)
+								}
+							*/
+						case "exit":
+							/*
+								if err := exitHandler(); err != nil {
+									log.Printf("error sending exitHandler from cmd `exit`: %v", err)
+								}
+							*/
+						default:
+							err := w.Write(nil, c, []byte("huh?\n\n> "))
+							if err != nil {
+								log.Printf("error writing to connection: %v", err)
+							}
+						}
+					} else {
+						log.Println("watcher confirming write:", string(res.Buffer))
+					}
 				}
 			}
+			time.Sleep(time.Second)
 		}
-	}()
+		log.Println("watcher controlloop closed!")
-
+	}(&WatcherControl)
-	time.Sleep(time.Millisecond)
+	log.Println("main thread waiting on wg")
 	wg.Wait()
 	log.Printf("Goodbye %s!", c.RemoteAddr())
 }
 
-func sendClientText(c net.Conn, s string) error {
+func sendClientText(w *gaio.Watcher, c net.Conn, s string) error {
-	n, err := c.Write([]byte(s))
+	err := w.Write(nil, c, []byte(s))
-	if err != nil { //	svr.ListenAndServe()
+	if err != nil {
-
 		log.Printf("error writing to connection: %v", err)
 		return err
-	} else {
-		log.Printf("wrote %d bytes to connection", n)
 	}
 	return nil
 }
 
-func welcomeHandler(c *net.Conn) error {
+func welcomeHandler() []byte {
 	const bannerText = "\x1b[2J\x1b[H\x1b[31m\x1b[J\r\n" + `
 
     _       __     _ ` + "" + `
@@ -163,13 +243,13 @@ func welcomeHandler(c *net.Conn) error {
                         ___/ / /_/ /_/ / /_/ / / /_/ (__  ) ` + "" + `
                        /____/\__/\__,_/\__,_/_/\____/____/  ` + "\x1b[32m\r\n\r\n\r\n" + `
    Help is available: type help` + "\r\n\r\n> "
-	err := sendClientText(*c, bannerText)
+
-	if err != nil {
+	return []byte(bannerText)
-		log.Printf("error writing to connection: %v", err)
-	}
-	return nil
 }
 
+/*
+
+
 func exitHandler(c net.Conn) error {
 	const exitMessage = "\x1b[2J\x1b[H\x1b[31m\x1b[J\r\n" + `
 
@@ -258,3 +338,4 @@ func doorHandler(c *net.Conn) error {
 	}
 	return nil
 }
+*/