p2p/discover: use separate rand.Source instances in tests

rand.Source isn't safe for concurrent use.

p2p/discover/node_test.go

@@ -13,11 +13,6 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
-var (
-	quickrand = rand.New(rand.NewSource(time.Now().Unix()))
-	quickcfg  = &quick.Config{MaxCount: 5000, Rand: quickrand}
-)
-
 var parseNodeTests = []struct {
 	rawurl     string
 	wantError  string
@@ -176,7 +171,7 @@ func TestNodeID_distcmp(t *testing.T) {
 		bbig := new(big.Int).SetBytes(b[:])
 		return new(big.Int).Xor(tbig, abig).Cmp(new(big.Int).Xor(tbig, bbig))
 	}
-	if err := quick.CheckEqual(distcmp, distcmpBig, quickcfg); err != nil {
+	if err := quick.CheckEqual(distcmp, distcmpBig, quickcfg()); err != nil {
 		t.Error(err)
 	}
 }
@@ -195,7 +190,7 @@ func TestNodeID_logdist(t *testing.T) {
 		abig, bbig := new(big.Int).SetBytes(a[:]), new(big.Int).SetBytes(b[:])
 		return new(big.Int).Xor(abig, bbig).BitLen()
 	}
-	if err := quick.CheckEqual(logdist, logdistBig, quickcfg); err != nil {
+	if err := quick.CheckEqual(logdist, logdistBig, quickcfg()); err != nil {
 		t.Error(err)
 	}
 }
@@ -211,9 +206,10 @@ func TestNodeID_logdistEqual(t *testing.T) {
 func TestNodeID_hashAtDistance(t *testing.T) {
 	// we don't use quick.Check here because its output isn't
 	// very helpful when the test fails.
-	for i := 0; i < quickcfg.MaxCount; i++ {
-		a := gen(common.Hash{}, quickrand).(common.Hash)
-		dist := quickrand.Intn(len(common.Hash{}) * 8)
+	cfg := quickcfg()
+	for i := 0; i < cfg.MaxCount; i++ {
+		a := gen(common.Hash{}, cfg.Rand).(common.Hash)
+		dist := cfg.Rand.Intn(len(common.Hash{}) * 8)
 		result := hashAtDistance(a, dist)
 		actualdist := logdist(result, a)
 
@@ -225,7 +221,14 @@ func TestNodeID_hashAtDistance(t *testing.T) {
 	}
 }
 
-// TODO: this can be dropped when we require Go >= 1.5
+func quickcfg() *quick.Config {
+	return &quick.Config{
+		MaxCount: 5000,
+		Rand:     rand.New(rand.NewSource(time.Now().Unix())),
+	}
+}
+
+// TODO: The Generate method can be dropped when we require Go >= 1.5
 // because testing/quick learned to generate arrays in 1.5.
 
 func (NodeID) Generate(rand *rand.Rand, size int) reflect.Value {

p2p/discover/table_test.go

@@ -9,6 +9,7 @@ import (
 	"reflect"
 	"testing"
 	"testing/quick"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -74,7 +75,7 @@ func TestBucket_bumpNoDuplicates(t *testing.T) {
 	t.Parallel()
 	cfg := &quick.Config{
 		MaxCount: 1000,
-		Rand:     quickrand,
+		Rand:     rand.New(rand.NewSource(time.Now().Unix())),
 		Values: func(args []reflect.Value, rand *rand.Rand) {
 			// generate a random list of nodes. this will be the content of the bucket.
 			n := rand.Intn(bucketSize-1) + 1
@@ -205,7 +206,7 @@ func TestTable_closest(t *testing.T) {
 		}
 		return true
 	}
-	if err := quick.Check(test, quickcfg); err != nil {
+	if err := quick.Check(test, quickcfg()); err != nil {
 		t.Error(err)
 	}
 }
@@ -213,7 +214,7 @@ func TestTable_closest(t *testing.T) {
 func TestTable_ReadRandomNodesGetAll(t *testing.T) {
 	cfg := &quick.Config{
 		MaxCount: 200,
-		Rand:     quickrand,
+		Rand:     rand.New(rand.NewSource(time.Now().Unix())),
 		Values: func(args []reflect.Value, rand *rand.Rand) {
 			args[0] = reflect.ValueOf(make([]*Node, rand.Intn(1000)))
 		},
@@ -221,7 +222,7 @@ func TestTable_ReadRandomNodesGetAll(t *testing.T) {
 	test := func(buf []*Node) bool {
 		tab := newTable(nil, NodeID{}, &net.UDPAddr{}, "")
 		for i := 0; i < len(buf); i++ {
-			ld := quickrand.Intn(len(tab.buckets))
+			ld := cfg.Rand.Intn(len(tab.buckets))
 			tab.add([]*Node{nodeAtDistance(tab.self.sha, ld)})
 		}
 		gotN := tab.ReadRandomNodes(buf)