eth/protocols/snap, p2p/msgrate: support overriding max TTL

eth/protocols/snap/sync_test.go

@@ -794,15 +794,8 @@ func TestMultiSyncManyUseless(t *testing.T) {
 	verifyTrie(syncer.db, sourceAccountTrie.Hash(), t)
 }
 
-/*
 // TestMultiSyncManyUseless contains one good peer, and many which doesn't return anything valuable at all
 func TestMultiSyncManyUselessWithLowTimeout(t *testing.T) {
-	// We're setting the timeout to very low, to increase the chance of the timeout
-	// being triggered. This was previously a cause of panic, when a response
-	// arrived simultaneously as a timeout was triggered.
-	defer func(old time.Duration) { requestTimeout = old }(requestTimeout)
-	requestTimeout = time.Millisecond
-
 	var (
 		once   sync.Once
 		cancel = make(chan struct{})
@@ -839,6 +832,11 @@ func TestMultiSyncManyUselessWithLowTimeout(t *testing.T) {
 		mkSource("noStorage", true, false, true),
 		mkSource("noTrie", true, true, false),
 	)
+	// We're setting the timeout to very low, to increase the chance of the timeout
+	// being triggered. This was previously a cause of panic, when a response
+	// arrived simultaneously as a timeout was triggered.
+	syncer.rates.OverrideTTLLimit = time.Millisecond
+
 	done := checkStall(t, term)
 	if err := syncer.Sync(sourceAccountTrie.Hash(), cancel); err != nil {
 		t.Fatalf("sync failed: %v", err)
@@ -849,10 +847,6 @@ func TestMultiSyncManyUselessWithLowTimeout(t *testing.T) {
 
 // TestMultiSyncManyUnresponsive contains one good peer, and many which doesn't respond at all
 func TestMultiSyncManyUnresponsive(t *testing.T) {
-	// We're setting the timeout to very low, to make the test run a bit faster
-	defer func(old time.Duration) { requestTimeout = old }(requestTimeout)
-	requestTimeout = time.Millisecond
-
 	var (
 		once   sync.Once
 		cancel = make(chan struct{})
@@ -889,13 +883,16 @@ func TestMultiSyncManyUnresponsive(t *testing.T) {
 		mkSource("noStorage", true, false, true),
 		mkSource("noTrie", true, true, false),
 	)
+	// We're setting the timeout to very low, to make the test run a bit faster
+	syncer.rates.OverrideTTLLimit = time.Millisecond
+
 	done := checkStall(t, term)
 	if err := syncer.Sync(sourceAccountTrie.Hash(), cancel); err != nil {
 		t.Fatalf("sync failed: %v", err)
 	}
 	close(done)
 	verifyTrie(syncer.db, sourceAccountTrie.Hash(), t)
-}*/
+}
 
 func checkStall(t *testing.T, term func()) chan struct{} {
 	testDone := make(chan struct{})

p2p/msgrate/msgrate.go

@@ -226,6 +226,10 @@ type Trackers struct {
 	// run every now and again.
 	tuned time.Time
 
+	// The fields below can be used to override certain default values. Their
+	// purpose is to allow quicker tests. Don't use them in production.
+	OverrideTTLLimit time.Duration
+
 	log  log.Logger
 	lock sync.RWMutex
 }
@@ -237,6 +241,7 @@ func NewTrackers(log log.Logger) *Trackers {
 		roundtrip:        rttMaxEstimate,
 		confidence:       1,
 		tuned:            time.Now(),
+		OverrideTTLLimit: ttlLimit,
 		log:              log,
 	}
 }
@@ -369,8 +374,8 @@ func (t *Trackers) TargetTimeout() time.Duration {
 // during QoS tuning.
 func (t *Trackers) targetTimeout() time.Duration {
 	timeout := time.Duration(ttlScaling * float64(t.roundtrip) / t.confidence)
-	if timeout > ttlLimit {
+	if timeout > t.OverrideTTLLimit {
-		timeout = ttlLimit
+		timeout = t.OverrideTTLLimit
 	}
 	return timeout
 }