From 03cf170900a47e66b256f8466c05d850e027bd79 Mon Sep 17 00:00:00 2001
From: Christian Worm Mortensen <cworm@akamai.com>
Date: Tue, 9 Apr 2024 15:10:17 +0200
Subject: [PATCH] Take lock when reading clock information. This is to avoid
 races reported by the go race detector.

---
 qdisc_linux.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/qdisc_linux.go b/qdisc_linux.go
index 3c3780d..9c53885 100644
--- a/qdisc_linux.go
+++ b/qdisc_linux.go
@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"strconv"
 	"strings"
+	"sync"
 	"syscall"
 
 	"github.com/vishvananda/netlink/nl"
@@ -688,6 +689,9 @@ var (
 	tickInUsec  float64
 	clockFactor float64
 	hz          float64
+
+	// Without this, the go race detector may report races.
+	initClockMutex sync.Mutex
 )
 
 func initClock() {
@@ -722,6 +726,8 @@ func initClock() {
 }
 
 func TickInUsec() float64 {
+	initClockMutex.Lock()
+	defer initClockMutex.Unlock()
 	if tickInUsec == 0.0 {
 		initClock()
 	}
@@ -729,6 +735,8 @@ func TickInUsec() float64 {
 }
 
 func ClockFactor() float64 {
+	initClockMutex.Lock()
+	defer initClockMutex.Unlock()
 	if clockFactor == 0.0 {
 		initClock()
 	}
@@ -736,6 +744,8 @@ func ClockFactor() float64 {
 }
 
 func Hz() float64 {
+	initClockMutex.Lock()
+	defer initClockMutex.Unlock()
 	if hz == 0.0 {
 		initClock()
 	}