test(server): drive fd sources over raw socketpairs and report dispatch errno

commit: c5dcda01b68bb540cd69507bdfa3a527b7f12081
author: brice · 13h ago · 2026-10-22 07:07 UTC
parent: 5042ed7
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email
checks: 3/4

1 file · +19 -8

M server/xwm_test.go +19 -8


@@ -47,7 +47,7 @@ func registry(t testing.TB, d *Display, fd int) int {
47	47		t.Fatal(err)
48	48		}
49	49		if xwmDispatch(d) < 0 {
50		-	t.Fatal("dispatch failed")
	50	+	t.Fatalf("dispatch failed: errno=%v", lastErrno())
51	51		}
52	52		wlDisplayFlushClients(d.c)
53	53		var buf [4096]byte

@@ -116,7 +116,8 @@ func TestGlobalFilter(t *testing.T) {
116	116
117	117		func TestWritableInterest(t *testing.T) {
118	118		d := xwmDisplay(t)
119		-	client, fd := xwmClient(t, d)
	119	+	fds := xwmSocketpair(t)
	120	+	fd := fds[0]
120	121		reads, writes := 0, 0
121	122		s, err := d.AddFDRW(fd, func() { reads++ }, func() { writes++ })
122	123		if err != nil {

@@ -124,7 +125,7 @@ func TestWritableInterest(t *testing.T) {
124	125		}
125	126		dispatch := func() {
126	127		if xwmDispatch(d) < 0 {
127		-	t.Fatal("dispatch failed")
	128	+	t.Fatalf("dispatch failed: errno=%v", lastErrno())
128	129		}
129	130		}
130	131		dispatch()

@@ -151,10 +152,7 @@ func TestWritableInterest(t *testing.T) {
151	152		t.Fatal("writable not disabled")
152	153		}
153	154		// Readable callbacks also stay allocation-free through the real C loop.
154		-	serverFD, err := client.FD()
155		-	if err != nil {
156		-	t.Fatal(err)
157		-	}
	155	+	serverFD := fds[1]
158	156		var payload = [1]byte{1}
159	157		if _, err := unix.Write(serverFD, payload[:]); err != nil {
160	158		t.Fatal(err)

@@ -213,7 +211,8 @@ func BenchmarkGlobalFilter(b *testing.B) {
213	211
214	212		func BenchmarkFDCallback(b *testing.B) {
215	213		d := xwmDisplay(b)
216		-	_, fd := xwmClient(b, d)
	214	+	fds := xwmSocketpair(b)
	215	+	fd := fds[0]
217	216		s, err := d.AddFDRW(fd, func() {}, func() {})
218	217		if err != nil {
219	218		b.Fatal(err)

@@ -370,3 +369,15 @@ func xwmDispatch(d *Display) int32 {
370	369		}
371	370		return -1
372	371		}
	372	+
	373	+	// FD sources use raw sockets, not Wayland clients: arbitrary payloads must
	374	+	// never enter libwayland's protocol transport or its flush/error handling.
	375	+	func xwmSocketpair(t testing.TB) [2]int {
	376	+	t.Helper()
	377	+	fds, err := unix.Socketpair(unix.AF_UNIX, unix.SOCK_STREAM\|unix.SOCK_NONBLOCK\|unix.SOCK_CLOEXEC, 0)
	378	+	if err != nil {
	379	+	t.Fatal(err)
	380	+	}
	381	+	t.Cleanup(func() { unix.Close(fds[0]); unix.Close(fds[1]) })
	382	+	return fds
	383	+	}

 		t.Fatal(err)
 	}
 	if xwmDispatch(d) < 0 {
-		t.Fatal("dispatch failed")
+		t.Fatalf("dispatch failed: errno=%v", lastErrno())
 	}
 	wlDisplayFlushClients(d.c)
 	var buf [4096]byte
 func TestWritableInterest(t *testing.T) {
 	d := xwmDisplay(t)
-	client, fd := xwmClient(t, d)
+	fds := xwmSocketpair(t)
+	fd := fds[0]
 	reads, writes := 0, 0
 	s, err := d.AddFDRW(fd, func() { reads++ }, func() { writes++ })
 	if err != nil {
 	}
 	dispatch := func() {
 		if xwmDispatch(d) < 0 {
-			t.Fatal("dispatch failed")
+			t.Fatalf("dispatch failed: errno=%v", lastErrno())
 		}
 	}
 	dispatch()
 		t.Fatal("writable not disabled")
 	}
 	// Readable callbacks also stay allocation-free through the real C loop.
-	serverFD, err := client.FD()
+	serverFD := fds[1]
-	if err != nil {
-		t.Fatal(err)
-	}
 	var payload = [1]byte{1}
 	if _, err := unix.Write(serverFD, payload[:]); err != nil {
 		t.Fatal(err)
 func BenchmarkFDCallback(b *testing.B) {
 	d := xwmDisplay(b)
-	_, fd := xwmClient(b, d)
+	fds := xwmSocketpair(b)
+	fd := fds[0]
 	s, err := d.AddFDRW(fd, func() {}, func() {})
 	if err != nil {
 		b.Fatal(err)
 	}
 	return -1
 }
+// FD sources use raw sockets, not Wayland clients: arbitrary payloads must
+// never enter libwayland's protocol transport or its flush/error handling.
+func xwmSocketpair(t testing.TB) [2]int {
+	t.Helper()
+	fds, err := unix.Socketpair(unix.AF_UNIX, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { unix.Close(fds[0]); unix.Close(fds[1]) })
+	return fds
+}