From 476a3bc84c65b00fdfecb777c959dc9c87fbaff2 Mon Sep 17 00:00:00 2001
From: Mark McGranaghan <mmcgrana@gmail.com>
Date: Wed, 19 Sep 2012 17:45:54 -0700
Subject: [PATCH] graceful. not even mad

---
 README                                  | 24 +++++--
 src/34-embedding.go                     |  4 ++
 src/xx-http-server-graceful-shutdown.go | 86 +++++++++++++++++++++++++
 www/index.md                            |  2 +
 4 files changed, 112 insertions(+), 4 deletions(-)
 create mode 100644 src/xx-http-server-graceful-shutdown.go

diff --git a/README b/README
index 6aab25c..a058f10 100644
--- a/README
+++ b/README
@@ -33,12 +33,25 @@ gobyexample.com signups
 * updates forever
 * no drm
 
+= sources
+* effective go
+* chinese web apps book
+* http://news.ycombinator.com/item?id=4543818
+
 = topics
+* web app
+  * serve static files
+  * log requests
+  * basic auth
+  * force https
+  * force canonical host
+  * not found page
+  * error page
+  * graceful shutdown
+* string formatting
+* mongo
 * worker pool
 * rate limiting
-
-* string formatting
-* web app
 * time formatting
 * typed json parse/unparse
 * gzip
@@ -52,7 +65,9 @@ gobyexample.com signups
 * oauth for google domains
 * testing
 * markdown (blackfriday)
-* mongo
+* init functions
+* using gofmt
+* scrolls style logging
 
 * setting up go env, hello world
 * deploying to heroku
@@ -66,3 +81,4 @@ command line client for public json api
 redis server
 github webook receiver
 campfire bot
+http://www.youtube.com/watch?v=-i0hat7pdpk
diff --git a/src/34-embedding.go b/src/34-embedding.go
index 544abca..290baf1 100644
--- a/src/34-embedding.go
+++ b/src/34-embedding.go
@@ -49,3 +49,7 @@ func main() {
 	}
 	fmt.Println(area)
 }
+
+// == todo
+// is this named wrong?
+// note about embedding access
diff --git a/src/xx-http-server-graceful-shutdown.go b/src/xx-http-server-graceful-shutdown.go
new file mode 100644
index 0000000..b556a22
--- /dev/null
+++ b/src/xx-http-server-graceful-shutdown.go
@@ -0,0 +1,86 @@
+package main
+
+import ("net"; "net/http"; "time"; "os"; "os/signal"; "syscall"; "fmt"; "sync/atomic")
+
+func slow(res http.ResponseWriter, req *http.Request) {
+	fmt.Println("respond at=start")
+	time.Sleep(time.Second * 5)
+	res.Header().Set("Content-Type", "text/plain")
+	fmt.Fprintln(res, "Finally.")
+	fmt.Println("respond at=finish")
+}
+
+var connCount int64 = 0
+
+type watchedConn struct {
+	net.Conn
+}
+
+func (w *watchedConn) Close() error {
+	atomic.AddInt64(&connCount, -1)
+ 	return w.Conn.Close()
+}
+
+type watchedListener struct {
+	net.Listener
+}
+
+func (l *watchedListener) Accept() (net.Conn, error) {
+	conn, err := l.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+	atomic.AddInt64(&connCount, 1)
+	return &watchedConn{Conn: conn}, nil
+}
+
+func main() {
+	stop := make(chan bool, 1)
+	sig := make(chan os.Signal, 1)
+	
+	server := &http.Server{Handler: http.HandlerFunc(slow)}
+	fmt.Println("listen at=start")
+	listener, listenErr := net.Listen("tcp", ":5000")
+	if listenErr != nil { panic(listenErr) }
+	wListener := &watchedListener{Listener: listener}
+	fmt.Println("listen at=finish")
+
+	go func() {
+		<-stop
+		fmt.Println("close at=start")
+		closeErr := wListener.Close()
+		if closeErr != nil { panic(closeErr) }
+		fmt.Println("close at=finish")
+	}()
+
+	go func() {
+		signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
+		fmt.Println("trap at=start")
+		<- sig
+		stop <- true
+		fmt.Println("trap at=finish")
+	}()
+
+	fmt.Println("serve at=start")
+	server.Serve(wListener)	
+	fmt.Println("serve at=finish")
+	for {
+		connCountCurrent := atomic.LoadInt64(&connCount)
+		if connCountCurrent > 0 {
+			fmt.Println("wait at=pending remaining=", connCountCurrent)
+			time.Sleep(time.Second)
+		} else {
+			fmt.Println("wait at=finish remaining=", connCountCurrent)
+			return
+		}
+	}
+}
+
+// == running
+// $ cd src
+// $ go build xx-http-server-graceful-shutdown.go
+// $ ./xx-http-server-graceful-shutdown
+//
+// $ curl -i http://127.0.0.1:5000/
+//
+// ^C
diff --git a/www/index.md b/www/index.md
index b34a326..1061241 100644
--- a/www/index.md
+++ b/www/index.md
@@ -7,7 +7,9 @@ consisting of more than a hundred complete Go programs. The book
 covers everything from getting started to writing sophisticated
 concurrent programs.
 
+Sign up to hear when an early release is ready:
 
+[ you@domain.com]
 
 You'll learn the basic of Go and how to build real-world programs
 like database-backed web sites.