control/controlclient/auto.go

@@ -472,13 +472,14 @@ func (mrs mapRoutineState) UpdateNetmapDelta(muts []netmap.NodeMutation) bool {
 	c.mu.Lock()
 	goodState := c.loggedIn && c.inMapPoll
 	ndu, canDelta := c.observer.(NetmapDeltaUpdater)
+	mapCtx := c.mapCtx
 	c.mu.Unlock()
 
 	if !goodState || !canDelta {
 		return false
 	}
 
-	ctx, cancel := context.WithTimeout(c.mapCtx, 2*time.Second)
+	ctx, cancel := context.WithTimeout(mapCtx, 2*time.Second)
 	defer cancel()
 
 	ch := make(chan bool, 1)
@@ -508,11 +509,12 @@ func (mrs mapRoutineState) UpdatePacketFilter(rules views.Slice[tailcfg.FilterRu
 	c.mu.Lock()
 	goodState := c.loggedIn && c.inMapPoll
 	pfu, ok := c.observer.(PacketFilterUpdater)
+	mapCtx := c.mapCtx
 	c.mu.Unlock()
 	if !goodState || !ok {
 		return false
 	}
-	ctx, cancel := context.WithTimeout(c.mapCtx, 2*time.Second)
+	ctx, cancel := context.WithTimeout(mapCtx, 2*time.Second)
 	defer cancel()
 	ch := make(chan bool, 1)
 	c.observerQueue.Add(func() {
@@ -536,11 +538,12 @@ func (mrs mapRoutineState) UpdateUserProfiles(profiles map[tailcfg.UserID]tailcf
 	c.mu.Lock()
 	goodState := c.loggedIn && c.inMapPoll
 	upu, ok := c.observer.(UserProfileUpdater)
+	mapCtx := c.mapCtx
 	c.mu.Unlock()
 	if !goodState || !ok {
 		return false
 	}
-	ctx, cancel := context.WithTimeout(c.mapCtx, 2*time.Second)
+	ctx, cancel := context.WithTimeout(mapCtx, 2*time.Second)
 	defer cancel()
 	ch := make(chan bool, 1)
 	c.observerQueue.Add(func() {
@@ -561,13 +564,14 @@ func (mrs mapRoutineState) PatchDiscoKey(pub key.NodePublic, disco key.DiscoPubl
 	c.mu.Lock()
 	goodState := c.loggedIn && c.inMapPoll
 	dun, ok := c.observer.(patchDiscoKeyer)
+	mapCtx := c.mapCtx
 	c.mu.Unlock()
 
 	if !goodState || !ok {
 		return
 	}
 
-	ctx, cancel := context.WithTimeout(c.mapCtx, 2*time.Second)
+	ctx, cancel := context.WithTimeout(mapCtx, 2*time.Second)
 	defer cancel()
 
 	c.observerQueue.RunSync(ctx, func() {

control/controlclient/auto_test.go

@@ -0,0 +1,66 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+package controlclient
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"tailscale.com/tailcfg"
+)
+
+type userProfileUpdateObserver struct{}
+
+func (userProfileUpdateObserver) SetControlClientStatus(Client, Status) {}
+
+func (userProfileUpdateObserver) UpdateUserProfiles(map[tailcfg.UserID]tailcfg.UserProfileView) bool {
+	return true
+}
+
+func TestMapRoutineStateUpdateUserProfilesConcurrentCancelMapCtx(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	c := &Auto{
+		logf:      func(string, ...any) {},
+		observer:  userProfileUpdateObserver{},
+		mapCtx:    ctx,
+		mapCancel: cancel,
+		loggedIn:  true,
+		inMapPoll: true,
+	}
+	mrs := mapRoutineState{c: c}
+
+	start := make(chan struct{})
+	var wg sync.WaitGroup
+	for range 4 {
+		wg.Go(func() {
+			<-start
+			for range 2000 {
+				c.mu.Lock()
+				c.cancelMapCtxLocked()
+				c.mu.Unlock()
+			}
+		})
+	}
+	for range 4 {
+		wg.Go(func() {
+			<-start
+			for range 2000 {
+				mrs.UpdateUserProfiles(nil)
+			}
+		})
+	}
+
+	close(start)
+	wg.Wait()
+
+	waitCtx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	defer cancel()
+	if err := c.observerQueue.Wait(waitCtx); err != nil {
+		t.Fatal(err)
+	}
+	c.observerQueue.Shutdown()
+	c.mapCancel()
+}