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// Copyright 2017 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 runtime_test
import (
. "runtime"
"strconv"
"testing"
_ "unsafe" // for go:linkname
)
func TestReadRandom(t *testing.T) {
if *ReadRandomFailed {
switch GOOS {
default:
t.Fatalf("readRandom failed at startup")
case "plan9":
// ok
}
}
}
func BenchmarkFastrand(b *testing.B) {
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
Fastrand()
}
})
}
func BenchmarkFastrand64(b *testing.B) {
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
Fastrand64()
}
})
}
func BenchmarkFastrandHashiter(b *testing.B) {
var m = make(map[int]int, 10)
for i := 0; i < 10; i++ {
m[i] = i
}
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
for range m {
break
}
}
})
}
var sink32 uint32
func BenchmarkFastrandn(b *testing.B) {
for n := uint32(2); n <= 5; n++ {
b.Run(strconv.Itoa(int(n)), func(b *testing.B) {
for i := 0; i < b.N; i++ {
sink32 = Fastrandn(n)
}
})
}
}
//go:linkname fastrand runtime.fastrand
func fastrand() uint32
//go:linkname fastrandn runtime.fastrandn
func fastrandn(uint32) uint32
//go:linkname fastrand64 runtime.fastrand64
func fastrand64() uint64
func TestLegacyFastrand(t *testing.T) {
// Testing mainly that the calls work at all,
// but check that all three don't return the same number (1 in 2^64 chance)
{
x, y, z := fastrand(), fastrand(), fastrand()
if x == y && y == z {
t.Fatalf("fastrand three times = %#x, %#x, %#x, want different numbers", x, y, z)
}
}
{
x, y, z := fastrandn(1e9), fastrandn(1e9), fastrandn(1e9)
if x == y && y == z {
t.Fatalf("fastrandn three times = %#x, %#x, %#x, want different numbers", x, y, z)
}
}
{
x, y, z := fastrand64(), fastrand64(), fastrand64()
if x == y && y == z {
t.Fatalf("fastrand64 three times = %#x, %#x, %#x, want different numbers", x, y, z)
}
}
}
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