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go/misc/cgo/stdio/fib.go
Russ Cox 84dc501d20 test/run: use go tool compile + link instead of go run when possible
This cuts 6 seconds off all.bash with the new go command.
Not a ton, but also an easy 6 seconds to grab.

The -tags=use_go_run in the misc/cgo tests is just some
go command flag that will make run.go use go run,
but without making everything look stale.
(Those tests have relative imports,
so go tool compile+link is not enough.)

Change-Id: I43bf4bb661d3adde2b2d4aad5e8f64b97bc69ba9
Reviewed-on: https://go-review.googlesource.com/73994
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-31 13:21:05 +00:00

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986 B
Go

// cmpout -tags=use_go_run
// 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.
// +build test_run
// 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"
"strconv"
"../stdio"
)
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.FormatInt(j, 10) + "\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
}
}