blob: aac8fed4ef1b6971f069d2ea50178b9a7de22b58 [file] [log] [blame]
// Copyright 2015 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 race
package race_test
import (
"bytes"
"fmt"
"reflect"
"runtime"
"testing"
)
func TestRandomScheduling(t *testing.T) {
// Scheduler is most consistent with GOMAXPROCS=1.
// Use that to make the test most likely to fail.
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
const N = 10
out := make([][]int, N)
for i := 0; i < N; i++ {
c := make(chan int, N)
for j := 0; j < N; j++ {
go func(j int) {
c <- j
}(j)
}
row := make([]int, N)
for j := 0; j < N; j++ {
row[j] = <-c
}
out[i] = row
}
for i := 0; i < N; i++ {
if !reflect.DeepEqual(out[0], out[i]) {
return // found a different order
}
}
var buf bytes.Buffer
for i := 0; i < N; i++ {
fmt.Fprintf(&buf, "%v\n", out[i])
}
t.Fatalf("consistent goroutine execution order:\n%v", buf.String())
}