Imported Upstream version 60upstream/60

1 files changed, 43 insertions, 0 deletions

diff --git a/misc/cgo/stdio/chain.go b/misc/cgo/stdio/chain.go
new file mode 100644
index 000000000..c188b2dd9
--- /dev/null
+++ b/misc/cgo/stdio/chain.go
@@ -0,0 +1,43 @@
+// Copyright 2009 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.
+
+// Pass numbers along a chain of threads.
+
+package main
+
+import (
+	"runtime"
+	"stdio"
+	"strconv"
+)
+
+const N = 10
+const R = 5
+
+func link(left chan<- int, right <-chan int) {
+	// Keep the links in dedicated operating system
+	// threads, so that this program tests coordination
+	// between pthreads and not just goroutines.
+	runtime.LockOSThread()
+	for {
+		v := <-right
+		stdio.Stdout.WriteString(strconv.Itoa(v) + "\n")
+		left <- 1 + v
+	}
+}
+
+func main() {
+	leftmost := make(chan int)
+	var left chan int
+	right := leftmost
+	for i := 0; i < N; i++ {
+		left, right = right, make(chan int)
+		go link(left, right)
+	}
+	for i := 0; i < R; i++ {
+		right <- 0
+		x := <-leftmost
+		stdio.Stdout.WriteString(strconv.Itoa(x) + "\n")
+	}
+}