1 files changed, 47 insertions, 0 deletions
diff --git a/misc/cgo/stdio/fib.go b/misc/cgo/stdio/fib.go
new file mode 100644
index 000000000..c02e31fd8
--- /dev/null
+++ b/misc/cgo/stdio/fib.go
@@ -0,0 +1,47 @@
+// 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.
+
+// Compute Fibonacci numbers with two goroutines
+// that pass integers back and forth.  No actual
+// concurrency, just threads and synchronization
+// and foreign code on multiple pthreads.
+
+package main
+
+import (
+	"runtime"
+	"stdio"
+	"strconv"
+)
+
+func fibber(c, out chan int64, i int64) {
+	// Keep the fibbers in dedicated operating system
+	// threads, so that this program tests coordination
+	// between pthreads and not just goroutines.
+	runtime.LockOSThread()
+
+	if i == 0 {
+		c <- i
+	}
+	for {
+		j := <-c
+		stdio.Stdout.WriteString(strconv.Itoa64(j) + "\n")
+		out <- j
+		<-out
+		i += j
+		c <- i
+	}
+}
+
+func main() {
+	c := make(chan int64)
+	out := make(chan int64)
+	go fibber(c, out, 0)
+	go fibber(c, out, 1)
+	<-out
+	for i := 0; i < 90; i++ {
+		out <- 1
+		<-out
+	}
+}