storelimit: fix datarace on reset

Signed-off-by: lhy1024 <[email protected]>

pkg/core/storelimit/store_limit.go

@@ -17,6 +17,7 @@ package storelimit
 import (
 	"github.com/tikv/pd/pkg/core/constant"
 	"github.com/tikv/pd/pkg/ratelimit"
+	"github.com/tikv/pd/pkg/utils/syncutil"
 )
 
 const (
@@ -106,7 +107,7 @@ func (l *StoreRateLimit) Rate(typ Type) float64 {
 	if l.limits[typ] == nil {
 		return 0.0
 	}
-	return l.limits[typ].ratePerSec
+	return l.limits[typ].GetRatePerSec()
 }
 
 // Take takes count tokens from the bucket without blocking.
@@ -128,12 +129,15 @@ func (l *StoreRateLimit) Reset(rate float64, typ Type) {
 
 // limit the operators of a store
 type limit struct {
+	syncutil.RWMutex
 	limiter    *ratelimit.RateLimiter
 	ratePerSec float64
 }
 
 // Reset resets the rate limit.
 func (l *limit) Reset(ratePerSec float64) {
+	l.Lock()
+	defer l.Unlock()
 	if l.ratePerSec == ratePerSec {
 		return
 	}
@@ -155,6 +159,8 @@ func (l *limit) Reset(ratePerSec float64) {
 // Available returns the number of available tokens
 // It returns true if the rate per second is zero.
 func (l *limit) Available(n int64) bool {
+	l.RLock()
+	defer l.RUnlock()
 	if l.ratePerSec == 0 {
 		return true
 	}
@@ -164,8 +170,16 @@ func (l *limit) Available(n int64) bool {
 
 // Take takes count tokens from the bucket without blocking.
 func (l *limit) Take(count int64) bool {
+	l.RLock()
+	defer l.RUnlock()
 	if l.ratePerSec == 0 {
 		return true
 	}
 	return l.limiter.AllowN(int(count))
 }
+
+func (l *limit) GetRatePerSec() float64 {
+	l.RLock()
+	defer l.RUnlock()
+	return l.ratePerSec
+}