multiple: switch to math/rand/v2 (#7711)

Co-authored-by: Arvind Bright <[email protected]>

balancer/endpointsharding/endpointsharding.go

@@ -28,10 +28,11 @@ package endpointsharding
 import (
 	"encoding/json"
 	"errors"
-	"math/rand"
 	"sync"
 	"sync/atomic"
 
+	rand "math/rand/v2"
+
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/balancer/base"
 	"google.golang.org/grpc/connectivity"
@@ -225,7 +226,7 @@ func (es *endpointSharding) updateState() {
 	p := &pickerWithChildStates{
 		pickers:     pickers,
 		childStates: childStates,
-		next:        uint32(rand.Intn(len(pickers))),
+		next:        uint32(rand.IntN(len(pickers))),
 	}
 	es.cc.UpdateState(balancer.State{
 		ConnectivityState: aggState,

balancer/grpclb/grpclb_picker.go

@@ -19,7 +19,7 @@
 package grpclb
 
 import (
-	"math/rand"
+	rand "math/rand/v2"
 	"sync"
 	"sync/atomic"
 
@@ -112,7 +112,7 @@ type rrPicker struct {
 func newRRPicker(readySCs []balancer.SubConn) *rrPicker {
 	return &rrPicker{
 		subConns:     readySCs,
-		subConnsNext: rand.Intn(len(readySCs)),
+		subConnsNext: rand.IntN(len(readySCs)),
 	}
 }
 
@@ -147,7 +147,7 @@ func newLBPicker(serverList []*lbpb.Server, readySCs []balancer.SubConn, stats *
 	return &lbPicker{
 		serverList:   serverList,
 		subConns:     readySCs,
-		subConnsNext: rand.Intn(len(readySCs)),
+		subConnsNext: rand.IntN(len(readySCs)),
 		stats:        stats,
 	}
 }

balancer/leastrequest/leastrequest.go

@@ -22,7 +22,7 @@ package leastrequest
 import (
 	"encoding/json"
 	"fmt"
-	"math/rand"
+	rand "math/rand/v2"
 	"sync/atomic"
 
 	"google.golang.org/grpc/balancer"

balancer/pickfirst/pickfirst.go

@@ -23,7 +23,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"math/rand"
+	rand "math/rand/v2"
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/balancer/pickfirst/internal"

balancer/rls/internal/adaptive/adaptive.go

@@ -20,15 +20,15 @@
 package adaptive
 
 import (
-	"math/rand"
+	rand "math/rand/v2"
 	"sync"
 	"time"
 )
 
 // For overriding in unittests.
 var (
-	timeNowFunc = func() time.Time { return time.Now() }
-	randFunc    = func() float64 { return rand.Float64() }
+	timeNowFunc = time.Now
+	randFunc    = rand.Float64
 )
 
 const (

balancer/roundrobin/roundrobin.go

@@ -22,7 +22,7 @@
 package roundrobin
 
 import (
-	"math/rand"
+	rand "math/rand/v2"
 	"sync/atomic"
 
 	"google.golang.org/grpc/balancer"
@@ -60,7 +60,7 @@ func (*rrPickerBuilder) Build(info base.PickerBuildInfo) balancer.Picker {
 		// Start at a random index, as the same RR balancer rebuilds a new
 		// picker when SubConn states change, and we don't want to apply excess
 		// load to the first server in the list.
-		next: uint32(rand.Intn(len(scs))),
+		next: uint32(rand.IntN(len(scs))),
 	}
 }
 

balancer/weightedroundrobin/balancer.go

@@ -23,7 +23,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"math/rand"
+	rand "math/rand/v2"
 	"sync"
 	"sync/atomic"
 	"time"

benchmark/benchmain/main.go

@@ -47,7 +47,7 @@ import (
 	"fmt"
 	"io"
 	"log"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"os"
 	"reflect"
@@ -283,7 +283,7 @@ func unconstrainedStreamBenchmark(start startFunc, stop ucStopFunc, bf stats.Fea
 				defer wg.Done()
 				for {
 					if maxSleep > 0 {
-						time.Sleep(time.Duration(rand.Intn(maxSleep)))
+						time.Sleep(time.Duration(rand.IntN(maxSleep)))
 					}
 					t := time.Now()
 					if t.After(bmEnd) {
@@ -574,7 +574,7 @@ func runBenchmark(caller rpcCallFunc, start startFunc, stop stopFunc, bf stats.F
 				defer wg.Done()
 				for {
 					if maxSleep > 0 {
-						time.Sleep(time.Duration(rand.Intn(maxSleep)))
+						time.Sleep(time.Duration(rand.IntN(maxSleep)))
 					}
 					t := time.Now()
 					if t.After(bmEnd) {

benchmark/benchmark.go

@@ -26,7 +26,7 @@ import (
 	"fmt"
 	"io"
 	"log"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"strconv"
 	"time"
@@ -187,7 +187,7 @@ func (s *testServer) UnconstrainedStreamingCall(stream testgrpc.BenchmarkService
 	go func() {
 		for {
 			if maxSleep > 0 {
-				time.Sleep(time.Duration(rand.Intn(maxSleep)))
+				time.Sleep(time.Duration(rand.IntN(maxSleep)))
 			}
 			var err error
 			if preloadMsgSize > 0 {

benchmark/stats/curve.go

@@ -24,7 +24,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"math"
-	"math/rand"
+	rand "math/rand/v2"
 	"os"
 	"sort"
 	"strconv"
@@ -74,7 +74,7 @@ func (pcr *payloadCurveRange) chooseRandom() int {
 		return int(pcr.from)
 	}
 
-	return int(rand.Int31n(pcr.to-pcr.from+1) + pcr.from)
+	return int(rand.Int32N(pcr.to-pcr.from+1) + pcr.from)
 }
 
 // sha256file is a helper function that returns a hex string matching the

benchmark/worker/benchmark_client.go

@@ -22,7 +22,7 @@ import (
 	"context"
 	"flag"
 	"math"
-	"math/rand"
+	rand "math/rand/v2"
 	"runtime"
 	"sync"
 	"time"

examples/features/debugging/server/main.go

@@ -23,7 +23,7 @@ package main
 import (
 	"context"
 	"log"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"time"
 
@@ -55,7 +55,7 @@ type slowServer struct {
 // SayHello implements helloworld.GreeterServer
 func (s *slowServer) SayHello(_ context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
 	// Delay 100ms ~ 200ms before replying
-	time.Sleep(time.Duration(100+rand.Intn(100)) * time.Millisecond)
+	time.Sleep(time.Duration(100+rand.IntN(100)) * time.Millisecond)
 	return &pb.HelloReply{Message: "Hello " + in.Name}, nil
 }
 

examples/features/xds/server/main.go

@@ -25,7 +25,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"os"
 

examples/route_guide/client/client.go

@@ -27,7 +27,7 @@ import (
 	"flag"
 	"io"
 	"log"
-	"math/rand"
+	rand "math/rand/v2"
 	"time"
 
 	"google.golang.org/grpc"
@@ -81,11 +81,10 @@ func printFeatures(client pb.RouteGuideClient, rect *pb.Rectangle) {
 // runRecordRoute sends a sequence of points to server and expects to get a RouteSummary from server.
 func runRecordRoute(client pb.RouteGuideClient) {
 	// Create a random number of random points
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
-	pointCount := int(r.Int31n(100)) + 2 // Traverse at least two points
+	pointCount := int(rand.Int32N(100)) + 2 // Traverse at least two points
 	var points []*pb.Point
 	for i := 0; i < pointCount; i++ {
-		points = append(points, randomPoint(r))
+		points = append(points, randomPoint())
 	}
 	log.Printf("Traversing %d points.", len(points))
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
@@ -146,9 +145,9 @@ func runRouteChat(client pb.RouteGuideClient) {
 	<-waitc
 }
 
-func randomPoint(r *rand.Rand) *pb.Point {
-	lat := (r.Int31n(180) - 90) * 1e7
-	long := (r.Int31n(360) - 180) * 1e7
+func randomPoint() *pb.Point {
+	lat := (rand.Int32N(180) - 90) * 1e7
+	long := (rand.Int32N(360) - 180) * 1e7
 	return &pb.Point{Latitude: lat, Longitude: long}
 }
 

internal/backoff/backoff.go

@@ -25,7 +25,7 @@ package backoff
 import (
 	"context"
 	"errors"
-	"math/rand"
+	rand "math/rand/v2"
 	"time"
 
 	grpcbackoff "google.golang.org/grpc/backoff"

internal/resolver/dns/dns_resolver.go

@@ -24,7 +24,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"os"
 	"strconv"
@@ -425,7 +425,7 @@ func chosenByPercentage(a *int) bool {
 	if a == nil {
 		return true
 	}
-	return rand.Intn(100)+1 <= *a
+	return rand.IntN(100)+1 <= *a
 }
 
 func canaryingSC(js string) string {

internal/serviceconfig/duration_test.go

@@ -21,7 +21,7 @@ package serviceconfig
 import (
 	"fmt"
 	"math"
-	"math/rand"
+	rand "math/rand/v2"
 	"strings"
 	"testing"
 	"time"

internal/transport/http2_server.go

@@ -25,7 +25,7 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"net/http"
 	"strconv"
@@ -1455,7 +1455,7 @@ func getJitter(v time.Duration) time.Duration {
 	}
 	// Generate a jitter between +/- 10% of the value.
 	r := int64(v / 10)
-	j := rand.Int63n(2*r) - r
+	j := rand.Int64N(2*r) - r
 	return time.Duration(j)
 }
 

internal/wrr/random.go

@@ -19,7 +19,7 @@ package wrr
 
 import (
 	"fmt"
-	"math/rand"
+	rand "math/rand/v2"
 	"sort"
 )
 
@@ -46,19 +46,19 @@ func NewRandom() WRR {
 	return &randomWRR{}
 }
 
-var randInt63n = rand.Int63n
+var randInt64n = rand.Int64N
 
 func (rw *randomWRR) Next() (item any) {
 	if len(rw.items) == 0 {
 		return nil
 	}
 	if rw.equalWeights {
-		return rw.items[randInt63n(int64(len(rw.items)))].item
+		return rw.items[randInt64n(int64(len(rw.items)))].item
 	}
 
 	sumOfWeights := rw.items[len(rw.items)-1].accumulatedWeight
 	// Random number in [0, sumOfWeights).
-	randomWeight := randInt63n(sumOfWeights)
+	randomWeight := randInt64n(sumOfWeights)
 	// Item's accumulated weights are in ascending order, because item's weight >= 0.
 	// Binary search rw.items to find first item whose accumulatedWeight > randomWeight
 	// The return i is guaranteed to be in range [0, len(rw.items)) because randomWeight < last item's accumulatedWeight

internal/wrr/wrr_test.go

@@ -20,7 +20,7 @@ package wrr
 import (
 	"errors"
 	"math"
-	"math/rand"
+	rand "math/rand/v2"
 	"strconv"
 	"testing"
 
@@ -146,7 +146,7 @@ func BenchmarkRandomWRRNext(b *testing.B) {
 			w := NewRandom()
 			var sumOfWeights int64
 			for i := 0; i < n; i++ {
-				weight := rand.Int63n(maxWeight + 1)
+				weight := rand.Int64N(maxWeight + 1)
 				w.Add(i, weight)
 				sumOfWeights += weight
 			}
@@ -188,6 +188,6 @@ func BenchmarkRandomWRRNext(b *testing.B) {
 }
 
 func init() {
-	r := rand.New(rand.NewSource(0))
-	randInt63n = r.Int63n
+	r := rand.New(rand.NewPCG(0, 0))
+	randInt64n = r.Int64N
 }

interop/stress/client/main.go

@@ -23,7 +23,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"math/rand"
+	rand "math/rand/v2"
 	"net"
 	"os"
 	"strconv"
@@ -130,7 +130,7 @@ func newWeightedRandomTestSelector(tests []testCaseWithWeight) *weightedRandomTe
 }
 
 func (selector weightedRandomTestSelector) getNextTest() string {
-	random := rand.Intn(selector.totalWeight)
+	random := rand.IntN(selector.totalWeight)
 	var weightSofar int
 	for _, test := range selector.tests {
 		weightSofar += test.weight

stream.go

@@ -23,7 +23,7 @@ import (
 	"errors"
 	"io"
 	"math"
-	"math/rand"
+	rand "math/rand/v2"
 	"strconv"
 	"sync"
 	"time"
@@ -710,7 +710,7 @@ func (a *csAttempt) shouldRetry(err error) (bool, error) {
 		if max := float64(rp.MaxBackoff); cur > max {
 			cur = max
 		}
-		dur = time.Duration(rand.Int63n(int64(cur)))
+		dur = time.Duration(rand.Int64N(int64(cur)))
 		cs.numRetriesSincePushback++
 	}