*: remove unnecessary rand init

pkg/core/region_tree.go

@@ -16,7 +16,6 @@ package core
 import (
 	"bytes"
 	"math/rand"
-	"time"
 
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pingcap/log"
@@ -343,7 +342,3 @@ func (t *regionTree) TotalWriteRate() (bytesRate, keysRate float64) {
 	}
 	return t.totalWriteBytesRate, t.totalWriteKeysRate
 }
-
-func init() {
-	rand.New(rand.NewSource(time.Now().UnixNano()))
-}

pkg/mcs/tso/server/server.go

@@ -18,7 +18,6 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"math/rand"
 	"net"
 	"net/http"
 	"net/url"
@@ -627,7 +626,6 @@ func (s *Server) startServer() (err error) {
 
 // CreateServer creates the Server
 func CreateServer(ctx context.Context, cfg *Config) *Server {
-	rand.New(rand.NewSource(time.Now().UnixNano()))
 	svr := &Server{
 		DiagnosticsServer: sysutil.NewDiagnosticsServer(cfg.Log.File.Filename),
 		startTimestamp:    time.Now().Unix(),

pkg/member/member.go

@@ -334,7 +334,8 @@ func (m *EmbeddedEtcdMember) ResignEtcdLeader(ctx context.Context, from string,
 	if len(etcdLeaderIDs) == 0 {
 		return errors.New("no valid pd to transfer etcd leader")
 	}
-	nextEtcdLeaderID := etcdLeaderIDs[rand.Intn(len(etcdLeaderIDs))]
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	nextEtcdLeaderID := etcdLeaderIDs[r.Intn(len(etcdLeaderIDs))]
 	return m.MoveEtcdLeader(ctx, m.ID(), nextEtcdLeaderID)
 }
 

pkg/movingaverage/moving_average_test.go

@@ -24,9 +24,9 @@ import (
 )
 
 func addRandData(ma MovingAvg, n int, mx float64) {
-	rand.New(rand.NewSource(time.Now().UnixNano()))
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	for i := 0; i < n; i++ {
-		ma.Add(rand.Float64() * mx)
+		ma.Add(r.Float64() * mx)
 	}
 }
 

pkg/schedule/filter/candidates.go

@@ -17,6 +17,7 @@ package filter
 import (
 	"math/rand"
 	"sort"
+	"time"
 
 	"github.com/tikv/pd/pkg/core"
 	"github.com/tikv/pd/pkg/schedule/config"
@@ -26,12 +27,13 @@ import (
 // StoreCandidates wraps store list and provide utilities to select source or
 // target store to schedule.
 type StoreCandidates struct {
+	r      *rand.Rand
 	Stores []*core.StoreInfo
 }
 
 // NewCandidates creates StoreCandidates with store list.
 func NewCandidates(stores []*core.StoreInfo) *StoreCandidates {
-	return &StoreCandidates{Stores: stores}
+	return &StoreCandidates{r: rand.New(rand.NewSource(time.Now().UnixNano())), Stores: stores}
 }
 
 // FilterSource keeps stores that can pass all source filters.
@@ -54,7 +56,7 @@ func (c *StoreCandidates) Sort(less StoreComparer) *StoreCandidates {
 
 // Shuffle reorders all candidates randomly.
 func (c *StoreCandidates) Shuffle() *StoreCandidates {
-	rand.Shuffle(len(c.Stores), func(i, j int) { c.Stores[i], c.Stores[j] = c.Stores[j], c.Stores[i] })
+	c.r.Shuffle(len(c.Stores), func(i, j int) { c.Stores[i], c.Stores[j] = c.Stores[j], c.Stores[i] })
 	return c
 }
 
@@ -108,7 +110,7 @@ func (c *StoreCandidates) RandomPick() *core.StoreInfo {
 	if len(c.Stores) == 0 {
 		return nil
 	}
-	return c.Stores[rand.Intn(len(c.Stores))]
+	return c.Stores[c.r.Intn(len(c.Stores))]
 }
 
 // PickAll return all stores in candidate list.

pkg/schedule/waiting_operator.go

@@ -16,7 +16,6 @@ package schedule
 
 import (
 	"math/rand"
-	"time"
 
 	"github.com/tikv/pd/pkg/schedule/operator"
 )
@@ -118,7 +117,3 @@ func NewWaitingOperatorStatus() *WaitingOperatorStatus {
 		make(map[string]uint64),
 	}
 }
-
-func init() {
-	rand.New(rand.NewSource(time.Now().UnixNano()))
-}

pkg/utils/etcdutil/etcdutil.go

@@ -316,8 +316,9 @@ func InitOrGetClusterID(c *clientv3.Client, key string) (uint64, error) {
 	defer cancel()
 
 	// Generate a random cluster ID.
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	ts := uint64(time.Now().Unix())
-	clusterID := (ts << 32) + uint64(rand.Uint32())
+	clusterID := (ts << 32) + uint64(r.Uint32())
 	value := typeutil.Uint64ToBytes(clusterID)
 
 	// Multiple servers may try to init the cluster ID at the same time.

server/server.go

@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"math/rand"
 	"net/http"
 	"os"
 	"path"
@@ -219,7 +218,6 @@ func CreateServer(ctx context.Context, cfg *config.Config, services []string, le
 		mode = APIServiceMode
 	}
 	log.Info(fmt.Sprintf("%s config", mode), zap.Reflect("config", cfg))
-	rand.New(rand.NewSource(time.Now().UnixNano()))
 	serviceMiddlewareCfg := config.NewServiceMiddlewareConfig()
 
 	s := &Server{