sort: use math/rand/v2 in tests and benchmarks

This allows to drop the use of deprecated rand.Seed in benchmarks.

Fixes #61142

Change-Id: I628848c0d4a500dc9a361930c393e47c3361a95c
Reviewed-on: https://go-review.googlesource.com/c/go/+/551155
Reviewed-by: Eli Bendersky <eliben@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/sort/sort_slices_benchmark_test.go b/src/sort/sort_slices_benchmark_test.go
index 37f3b1bc7e443ad94ec2be5aee8d2560a33dfdb0..069536df03b33ceea1ae2cbc59fcfc9805c9e268 100644 (file)
--- a/src/sort/sort_slices_benchmark_test.go
+++ b/src/sort/sort_slices_benchmark_test.go
@@ -5,7 +5,7 @@
 package sort_test
 
 import (
-       "math/rand"
+       "math/rand/v2"
        "slices"
        . "sort"
        "strconv"
@@ -18,10 +18,10 @@ import (
 // package).
 
 func makeRandomInts(n int) []int {
-       rand.Seed(42)
+       r := rand.New(rand.NewPCG(42, 0))
        ints := make([]int, n)
        for i := 0; i < n; i++ {
-               ints[i] = rand.Intn(n)
+               ints[i] = r.IntN(n)
        }
        return ints
 }
@@ -92,14 +92,14 @@ func BenchmarkSlicesIsSorted(b *testing.B) {
 // makeRandomStrings generates n random strings with alphabetic runes of
 // varying lengths.
 func makeRandomStrings(n int) []string {
-       rand.Seed(42)
+       r := rand.New(rand.NewPCG(42, 0))
        var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
        ss := make([]string, n)
        for i := 0; i < n; i++ {
                var sb stringspkg.Builder
-               slen := 2 + rand.Intn(50)
+               slen := 2 + r.IntN(50)
                for j := 0; j < slen; j++ {
-                       sb.WriteRune(letters[rand.Intn(len(letters))])
+                       sb.WriteRune(letters[r.IntN(len(letters))])
                }
                ss[i] = sb.String()
        }
@@ -156,10 +156,10 @@ func (s myStructs) Less(i, j int) bool { return s[i].n < s[j].n }
 func (s myStructs) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 
 func makeRandomStructs(n int) myStructs {
-       rand.Seed(42)
+       r := rand.New(rand.NewPCG(42, 0))
        structs := make([]*myStruct, n)
        for i := 0; i < n; i++ {
-               structs[i] = &myStruct{n: rand.Intn(n)}
+               structs[i] = &myStruct{n: r.IntN(n)}
        }
        return structs
 }

diff --git a/src/sort/sort_test.go b/src/sort/sort_test.go
index ccb89873afb4ef6bcd9db0c3d6edaad1eded3103..ba757a845aaed42a4ffb3c9ca2a9902f793a15e3 100644 (file)
--- a/src/sort/sort_test.go
+++ b/src/sort/sort_test.go
@@ -9,7 +9,7 @@ import (
        "fmt"
        "internal/testenv"
        "math"
-       "math/rand"
+       "math/rand/v2"
        "slices"
        . "sort"
        "strconv"
@@ -110,7 +110,7 @@ func TestSortLarge_Random(t *testing.T) {
        }
        data := make([]int, n)
        for i := 0; i < len(data); i++ {
-               data[i] = rand.Intn(100)
+               data[i] = rand.IntN(100)
        }
        if IntsAreSorted(data) {
                t.Fatalf("terrible rand.rand")
@@ -198,7 +198,7 @@ func TestNonDeterministicComparison(t *testing.T) {
        }()
 
        td := &nonDeterministicTestingData{
-               r: rand.New(rand.NewSource(0)),
+               r: rand.New(rand.NewPCG(0, 0)),
        }
 
        for i := 0; i < 10; i++ {
@@ -442,13 +442,13 @@ func testBentleyMcIlroy(t *testing.T, sort func(Interface), maxswap func(int) in
                                        case _Sawtooth:
                                                data[i] = i % m
                                        case _Rand:
-                                               data[i] = rand.Intn(m)
+                                               data[i] = rand.IntN(m)
                                        case _Stagger:
                                                data[i] = (i*m + i) % n
                                        case _Plateau:
                                                data[i] = min(i, m)
                                        case _Shuffle:
-                                               if rand.Intn(m) != 0 {
+                                               if rand.IntN(m) != 0 {
                                                        j += 2
                                                        data[i] = j
                                                } else {
@@ -648,7 +648,7 @@ func TestStability(t *testing.T) {
 
        // random distribution
        for i := 0; i < len(data); i++ {
-               data[i].a = rand.Intn(m)
+               data[i].a = rand.IntN(m)
        }
        if IsSorted(data) {
                t.Fatalf("terrible rand.rand")
@@ -704,7 +704,7 @@ func countOps(t *testing.T, algo func(Interface), name string) {
                        maxswap: 1<<31 - 1,
                }
                for i := 0; i < n; i++ {
-                       td.data[i] = rand.Intn(n / 5)
+                       td.data[i] = rand.IntN(n / 5)
                }
                algo(&td)
                t.Logf("%s %8d elements: %11d Swap, %10d Less", name, n, td.nswap, td.ncmp)