7099f68 fix(daemon): coalesce resize redraws · vev

M internal/usecase/daemon/client.go +59 -27


@@ -38,25 +38,28 @@ import (
38	38		)
39	39
40	40		type attachedClient struct {
41		-	tr ports.Transport
42		-	output *outputStateStream
43		-	overlays *overlayRuntime
44		-	clientID [16]byte
45		-	resumeCapable bool
46		-	resumeToken uint64
47		-	parked bool
48		-	echoAck atomic.Uint64
49		-	bars barCache // only touched while sendMu is held
50		-	composed composedFrameCache // only touched while sendMu is held
51		-	size domain.Size
52		-	keys *keys.Router
53		-	sess Guarded[*session]
54		-	mouseScan mouse.Scanner
55		-	themeMu sync.Mutex
56		-	theme themeui.Theme
57		-	clientTheme themeui.Theme
58		-	lastCursor cursorOut
59		-	recentNav recentSessionNavigator
	41	+	tr ports.Transport
	42	+	output *outputStateStream
	43	+	overlays *overlayRuntime
	44	+	clientID [16]byte
	45	+	resumeCapable bool
	46	+	resumeToken uint64
	47	+	parked bool
	48	+	echoAck atomic.Uint64
	49	+	bars barCache // only touched while sendMu is held
	50	+	composed composedFrameCache // only touched while sendMu is held
	51	+	resizePaint pendingByteTimer // guarded by sendMu
	52	+	resizePaintGeneration uint64 // guarded by sendMu
	53	+	resizePaintPending bool // guarded by sendMu
	54	+	size domain.Size
	55	+	keys *keys.Router
	56	+	sess Guarded[*session]
	57	+	mouseScan mouse.Scanner
	58	+	themeMu sync.Mutex
	59	+	theme themeui.Theme
	60	+	clientTheme themeui.Theme
	61	+	lastCursor cursorOut
	62	+	recentNav recentSessionNavigator
60	63		// historyNavMu protects historyNav and historyNavTimer. When paint needs
61	64		// several locks, take sendMu before historyNavMu, then Daemon.mu/session.mu.
62	65		historyNavMu sync.Mutex

@@ -104,6 +107,16 @@ func (p *pendingByteTimer) stop() {
104	107		}
105	108		}
106	109
	110	+	// cancelResizePaint invalidates callbacks before detaching or replacing an
	111	+	// attachment. It deliberately takes sendMu before any session/daemon lock.
	112	+	func (ac *attachedClient) cancelResizePaint() {
	113	+	ac.sendMu.Lock()
	114	+	ac.resizePaintGeneration++
	115	+	ac.resizePaintPending = false
	116	+	ac.resizePaint.stop()
	117	+	ac.sendMu.Unlock()
	118	+	}
	119	+
107	120		func (ac *attachedClient) initOverlays() {
108	121		if ac.overlays == nil {
109	122		ac.overlays = newOverlayRuntime(ac)

@@ -421,6 +434,7 @@ func (d Daemon) detachReplacedClient(old attachedClient) {
421	434		if old == nil {
422	435		return
423	436		}
	437	+	old.cancelResizePaint()
424	438		d.unregisterPreview(old)
425	439		old.setSession(nil)
426	440		d.log.Info("client displaced")

@@ -430,8 +444,9 @@ func (d Daemon) detachReplacedClient(old attachedClient) {
430	444		}
431	445
432	446		// firstPaint guarantees the freshly attached client sees the full screen: if
433		-	// the tab size differs from the client's it resizes first (which paints a
434		-	// full redraw), otherwise it forces a full paint against the fresh renderer.
	447	+	// the tab size differs from the client's it resizes first, then immediately
	448	+	// emits a full redraw. Attach must not wait for the resize-idle fallback
	449	+	// timer.
435	450		func (d Daemon) firstPaint(sess session, ac *attachedClient, clientSize domain.Size) {
436	451		tb := sess.activeTab()
437	452		if tb == nil {

@@ -442,9 +457,7 @@ func (d Daemon) firstPaint(sess session, ac *attachedClient, clientSize domain
442	457		tb.mu.Unlock()
443	458
444	459		if clientSize.Valid() && wsz != tabSize(clientSize) {
445		-	d.resize(sess, ac, clientSize)
446		-	d.activateTab(sess, sess.activeTab())
447		-	return
	460	+	d.resizeForFirstPaint(sess, ac, clientSize)
448	461		}
449	462		d.refreshBarScriptsIfDue(sess, d.clock.Now(), true)
450	463		d.paint(sess, ac, true)

@@ -523,6 +536,7 @@ func (d Daemon) clientGone(sess session, ac *attachedClient, failed ports.Tran
523	536		if !sess.detachIfCurrent(ac) {
524	537		return // already displaced by a newer client; nothing to do
525	538		}
	539	+	ac.cancelResizePaint()
526	540		d.unregisterPreview(ac)
527	541		sess.mu.Lock()
528	542		ephemeral := sess.ephemeral

@@ -575,14 +589,31 @@ func (d Daemon) applyTheme(sess session, ac *attachedClient, msg ports.Theme)
575	589		}
576	590
577	591		func (d Daemon) resize(sess session, ac *attachedClient, sz domain.Size) {
	592	+	d.resizeWithPaint(sess, ac, sz, true)
	593	+	}
	594	+
	595	+	// resizeForFirstPaint applies attach geometry without installing an idle timer:
	596	+	// firstPaint immediately emits the required full frame itself.
	597	+	func (d Daemon) resizeForFirstPaint(sess session, ac *attachedClient, sz domain.Size) {
	598	+	d.resizeWithPaint(sess, ac, sz, false)
	599	+	}
	600	+
	601	+	func (d Daemon) resizeWithPaint(sess session, ac *attachedClient, sz domain.Size, schedulePaint bool) {
578	602		if !sz.Valid() {
579	603		return
580	604		}
581	605		d.exitCopyMode(ac)
582		-	tbSize := tabSize(sz)
583	606		if ac != nil {
	607	+	// Suspend emission until every pane has adopted this geometry and the
	608	+	// bounded resize paint is armed. PTY readers remain independent.
	609	+	ac.sendMu.Lock()
	610	+	defer ac.sendMu.Unlock()
	611	+	if ac.currentSession() != sess {
	612	+	return
	613	+	}
584	614		ac.size = sz
585	615		}
	616	+	tbSize := tabSize(sz)
586	617
587	618		sess.mu.Lock()
588	619		tabs := append([]*tab(nil), sess.tabs...)

@@ -601,9 +632,9 @@ func (d Daemon) resize(sess session, ac *attachedClient, sz domain.Size) {
601	632		// outside tab.mu so its PTY resize cannot block tab state.
602	633		d.resizeActiveFloating(sess.activeTab())
603	634		markSnapshotDirty(sess)
604		-	if ac != nil {
	635	+	if ac != nil && schedulePaint {
605	636		d.refreshBarScriptsIfDue(sess, d.clock.Now(), true)
606		-	d.paint(sess, ac, true)
	637	+	d.scheduleResizePaintLocked(sess, ac)
607	638		}
608	639		}
609	640

@@ -614,6 +645,7 @@ func (d Daemon) detachOnSendError(sess session, ac *attachedClient, failed por
614	645		return
615	646		}
616	647		if sess.detachIfCurrent(ac) {
	648	+	ac.cancelResizePaint()
617	649		d.unregisterPreview(ac)
618	650		if d.parkAttachment(sess, ac) {
619	651		_ = ac.closeCapturedTransport(failed)

 )
 type attachedClient struct {
-	tr            ports.Transport
+	tr                    ports.Transport
-	output        *outputStateStream
+	output                *outputStateStream
-	overlays      *overlayRuntime
+	overlays              *overlayRuntime
-	clientID      [16]byte
+	clientID              [16]byte
-	resumeCapable bool
+	resumeCapable         bool
-	resumeToken   uint64
+	resumeToken           uint64
-	parked        bool
+	parked                bool
-	echoAck       atomic.Uint64
+	echoAck               atomic.Uint64
-	bars          barCache           // only touched while sendMu is held
+	bars                  barCache           // only touched while sendMu is held
-	composed      composedFrameCache // only touched while sendMu is held
+	composed              composedFrameCache // only touched while sendMu is held
-	size          domain.Size
+	resizePaint           pendingByteTimer   // guarded by sendMu
-	keys          *keys.Router
+	resizePaintGeneration uint64             // guarded by sendMu
-	sess          Guarded[*session]
+	resizePaintPending    bool               // guarded by sendMu
-	mouseScan     mouse.Scanner
+	size                  domain.Size
-	themeMu       sync.Mutex
+	keys                  *keys.Router
-	theme         themeui.Theme
+	sess                  Guarded[*session]
-	clientTheme   themeui.Theme
+	mouseScan             mouse.Scanner
-	lastCursor    cursorOut
+	themeMu               sync.Mutex
-	recentNav     recentSessionNavigator
+	theme                 themeui.Theme
+	clientTheme           themeui.Theme
+	lastCursor            cursorOut
+	recentNav             recentSessionNavigator
 	// historyNavMu protects historyNav and historyNavTimer. When paint needs
 	// several locks, take sendMu before historyNavMu, then Daemon.mu/session.mu.
 	historyNavMu    sync.Mutex
 	}
 }
+// cancelResizePaint invalidates callbacks before detaching or replacing an
+// attachment. It deliberately takes sendMu before any session/daemon lock.
+func (ac *attachedClient) cancelResizePaint() {
+	ac.sendMu.Lock()
+	ac.resizePaintGeneration++
+	ac.resizePaintPending = false
+	ac.resizePaint.stop()
+	ac.sendMu.Unlock()
+}
 func (ac *attachedClient) initOverlays() {
 	if ac.overlays == nil {
 		ac.overlays = newOverlayRuntime(ac)
 	if old == nil {
 		return
 	}
+	old.cancelResizePaint()
 	d.unregisterPreview(old)
 	old.setSession(nil)
 	d.log.Info("client displaced")
 }
 // firstPaint guarantees the freshly attached client sees the full screen: if
-// the tab size differs from the client's it resizes first (which paints a
+// the tab size differs from the client's it resizes first, then immediately
-// full redraw), otherwise it forces a full paint against the fresh renderer.
+// emits a full redraw. Attach must not wait for the resize-idle fallback
+// timer.
 func (d *Daemon) firstPaint(sess *session, ac *attachedClient, clientSize domain.Size) {
 	tb := sess.activeTab()
 	if tb == nil {
 	tb.mu.Unlock()
 	if clientSize.Valid() && wsz != tabSize(clientSize) {
-		d.resize(sess, ac, clientSize)
+		d.resizeForFirstPaint(sess, ac, clientSize)
-		d.activateTab(sess, sess.activeTab())
-		return
 	}
 	d.refreshBarScriptsIfDue(sess, d.clock.Now(), true)
 	d.paint(sess, ac, true)
 	if !sess.detachIfCurrent(ac) {
 		return // already displaced by a newer client; nothing to do
 	}
+	ac.cancelResizePaint()
 	d.unregisterPreview(ac)
 	sess.mu.Lock()
 	ephemeral := sess.ephemeral
 }
 func (d *Daemon) resize(sess *session, ac *attachedClient, sz domain.Size) {
+	d.resizeWithPaint(sess, ac, sz, true)
+}
+// resizeForFirstPaint applies attach geometry without installing an idle timer:
+// firstPaint immediately emits the required full frame itself.
+func (d *Daemon) resizeForFirstPaint(sess *session, ac *attachedClient, sz domain.Size) {
+	d.resizeWithPaint(sess, ac, sz, false)
+}
+func (d *Daemon) resizeWithPaint(sess *session, ac *attachedClient, sz domain.Size, schedulePaint bool) {
 	if !sz.Valid() {
 		return
 	}
 	d.exitCopyMode(ac)
-	tbSize := tabSize(sz)
 	if ac != nil {
+		// Suspend emission until every pane has adopted this geometry and the
+		// bounded resize paint is armed. PTY readers remain independent.
+		ac.sendMu.Lock()
+		defer ac.sendMu.Unlock()
+		if ac.currentSession() != sess {
+			return
+		}
 		ac.size = sz
 	}
+	tbSize := tabSize(sz)
 	sess.mu.Lock()
 	tabs := append([]*tab(nil), sess.tabs...)
 	// outside tab.mu so its PTY resize cannot block tab state.
 	d.resizeActiveFloating(sess.activeTab())
 	markSnapshotDirty(sess)
-	if ac != nil {
+	if ac != nil && schedulePaint {
 		d.refreshBarScriptsIfDue(sess, d.clock.Now(), true)
-		d.paint(sess, ac, true)
+		d.scheduleResizePaintLocked(sess, ac)
 	}
 }
 		return
 	}
 	if sess.detachIfCurrent(ac) {
+		ac.cancelResizePaint()
 		d.unregisterPreview(ac)
 		if d.parkAttachment(sess, ac) {
 			_ = ac.closeCapturedTransport(failed)

M internal/usecase/daemon/output_state_sync_test.go +96 -0


@@ -3,6 +3,7 @@ package daemon
3	3		import (
4	4		"errors"
5	5		"io"
	6	+	"strings"
6	7		"sync"
7	8		"testing"
8	9		"time"

@@ -269,6 +270,101 @@ func TestFailedPaintSendRollsBackOutputState(t *testing.T) {
269	270		require.Zero(t, ac.output.acked)
270	271		}
271	272
	273	+	func TestResizeGrowthFirstFrameIncludesConcurrentPTYRedraw(t *testing.T) {
	274	+	for _, tc := range []struct {
	275	+	name string
	276	+	window uint64
	277	+	}{
	278	+	{name: "datagram window", window: 1},
	279	+	{name: "stream window", window: maxUnackedOutputStates},
	280	+	} {
	281	+	t.Run(tc.name, func(t *testing.T) {
	282	+	p, releasePTY := newBlockingPTY(t)
	283	+	defer releasePTY()
	284	+	d, sess, ac, sends := newManualSessionWithPTYs(t, p)
	285	+	ac.output.maxOutstanding = tc.window
	286	+	pane := sess.activeTab().focusedPane()
	287	+
	288	+	pane.screen.Write([]byte(strings.Repeat("A", 79)))
	289	+	d.paint(sess, ac, true)
	290	+	client := vt.NewScreen(80, 24)
	291	+	initial := mustApplyOutput(t, client, awaitFrame(t, sends, ports.MsgOutput))
	292	+	ac.ackOutputState(initial.NewStateNum)
	293	+
	294	+	// The child can redraw the newly exposed columns while the resize
	295	+	// output is being prepared. The first visible grown frame must contain
	296	+	// that redraw, regardless of the negotiated output window.
	297	+	d.resize(sess, ac, domain.Size{Cols: 120, Rows: 24})
	298	+	pane.screen.Write([]byte("\x1b[1;81H" + strings.Repeat("B", 40)))
	299	+	d.paint(sess, ac, false)
	300	+
	301	+	client.Resize(120, 24)
	302	+	mustApplyOutput(t, client, awaitFrame(t, sends, ports.MsgOutput))
	303	+	require.Equal(t, 'B', client.Frame.At(100, 1).Rune,
	304	+	"first grown frame exposed stale pre-SIGWINCH pane content")
	305	+	requireNoOutputFrame(t, sends)
	306	+	})
	307	+	}
	308	+	}
	309	+
	310	+	func TestResizeWithoutPTYOutputFlushesOneFullFrameAtDeadline(t *testing.T) {
	311	+	p, releasePTY := newBlockingPTY(t)
	312	+	defer releasePTY()
	313	+	d, sess, ac, sends := newManualSessionWithPTYs(t, p)
	314	+	clk := &signalClock{timers: make(chan *signalTimer, 1)}
	315	+	d.clock = clk
	316	+
	317	+	d.resize(sess, ac, domain.Size{Cols: 120, Rows: 24})
	318	+	var timer *signalTimer
	319	+	select {
	320	+	case timer = <-clk.timers:
	321	+	case <-time.After(time.Second):
	322	+	t.Fatal("resize did not schedule a bounded paint")
	323	+	}
	324	+	requireNoOutputFrame(t, sends)
	325	+
	326	+	timer.ch <- time.Now()
	327	+	frame := awaitFrame(t, sends, ports.MsgOutput)
	328	+	client := vt.NewScreen(120, 24)
	329	+	out := mustApplyOutput(t, client, frame)
	330	+	require.Zero(t, out.BaseStateNum)
	331	+	require.Contains(t, screenLineText(client, 0), "1")
	332	+	require.Contains(t, screenLineText(client, 23), "work")
	333	+	require.Equal(t, domain.Size{Cols: 120, Rows: 24}, ac.size)
	334	+	requireNoOutputFrame(t, sends)
	335	+	}
	336	+
	337	+	func TestResizeBurstFlushesOnlyLatestGeometry(t *testing.T) {
	338	+	p, releasePTY := newBlockingPTY(t)
	339	+	defer releasePTY()
	340	+	d, sess, ac, sends := newManualSessionWithPTYs(t, p)
	341	+	clk := &signalClock{timers: make(chan *signalTimer, 2)}
	342	+	d.clock = clk
	343	+
	344	+	d.resize(sess, ac, domain.Size{Cols: 100, Rows: 24})
	345	+	var first *signalTimer
	346	+	select {
	347	+	case first = <-clk.timers:
	348	+	case <-time.After(time.Second):
	349	+	t.Fatal("first resize did not schedule a bounded paint")
	350	+	}
	351	+	d.resize(sess, ac, domain.Size{Cols: 120, Rows: 24})
	352	+	var latest *signalTimer
	353	+	select {
	354	+	case latest = <-clk.timers:
	355	+	case <-time.After(time.Second):
	356	+	t.Fatal("latest resize did not replace the bounded paint")
	357	+	}
	358	+
	359	+	first.ch <- time.Now()
	360	+	requireNoOutputFrame(t, sends)
	361	+	latest.ch <- time.Now()
	362	+	awaitFrame(t, sends, ports.MsgOutput)
	363	+	require.Equal(t, domain.Size{Cols: 120, Rows: 24}, ac.size)
	364	+	require.Equal(t, 120, sess.activeTab().focusedPane().screen.Frame.Width)
	365	+	requireNoOutputFrame(t, sends)
	366	+	}
	367	+
272	368		func TestDatagramWindowOneCoalescesPaintsUntilMsgAck(t *testing.T) {
273	369		p, releasePTY := newBlockingPTY(t)
274	370		defer releasePTY()


@@ -3,6 +3,7 @@ package daemon
3	import (	3		import (
4	"errors"	4		"errors"
5	"io"	5		"io"
		6	+	"strings"
6	"sync"	7		"sync"
7	"testing"	8		"testing"
8	"time"	9		"time"

@@ -269,6 +270,101 @@ func TestFailedPaintSendRollsBackOutputState(t *testing.T) {
269	require.Zero(t, ac.output.acked)	270		require.Zero(t, ac.output.acked)
270	}	271		}
271		272
		273	+	func TestResizeGrowthFirstFrameIncludesConcurrentPTYRedraw(t *testing.T) {
		274	+	for _, tc := range []struct {
		275	+	name string
		276	+	window uint64
		277	+	}{
		278	+	{name: "datagram window", window: 1},
		279	+	{name: "stream window", window: maxUnackedOutputStates},
		280	+	} {
		281	+	t.Run(tc.name, func(t *testing.T) {
		282	+	p, releasePTY := newBlockingPTY(t)
		283	+	defer releasePTY()
		284	+	d, sess, ac, sends := newManualSessionWithPTYs(t, p)
		285	+	ac.output.maxOutstanding = tc.window
		286	+	pane := sess.activeTab().focusedPane()
		287	+
		288	+	pane.screen.Write([]byte(strings.Repeat("A", 79)))
		289	+	d.paint(sess, ac, true)
		290	+	client := vt.NewScreen(80, 24)
		291	+	initial := mustApplyOutput(t, client, awaitFrame(t, sends, ports.MsgOutput))
		292	+	ac.ackOutputState(initial.NewStateNum)
		293	+
		294	+	// The child can redraw the newly exposed columns while the resize
		295	+	// output is being prepared. The first visible grown frame must contain
		296	+	// that redraw, regardless of the negotiated output window.
		297	+	d.resize(sess, ac, domain.Size{Cols: 120, Rows: 24})
		298	+	pane.screen.Write([]byte("\x1b[1;81H" + strings.Repeat("B", 40)))
		299	+	d.paint(sess, ac, false)
		300	+
		301	+	client.Resize(120, 24)
		302	+	mustApplyOutput(t, client, awaitFrame(t, sends, ports.MsgOutput))
		303	+	require.Equal(t, 'B', client.Frame.At(100, 1).Rune,
		304	+	"first grown frame exposed stale pre-SIGWINCH pane content")
		305	+	requireNoOutputFrame(t, sends)
		306	+	})
		307	+	}
		308	+	}
		309	+
		310	+	func TestResizeWithoutPTYOutputFlushesOneFullFrameAtDeadline(t *testing.T) {
		311	+	p, releasePTY := newBlockingPTY(t)
		312	+	defer releasePTY()
		313	+	d, sess, ac, sends := newManualSessionWithPTYs(t, p)
		314	+	clk := &signalClock{timers: make(chan *signalTimer, 1)}
		315	+	d.clock = clk
		316	+
		317	+	d.resize(sess, ac, domain.Size{Cols: 120, Rows: 24})
		318	+	var timer *signalTimer
		319	+	select {
		320	+	case timer = <-clk.timers:
		321	+	case <-time.After(time.Second):
		322	+	t.Fatal("resize did not schedule a bounded paint")
		323	+	}
		324	+	requireNoOutputFrame(t, sends)
		325	+
		326	+	timer.ch <- time.Now()
		327	+	frame := awaitFrame(t, sends, ports.MsgOutput)
		328	+	client := vt.NewScreen(120, 24)
		329	+	out := mustApplyOutput(t, client, frame)
		330	+	require.Zero(t, out.BaseStateNum)
		331	+	require.Contains(t, screenLineText(client, 0), "1")
		332	+	require.Contains(t, screenLineText(client, 23), "work")
		333	+	require.Equal(t, domain.Size{Cols: 120, Rows: 24}, ac.size)
		334	+	requireNoOutputFrame(t, sends)
		335	+	}
		336	+
		337	+	func TestResizeBurstFlushesOnlyLatestGeometry(t *testing.T) {
		338	+	p, releasePTY := newBlockingPTY(t)
		339	+	defer releasePTY()
		340	+	d, sess, ac, sends := newManualSessionWithPTYs(t, p)
		341	+	clk := &signalClock{timers: make(chan *signalTimer, 2)}
		342	+	d.clock = clk
		343	+
		344	+	d.resize(sess, ac, domain.Size{Cols: 100, Rows: 24})
		345	+	var first *signalTimer
		346	+	select {
		347	+	case first = <-clk.timers:
		348	+	case <-time.After(time.Second):
		349	+	t.Fatal("first resize did not schedule a bounded paint")
		350	+	}
		351	+	d.resize(sess, ac, domain.Size{Cols: 120, Rows: 24})
		352	+	var latest *signalTimer
		353	+	select {
		354	+	case latest = <-clk.timers:
		355	+	case <-time.After(time.Second):
		356	+	t.Fatal("latest resize did not replace the bounded paint")
		357	+	}
		358	+
		359	+	first.ch <- time.Now()
		360	+	requireNoOutputFrame(t, sends)
		361	+	latest.ch <- time.Now()
		362	+	awaitFrame(t, sends, ports.MsgOutput)
		363	+	require.Equal(t, domain.Size{Cols: 120, Rows: 24}, ac.size)
		364	+	require.Equal(t, 120, sess.activeTab().focusedPane().screen.Frame.Width)
		365	+	requireNoOutputFrame(t, sends)
		366	+	}
		367	+
272	func TestDatagramWindowOneCoalescesPaintsUntilMsgAck(t *testing.T) {	368		func TestDatagramWindowOneCoalescesPaintsUntilMsgAck(t *testing.T) {
273	p, releasePTY := newBlockingPTY(t)	369		p, releasePTY := newBlockingPTY(t)
274	defer releasePTY()	370		defer releasePTY()

M internal/usecase/daemon/picker_test.go +3 -0


@@ -531,6 +531,9 @@ func TestPickerResizeRecomposesModal(t *testing.T) {
531	531		d.enterPicker(sess, ac)
532	532		awaitFrame(t, sends, ports.MsgOutput)
533	533		d.resize(sess, ac, domain.Size{Cols: 100, Rows: 30})
	534	+	// Picker recomposition is the relevant event here; do not depend on a real
	535	+	// resize-idle timer in this synchronous rendering test.
	536	+	d.paint(sess, ac, false)
534	537
535	538		out := awaitFrame(t, sends, ports.MsgOutput)
536	539		msg, err := ports.UnmarshalOutput(out.Payload)


@@ -531,6 +531,9 @@ func TestPickerResizeRecomposesModal(t *testing.T) {
531	d.enterPicker(sess, ac)	531		d.enterPicker(sess, ac)
532	awaitFrame(t, sends, ports.MsgOutput)	532		awaitFrame(t, sends, ports.MsgOutput)
533	d.resize(sess, ac, domain.Size{Cols: 100, Rows: 30})	533		d.resize(sess, ac, domain.Size{Cols: 100, Rows: 30})
		534	+	// Picker recomposition is the relevant event here; do not depend on a real
		535	+	// resize-idle timer in this synchronous rendering test.
		536	+	d.paint(sess, ac, false)
534		537
535	out := awaitFrame(t, sends, ports.MsgOutput)	538		out := awaitFrame(t, sends, ports.MsgOutput)
536	msg, err := ports.UnmarshalOutput(out.Payload)	539		msg, err := ports.UnmarshalOutput(out.Payload)

M internal/usecase/daemon/render.go +23 -0


@@ -312,7 +312,21 @@ func titleBarPaneIDs(placements []layout.Placement, ok bool) []layout.PaneID {
312	312		return ids
313	313		}
314	314
	315	+	func (d Daemon) scheduleResizePaintLocked(sess session, ac *attachedClient) {
	316	+	ac.resizePaint.stop()
	317	+	ac.resizePaintGeneration++
	318	+	generation := ac.resizePaintGeneration
	319	+	ac.resizePaintPending = true
	320	+	ac.resizePaint.retain(d.clock, maxDebounceInterval, func(ports.Timer) {
	321	+	d.paintForResizeGeneration(sess, ac, true, generation)
	322	+	})
	323	+	}
	324	+
315	325		func (d Daemon) paint(sess session, ac *attachedClient, reset bool) {
	326	+	d.paintForResizeGeneration(sess, ac, reset, 0)
	327	+	}
	328	+
	329	+	func (d Daemon) paintForResizeGeneration(sess session, ac *attachedClient, reset bool, resizeGeneration uint64) {
316	330		tb := sess.activeTab()
317	331		if tb == nil {
318	332		return

@@ -324,6 +338,15 @@ func (d Daemon) paint(sess session, ac *attachedClient, reset bool) {
324	338		ac.sendMu.Unlock()
325	339		return
326	340		}
	341	+	if resizeGeneration != 0 && (!ac.resizePaintPending \|\| ac.resizePaintGeneration != resizeGeneration) {
	342	+	ac.sendMu.Unlock()
	343	+	return
	344	+	}
	345	+	if ac.resizePaintPending {
	346	+	ac.resizePaint.stop()
	347	+	ac.resizePaintPending = false
	348	+	reset = true
	349	+	}
327	350		// Ack-gated coalescing: while the client is at least maxUnackedOutputStates
328	351		// behind, skip composing another diff and mark the paint deferred. The
329	352		// MsgOutputAck handler flushes one cumulative paint once acks catch up. A


@@ -312,7 +312,21 @@ func titleBarPaneIDs(placements []layout.Placement, ok bool) []layout.PaneID {
312	return ids	312		return ids
313	}	313		}
314		314
		315	+	func (d Daemon) scheduleResizePaintLocked(sess session, ac *attachedClient) {
		316	+	ac.resizePaint.stop()
		317	+	ac.resizePaintGeneration++
		318	+	generation := ac.resizePaintGeneration
		319	+	ac.resizePaintPending = true
		320	+	ac.resizePaint.retain(d.clock, maxDebounceInterval, func(ports.Timer) {
		321	+	d.paintForResizeGeneration(sess, ac, true, generation)
		322	+	})
		323	+	}
		324	+
315	func (d Daemon) paint(sess session, ac *attachedClient, reset bool) {	325		func (d Daemon) paint(sess session, ac *attachedClient, reset bool) {
		326	+	d.paintForResizeGeneration(sess, ac, reset, 0)
		327	+	}
		328	+
		329	+	func (d Daemon) paintForResizeGeneration(sess session, ac *attachedClient, reset bool, resizeGeneration uint64) {
316	tb := sess.activeTab()	330		tb := sess.activeTab()
317	if tb == nil {	331		if tb == nil {
318	return	332		return

@@ -324,6 +338,15 @@ func (d Daemon) paint(sess session, ac *attachedClient, reset bool) {
324	ac.sendMu.Unlock()	338		ac.sendMu.Unlock()
325	return	339		return
326	}	340		}
		341	+	if resizeGeneration != 0 && (!ac.resizePaintPending \|\| ac.resizePaintGeneration != resizeGeneration) {
		342	+	ac.sendMu.Unlock()
		343	+	return
		344	+	}
		345	+	if ac.resizePaintPending {
		346	+	ac.resizePaint.stop()
		347	+	ac.resizePaintPending = false
		348	+	reset = true
		349	+	}
327	// Ack-gated coalescing: while the client is at least maxUnackedOutputStates	350		// Ack-gated coalescing: while the client is at least maxUnackedOutputStates
328	// behind, skip composing another diff and mark the paint deferred. The	351		// behind, skip composing another diff and mark the paint deferred. The
329	// MsgOutputAck handler flushes one cumulative paint once acks catch up. A	352		// MsgOutputAck handler flushes one cumulative paint once acks catch up. A

M internal/usecase/daemon/render_test.go +3 -0


@@ -932,6 +932,9 @@ func TestResizeOrdersPTYBeforeScreen(t *testing.T) {
932	932		ac.setSession(sess)
933	933
934	934		d.resize(sess, ac, newSize)
	935	+	// This test verifies resize ordering, not the idle fallback. Consume the
	936	+	// pending resize paint deterministically under the non-firing stub clock.
	937	+	d.paint(sess, ac, false)
935	938
936	939		require.Equal(t, 80, screenWidthAtResize, "pty.Resize must run before screen.Resize")
937	940		require.Equal(t, 100, win.focusedPane().screen.Frame.Width, "screen resized after pty")


@@ -932,6 +932,9 @@ func TestResizeOrdersPTYBeforeScreen(t *testing.T) {
932	ac.setSession(sess)	932		ac.setSession(sess)
933		933
934	d.resize(sess, ac, newSize)	934		d.resize(sess, ac, newSize)
		935	+	// This test verifies resize ordering, not the idle fallback. Consume the
		936	+	// pending resize paint deterministically under the non-firing stub clock.
		937	+	d.paint(sess, ac, false)
935		938
936	require.Equal(t, 80, screenWidthAtResize, "pty.Resize must run before screen.Resize")	939		require.Equal(t, 80, screenWidthAtResize, "pty.Resize must run before screen.Resize")
937	require.Equal(t, 100, win.focusedPane().screen.Frame.Width, "screen resized after pty")	940		require.Equal(t, 100, win.focusedPane().screen.Frame.Width, "screen resized after pty")

M internal/usecase/daemon/resume.go +4 -2


@@ -48,8 +48,10 @@ func (d Daemon) parkAttachment(sess session, ac *attachedClient) bool {
48	48		if !d.prepareParkAttachment(sess, ac) {
49	49		return false
50	50		}
51		-	// Drop any deferred diff so a resumed client starts clean; resume forces a
52		-	// full reset repaint anyway.
	51	+	// A parked attachment has no valid visible destination. Retire both the
	52	+	// deferred diff and any resize-idle callback before registering its grace
	53	+	// timer; resume performs a fresh full paint.
	54	+	ac.cancelResizePaint()
53	55		ac.clearPaintDeferred()
54	56		d.mu.Lock()
55	57		if d.closing {

 	if !d.prepareParkAttachment(sess, ac) {
 		return false
 	}
-	// Drop any deferred diff so a resumed client starts clean; resume forces a
+	// A parked attachment has no valid visible destination. Retire both the
-	// full reset repaint anyway.
+	// deferred diff and any resize-idle callback before registering its grace
+	// timer; resume performs a fresh full paint.
+	ac.cancelResizePaint()
 	ac.clearPaintDeferred()
 	d.mu.Lock()
 	if d.closing {

M internal/usecase/daemon/session.go +1 -0


@@ -730,6 +730,7 @@ func (d Daemon) killSession(sess session, reason uint8, purge bool) error {
730	730		sess.client = nil
731	731		sess.mu.Unlock()
732	732		if ac != nil {
	733	+	ac.cancelResizePaint()
733	734		d.unregisterPreview(ac)
734	735		ac.setSession(nil)
735	736		}


@@ -730,6 +730,7 @@ func (d Daemon) killSession(sess session, reason uint8, purge bool) error {
730	sess.client = nil	730		sess.client = nil
731	sess.mu.Unlock()	731		sess.mu.Unlock()
732	if ac != nil {	732		if ac != nil {
		733	+	ac.cancelResizePaint()
733	d.unregisterPreview(ac)	734		d.unregisterPreview(ac)
734	ac.setSession(nil)	735		ac.setSession(nil)
735	}	736		}

M internal/usecase/daemon/status_test.go +5 -1


@@ -927,7 +927,8 @@ func TestStatusBarCopyFeedbackBoundaryWidths(t *testing.T) {
927	927		func TestStatusRepaintsOnCreateSwitchAndResize(t *testing.T) {
928	928		p1, releasePTY1 := newBlockingPTY(t)
929	929		p2, releasePTY2 := newBlockingPTY(t)
930		-	d := newTestDaemon(t, newFactorySeq(t, p1, p2), stubClock{})
	930	+	clock := &signalClock{timers: make(chan *signalTimer, 1)}
	931	+	d := newTestDaemon(t, newFactorySeq(t, p1, p2), clock)
931	932		tr, sends, releaseConn := newConn(t,
932	933		mustHello(ports.IntentNew, "work", domain.Size{Cols: 20, Rows: 5}),
933	934		frameInput([]byte("\x1b ")),

@@ -943,6 +944,9 @@ func TestStatusRepaintsOnCreateSwitchAndResize(t *testing.T) {
943	944		palette := awaitFrame(t, sends, ports.MsgOutput)
944	945		created := awaitFrame(t, sends, ports.MsgOutput)
945	946		switched := awaitFrame(t, sends, ports.MsgOutput)
	947	+	// The resize frame is intentionally idle-coalesced; fire its fake-clock
	948	+	// deadline rather than relying on the old synchronous behavior.
	949	+	(<-clock.timers).ch <- time.Time{}
946	950		resized := awaitFrame(t, sends, ports.MsgOutput)
947	951
948	952		_ = palette

 func TestStatusRepaintsOnCreateSwitchAndResize(t *testing.T) {
 	p1, releasePTY1 := newBlockingPTY(t)
 	p2, releasePTY2 := newBlockingPTY(t)
-	d := newTestDaemon(t, newFactorySeq(t, p1, p2), stubClock{})
+	clock := &signalClock{timers: make(chan *signalTimer, 1)}
+	d := newTestDaemon(t, newFactorySeq(t, p1, p2), clock)
 	tr, sends, releaseConn := newConn(t,
 		mustHello(ports.IntentNew, "work", domain.Size{Cols: 20, Rows: 5}),
 		frameInput([]byte("\x1b ")),
 	palette := awaitFrame(t, sends, ports.MsgOutput)
 	created := awaitFrame(t, sends, ports.MsgOutput)
 	switched := awaitFrame(t, sends, ports.MsgOutput)
+	// The resize frame is intentionally idle-coalesced; fire its fake-clock
+	// deadline rather than relying on the old synchronous behavior.
+	(<-clock.timers).ch <- time.Time{}
 	resized := awaitFrame(t, sends, ports.MsgOutput)
 	_ = palette