From 995c816a7a9190db1ac0870cf2c424385b03ac4b Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Fri, 30 Aug 2024 00:23:50 -0700
Subject: [PATCH] internal/testenv: use sync.OnceValues for hasSymlink

On some platforms (android, wasip1) this function is called many
times which probably results in some slowdown, especially for wasip1.

Wrap it into sync.OnceValues.

Change-Id: Id290ffd8d1e7ad806302f457e8fff2e3123b49a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/609418
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
---
 src/internal/testenv/testenv_notwin.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/internal/testenv/testenv_notwin.go b/src/internal/testenv/testenv_notwin.go
index 30e159a6ec..9dddea94d0 100644
--- a/src/internal/testenv/testenv_notwin.go
+++ b/src/internal/testenv/testenv_notwin.go
@@ -11,9 +11,10 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"sync"
 )
 
-func hasSymlink() (ok bool, reason string) {
+var hasSymlink = sync.OnceValues(func() (ok bool, reason string) {
 	switch runtime.GOOS {
 	case "plan9":
 		return false, ""
@@ -43,4 +44,4 @@ func hasSymlink() (ok bool, reason string) {
 	}
 
 	return true, ""
-}
+})
-- 
2.48.1