From 1e0aa22d719571bea0bdcf832b512f681f3325cb Mon Sep 17 00:00:00 2001
From: Aoang <aoang@x2oe.com>
Date: Mon, 11 Mar 2024 20:56:04 +0800
Subject: [PATCH] Switch to use math/rand/v2.Uint32N and clean runtime.fastrand

Signed-off-by: Aoang <aoang@x2oe.com>
---
 go/hack/runtime.go             | 3 ---
 go/pools/smartconnpool/pool.go | 5 ++---
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/go/hack/runtime.go b/go/hack/runtime.go
index 83428504818..74bce583a84 100644
--- a/go/hack/runtime.go
+++ b/go/hack/runtime.go
@@ -46,6 +46,3 @@ func Atof64(s string) (float64, int, error)
 
 //go:linkname Atof32 strconv.atof32
 func Atof32(s string) (float32, int, error)
-
-//go:linkname FastRand runtime.fastrand
-func FastRand() uint32
diff --git a/go/pools/smartconnpool/pool.go b/go/pools/smartconnpool/pool.go
index 7c10d6ba4b0..a4317dc8447 100644
--- a/go/pools/smartconnpool/pool.go
+++ b/go/pools/smartconnpool/pool.go
@@ -18,12 +18,12 @@ package smartconnpool
 
 import (
 	"context"
+	"math/rand/v2"
 	"slices"
 	"sync"
 	"sync/atomic"
 	"time"
 
-	"vitess.io/vitess/go/hack"
 	"vitess.io/vitess/go/vt/log"
 	vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
 	"vitess.io/vitess/go/vt/servenv"
@@ -373,8 +373,7 @@ func (pool *ConnPool[D]) extendedMaxLifetime() time.Duration {
 	if maxLifetime == 0 {
 		return 0
 	}
-	extended := hack.FastRand() % uint32(maxLifetime)
-	return time.Duration(maxLifetime) + time.Duration(extended)
+	return time.Duration(maxLifetime) + time.Duration(rand.Uint32N(uint32(maxLifetime)))
 }
 
 func (pool *ConnPool[C]) connReopen(ctx context.Context, dbconn *Pooled[C], now time.Time) error {