doc: add Go Concurrency Patterns: Timing out, moving on article

Originally published on The Go Programming Language Blog, September 23, 2010.

http://blog.golang.org/2010/09/go-concurrency-patterns-timing-out-and.html

Update issue 2547.

R=golang-dev, adg
CC=golang-dev
http://codereview.appspot.com/5815044

Committer: Andrew Gerrand <adg@golang.org>

3 files changed, 61 insertions, 1 deletions

diff --git a/doc/progs/run b/doc/progs/run
index 4d183530c..3bd50beda 100755
--- a/doc/progs/run
+++ b/doc/progs/run
@@ -41,7 +41,12 @@ if [ "$goos" == "freebsd" ]; then
 	c_go_cgo="cgo3 cgo4"
 fi
 
-all=$(echo $defer_panic_recover $effective_go $error_handling $law_of_reflection $c_go_cgo slices go1)
+timeout="
+	timeout1
+	timeout2
+"
+
+all=$(echo $defer_panic_recover $effective_go $error_handling $law_of_reflection $c_go_cgo $timeout slices go1)
 
 for i in $all; do
 	go build $i.go
diff --git a/doc/progs/timeout1.go b/doc/progs/timeout1.go
new file mode 100644
index 000000000..a6c95624c
--- /dev/null
+++ b/doc/progs/timeout1.go
@@ -0,0 +1,28 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+package timeout
+
+import (
+	"time"
+)
+
+func Timeout() {
+	ch := make(chan bool, 1)
+	timeout := make(chan bool, 1)
+	go func() {
+		time.Sleep(1e9) // one second
+		timeout <- true
+	}()
+
+	// STOP OMIT
+
+	select {
+	case <-ch:
+		// a read from ch has occurred
+	case <-timeout:
+		// the read from ch has timed out
+	}
+
+	// STOP OMIT
+}
diff --git a/doc/progs/timeout2.go b/doc/progs/timeout2.go
new file mode 100644
index 000000000..7145bc93e
--- /dev/null
+++ b/doc/progs/timeout2.go
@@ -0,0 +1,27 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+package query
+
+type Conn string
+
+func (c Conn) DoQuery(query string) Result {
+	return Result("result")
+}
+
+type Result string
+
+func Query(conns []Conn, query string) Result {
+	ch := make(chan Result, 1)
+	for _, conn := range conns {
+		go func(c Conn) {
+			select {
+			case ch <- c.DoQuery(query):
+			default:
+			}
+		}(conn)
+	}
+	return <-ch
+}
+
+// STOP OMIT