cmd/testwrapper: handle build failures

`go test -json` outputs invalid JSON when a build fails.
Handle that case by reseting the json.Decode and continuing to read.

Updates #8493

Signed-off-by: Maisem Ali <maisem@tailscale.com>

client/tailscale/localclient.go

@@ -946,21 +946,6 @@ func (lc *LocalClient) NetworkLockForceLocalDisable(ctx context.Context) error {
 	return nil
 }
 
-// NetworkLockVerifySigningDeeplink verifies the network lock deeplink contained
-// in url and returns information extracted from it.
-func (lc *LocalClient) NetworkLockVerifySigningDeeplink(ctx context.Context, url string) (*tka.DeeplinkValidationResult, error) {
-	vr := struct {
-		URL string
-	}{url}
-
-	body, err := lc.send(ctx, "POST", "/localapi/v0/tka/verify-deeplink", 200, jsonBody(vr))
-	if err != nil {
-		return nil, fmt.Errorf("sending verify-deeplink: %w", err)
-	}
-
-	return decodeJSON[*tka.DeeplinkValidationResult](body)
-}
-
 // SetServeConfig sets or replaces the serving settings.
 // If config is nil, settings are cleared and serving is disabled.
 func (lc *LocalClient) SetServeConfig(ctx context.Context, config *ipn.ServeConfig) error {

cmd/derper/cert.go

@@ -72,7 +72,7 @@ func NewManualCertManager(certdir, hostname string) (certProvider, error) {
 		return nil, fmt.Errorf("can not load cert: %w", err)
 	}
 	if err := x509Cert.VerifyHostname(hostname); err != nil {
-		// return nil, fmt.Errorf("cert invalid for hostname %q: %w", hostname, err)
+		return nil, fmt.Errorf("cert invalid for hostname %q: %w", hostname, err)
 	}
 	return &manualCertManager{cert: &cert, hostname: hostname}, nil
 }
@@ -89,7 +89,7 @@ func (m *manualCertManager) TLSConfig() *tls.Config {
 
 func (m *manualCertManager) getCertificate(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
 	if hi.ServerName != m.hostname {
-		//return nil, fmt.Errorf("cert mismatch with hostname: %q", hi.ServerName)
+		return nil, fmt.Errorf("cert mismatch with hostname: %q", hi.ServerName)
 	}
 
 	// Return a shallow copy of the cert so the caller can append to its

cmd/testwrapper/testwrapper.go

@@ -81,6 +81,7 @@ func runTests(ctx context.Context, attempt int, pt *packageTests, otherArgs []st
 	if err != nil {
 		log.Printf("error creating stdout pipe: %v", err)
 	}
+	defer r.Close()
 	cmd.Stderr = os.Stderr
 
 	cmd.Env = os.Environ()
@@ -104,6 +105,15 @@ func runTests(ctx context.Context, attempt int, pt *packageTests, otherArgs []st
 			if errors.Is(err, io.EOF) || errors.Is(err, os.ErrClosed) {
 				break
 			}
+
+			// `go test -json` outputs invalid JSON when a build fails.
+			// In that case, discard the the output and start reading again.
+			// The build error will be printed to stderr.
+			// See: https://github.com/golang/go/issues/35169
+			if _, ok := err.(*json.SyntaxError); ok {
+				jd = json.NewDecoder(r)
+				continue
+			}
 			panic(err)
 		}
 		if goOutput.Test == "" {

control/controlclient/noise.go

@@ -287,25 +287,6 @@ func (nc *NoiseClient) GetSingleUseRoundTripper(ctx context.Context) (http.Round
 	return nil, nil, errors.New("[unexpected] failed to reserve a request on a connection")
 }
 
-// contextErr is an error that wraps another error and is used to indicate that
-// the error was because a context expired.
-type contextErr struct {
-	err error
-}
-
-func (e contextErr) Error() string {
-	return e.err.Error()
-}
-
-func (e contextErr) Unwrap() error {
-	return e.err
-}
-
-// getConn returns a noiseConn that can be used to make requests to the
-// coordination server. It may return a cached connection or create a new one.
-// Dials are singleflighted, so concurrent calls to getConn may only dial once.
-// As such, context values may not be respected as there are no guarantees that
-// the context passed to getConn is the same as the context passed to dial.
 func (nc *NoiseClient) getConn(ctx context.Context) (*noiseConn, error) {
 	nc.mu.Lock()
 	if last := nc.last; last != nil && last.canTakeNewRequest() {
@@ -314,35 +295,11 @@ func (nc *NoiseClient) getConn(ctx context.Context) (*noiseConn, error) {
 	}
 	nc.mu.Unlock()
 
-	for {
-		// We singeflight the dial to avoid making multiple connections, however
-		// that means that we can't simply cancel the dial if the context is
-		// canceled. Instead, we have to additionally check that the context
-		// which was canceled is our context and retry if our context is still
-		// valid.
-		conn, err, _ := nc.sfDial.Do(struct{}{}, func() (*noiseConn, error) {
-			c, err := nc.dial(ctx)
-			if err != nil {
-				if ctx.Err() != nil {
-					return nil, contextErr{ctx.Err()}
-				}
-				return nil, err
-			}
-			return c, nil
-		})
-		var ce contextErr
-		if err == nil || !errors.As(err, &ce) {
-			return conn, err
-		}
-		if ctx.Err() == nil {
-			// The dial failed because of a context error, but our context
-			// is still valid. Retry.
-			continue
-		}
-		// The dial failed because our context was canceled. Return the
-		// underlying error.
-		return nil, ce.Unwrap()
+	conn, err, _ := nc.sfDial.Do(struct{}{}, nc.dial)
+	if err != nil {
+		return nil, err
 	}
+	return conn, nil
 }
 
 func (nc *NoiseClient) RoundTrip(req *http.Request) (*http.Response, error) {
@@ -387,7 +344,7 @@ func (nc *NoiseClient) Close() error {
 
 // dial opens a new connection to tailcontrol, fetching the server noise key
 // if not cached.
-func (nc *NoiseClient) dial(ctx context.Context) (*noiseConn, error) {
+func (nc *NoiseClient) dial() (*noiseConn, error) {
 	nc.mu.Lock()
 	connID := nc.nextID
 	nc.nextID++
@@ -435,7 +392,7 @@ func (nc *NoiseClient) dial(ctx context.Context) (*noiseConn, error) {
 	}
 
 	timeout := time.Duration(timeoutSec * float64(time.Second))
-	ctx, cancel := context.WithTimeout(ctx, timeout)
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 
 	clientConn, err := (&controlhttp.Dialer{

ipn/ipnlocal/local.go

@@ -742,6 +742,7 @@ func (b *LocalBackend) populatePeerStatusLocked(sb *ipnstate.StatusBuilder) {
 			HostName:     p.Hostinfo.Hostname(),
 			DNSName:      p.Name,
 			OS:           p.Hostinfo.OS(),
+			KeepAlive:    p.KeepAlive,
 			LastSeen:     lastSeen,
 			Online:       p.Online != nil && *p.Online,
 			ShareeNode:   p.Hostinfo.ShareeNode(),

ipn/ipnstate/ipnstate.go

@@ -223,8 +223,9 @@ type PeerStatus struct {
 	LastSeen       time.Time // last seen to tailcontrol; only present if offline
 	LastHandshake  time.Time // with local wireguard
 	Online         bool      // whether node is connected to the control plane
-	ExitNode       bool      // true if this is the currently selected exit node.
-	ExitNodeOption bool      // true if this node can be an exit node (offered && approved)
+	KeepAlive      bool
+	ExitNode       bool // true if this is the currently selected exit node.
+	ExitNodeOption bool // true if this node can be an exit node (offered && approved)
 
 	// Active is whether the node was recently active. The
 	// definition is somewhat undefined but has historically and
@@ -436,6 +437,9 @@ func (sb *StatusBuilder) AddPeer(peer key.NodePublic, st *PeerStatus) {
 	if st.InEngine {
 		e.InEngine = true
 	}
+	if st.KeepAlive {
+		e.KeepAlive = true
+	}
 	if st.ExitNode {
 		e.ExitNode = true
 	}

net/dns/recursive/recursive_test.go

@@ -36,9 +36,9 @@ func init() {
 }
 
 func newResolver(tb testing.TB) *Resolver {
-	clock := tstest.NewClock(tstest.ClockOpts{
+	clock := &tstest.Clock{
 		Step: 50 * time.Millisecond,
-	})
+	}
 	return &Resolver{
 		Logf:    tb.Logf,
 		timeNow: clock.Now,

net/dnscache/messagecache_test.go

@@ -18,9 +18,9 @@ import (
 )
 
 func TestMessageCache(t *testing.T) {
-	clock := tstest.NewClock(tstest.ClockOpts{
+	clock := &tstest.Clock{
 		Start: time.Date(1987, 11, 1, 0, 0, 0, 0, time.UTC),
-	})
+	}
 	mc := &MessageCache{Clock: clock.Now}
 	mc.SetMaxCacheSize(2)
 	clock.Advance(time.Second)

tailcfg/tailcfg.go

@@ -242,6 +242,8 @@ type Node struct {
 	// current node doesn't have permission to know.
 	Online *bool `json:",omitempty"`
 
+	KeepAlive bool `json:",omitempty"` // open and keep open a connection to this peer
+
 	MachineAuthorized bool `json:",omitempty"` // TODO(crawshaw): replace with MachineStatus
 
 	// Capabilities are capabilities that the node has.
@@ -1282,7 +1284,7 @@ type DNSConfig struct {
 	// match.
 	//
 	// Matches are case insensitive.
-	ExitNodeFilteredSet []string `json:",omitempty"`
+	ExitNodeFilteredSet []string
 }
 
 // DNSRecord is an extra DNS record to add to MagicDNS.

tailcfg/tailcfg_clone.go

@@ -93,6 +93,7 @@ var _NodeCloneNeedsRegeneration = Node(struct {
 	PrimaryRoutes                 []netip.Prefix
 	LastSeen                      *time.Time
 	Online                        *bool
+	KeepAlive                     bool
 	MachineAuthorized             bool
 	Capabilities                  []string
 	UnsignedPeerAPIOnly           bool

tailcfg/tailcfg_test.go

@@ -347,7 +347,7 @@ func TestNodeEqual(t *testing.T) {
 		"Key", "KeyExpiry", "KeySignature", "Machine", "DiscoKey",
 		"Addresses", "AllowedIPs", "Endpoints", "DERP", "Hostinfo",
 		"Created", "Cap", "Tags", "PrimaryRoutes",
-		"LastSeen", "Online", "MachineAuthorized",
+		"LastSeen", "Online", "KeepAlive", "MachineAuthorized",
 		"Capabilities",
 		"UnsignedPeerAPIOnly",
 		"ComputedName", "computedHostIfDifferent", "ComputedNameWithHost",

tailcfg/tailcfg_view.go

@@ -168,6 +168,7 @@ func (v NodeView) Online() *bool {
 	return &x
 }
 
+func (v NodeView) KeepAlive() bool                   { return v.ж.KeepAlive }
 func (v NodeView) MachineAuthorized() bool           { return v.ж.MachineAuthorized }
 func (v NodeView) Capabilities() views.Slice[string] { return views.SliceOf(v.ж.Capabilities) }
 func (v NodeView) UnsignedPeerAPIOnly() bool         { return v.ж.UnsignedPeerAPIOnly }
@@ -209,6 +210,7 @@ var _NodeViewNeedsRegeneration = Node(struct {
 	PrimaryRoutes                 []netip.Prefix
 	LastSeen                      *time.Time
 	Online                        *bool
+	KeepAlive                     bool
 	MachineAuthorized             bool
 	Capabilities                  []string
 	UnsignedPeerAPIOnly           bool

tempfork/heap/heap.go

@@ -1,121 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package heap provides heap operations for any type that implements
-// heap.Interface. A heap is a tree with the property that each node is the
-// minimum-valued node in its subtree.
-//
-// The minimum element in the tree is the root, at index 0.
-//
-// A heap is a common way to implement a priority queue. To build a priority
-// queue, implement the Heap interface with the (negative) priority as the
-// ordering for the Less method, so Push adds items while Pop removes the
-// highest-priority item from the queue. The Examples include such an
-// implementation; the file example_pq_test.go has the complete source.
-//
-// This package is a copy of the Go standard library's
-// container/heap, but using generics.
-package heap
-
-import "sort"
-
-// The Interface type describes the requirements
-// for a type using the routines in this package.
-// Any type that implements it may be used as a
-// min-heap with the following invariants (established after
-// Init has been called or if the data is empty or sorted):
-//
-//	!h.Less(j, i) for 0 <= i < h.Len() and 2*i+1 <= j <= 2*i+2 and j < h.Len()
-//
-// Note that Push and Pop in this interface are for package heap's
-// implementation to call. To add and remove things from the heap,
-// use heap.Push and heap.Pop.
-type Interface[V any] interface {
-	sort.Interface
-	Push(x V) // add x as element Len()
-	Pop() V   // remove and return element Len() - 1.
-}
-
-// Init establishes the heap invariants required by the other routines in this package.
-// Init is idempotent with respect to the heap invariants
-// and may be called whenever the heap invariants may have been invalidated.
-// The complexity is O(n) where n = h.Len().
-func Init[V any](h Interface[V]) {
-	// heapify
-	n := h.Len()
-	for i := n/2 - 1; i >= 0; i-- {
-		down(h, i, n)
-	}
-}
-
-// Push pushes the element x onto the heap.
-// The complexity is O(log n) where n = h.Len().
-func Push[V any](h Interface[V], x V) {
-	h.Push(x)
-	up(h, h.Len()-1)
-}
-
-// Pop removes and returns the minimum element (according to Less) from the heap.
-// The complexity is O(log n) where n = h.Len().
-// Pop is equivalent to Remove(h, 0).
-func Pop[V any](h Interface[V]) V {
-	n := h.Len() - 1
-	h.Swap(0, n)
-	down(h, 0, n)
-	return h.Pop()
-}
-
-// Remove removes and returns the element at index i from the heap.
-// The complexity is O(log n) where n = h.Len().
-func Remove[V any](h Interface[V], i int) V {
-	n := h.Len() - 1
-	if n != i {
-		h.Swap(i, n)
-		if !down(h, i, n) {
-			up(h, i)
-		}
-	}
-	return h.Pop()
-}
-
-// Fix re-establishes the heap ordering after the element at index i has changed its value.
-// Changing the value of the element at index i and then calling Fix is equivalent to,
-// but less expensive than, calling Remove(h, i) followed by a Push of the new value.
-// The complexity is O(log n) where n = h.Len().
-func Fix[V any](h Interface[V], i int) {
-	if !down(h, i, h.Len()) {
-		up(h, i)
-	}
-}
-
-func up[V any](h Interface[V], j int) {
-	for {
-		i := (j - 1) / 2 // parent
-		if i == j || !h.Less(j, i) {
-			break
-		}
-		h.Swap(i, j)
-		j = i
-	}
-}
-
-func down[V any](h Interface[V], i0, n int) bool {
-	i := i0
-	for {
-		j1 := 2*i + 1
-		if j1 >= n || j1 < 0 { // j1 < 0 after int overflow
-			break
-		}
-		j := j1 // left child
-		if j2 := j1 + 1; j2 < n && h.Less(j2, j1) {
-			j = j2 // = 2*i + 2  // right child
-		}
-		if !h.Less(j, i) {
-			break
-		}
-		h.Swap(i, j)
-		i = j
-	}
-	return i > i0
-}

tempfork/heap/heap_test.go

@@ -1,216 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package heap
-
-import (
-	"math/rand"
-	"testing"
-
-	"golang.org/x/exp/constraints"
-)
-
-type myHeap[T constraints.Ordered] []T
-
-func (h *myHeap[T]) Less(i, j int) bool {
-	return (*h)[i] < (*h)[j]
-}
-
-func (h *myHeap[T]) Swap(i, j int) {
-	(*h)[i], (*h)[j] = (*h)[j], (*h)[i]
-}
-
-func (h *myHeap[T]) Len() int {
-	return len(*h)
-}
-
-func (h *myHeap[T]) Pop() (v T) {
-	*h, v = (*h)[:h.Len()-1], (*h)[h.Len()-1]
-	return
-}
-
-func (h *myHeap[T]) Push(v T) {
-	*h = append(*h, v)
-}
-
-func (h myHeap[T]) verify(t *testing.T, i int) {
-	t.Helper()
-	n := h.Len()
-	j1 := 2*i + 1
-	j2 := 2*i + 2
-	if j1 < n {
-		if h.Less(j1, i) {
-			t.Errorf("heap invariant invalidated [%d] = %v > [%d] = %v", i, h[i], j1, h[j1])
-			return
-		}
-		h.verify(t, j1)
-	}
-	if j2 < n {
-		if h.Less(j2, i) {
-			t.Errorf("heap invariant invalidated [%d] = %v > [%d] = %v", i, h[i], j1, h[j2])
-			return
-		}
-		h.verify(t, j2)
-	}
-}
-
-func TestInit0(t *testing.T) {
-	h := new(myHeap[int])
-	for i := 20; i > 0; i-- {
-		h.Push(0) // all elements are the same
-	}
-	Init[int](h)
-	h.verify(t, 0)
-
-	for i := 1; h.Len() > 0; i++ {
-		x := Pop[int](h)
-		h.verify(t, 0)
-		if x != 0 {
-			t.Errorf("%d.th pop got %d; want %d", i, x, 0)
-		}
-	}
-}
-
-func TestInit1(t *testing.T) {
-	h := new(myHeap[int])
-	for i := 20; i > 0; i-- {
-		h.Push(i) // all elements are different
-	}
-	Init[int](h)
-	h.verify(t, 0)
-
-	for i := 1; h.Len() > 0; i++ {
-		x := Pop[int](h)
-		h.verify(t, 0)
-		if x != i {
-			t.Errorf("%d.th pop got %d; want %d", i, x, i)
-		}
-	}
-}
-
-func Test(t *testing.T) {
-	h := new(myHeap[int])
-	h.verify(t, 0)
-
-	for i := 20; i > 10; i-- {
-		h.Push(i)
-	}
-	Init[int](h)
-	h.verify(t, 0)
-
-	for i := 10; i > 0; i-- {
-		Push[int](h, i)
-		h.verify(t, 0)
-	}
-
-	for i := 1; h.Len() > 0; i++ {
-		x := Pop[int](h)
-		if i < 20 {
-			Push[int](h, 20+i)
-		}
-		h.verify(t, 0)
-		if x != i {
-			t.Errorf("%d.th pop got %d; want %d", i, x, i)
-		}
-	}
-}
-
-func TestRemove0(t *testing.T) {
-	h := new(myHeap[int])
-	for i := 0; i < 10; i++ {
-		h.Push(i)
-	}
-	h.verify(t, 0)
-
-	for h.Len() > 0 {
-		i := h.Len() - 1
-		x := Remove[int](h, i)
-		if x != i {
-			t.Errorf("Remove(%d) got %d; want %d", i, x, i)
-		}
-		h.verify(t, 0)
-	}
-}
-
-func TestRemove1(t *testing.T) {
-	h := new(myHeap[int])
-	for i := 0; i < 10; i++ {
-		h.Push(i)
-	}
-	h.verify(t, 0)
-
-	for i := 0; h.Len() > 0; i++ {
-		x := Remove[int](h, 0)
-		if x != i {
-			t.Errorf("Remove(0) got %d; want %d", x, i)
-		}
-		h.verify(t, 0)
-	}
-}
-
-func TestRemove2(t *testing.T) {
-	N := 10
-
-	h := new(myHeap[int])
-	for i := 0; i < N; i++ {
-		h.Push(i)
-	}
-	h.verify(t, 0)
-
-	m := make(map[int]bool)
-	for h.Len() > 0 {
-		m[Remove[int](h, (h.Len()-1)/2)] = true
-		h.verify(t, 0)
-	}
-
-	if len(m) != N {
-		t.Errorf("len(m) = %d; want %d", len(m), N)
-	}
-	for i := 0; i < len(m); i++ {
-		if !m[i] {
-			t.Errorf("m[%d] doesn't exist", i)
-		}
-	}
-}
-
-func BenchmarkDup(b *testing.B) {
-	const n = 10000
-	h := make(myHeap[int], 0, n)
-	for i := 0; i < b.N; i++ {
-		for j := 0; j < n; j++ {
-			Push[int](&h, 0) // all elements are the same
-		}
-		for h.Len() > 0 {
-			Pop[int](&h)
-		}
-	}
-}
-
-func TestFix(t *testing.T) {
-	h := new(myHeap[int])
-	h.verify(t, 0)
-
-	for i := 200; i > 0; i -= 10 {
-		Push[int](h, i)
-	}
-	h.verify(t, 0)
-
-	if (*h)[0] != 10 {
-		t.Fatalf("Expected head to be 10, was %d", (*h)[0])
-	}
-	(*h)[0] = 210
-	Fix[int](h, 0)
-	h.verify(t, 0)
-
-	for i := 100; i > 0; i-- {
-		elem := rand.Intn(h.Len())
-		if i&1 == 0 {
-			(*h)[elem] *= 2
-		} else {
-			(*h)[elem] /= 2
-		}
-		Fix[int](h, elem)
-		h.verify(t, 0)
-	}
-}

tsnet/tsnet_test.go

@@ -283,7 +283,6 @@ func TestConn(t *testing.T) {
 }
 
 func TestLoopbackLocalAPI(t *testing.T) {
-	flakytest.Mark(t, "https://github.com/tailscale/tailscale/issues/8557")
 	tstest.ResourceCheck(t)
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()

tstest/clock.go

@@ -4,686 +4,57 @@
 package tstest
 
 import (
-	"container/heap"
 	"sync"
 	"time"
-
-	"tailscale.com/tstime"
-	"tailscale.com/util/mak"
 )
 
-// ClockOpts is used to configure the initial settings for a Clock. Once the
-// settings are configured as desired, call NewClock to get the resulting Clock.
-type ClockOpts struct {
-	// Start is the starting time for the Clock. When FollowRealTime is false,
-	// Start is also the value that will be returned by the first call
-	// to Clock.Now.
-	Start time.Time
-	// Step is the amount of time the Clock will advance whenever Clock.Now is
-	// called. If set to zero, the Clock will only advance when Clock.Advance is
-	// called and/or if FollowRealTime is true.
-	//
-	// FollowRealTime and Step cannot be enabled at the same time.
-	Step time.Duration
-
-	// TimerChannelSize configures the maximum buffered ticks that are
-	// permitted in the channel of any Timer and Ticker created by this Clock.
-	// The special value 0 means to use the default of 1. The buffer may need to
-	// be increased if time is advanced by more than a single tick and proper
-	// functioning of the test requires that the ticks are not lost.
-	TimerChannelSize int
-
-	// FollowRealTime makes the simulated time increment along with real time.
-	// It is a compromise between determinism and the difficulty of explicitly
-	// managing the simulated time via Step or Clock.Advance. When
-	// FollowRealTime is set, calls to Now() and PeekNow() will add the
-	// elapsed real-world time to the simulated time.
-	//
-	// FollowRealTime and Step cannot be enabled at the same time.
-	FollowRealTime bool
-}
-
-// NewClock creates a Clock with the specified settings. To create a
-// Clock with only the default settings, new(Clock) is equivalent, except that
-// the start time will not be computed until one of the receivers is called.
-func NewClock(co ClockOpts) *Clock {
-	if co.FollowRealTime && co.Step != 0 {
-		panic("only one of FollowRealTime and Step are allowed in NewClock")
-	}
-
-	return newClockInternal(co, nil)
-}
-
-// newClockInternal creates a Clock with the specified settings and allows
-// specifying a non-standard realTimeClock.
-func newClockInternal(co ClockOpts, rtClock tstime.Clock) *Clock {
-	if !co.FollowRealTime && rtClock != nil {
-		panic("rtClock can only be set with FollowRealTime enabled")
-	}
-
-	if co.FollowRealTime && rtClock == nil {
-		rtClock = new(tstime.StdClock)
-	}
-
-	c := &Clock{
-		start:            co.Start,
-		realTimeClock:    rtClock,
-		step:             co.Step,
-		timerChannelSize: co.TimerChannelSize,
-	}
-	c.init() // init now to capture the current time when co.Start.IsZero()
-	return c
-}
-
 // Clock is a testing clock that advances every time its Now method is
-// called, beginning at its start time. If no start time is specified using
-// ClockBuilder, an arbitrary start time will be selected when the Clock is
-// created and can be retrieved by calling Clock.Start().
+// called, beginning at Start.
+//
+// The zero value starts virtual time at an arbitrary value recorded
+// in Start on the first call to Now, and time never advances.
 type Clock struct {
-	// start is the first value returned by Now. It must not be modified after
-	// init is called.
-	start time.Time
+	// Start is the first value returned by Now.
+	Start time.Time
+	// Step is how much to advance with each Now call.
+	Step time.Duration
+	// Present is the time that the next Now call will receive.
+	Present time.Time
 
-	// realTimeClock, if not nil, indicates that the Clock shall move forward
-	// according to realTimeClock + the accumulated calls to Advance. This can
-	// make writing tests easier that require some control over the clock but do
-	// not need exact control over the clock. While step can also be used for
-	// this purpose, it is harder to control how quickly time moves using step.
-	realTimeClock tstime.Clock
-
-	initOnce sync.Once
-	mu       sync.Mutex
-
-	// step is how much to advance with each Now call.
-	step time.Duration
-	// present is the last value returned by Now (and will be returned again by
-	// PeekNow).
-	present time.Time
-	// realTime is the time from realTimeClock corresponding to the current
-	// value of present.
-	realTime time.Time
-	// skipStep indicates that the next call to Now should not add step to
-	// present. This occurs after initialization and after Advance.
-	skipStep bool
-	// timerChannelSize is the buffer size to use for channels created by
-	// NewTimer and NewTicker.
-	timerChannelSize int
-
-	events eventManager
-}
-
-func (c *Clock) init() {
-	c.initOnce.Do(func() {
-		if c.realTimeClock != nil {
-			c.realTime = c.realTimeClock.Now()
-		}
-		if c.start.IsZero() {
-			if c.realTime.IsZero() {
-				c.start = time.Now()
-			} else {
-				c.start = c.realTime
-			}
-		}
-		if c.timerChannelSize == 0 {
-			c.timerChannelSize = 1
-		}
-		c.present = c.start
-		c.skipStep = true
-		c.events.AdvanceTo(c.present)
-	})
+	sync.Mutex
 }
 
 // Now returns the virtual clock's current time, and advances it
 // according to its step configuration.
 func (c *Clock) Now() time.Time {
-	c.init()
-	rt := c.maybeGetRealTime()
+	c.Lock()
+	defer c.Unlock()
+	c.initLocked()
+	step := c.Step
+	ret := c.Present
+	c.Present = c.Present.Add(step)
+	return ret
+}
 
-	c.mu.Lock()
-	defer c.mu.Unlock()
+func (c *Clock) Advance(d time.Duration) {
+	c.Lock()
+	defer c.Unlock()
+	c.initLocked()
+	c.Present = c.Present.Add(d)
+}
 
-	step := c.step
-	if c.skipStep {
-		step = 0
-		c.skipStep = false
+func (c *Clock) initLocked() {
+	if c.Start.IsZero() {
+		c.Start = time.Now()
 	}
-	c.advanceLocked(rt, step)
-
-	return c.present
-}
-
-func (c *Clock) maybeGetRealTime() time.Time {
-	if c.realTimeClock == nil {
-		return time.Time{}
-	}
-	return c.realTimeClock.Now()
-}
-
-func (c *Clock) advanceLocked(now time.Time, add time.Duration) {
-	if !now.IsZero() {
-		add += now.Sub(c.realTime)
-		c.realTime = now
-	}
-	if add == 0 {
-		return
-	}
-	c.present = c.present.Add(add)
-	c.events.AdvanceTo(c.present)
-}
-
-// PeekNow returns the last time reported by Now. If Now has never been called,
-// PeekNow returns the same value as GetStart.
-func (c *Clock) PeekNow() time.Time {
-	c.init()
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.present
-}
-
-// Advance moves simulated time forward or backwards by a relative amount. Any
-// Timer or Ticker that is waiting will fire at the requested point in simulated
-// time. Advance returns the new simulated time. If this Clock follows real time
-// then the next call to Now will equal the return value of Advance + the
-// elapsed time since calling Advance. Otherwise, the next call to Now will
-// equal the return value of Advance, regardless of the current step.
-func (c *Clock) Advance(d time.Duration) time.Time {
-	c.init()
-	rt := c.maybeGetRealTime()
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.skipStep = true
-
-	c.advanceLocked(rt, d)
-	return c.present
-}
-
-// AdvanceTo moves simulated time to a new absolute value. Any Timer or Ticker
-// that is waiting will fire at the requested point in simulated time. If this
-// Clock follows real time then the next call to Now will equal t + the elapsed
-// time since calling Advance. Otherwise, the next call to Now will equal t,
-// regardless of the configured step.
-func (c *Clock) AdvanceTo(t time.Time) {
-	c.init()
-	rt := c.maybeGetRealTime()
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.skipStep = true
-	c.realTime = rt
-	c.present = t
-	c.events.AdvanceTo(c.present)
-}
-
-// GetStart returns the initial simulated time when this Clock was created.
-func (c *Clock) GetStart() time.Time {
-	c.init()
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.start
-}
-
-// GetStep returns the amount that simulated time advances on every call to Now.
-func (c *Clock) GetStep() time.Duration {
-	c.init()
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.step
-}
-
-// SetStep updates the amount that simulated time advances on every call to Now.
-func (c *Clock) SetStep(d time.Duration) {
-	c.init()
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.step = d
-}
-
-// SetTimerChannelSize changes the channel size for any Timer or Ticker created
-// in the future. It does not affect those that were already created.
-func (c *Clock) SetTimerChannelSize(n int) {
-	c.init()
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.timerChannelSize = n
-}
-
-// NewTicker returns a Ticker that uses this Clock for accessing the current
-// time.
-func (c *Clock) NewTicker(d time.Duration) (tstime.TickerController, <-chan time.Time) {
-	c.init()
-	rt := c.maybeGetRealTime()
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	c.advanceLocked(rt, 0)
-	t := &Ticker{
-		nextTrigger: c.present.Add(d),
-		period:      d,
-		em:          &c.events,
-	}
-	t.init(c.timerChannelSize)
-	return t, t.C
-}
-
-// NewTimer returns a Timer that uses this Clock for accessing the current
-// time.
-func (c *Clock) NewTimer(d time.Duration) (tstime.TimerController, <-chan time.Time) {
-	c.init()
-	rt := c.maybeGetRealTime()
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	c.advanceLocked(rt, 0)
-	t := &Timer{
-		nextTrigger: c.present.Add(d),
-		em:          &c.events,
-	}
-	t.init(c.timerChannelSize, nil)
-	return t, t.C
-}
-
-// AfterFunc returns a Timer that calls f when it fires, using this Clock for
-// accessing the current time.
-func (c *Clock) AfterFunc(d time.Duration, f func()) tstime.TimerController {
-	c.init()
-	rt := c.maybeGetRealTime()
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	c.advanceLocked(rt, 0)
-	t := &Timer{
-		nextTrigger: c.present.Add(d),
-		em:          &c.events,
-	}
-	t.init(c.timerChannelSize, f)
-	return t
-}
-
-// eventHandler offers a common interface for Timer and Ticker events to avoid
-// code duplication in eventManager.
-type eventHandler interface {
-	// Fire signals the event. The provided time is written to the event's
-	// channel as the current time. The return value is the next time this event
-	// should fire, otherwise if it is zero then the event will be removed from
-	// the eventManager.
-	Fire(time.Time) time.Time
-}
-
-// event tracks details about an upcoming Timer or Ticker firing.
-type event struct {
-	position int       // The current index in the heap, needed for heap.Fix and heap.Remove.
-	when     time.Time // A cache of the next time the event triggers to avoid locking issues if we were to get it from eh.
-	eh       eventHandler
-}
-
-// eventManager tracks pending events created by Timer and Ticker. eventManager
-// implements heap.Interface for efficient lookups of the next event.
-type eventManager struct {
-	// clock is a real time clock for scheduling events with. When clock is nil,
-	// events only fire when AdvanceTo is called by the simulated clock that
-	// this eventManager belongs to. When clock is not nil, events may fire when
-	// timer triggers.
-	clock tstime.Clock
-
-	mu            sync.Mutex
-	now           time.Time
-	heap          []*event
-	reverseLookup map[eventHandler]*event
-
-	// timer is an AfterFunc that triggers at heap[0].when.Sub(now) relative to
-	// the time represented by clock. In other words, if clock is real world
-	// time, then if an event is scheduled 1 second into the future in the
-	// simulated time, then the event will trigger after 1 second of actual test
-	// execution time (unless the test advances simulated time, in which case
-	// the timer is updated accordingly). This makes tests easier to write in
-	// situations where the simulated time only needs to be partially
-	// controlled, and the test writer wishes for simulated time to pass with an
-	// offset but still synchronized with the real world.
-	//
-	// In the future, this could be extended to allow simulated time to run at a
-	// multiple of real world time.
-	timer tstime.TimerController
-}
-
-func (em *eventManager) handleTimer() {
-	rt := em.clock.Now()
-	em.AdvanceTo(rt)
-}
-
-// Push implements heap.Interface.Push and must only be called by heap funcs
-// with em.mu already held.
-func (em *eventManager) Push(x any) {
-	e, ok := x.(*event)
-	if !ok {
-		panic("incorrect event type")
-	}
-	if e == nil {
-		panic("nil event")
-	}
-
-	mak.Set(&em.reverseLookup, e.eh, e)
-	e.position = len(em.heap)
-	em.heap = append(em.heap, e)
-}
-
-// Pop implements heap.Interface.Pop and must only be called by heap funcs with
-// em.mu already held.
-func (em *eventManager) Pop() any {
-	e := em.heap[len(em.heap)-1]
-	em.heap = em.heap[:len(em.heap)-1]
-	delete(em.reverseLookup, e.eh)
-	return e
-}
-
-// Len implements sort.Interface.Len and must only be called by heap funcs with
-// em.mu already held.
-func (em *eventManager) Len() int {
-	return len(em.heap)
-}
-
-// Less implements sort.Interface.Less and must only be called by heap funcs
-// with em.mu already held.
-func (em *eventManager) Less(i, j int) bool {
-	return em.heap[i].when.Before(em.heap[j].when)
-}
-
-// Swap implements sort.Interface.Swap and must only be called by heap funcs
-// with em.mu already held.
-func (em *eventManager) Swap(i, j int) {
-	em.heap[i], em.heap[j] = em.heap[j], em.heap[i]
-	em.heap[i].position = i
-	em.heap[j].position = j
-}
-
-// Reschedule adds/updates/deletes an event in the heap, whichever
-// operation is applicable (use a zero time to delete).
-func (em *eventManager) Reschedule(eh eventHandler, t time.Time) {
-	em.mu.Lock()
-	defer em.mu.Unlock()
-	defer em.updateTimerLocked()
-
-	e, ok := em.reverseLookup[eh]
-	if !ok {
-		if t.IsZero() {
-			// eh is not scheduled and also not active, so do nothing.
-			return
-		}
-		// eh is not scheduled but is active, so add it.
-		heap.Push(em, &event{
-			when: t,
-			eh:   eh,
-		})
-		em.processEventsLocked(em.now) // This is always safe and required when !t.After(em.now).
-		return
-	}
-
-	if t.IsZero() {
-		// e is scheduled but not active, so remove it.
-		heap.Remove(em, e.position)
-		return
-	}
-
-	// e is scheduled and active, so update it.
-	e.when = t
-	heap.Fix(em, e.position)
-	em.processEventsLocked(em.now) // This is always safe and required when !t.After(em.now).
-}
-
-// AdvanceTo updates the current time to tm and fires all events scheduled
-// before or equal to tm. When an event fires, it may request rescheduling and
-// the rescheduled events will be combined with the other existing events that
-// are waiting, and will be run in the unified ordering. A poorly behaved event
-// may theoretically prevent this from ever completing, but both Timer and
-// Ticker require positive steps into the future.
-func (em *eventManager) AdvanceTo(tm time.Time) {
-	em.mu.Lock()
-	defer em.mu.Unlock()
-	defer em.updateTimerLocked()
-
-	em.processEventsLocked(tm)
-	em.now = tm
-}
-
-// Now returns the cached current time. It is intended for use by a Timer or
-// Ticker that needs to convert a relative time to an absolute time.
-func (em *eventManager) Now() time.Time {
-	em.mu.Lock()
-	defer em.mu.Unlock()
-	return em.now
-}
-
-func (em *eventManager) processEventsLocked(tm time.Time) {
-	for len(em.heap) > 0 && !em.heap[0].when.After(tm) {
-		// Ideally some jitter would be added here but it's difficult to do so
-		// in a deterministic fashion.
-		em.now = em.heap[0].when
-
-		if nextFire := em.heap[0].eh.Fire(em.now); !nextFire.IsZero() {
-			em.heap[0].when = nextFire
-			heap.Fix(em, 0)
-		} else {
-			heap.Pop(em)
-		}
+	if c.Present.Before(c.Start) {
+		c.Present = c.Start
 	}
 }
 
-func (em *eventManager) updateTimerLocked() {
-	if em.clock == nil {
-		return
-	}
-	if len(em.heap) == 0 {
-		if em.timer != nil {
-			em.timer.Stop()
-		}
-		return
-	}
-
-	timeToEvent := em.heap[0].when.Sub(em.now)
-	if em.timer == nil {
-		em.timer = em.clock.AfterFunc(timeToEvent, em.handleTimer)
-		return
-	}
-	em.timer.Reset(timeToEvent)
-}
-
-// Ticker is a time.Ticker lookalike for use in tests that need to control when
-// events fire. Ticker could be made standalone in future but for now is
-// expected to be paired with a Clock and created by Clock.NewTicker.
-type Ticker struct {
-	C <-chan time.Time // The channel on which ticks are delivered.
-
-	// em is the eventManager to be notified when nextTrigger changes.
-	// eventManager has its own mutex, and the pointer is immutable, therefore
-	// em can be accessed without holding mu.
-	em *eventManager
-
-	c chan<- time.Time // The writer side of C.
-
-	mu sync.Mutex
-
-	// nextTrigger is the time of the ticker's next scheduled activation. When
-	// Fire activates the ticker, nextTrigger is the timestamp written to the
-	// channel.
-	nextTrigger time.Time
-
-	// period is the duration that is added to nextTrigger when the ticker
-	// fires.
-	period time.Duration
-}
-
-func (t *Ticker) init(channelSize int) {
-	if channelSize <= 0 {
-		panic("ticker channel size must be non-negative")
-	}
-	c := make(chan time.Time, channelSize)
-	t.c = c
-	t.C = c
-	t.em.Reschedule(t, t.nextTrigger)
-}
-
-// Fire triggers the ticker. curTime is the timestamp to write to the channel.
-// The next trigger time for the ticker is updated to the last computed trigger
-// time + the ticker period (set at creation or using Reset). The next trigger
-// time is computed this way to match standard time.Ticker behavior, which
-// prevents accumulation of long term drift caused by delays in event execution.
-func (t *Ticker) Fire(curTime time.Time) time.Time {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	if t.nextTrigger.IsZero() {
-		return time.Time{}
-	}
-	select {
-	case t.c <- curTime:
-	default:
-	}
-	t.nextTrigger = t.nextTrigger.Add(t.period)
-
-	return t.nextTrigger
-}
-
-// Reset adjusts the Ticker's period to d and reschedules the next fire time to
-// the current simulated time + d.
-func (t *Ticker) Reset(d time.Duration) {
-	if d <= 0 {
-		// The standard time.Ticker requires a positive period.
-		panic("non-positive period for Ticker.Reset")
-	}
-
-	now := t.em.Now()
-
-	t.mu.Lock()
-	t.resetLocked(now.Add(d), d)
-	t.mu.Unlock()
-
-	t.em.Reschedule(t, t.nextTrigger)
-}
-
-// ResetAbsolute adjusts the Ticker's period to d and reschedules the next fire
-// time to nextTrigger.
-func (t *Ticker) ResetAbsolute(nextTrigger time.Time, d time.Duration) {
-	if nextTrigger.IsZero() {
-		panic("zero nextTrigger time for ResetAbsolute")
-	}
-	if d <= 0 {
-		panic("non-positive period for ResetAbsolute")
-	}
-
-	t.mu.Lock()
-	t.resetLocked(nextTrigger, d)
-	t.mu.Unlock()
-
-	t.em.Reschedule(t, t.nextTrigger)
-}
-
-func (t *Ticker) resetLocked(nextTrigger time.Time, d time.Duration) {
-	t.nextTrigger = nextTrigger
-	t.period = d
-}
-
-// Stop deactivates the Ticker.
-func (t *Ticker) Stop() {
-	t.mu.Lock()
-	t.nextTrigger = time.Time{}
-	t.mu.Unlock()
-
-	t.em.Reschedule(t, t.nextTrigger)
-}
-
-// Timer is a time.Timer lookalike for use in tests that need to control when
-// events fire. Timer could be made standalone in future but for now must be
-// paired with a Clock and created by Clock.NewTimer.
-type Timer struct {
-	C <-chan time.Time // The channel on which ticks are delivered.
-
-	// em is the eventManager to be notified when nextTrigger changes.
-	// eventManager has its own mutex, and the pointer is immutable, therefore
-	// em can be accessed without holding mu.
-	em *eventManager
-
-	f func(time.Time) // The function to call when the timer expires.
-
-	mu sync.Mutex
-
-	// nextTrigger is the time of the ticker's next scheduled activation. When
-	// Fire activates the ticker, nextTrigger is the timestamp written to the
-	// channel.
-	nextTrigger time.Time
-}
-
-func (t *Timer) init(channelSize int, afterFunc func()) {
-	if channelSize <= 0 {
-		panic("ticker channel size must be non-negative")
-	}
-	c := make(chan time.Time, channelSize)
-	t.C = c
-	if afterFunc == nil {
-		t.f = func(curTime time.Time) {
-			select {
-			case c <- curTime:
-			default:
-			}
-		}
-	} else {
-		t.f = func(_ time.Time) { afterFunc() }
-	}
-	t.em.Reschedule(t, t.nextTrigger)
-}
-
-// Fire triggers the ticker. curTime is the timestamp to write to the channel.
-// The next trigger time for the ticker is updated to the last computed trigger
-// time + the ticker period (set at creation or using Reset). The next trigger
-// time is computed this way to match standard time.Ticker behavior, which
-// prevents accumulation of long term drift caused by delays in event execution.
-func (t *Timer) Fire(curTime time.Time) time.Time {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	if t.nextTrigger.IsZero() {
-		return time.Time{}
-	}
-	t.nextTrigger = time.Time{}
-	t.f(curTime)
-	return time.Time{}
-}
-
-// Reset reschedules the next fire time to the current simulated time + d.
-// Reset reports whether the timer was still active before the reset.
-func (t *Timer) Reset(d time.Duration) bool {
-	if d <= 0 {
-		// The standard time.Timer requires a positive delay.
-		panic("non-positive delay for Timer.Reset")
-	}
-
-	return t.reset(t.em.Now().Add(d))
-}
-
-// ResetAbsolute reschedules the next fire time to nextTrigger.
-// ResetAbsolute reports whether the timer was still active before the reset.
-func (t *Timer) ResetAbsolute(nextTrigger time.Time) bool {
-	if nextTrigger.IsZero() {
-		panic("zero nextTrigger time for ResetAbsolute")
-	}
-
-	return t.reset(nextTrigger)
-}
-
-// Stop deactivates the Timer. Stop reports whether the timer was active before
-// stopping.
-func (t *Timer) Stop() bool {
-	return t.reset(time.Time{})
-}
-
-func (t *Timer) reset(nextTrigger time.Time) bool {
-	t.mu.Lock()
-	wasActive := !t.nextTrigger.IsZero()
-	t.nextTrigger = nextTrigger
-	t.mu.Unlock()
-
-	t.em.Reschedule(t, t.nextTrigger)
-	return wasActive
+// Reset rewinds the virtual clock to its start time.
+func (c *Clock) Reset() {
+	c.Lock()
+	defer c.Unlock()
+	c.Present = c.Start
 }

tstime/tstime.go

@@ -59,79 +59,3 @@ func Sleep(ctx context.Context, d time.Duration) bool {
 		return true
 	}
 }
-
-// Clock offers a subset of the functionality from the std/time package.
-// Normally, applications will use the StdClock implementation that calls the
-// appropriate std/time exported funcs. The advantage of using Clock is that
-// tests can substitute a different implementation, allowing the test to control
-// time precisely, something required for certain types of tests to be possible
-// at all, speeds up execution by not needing to sleep, and can dramatically
-// reduce the risk of flakes due to tests executing too slowly or quickly.
-type Clock interface {
-	// Now returns the current time, as in time.Now.
-	Now() time.Time
-	// NewTimer returns a timer whose notion of the current time is controlled
-	// by this Clock. It follows the semantics of time.NewTimer as closely as
-	// possible but is adapted to return an interface, so the channel needs to
-	// be returned as well.
-	NewTimer(d time.Duration) (TimerController, <-chan time.Time)
-	// NewTicker returns a ticker whose notion of the current time is controlled
-	// by this Clock. It follows the semantics of time.NewTicker as closely as
-	// possible but is adapted to return an interface, so the channel needs to
-	// be returned as well.
-	NewTicker(d time.Duration) (TickerController, <-chan time.Time)
-	// AfterFunc returns a ticker whose notion of the current time is controlled
-	// by this Clock. When the ticker expires, it will call the provided func.
-	// It follows the semantics of time.AfterFunc.
-	AfterFunc(d time.Duration, f func()) TimerController
-}
-
-// TickerController offers the receivers of a time.Ticker to ensure
-// compatibility with standard timers, but allows for the option of substituting
-// a standard timer with something else for testing purposes.
-type TickerController interface {
-	// Reset follows the same semantics as with time.Ticker.Reset.
-	Reset(d time.Duration)
-	// Stop follows the same semantics as with time.Ticker.Stop.
-	Stop()
-}
-
-// TimerController offers the receivers of a time.Timer to ensure
-// compatibility with standard timers, but allows for the option of substituting
-// a standard timer with something else for testing purposes.
-type TimerController interface {
-	// Reset follows the same semantics as with time.Timer.Reset.
-	Reset(d time.Duration) bool
-	// Stop follows the same semantics as with time.Timer.Stop.
-	Stop() bool
-}
-
-// StdClock is a simple implementation of Clock using the relevant funcs in the
-// std/time package.
-type StdClock struct{}
-
-// Now calls time.Now.
-func (StdClock) Now() time.Time {
-	return time.Now()
-}
-
-// NewTimer calls time.NewTimer. As an interface does not allow for struct
-// members and other packages cannot add receivers to another package, the
-// channel is also returned because it would be otherwise inaccessible.
-func (StdClock) NewTimer(d time.Duration) (TimerController, <-chan time.Time) {
-	t := time.NewTimer(d)
-	return t, t.C
-}
-
-// NewTicker calls time.NewTicker. As an interface does not allow for struct
-// members and other packages cannot add receivers to another package, the
-// channel is also returned because it would be otherwise inaccessible.
-func (StdClock) NewTicker(d time.Duration) (TickerController, <-chan time.Time) {
-	t := time.NewTicker(d)
-	return t, t.C
-}
-
-// AfterFunc calls time.AfterFunc.
-func (StdClock) AfterFunc(d time.Duration, f func()) TimerController {
-	return time.AfterFunc(d, f)
-}

tsweb/tsweb_test.go

@@ -65,7 +65,10 @@ func TestStdHandler(t *testing.T) {
 		testErr = errors.New("test error")
 		bgCtx   = context.Background()
 		// canceledCtx, cancel = context.WithCancel(bgCtx)
-		startTime = time.Unix(1687870000, 1234)
+		clock = tstest.Clock{
+			Start: time.Now(),
+			Step:  time.Second,
+		}
 	)
 	// cancel()
 
@@ -83,7 +86,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/"),
 			wantCode: 200,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				TLS:        false,
@@ -100,7 +103,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 404,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -116,7 +119,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 404,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -133,7 +136,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 404,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -150,7 +153,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 500,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -167,7 +170,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 500,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -184,7 +187,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 500,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -201,7 +204,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 200,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -218,7 +221,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 200,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -235,7 +238,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 200,
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				Host:       "example.com",
@@ -257,7 +260,7 @@ func TestStdHandler(t *testing.T) {
 			r:        req(bgCtx, "http://example.com/foo"),
 			wantCode: 200,
 			wantLog: AccessLogRecord{
-				When:    startTime,
+				When:    clock.Start,
 				Seconds: 1.0,
 
 				Proto:      "HTTP/1.1",
@@ -276,7 +279,7 @@ func TestStdHandler(t *testing.T) {
 				http.Error(w, e.Msg, 200)
 			},
 			wantLog: AccessLogRecord{
-				When:       startTime,
+				When:       clock.Start,
 				Seconds:    1.0,
 				Proto:      "HTTP/1.1",
 				TLS:        false,
@@ -299,10 +302,7 @@ func TestStdHandler(t *testing.T) {
 				t.Logf(fmt, args...)
 			}
 
-			clock := tstest.NewClock(tstest.ClockOpts{
-				Start: startTime,
-				Step:  time.Second,
-			})
+			clock.Reset()
 
 			rec := noopHijacker{httptest.NewRecorder(), false}
 			h := StdHandler(test.rh, HandlerOptions{Logf: logf, Now: clock.Now, OnError: test.errHandler})

util/deephash/deephash_test.go

@@ -581,8 +581,8 @@ func TestGetTypeHasher(t *testing.T) {
 		{
 			name:  "tailcfg.Node",
 			val:   &tailcfg.Node{},
-			out:   "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
-			out32: "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+			out:   "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+			out32: "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\tn\x88\xf1\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
 		},
 	}
 	for _, tt := range tests {

version/prop.go

@@ -88,7 +88,7 @@ func IsAppleTV() bool {
 		return false
 	}
 	return isAppleTV.Get(func() bool {
-		return strings.EqualFold(os.Getenv("XPC_SERVICE_NAME"), "io.tailscale.ipn.ios.network-extension-tvos")
+		return strings.EqualFold(os.Getenv("XPC_SERVICE_NAME"), "io.tailscale.ipn.tvos.network-extension")
 	})
 }
 

wgengine/magicsock/magicsock.go

@@ -30,7 +30,6 @@ import (
 
 	"github.com/tailscale/wireguard-go/conn"
 	"go4.org/mem"
-	"golang.org/x/exp/maps"
 	"golang.org/x/net/ipv4"
 	"golang.org/x/net/ipv6"
 	"tailscale.com/control/controlclient"
@@ -4410,12 +4409,16 @@ func (de *endpoint) addrForWireGuardSendLocked(now mono.Time) (udpAddr netip.Add
 		return udpAddr, false
 	}
 
-	candidates := maps.Keys(de.endpointState)
-	if len(candidates) == 0 {
-		de.c.logf("magicsock: addrForSendWireguardLocked: [unexpected] no candidates available for endpoint")
-		return udpAddr, false
+	candidates := make([]netip.AddrPort, 0, len(de.endpointState))
+	for ipp := range de.endpointState {
+		if ipp.Addr().Is4() && de.c.noV4.Load() {
+			continue
+		}
+		if ipp.Addr().Is6() && de.c.noV6.Load() {
+			continue
+		}
+		candidates = append(candidates, ipp)
 	}
-
 	// Randomly select an address to use until we retrieve latency information
 	// and give it a short trustBestAddrUntil time so we avoid flapping between
 	// addresses while waiting on latency information to be populated.

wgengine/magicsock/magicsock_test.go

@@ -2809,6 +2809,36 @@ func TestAddrForSendLockedForWireGuardOnly(t *testing.T) {
 			},
 			want: netip.MustParseAddrPort("[2345:0425:2CA1:0000:0000:0567:5673:23b5]:222"),
 		},
+		{
+			name:       "choose IPv4 when IPv6 is not useable",
+			sendWGPing: false,
+			noV6:       true,
+			ep: []endpointDetails{
+				{
+					addrPort: netip.MustParseAddrPort("1.1.1.1:111"),
+					latency:  100 * time.Millisecond,
+				},
+				{
+					addrPort: netip.MustParseAddrPort("[1::1]:567"),
+				},
+			},
+			want: netip.MustParseAddrPort("1.1.1.1:111"),
+		},
+		{
+			name:       "choose IPv6 when IPv4 is not useable",
+			sendWGPing: false,
+			noV4:       true,
+			ep: []endpointDetails{
+				{
+					addrPort: netip.MustParseAddrPort("1.1.1.1:111"),
+				},
+				{
+					addrPort: netip.MustParseAddrPort("[1::1]:567"),
+					latency:  100 * time.Millisecond,
+				},
+			},
+			want: netip.MustParseAddrPort("[1::1]:567"),
+		},
 		{
 			name:       "choose IPv6 address when latency is the same for v4 and v6",
 			sendWGPing: true,
@@ -2835,6 +2865,8 @@ func TestAddrForSendLockedForWireGuardOnly(t *testing.T) {
 				noV6: atomic.Bool{},
 			},
 		}
+		endpoint.c.noV4.Store(test.noV4)
+		endpoint.c.noV6.Store(test.noV6)
 
 		for _, epd := range test.ep {
 			endpoint.endpointState[epd.addrPort] = &endpointState{}

wgengine/wgcfg/nmcfg/nmcfg.go

@@ -96,6 +96,9 @@ func WGCfg(nm *netmap.NetworkMap, logf logger.Logf, flags netmap.WGConfigFlags,
 			DiscoKey:  peer.DiscoKey,
 		})
 		cpeer := &cfg.Peers[len(cfg.Peers)-1]
+		if peer.KeepAlive {
+			cpeer.PersistentKeepalive = 25 // seconds
+		}
 
 		didExitNodeWarn := false
 		cpeer.V4MasqAddr = peer.SelfNodeV4MasqAddrForThisPeer

words/tails.txt

@@ -544,4 +544,3 @@ shrimp
 prawn
 lobster
 chipmunk
-tails