feat(server): prove libwayland-server bindings without cgo

Bind non-varargs libwayland-server entry points through purego, build wl_interface tables in mmap memory, and route requests through one shared dispatcher. Feasibility tests cover wayland-info, request/event roundtrip, and resource cleanup on disconnect.

commit: 54d04f6111e760cd53c6cd28a9e8e8273f8c6ada
author: brice · 29d ago · 2026-09-23 09:52 UTC
parent: none (root commit)
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

14 files · +775 -0

A .github/workflows/ci.yml +17 -0

@@ -0,0 +1,17 @@
	1	+	name: ci
	2	+
	3	+	on:
	4	+	push:
	5	+	pull_request:
	6	+
	7	+	jobs:
	8	+	test:
	9	+	runs-on: ubuntu-latest
	10	+	steps:
	11	+	- uses: actions/checkout@v4
	12	+	- uses: actions/setup-go@v5
	13	+	with:
	14	+	go-version: '1.27'
	15	+	- run: sudo apt-get install -y libwayland-server0 libwayland-client0 wayland-utils
	16	+	- run: make check
	17	+	- run: make race

@@ -0,0 +1,17 @@
	1	+	name: ci
	2	+
	3	+	on:
	4	+	push:
	5	+	pull_request:
	6	+
	7	+	jobs:
	8	+	test:
	9	+	runs-on: ubuntu-latest
	10	+	steps:
	11	+	- uses: actions/checkout@v4
	12	+	- uses: actions/setup-go@v5
	13	+	with:
	14	+	go-version: '1.27'
	15	+	- run: sudo apt-get install -y libwayland-server0 libwayland-client0 wayland-utils
	16	+	- run: make check
	17	+	- run: make race

A .gitignore +5 -0

@@ -0,0 +1,5 @@
	1	+	*.test
	2	+	*.out
	3	+	coverage.txt
	4	+	.DS_Store
	5	+	.worktrees/

@@ -0,0 +1,5 @@
	1	+	*.test
	2	+	*.out
	3	+	coverage.txt
	4	+	.DS_Store
	5	+	.worktrees/

A AGENTS.md +8 -0

@@ -0,0 +1,8 @@
	1	+	# Repository rules
	2	+
	3	+	- Go 1.27 only.
	4	+	- Library code must build with `CGO_ENABLED=0`.
	5	+	- Use only non-varargs libwayland entry points (no `va_list`).
	6	+	- Make all libwayland calls on one OS-locked goroutine.
	7	+	- C-visible memory must never be Go-GC-managed.
	8	+	- Use signed conventional commits: `type(scope): description`.

@@ -0,0 +1,8 @@
	1	+	# Repository rules
	2	+
	3	+	- Go 1.27 only.
	4	+	- Library code must build with `CGO_ENABLED=0`.
	5	+	- Use only non-varargs libwayland entry points (no `va_list`).
	6	+	- Make all libwayland calls on one OS-locked goroutine.
	7	+	- C-visible memory must never be Go-GC-managed.
	8	+	- Use signed conventional commits: `type(scope): description`.

A LICENSE +21 -0

@@ -0,0 +1,21 @@
	1	+	MIT License
	2	+
	3	+	Copyright (c) 2026 bnema
	4	+
	5	+	Permission is hereby granted, free of charge, to any person obtaining a copy
	6	+	of this software and associated documentation files (the "Software"), to deal
	7	+	in the Software without restriction, including without limitation the rights
	8	+	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	9	+	copies of the Software, and to permit persons to whom the Software is
	10	+	furnished to do so, subject to the following conditions:
	11	+
	12	+	The above copyright notice and this permission notice shall be included in all
	13	+	copies or substantial portions of the Software.
	14	+
	15	+	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	+	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	+	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	18	+	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	+	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	20	+	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	21	+	SOFTWARE.

@@ -0,0 +1,21 @@
	1	+	MIT License
	2	+
	3	+	Copyright (c) 2026 bnema
	4	+
	5	+	Permission is hereby granted, free of charge, to any person obtaining a copy
	6	+	of this software and associated documentation files (the "Software"), to deal
	7	+	in the Software without restriction, including without limitation the rights
	8	+	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	9	+	copies of the Software, and to permit persons to whom the Software is
	10	+	furnished to do so, subject to the following conditions:
	11	+
	12	+	The above copyright notice and this permission notice shall be included in all
	13	+	copies or substantial portions of the Software.
	14	+
	15	+	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	+	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	+	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	18	+	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	+	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	20	+	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	21	+	SOFTWARE.

A Makefile +13 -0

@@ -0,0 +1,13 @@
	1	+	.PHONY: test vet race check
	2	+
	3	+	test:
	4	+	CGO_ENABLED=0 go test ./...
	5	+
	6	+	vet:
	7	+	CGO_ENABLED=0 go vet ./...
	8	+
	9	+	# The race detector needs cgo only for the test binary; library code stays cgo-free.
	10	+	race:
	11	+	CGO_ENABLED=1 go test -race ./...
	12	+
	13	+	check: vet test

@@ -0,0 +1,13 @@
	1	+	.PHONY: test vet race check
	2	+
	3	+	test:
	4	+	CGO_ENABLED=0 go test ./...
	5	+
	6	+	vet:
	7	+	CGO_ENABLED=0 go vet ./...
	8	+
	9	+	# The race detector needs cgo only for the test binary; library code stays cgo-free.
	10	+	race:
	11	+	CGO_ENABLED=1 go test -race ./...
	12	+
	13	+	check: vet test

A README.md +21 -0

@@ -0,0 +1,21 @@
	1	+	# purego-libwayland
	2	+
	3	+	Go bindings for libwayland without cgo, loaded at runtime through github.com/bnema/purego.
	4	+
	5	+	## Status
	6	+
	7	+	Early v0.x. Server side first; client side planned.
	8	+
	9	+	## Requirements
	10	+
	11	+	Linux, Go 1.27, and `libwayland-server.so.0` at runtime.
	12	+
	13	+	## Build
	14	+
	15	+	```sh
	16	+	CGO_ENABLED=0 go build ./...
	17	+	```
	18	+
	19	+	## License
	20	+
	21	+	MIT.

@@ -0,0 +1,21 @@
	1	+	# purego-libwayland
	2	+
	3	+	Go bindings for libwayland without cgo, loaded at runtime through github.com/bnema/purego.
	4	+
	5	+	## Status
	6	+
	7	+	Early v0.x. Server side first; client side planned.
	8	+
	9	+	## Requirements
	10	+
	11	+	Linux, Go 1.27, and `libwayland-server.so.0` at runtime.
	12	+
	13	+	## Build
	14	+
	15	+	```sh
	16	+	CGO_ENABLED=0 go build ./...
	17	+	```
	18	+
	19	+	## License
	20	+
	21	+	MIT.

A go.mod +9 -0

@@ -0,0 +1,9 @@
	1	+	module github.com/bnema/purego-libwayland
	2	+
	3	+	go 1.27
	4	+
	5	+	require (
	6	+	github.com/bnema/purego v0.11.0-bnema.4
	7	+	github.com/bnema/wlturbo v0.2.0
	8	+	golang.org/x/sys v0.48.0
	9	+	)

@@ -0,0 +1,9 @@
	1	+	module github.com/bnema/purego-libwayland
	2	+
	3	+	go 1.27
	4	+
	5	+	require (
	6	+	github.com/bnema/purego v0.11.0-bnema.4
	7	+	github.com/bnema/wlturbo v0.2.0
	8	+	golang.org/x/sys v0.48.0
	9	+	)

A go.sum +6 -0 generated file: collapsed

load diff

A internal/proto/core.go +55 -0

@@ -0,0 +1,55 @@
	1	+	// Package proto holds hand-written core interfaces for the feasibility
	2	+	// prototype. The generator replaces this package.
	3	+	package proto
	4	+
	5	+	import (
	6	+	"sync"
	7	+
	8	+	"github.com/bnema/purego-libwayland/server"
	9	+	)
	10	+
	11	+	var (
	12	+	Compositor = &server.Interface{Name: "wl_compositor", Version: 1}
	13	+	Surface = &server.Interface{Name: "wl_surface", Version: 1}
	14	+	Region = &server.Interface{Name: "wl_region", Version: 1}
	15	+	Callback = &server.Interface{Name: "wl_callback", Version: 1}
	16	+	)
	17	+
	18	+	// Opcodes used by the prototype.
	19	+	const (
	20	+	CompositorCreateSurface = 0
	21	+	CompositorCreateRegion = 1
	22	+	SurfaceDestroy = 0
	23	+	SurfaceFrame = 3
	24	+	SurfaceCommit = 6
	25	+	RegionDestroy = 0
	26	+	CallbackDone = 0
	27	+	)
	28	+
	29	+	var initOnce = sync.OnceValue(initInterfaces)
	30	+
	31	+	// Init builds the C tables once per process.
	32	+	func Init() error { return initOnce() }
	33	+
	34	+	func initInterfaces() error {
	35	+	Compositor.Requests = []server.Message{
	36	+	{Name: "create_surface", Signature: "n", Types: []*server.Interface{Surface}},
	37	+	{Name: "create_region", Signature: "n", Types: []*server.Interface{Region}},
	38	+	}
	39	+	Surface.Requests = []server.Message{
	40	+	{Name: "destroy", Signature: ""},
	41	+	{Name: "attach", Signature: "?oii", Types: []*server.Interface{nil, nil, nil}},
	42	+	{Name: "damage", Signature: "iiii"},
	43	+	{Name: "frame", Signature: "n", Types: []*server.Interface{Callback}},
	44	+	{Name: "set_opaque_region", Signature: "?o", Types: []*server.Interface{Region}},
	45	+	{Name: "set_input_region", Signature: "?o", Types: []*server.Interface{Region}},
	46	+	{Name: "commit", Signature: ""},
	47	+	}
	48	+	Region.Requests = []server.Message{
	49	+	{Name: "destroy", Signature: ""},
	50	+	{Name: "add", Signature: "iiii"},
	51	+	{Name: "subtract", Signature: "iiii"},
	52	+	}
	53	+	Callback.Events = []server.Message{{Name: "done", Signature: "u"}}
	54	+	return server.NewInterfaces(Compositor, Surface, Region, Callback)
	55	+	}

@@ -0,0 +1,55 @@
	1	+	// Package proto holds hand-written core interfaces for the feasibility
	2	+	// prototype. The generator replaces this package.
	3	+	package proto
	4	+
	5	+	import (
	6	+	"sync"
	7	+
	8	+	"github.com/bnema/purego-libwayland/server"
	9	+	)
	10	+
	11	+	var (
	12	+	Compositor = &server.Interface{Name: "wl_compositor", Version: 1}
	13	+	Surface = &server.Interface{Name: "wl_surface", Version: 1}
	14	+	Region = &server.Interface{Name: "wl_region", Version: 1}
	15	+	Callback = &server.Interface{Name: "wl_callback", Version: 1}
	16	+	)
	17	+
	18	+	// Opcodes used by the prototype.
	19	+	const (
	20	+	CompositorCreateSurface = 0
	21	+	CompositorCreateRegion = 1
	22	+	SurfaceDestroy = 0
	23	+	SurfaceFrame = 3
	24	+	SurfaceCommit = 6
	25	+	RegionDestroy = 0
	26	+	CallbackDone = 0
	27	+	)
	28	+
	29	+	var initOnce = sync.OnceValue(initInterfaces)
	30	+
	31	+	// Init builds the C tables once per process.
	32	+	func Init() error { return initOnce() }
	33	+
	34	+	func initInterfaces() error {
	35	+	Compositor.Requests = []server.Message{
	36	+	{Name: "create_surface", Signature: "n", Types: []*server.Interface{Surface}},
	37	+	{Name: "create_region", Signature: "n", Types: []*server.Interface{Region}},
	38	+	}
	39	+	Surface.Requests = []server.Message{
	40	+	{Name: "destroy", Signature: ""},
	41	+	{Name: "attach", Signature: "?oii", Types: []*server.Interface{nil, nil, nil}},
	42	+	{Name: "damage", Signature: "iiii"},
	43	+	{Name: "frame", Signature: "n", Types: []*server.Interface{Callback}},
	44	+	{Name: "set_opaque_region", Signature: "?o", Types: []*server.Interface{Region}},
	45	+	{Name: "set_input_region", Signature: "?o", Types: []*server.Interface{Region}},
	46	+	{Name: "commit", Signature: ""},
	47	+	}
	48	+	Region.Requests = []server.Message{
	49	+	{Name: "destroy", Signature: ""},
	50	+	{Name: "add", Signature: "iiii"},
	51	+	{Name: "subtract", Signature: "iiii"},
	52	+	}
	53	+	Callback.Events = []server.Message{{Name: "done", Signature: "u"}}
	54	+	return server.NewInterfaces(Compositor, Surface, Region, Callback)
	55	+	}

A internal/proto/feasibility_test.go +199 -0

@@ -0,0 +1,199 @@
	1	+	package proto_test
	2	+
	3	+	import (
	4	+	"context"
	5	+	"os/exec"
	6	+	"path/filepath"
	7	+	"strings"
	8	+	"testing"
	9	+	"time"
	10	+
	11	+	"github.com/bnema/purego-libwayland/internal/proto"
	12	+	"github.com/bnema/purego-libwayland/server"
	13	+	"github.com/bnema/wlturbo"
	14	+	"golang.org/x/sys/unix"
	15	+	)
	16	+
	17	+	// startServer runs a display with a wl_compositor global on a private socket.
	18	+	// commits counts wl_surface.commit requests received by Go handlers.
	19	+	func startServer(t testing.T) (socket string, d server.Display, commits chan uint32) {
	20	+	t.Helper()
	21	+	if err := proto.Init(); err != nil {
	22	+	t.Fatal(err)
	23	+	}
	24	+	d, err := server.NewDisplay()
	25	+	if err != nil {
	26	+	t.Fatal(err)
	27	+	}
	28	+	socket = filepath.Join(t.TempDir(), "wayland-test")
	29	+	// libwayland takes ownership of the listening fd.
	30	+	fd, err := unix.Socket(unix.AF_UNIX, unix.SOCK_STREAM\|unix.SOCK_CLOEXEC, 0)
	31	+	if err != nil {
	32	+	t.Fatal(err)
	33	+	}
	34	+	if err := unix.Bind(fd, &unix.SockaddrUnix{Name: socket}); err != nil {
	35	+	t.Fatal(err)
	36	+	}
	37	+	if err := unix.Listen(fd, 128); err != nil {
	38	+	t.Fatal(err)
	39	+	}
	40	+	if err := d.AddSocketFD(fd); err != nil {
	41	+	t.Fatal(err)
	42	+	}
	43	+
	44	+	commits = make(chan uint32, 16)
	45	+	var serial uint32
	46	+	surface := func(r *server.Resource, op uint32, args []server.Arg) {
	47	+	switch op {
	48	+	case proto.SurfaceDestroy:
	49	+	r.Destroy()
	50	+	case proto.SurfaceFrame:
	51	+	cb, err := r.Client().CreateResource(proto.Callback, 1, args[0].NewID(), nil)
	52	+	if err != nil {
	53	+	t.Error(err)
	54	+	return
	55	+	}
	56	+	serial++
	57	+	cb.PostEvent(proto.CallbackDone, server.Uint(serial))
	58	+	cb.Destroy()
	59	+	case proto.SurfaceCommit:
	60	+	commits <- r.ID()
	61	+	}
	62	+	}
	63	+	compositor := func(r *server.Resource, op uint32, args []server.Arg) {
	64	+	iface, h := proto.Surface, server.Handler(surface)
	65	+	if op == proto.CompositorCreateRegion {
	66	+	iface, h = proto.Region, func(r *server.Resource, op uint32, _ []server.Arg) {
	67	+	if op == proto.RegionDestroy {
	68	+	r.Destroy()
	69	+	}
	70	+	}
	71	+	}
	72	+	if _, err := r.Client().CreateResource(iface, r.Version(), args[0].NewID(), h); err != nil {
	73	+	t.Error(err)
	74	+	}
	75	+	}
	76	+	err = d.CreateGlobal(proto.Compositor, 1, func(c server.Client, version, id uint32) {
	77	+	if _, err := c.CreateResource(proto.Compositor, int32(version), id, compositor); err != nil {
	78	+	t.Error(err)
	79	+	}
	80	+	})
	81	+	if err != nil {
	82	+	t.Fatal(err)
	83	+	}
	84	+
	85	+	ctx, cancel := context.WithCancel(context.Background())
	86	+	done := make(chan error, 1)
	87	+	go func() { done <- d.Run(ctx) }()
	88	+	t.Cleanup(func() {
	89	+	cancel()
	90	+	if err := <-done; err != nil {
	91	+	t.Error(err)
	92	+	}
	93	+	})
	94	+	return socket, d, commits
	95	+	}
	96	+
	97	+	// Gates 1 and 2: the global exists and wayland-info lists it.
	98	+	func TestWaylandInfoListsCompositor(t *testing.T) {
	99	+	if _, err := exec.LookPath("wayland-info"); err != nil {
	100	+	t.Skip("wayland-info not installed")
	101	+	}
	102	+	socket, _, _ := startServer(t)
	103	+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	104	+	defer cancel()
	105	+	cmd := exec.CommandContext(ctx, "wayland-info")
	106	+	cmd.Env = []string{"XDG_RUNTIME_DIR=" + filepath.Dir(socket), "WAYLAND_DISPLAY=" + filepath.Base(socket)}
	107	+	out, err := cmd.CombinedOutput()
	108	+	if err != nil {
	109	+	t.Fatalf("wayland-info: %v\n%s", err, out)
	110	+	}
	111	+	if !strings.Contains(string(out), "wl_compositor") {
	112	+	t.Fatalf("wl_compositor missing from wayland-info output:\n%s", out)
	113	+	}
	114	+	}
	115	+
	116	+	// Gates 3 and 4: requests reach Go handlers, events reach the client, and a
	117	+	// disconnect frees every resource. Run repeatedly and under -race.
	118	+	func TestRequestEventRoundtripAndDisconnect(t *testing.T) {
	119	+	socket, d, commits := startServer(t)
	120	+
	121	+	for round := range 20 {
	122	+	c, err := wlturbo.Connect(socket)
	123	+	if err != nil {
	124	+	t.Fatal(err)
	125	+	}
	126	+	if err := c.Roundtrip(); err != nil {
	127	+	t.Fatal(err)
	128	+	}
	129	+	g, ok := c.Registry().FindGlobal("wl_compositor")
	130	+	if !ok {
	131	+	t.Fatal("wl_compositor not advertised")
	132	+	}
	133	+	comp, err := c.Registry().BindID(g.Name, g.Interface, 1)
	134	+	if err != nil {
	135	+	t.Fatal(err)
	136	+	}
	137	+	surf := c.AllocateID()
	138	+	must(t, c.SendRequest(comp, proto.CompositorCreateSurface, surf))
	139	+	cb := c.AllocateID()
	140	+	gotDone := make(chan uint32, 1)
	141	+	cbProxy := &doneProxy{done: gotDone}
	142	+	cbProxy.SetID(cb)
	143	+	c.Context().Register(cbProxy)
	144	+	must(t, c.SendRequest(surf, proto.SurfaceFrame, cb))
	145	+	must(t, c.SendRequest(surf, proto.SurfaceCommit))
	146	+	must(t, c.Roundtrip())
	147	+
	148	+	select {
	149	+	case id := <-commits:
	150	+	if id != surf {
	151	+	t.Fatalf("commit on %d, want %d", id, surf)
	152	+	}
	153	+	case <-time.After(2 * time.Second):
	154	+	t.Fatal("commit never reached the Go handler")
	155	+	}
	156	+	select {
	157	+	case serial := <-gotDone:
	158	+	if serial != uint32(round+1) {
	159	+	t.Fatalf("callback serial %d, want %d", serial, round+1)
	160	+	}
	161	+	default:
	162	+	t.Fatal("wl_callback.done never reached the client")
	163	+	}
	164	+	_ = c.Close()
	165	+
	166	+	// libwayland frees the client's resources once it notices the hangup.
	167	+	deadline := time.Now().Add(2 * time.Second)
	168	+	for {
	169	+	var n int
	170	+	d.Do(func() { n = server.LiveResources() })
	171	+	if n == 0 {
	172	+	break
	173	+	}
	174	+	if time.Now().After(deadline) {
	175	+	t.Fatalf("round %d: %d resources still alive after disconnect", round, n)
	176	+	}
	177	+	time.Sleep(5 * time.Millisecond)
	178	+	}
	179	+	}
	180	+	}
	181	+
	182	+	// doneProxy records wl_callback.done.
	183	+	type doneProxy struct {
	184	+	wlturbo.BaseProxy
	185	+	done chan uint32
	186	+	}
	187	+
	188	+	func (p doneProxy) Dispatch(e wlturbo.Event) {
	189	+	if e.Opcode == proto.CallbackDone {
	190	+	p.done <- e.Uint32()
	191	+	}
	192	+	}
	193	+
	194	+	func must(t *testing.T, err error) {
	195	+	t.Helper()
	196	+	if err != nil {
	197	+	t.Fatal(err)
	198	+	}
	199	+	}

@@ -0,0 +1,199 @@
	1	+	package proto_test
	2	+
	3	+	import (
	4	+	"context"
	5	+	"os/exec"
	6	+	"path/filepath"
	7	+	"strings"
	8	+	"testing"
	9	+	"time"
	10	+
	11	+	"github.com/bnema/purego-libwayland/internal/proto"
	12	+	"github.com/bnema/purego-libwayland/server"
	13	+	"github.com/bnema/wlturbo"
	14	+	"golang.org/x/sys/unix"
	15	+	)
	16	+
	17	+	// startServer runs a display with a wl_compositor global on a private socket.
	18	+	// commits counts wl_surface.commit requests received by Go handlers.
	19	+	func startServer(t testing.T) (socket string, d server.Display, commits chan uint32) {
	20	+	t.Helper()
	21	+	if err := proto.Init(); err != nil {
	22	+	t.Fatal(err)
	23	+	}
	24	+	d, err := server.NewDisplay()
	25	+	if err != nil {
	26	+	t.Fatal(err)
	27	+	}
	28	+	socket = filepath.Join(t.TempDir(), "wayland-test")
	29	+	// libwayland takes ownership of the listening fd.
	30	+	fd, err := unix.Socket(unix.AF_UNIX, unix.SOCK_STREAM\|unix.SOCK_CLOEXEC, 0)
	31	+	if err != nil {
	32	+	t.Fatal(err)
	33	+	}
	34	+	if err := unix.Bind(fd, &unix.SockaddrUnix{Name: socket}); err != nil {
	35	+	t.Fatal(err)
	36	+	}
	37	+	if err := unix.Listen(fd, 128); err != nil {
	38	+	t.Fatal(err)
	39	+	}
	40	+	if err := d.AddSocketFD(fd); err != nil {
	41	+	t.Fatal(err)
	42	+	}
	43	+
	44	+	commits = make(chan uint32, 16)
	45	+	var serial uint32
	46	+	surface := func(r *server.Resource, op uint32, args []server.Arg) {
	47	+	switch op {
	48	+	case proto.SurfaceDestroy:
	49	+	r.Destroy()
	50	+	case proto.SurfaceFrame:
	51	+	cb, err := r.Client().CreateResource(proto.Callback, 1, args[0].NewID(), nil)
	52	+	if err != nil {
	53	+	t.Error(err)
	54	+	return
	55	+	}
	56	+	serial++
	57	+	cb.PostEvent(proto.CallbackDone, server.Uint(serial))
	58	+	cb.Destroy()
	59	+	case proto.SurfaceCommit:
	60	+	commits <- r.ID()
	61	+	}
	62	+	}
	63	+	compositor := func(r *server.Resource, op uint32, args []server.Arg) {
	64	+	iface, h := proto.Surface, server.Handler(surface)
	65	+	if op == proto.CompositorCreateRegion {
	66	+	iface, h = proto.Region, func(r *server.Resource, op uint32, _ []server.Arg) {
	67	+	if op == proto.RegionDestroy {
	68	+	r.Destroy()
	69	+	}
	70	+	}
	71	+	}
	72	+	if _, err := r.Client().CreateResource(iface, r.Version(), args[0].NewID(), h); err != nil {
	73	+	t.Error(err)
	74	+	}
	75	+	}
	76	+	err = d.CreateGlobal(proto.Compositor, 1, func(c server.Client, version, id uint32) {
	77	+	if _, err := c.CreateResource(proto.Compositor, int32(version), id, compositor); err != nil {
	78	+	t.Error(err)
	79	+	}
	80	+	})
	81	+	if err != nil {
	82	+	t.Fatal(err)
	83	+	}
	84	+
	85	+	ctx, cancel := context.WithCancel(context.Background())
	86	+	done := make(chan error, 1)
	87	+	go func() { done <- d.Run(ctx) }()
	88	+	t.Cleanup(func() {
	89	+	cancel()
	90	+	if err := <-done; err != nil {
	91	+	t.Error(err)
	92	+	}
	93	+	})
	94	+	return socket, d, commits
	95	+	}
	96	+
	97	+	// Gates 1 and 2: the global exists and wayland-info lists it.
	98	+	func TestWaylandInfoListsCompositor(t *testing.T) {
	99	+	if _, err := exec.LookPath("wayland-info"); err != nil {
	100	+	t.Skip("wayland-info not installed")
	101	+	}
	102	+	socket, _, _ := startServer(t)
	103	+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	104	+	defer cancel()
	105	+	cmd := exec.CommandContext(ctx, "wayland-info")
	106	+	cmd.Env = []string{"XDG_RUNTIME_DIR=" + filepath.Dir(socket), "WAYLAND_DISPLAY=" + filepath.Base(socket)}
	107	+	out, err := cmd.CombinedOutput()
	108	+	if err != nil {
	109	+	t.Fatalf("wayland-info: %v\n%s", err, out)
	110	+	}
	111	+	if !strings.Contains(string(out), "wl_compositor") {
	112	+	t.Fatalf("wl_compositor missing from wayland-info output:\n%s", out)
	113	+	}
	114	+	}
	115	+
	116	+	// Gates 3 and 4: requests reach Go handlers, events reach the client, and a
	117	+	// disconnect frees every resource. Run repeatedly and under -race.
	118	+	func TestRequestEventRoundtripAndDisconnect(t *testing.T) {
	119	+	socket, d, commits := startServer(t)
	120	+
	121	+	for round := range 20 {
	122	+	c, err := wlturbo.Connect(socket)
	123	+	if err != nil {
	124	+	t.Fatal(err)
	125	+	}
	126	+	if err := c.Roundtrip(); err != nil {
	127	+	t.Fatal(err)
	128	+	}
	129	+	g, ok := c.Registry().FindGlobal("wl_compositor")
	130	+	if !ok {
	131	+	t.Fatal("wl_compositor not advertised")
	132	+	}
	133	+	comp, err := c.Registry().BindID(g.Name, g.Interface, 1)
	134	+	if err != nil {
	135	+	t.Fatal(err)
	136	+	}
	137	+	surf := c.AllocateID()
	138	+	must(t, c.SendRequest(comp, proto.CompositorCreateSurface, surf))
	139	+	cb := c.AllocateID()
	140	+	gotDone := make(chan uint32, 1)
	141	+	cbProxy := &doneProxy{done: gotDone}
	142	+	cbProxy.SetID(cb)
	143	+	c.Context().Register(cbProxy)
	144	+	must(t, c.SendRequest(surf, proto.SurfaceFrame, cb))
	145	+	must(t, c.SendRequest(surf, proto.SurfaceCommit))
	146	+	must(t, c.Roundtrip())
	147	+
	148	+	select {
	149	+	case id := <-commits:
	150	+	if id != surf {
	151	+	t.Fatalf("commit on %d, want %d", id, surf)
	152	+	}
	153	+	case <-time.After(2 * time.Second):
	154	+	t.Fatal("commit never reached the Go handler")
	155	+	}
	156	+	select {
	157	+	case serial := <-gotDone:
	158	+	if serial != uint32(round+1) {
	159	+	t.Fatalf("callback serial %d, want %d", serial, round+1)
	160	+	}
	161	+	default:
	162	+	t.Fatal("wl_callback.done never reached the client")
	163	+	}
	164	+	_ = c.Close()
	165	+
	166	+	// libwayland frees the client's resources once it notices the hangup.
	167	+	deadline := time.Now().Add(2 * time.Second)
	168	+	for {
	169	+	var n int
	170	+	d.Do(func() { n = server.LiveResources() })
	171	+	if n == 0 {
	172	+	break
	173	+	}
	174	+	if time.Now().After(deadline) {
	175	+	t.Fatalf("round %d: %d resources still alive after disconnect", round, n)
	176	+	}
	177	+	time.Sleep(5 * time.Millisecond)
	178	+	}
	179	+	}
	180	+	}
	181	+
	182	+	// doneProxy records wl_callback.done.
	183	+	type doneProxy struct {
	184	+	wlturbo.BaseProxy
	185	+	done chan uint32
	186	+	}
	187	+
	188	+	func (p doneProxy) Dispatch(e wlturbo.Event) {
	189	+	if e.Opcode == proto.CallbackDone {
	190	+	p.done <- e.Uint32()
	191	+	}
	192	+	}
	193	+
	194	+	func must(t *testing.T, err error) {
	195	+	t.Helper()
	196	+	if err != nil {
	197	+	t.Fatal(err)
	198	+	}
	199	+	}

A server/arena.go +46 -0

@@ -0,0 +1,46 @@
	1	+	package server
	2	+
	3	+	import (
	4	+	"encoding/binary"
	5	+	"fmt"
	6	+	"unsafe"
	7	+
	8	+	"golang.org/x/sys/unix"
	9	+	)
	10	+
	11	+	// arena is C-visible memory the Go GC never moves or frees. It holds
	12	+	// wl_interface and wl_message tables and their strings for the whole
	13	+	// process lifetime.
	14	+	type arena struct {
	15	+	mem []byte
	16	+	base uintptr
	17	+	off int
	18	+	}
	19	+
	20	+	func newArena(size int) (*arena, error) {
	21	+	mem, err := unix.Mmap(-1, 0, size, unix.PROT_READ\|unix.PROT_WRITE, unix.MAP_PRIVATE\|unix.MAP_ANONYMOUS)
	22	+	if err != nil {
	23	+	return nil, fmt.Errorf("arena: mmap: %w", err)
	24	+	}
	25	+	return &arena{mem: mem, base: uintptr(unsafe.Pointer(&mem[0]))}, nil
	26	+	}
	27	+
	28	+	// alloc returns the offset and C address of n zeroed, 8-byte aligned bytes.
	29	+	func (a *arena) alloc(n int) (int, uintptr) {
	30	+	a.off = (a.off + 7) &^ 7
	31	+	if a.off+n > len(a.mem) {
	32	+	panic("purego-libwayland: arena exhausted")
	33	+	}
	34	+	off := a.off
	35	+	a.off += n
	36	+	return off, a.base + uintptr(off)
	37	+	}
	38	+
	39	+	func (a *arena) cstring(s string) uintptr {
	40	+	off, addr := a.alloc(len(s) + 1)
	41	+	copy(a.mem[off:], s)
	42	+	return addr
	43	+	}
	44	+
	45	+	func (a *arena) putPtr(off int, v uintptr) { binary.LittleEndian.PutUint64(a.mem[off:], uint64(v)) }
	46	+	func (a *arena) putI32(off int, v int32) { binary.LittleEndian.PutUint32(a.mem[off:], uint32(v)) }

@@ -0,0 +1,46 @@
	1	+	package server
	2	+
	3	+	import (
	4	+	"encoding/binary"
	5	+	"fmt"
	6	+	"unsafe"
	7	+
	8	+	"golang.org/x/sys/unix"
	9	+	)
	10	+
	11	+	// arena is C-visible memory the Go GC never moves or frees. It holds
	12	+	// wl_interface and wl_message tables and their strings for the whole
	13	+	// process lifetime.
	14	+	type arena struct {
	15	+	mem []byte
	16	+	base uintptr
	17	+	off int
	18	+	}
	19	+
	20	+	func newArena(size int) (*arena, error) {
	21	+	mem, err := unix.Mmap(-1, 0, size, unix.PROT_READ\|unix.PROT_WRITE, unix.MAP_PRIVATE\|unix.MAP_ANONYMOUS)
	22	+	if err != nil {
	23	+	return nil, fmt.Errorf("arena: mmap: %w", err)
	24	+	}
	25	+	return &arena{mem: mem, base: uintptr(unsafe.Pointer(&mem[0]))}, nil
	26	+	}
	27	+
	28	+	// alloc returns the offset and C address of n zeroed, 8-byte aligned bytes.
	29	+	func (a *arena) alloc(n int) (int, uintptr) {
	30	+	a.off = (a.off + 7) &^ 7
	31	+	if a.off+n > len(a.mem) {
	32	+	panic("purego-libwayland: arena exhausted")
	33	+	}
	34	+	off := a.off
	35	+	a.off += n
	36	+	return off, a.base + uintptr(off)
	37	+	}
	38	+
	39	+	func (a *arena) cstring(s string) uintptr {
	40	+	off, addr := a.alloc(len(s) + 1)
	41	+	copy(a.mem[off:], s)
	42	+	return addr
	43	+	}
	44	+
	45	+	func (a *arena) putPtr(off int, v uintptr) { binary.LittleEndian.PutUint64(a.mem[off:], uint64(v)) }
	46	+	func (a *arena) putI32(off int, v int32) { binary.LittleEndian.PutUint32(a.mem[off:], uint32(v)) }

A server/display.go +204 -0

@@ -0,0 +1,204 @@
	1	+	package server
	2	+
	3	+	import (
	4	+	"context"
	5	+	"errors"
	6	+	"fmt"
	7	+	"runtime"
	8	+	"unsafe"
	9	+	)
	10	+
	11	+	// Arg is one raw union wl_argument value (int, uint, fixed, object pointer,
	12	+	// new_id, or fd).
	13	+	type Arg uint64
	14	+
	15	+	func Uint(v uint32) Arg { return Arg(v) }
	16	+	func Int(v int32) Arg { return Arg(uint32(v)) }
	17	+	func Object(r *Resource) Arg { return Arg(r.c) }
	18	+	func (a Arg) Uint() uint32 { return uint32(a) }
	19	+	func (a Arg) Int() int32 { return int32(uint32(a)) }
	20	+	func (a Arg) NewID() uint32 { return uint32(a) }
	21	+	func (a Arg) Resource() *Resource { return live.resources[uintptr(a)] }
	22	+
	23	+	// Handler receives every request sent to a resource.
	24	+	type Handler func(r *Resource, opcode uint32, args []Arg)
	25	+
	26	+	// BindFunc runs when a client binds a global.
	27	+	type BindFunc func(c Client, version, id uint32)
	28	+
	29	+	// Client is a connected wl_client.
	30	+	type Client struct{ c uintptr }
	31	+
	32	+	// Resource is a server-side wl_resource.
	33	+	type Resource struct {
	34	+	c uintptr
	35	+	iface *Interface
	36	+	handler Handler
	37	+	OnDestroy func()
	38	+	}
	39	+
	40	+	// live holds Go state reachable from C callbacks. It is only touched on the
	41	+	// display goroutine, so it needs no lock.
	42	+	var live = struct {
	43	+	resources map[uintptr]*Resource
	44	+	binds map[uintptr]BindFunc
	45	+	nextBind uintptr
	46	+	}{resources: map[uintptr]*Resource{}, binds: map[uintptr]BindFunc{}}
	47	+
	48	+	// Display owns a wl_display. All methods except Do must run on the goroutine
	49	+	// that calls Run, or before Run starts.
	50	+	type Display struct {
	51	+	c uintptr
	52	+	loop uintptr
	53	+	calls chan func()
	54	+	}
	55	+
	56	+	func NewDisplay() (*Display, error) {
	57	+	if err := load(); err != nil {
	58	+	return nil, err
	59	+	}
	60	+	c := wlDisplayCreate()
	61	+	if c == 0 {
	62	+	return nil, errors.New("purego-libwayland: wl_display_create failed")
	63	+	}
	64	+	return &Display{c: c, loop: wlDisplayGetEventLoop(c), calls: make(chan func())}, nil
	65	+	}
	66	+
	67	+	// AddSocketFD serves clients on an already bound, listening unix socket.
	68	+	func (d *Display) AddSocketFD(fd int) error {
	69	+	if wlDisplayAddSocketFD(d.c, int32(fd)) != 0 {
	70	+	return fmt.Errorf("purego-libwayland: wl_display_add_socket_fd(%d) failed", fd)
	71	+	}
	72	+	return nil
	73	+	}
	74	+
	75	+	func (d Display) CreateGlobal(iface Interface, version int32, bindFn BindFunc) error {
	76	+	live.nextBind++
	77	+	token := live.nextBind
	78	+	live.binds[token] = bindFn
	79	+	if wlGlobalCreate(d.c, iface.c, version, token, cbBind) == 0 {
	80	+	delete(live.binds, token)
	81	+	return fmt.Errorf("purego-libwayland: wl_global_create(%s) failed", iface.Name)
	82	+	}
	83	+	return nil
	84	+	}
	85	+
	86	+	// Run dispatches libwayland on one OS-locked goroutine until ctx is done.
	87	+	func (d *Display) Run(ctx context.Context) error {
	88	+	runtime.LockOSThread()
	89	+	defer runtime.UnlockOSThread()
	90	+	for {
	91	+	select {
	92	+	case <-ctx.Done():
	93	+	wlDisplayDestroyClients(d.c)
	94	+	wlDisplayDestroy(d.c)
	95	+	return nil
	96	+	case fn := <-d.calls:
	97	+	fn()
	98	+	default:
	99	+	}
	100	+	if wlEventLoopDispatch(d.loop, 5) < 0 {
	101	+	return errors.New("purego-libwayland: wl_event_loop_dispatch failed")
	102	+	}
	103	+	wlDisplayFlushClients(d.c)
	104	+	}
	105	+	}
	106	+
	107	+	// Do runs fn on the display goroutine and waits for it.
	108	+	func (d *Display) Do(fn func()) {
	109	+	done := make(chan struct{})
	110	+	d.calls <- func() { fn(); close(done) }
	111	+	<-done
	112	+	}
	113	+
	114	+	// LiveResources reports resources not yet destroyed. Display goroutine only.
	115	+	func LiveResources() int { return len(live.resources) }
	116	+
	117	+	func (c Client) CreateResource(iface Interface, version int32, id uint32, h Handler) (Resource, error) {
	118	+	rc := wlResourceCreate(c.c, iface.c, version, id)
	119	+	if rc == 0 {
	120	+	return nil, fmt.Errorf("purego-libwayland: wl_resource_create(%s) failed", iface.Name)
	121	+	}
	122	+	r := &Resource{c: rc, iface: iface, handler: h}
	123	+	live.resources[rc] = r
	124	+	wlResourceSetDispatcher(rc, cbDispatcher, implMarker(), 0, cbDestroy)
	125	+	return r, nil
	126	+	}
	127	+
	128	+	func (r *Resource) ID() uint32 { return wlResourceGetID(r.c) }
	129	+	func (r *Resource) Version() int32 { return wlResourceGetVersion(r.c) }
	130	+	func (r *Resource) Client() Client { return Client{wlResourceGetClient(r.c)} }
	131	+	func (r *Resource) Destroy() { wlResourceDestroy(r.c) }
	132	+	func (r Resource) Iface() Interface { return r.iface }
	133	+
	134	+	// PostEvent sends an event. String and array arguments are not supported yet.
	135	+	func (r *Resource) PostEvent(opcode uint32, args ...Arg) {
	136	+	var p unsafe.Pointer
	137	+	if len(args) > 0 {
	138	+	p = unsafe.Pointer(&args[0])
	139	+	}
	140	+	wlResourcePostEventArr(r.c, opcode, p)
	141	+	runtime.KeepAlive(args)
	142	+	}
	143	+
	144	+	// implMarker is a non-nil implementation pointer. libwayland only passes it
	145	+	// back to our dispatcher.
	146	+	func implMarker() uintptr {
	147	+	if marker == 0 {
	148	+	_, marker = tables.alloc(8)
	149	+	}
	150	+	return marker
	151	+	}
	152	+
	153	+	var marker uintptr
	154	+
	155	+	// --- C callbacks (display goroutine) ---
	156	+
	157	+	func dispatch(_ uintptr, target uintptr, opcode uint32, msg unsafe.Pointer, args unsafe.Pointer) int32 {
	158	+	r := live.resources[target]
	159	+	if r == nil \|\| r.handler == nil {
	160	+	return 0
	161	+	}
	162	+	n := argCount(msgSignature(msg))
	163	+	var a []Arg
	164	+	if n > 0 {
	165	+	a = append([]Arg(nil), unsafe.Slice((*Arg)(args), n)...)
	166	+	}
	167	+	r.handler(r, opcode, a)
	168	+	return 0
	169	+	}
	170	+
	171	+	func destroyed(res uintptr) {
	172	+	r := live.resources[res]
	173	+	delete(live.resources, res)
	174	+	if r != nil && r.OnDestroy != nil {
	175	+	r.OnDestroy()
	176	+	}
	177	+	}
	178	+
	179	+	func bind(client uintptr, data uintptr, version uint32, id uint32) {
	180	+	if fn := live.binds[data]; fn != nil {
	181	+	fn(Client{client}, version, id)
	182	+	}
	183	+	}
	184	+
	185	+	// msgSignature reads wl_message.signature.
	186	+	func msgSignature(msg unsafe.Pointer) string {
	187	+	p := (unsafe.Pointer)(unsafe.Add(msg, 8))
	188	+	n := 0
	189	+	for (byte)(unsafe.Add(p, n)) != 0 {
	190	+	n++
	191	+	}
	192	+	return string(unsafe.Slice((*byte)(p), n))
	193	+	}
	194	+
	195	+	// argCount counts arguments in a libwayland signature ("?oii", "2n", ...).
	196	+	func argCount(sig string) int {
	197	+	n := 0
	198	+	for _, ch := range sig {
	199	+	if ch != '?' && (ch < '0' \|\| ch > '9') {
	200	+	n++
	201	+	}
	202	+	}
	203	+	return n
	204	+	}

@@ -0,0 +1,204 @@
	1	+	package server
	2	+
	3	+	import (
	4	+	"context"
	5	+	"errors"
	6	+	"fmt"
	7	+	"runtime"
	8	+	"unsafe"
	9	+	)
	10	+
	11	+	// Arg is one raw union wl_argument value (int, uint, fixed, object pointer,
	12	+	// new_id, or fd).
	13	+	type Arg uint64
	14	+
	15	+	func Uint(v uint32) Arg { return Arg(v) }
	16	+	func Int(v int32) Arg { return Arg(uint32(v)) }
	17	+	func Object(r *Resource) Arg { return Arg(r.c) }
	18	+	func (a Arg) Uint() uint32 { return uint32(a) }
	19	+	func (a Arg) Int() int32 { return int32(uint32(a)) }
	20	+	func (a Arg) NewID() uint32 { return uint32(a) }
	21	+	func (a Arg) Resource() *Resource { return live.resources[uintptr(a)] }
	22	+
	23	+	// Handler receives every request sent to a resource.
	24	+	type Handler func(r *Resource, opcode uint32, args []Arg)
	25	+
	26	+	// BindFunc runs when a client binds a global.
	27	+	type BindFunc func(c Client, version, id uint32)
	28	+
	29	+	// Client is a connected wl_client.
	30	+	type Client struct{ c uintptr }
	31	+
	32	+	// Resource is a server-side wl_resource.
	33	+	type Resource struct {
	34	+	c uintptr
	35	+	iface *Interface
	36	+	handler Handler
	37	+	OnDestroy func()
	38	+	}
	39	+
	40	+	// live holds Go state reachable from C callbacks. It is only touched on the
	41	+	// display goroutine, so it needs no lock.
	42	+	var live = struct {
	43	+	resources map[uintptr]*Resource
	44	+	binds map[uintptr]BindFunc
	45	+	nextBind uintptr
	46	+	}{resources: map[uintptr]*Resource{}, binds: map[uintptr]BindFunc{}}
	47	+
	48	+	// Display owns a wl_display. All methods except Do must run on the goroutine
	49	+	// that calls Run, or before Run starts.
	50	+	type Display struct {
	51	+	c uintptr
	52	+	loop uintptr
	53	+	calls chan func()
	54	+	}
	55	+
	56	+	func NewDisplay() (*Display, error) {
	57	+	if err := load(); err != nil {
	58	+	return nil, err
	59	+	}
	60	+	c := wlDisplayCreate()
	61	+	if c == 0 {
	62	+	return nil, errors.New("purego-libwayland: wl_display_create failed")
	63	+	}
	64	+	return &Display{c: c, loop: wlDisplayGetEventLoop(c), calls: make(chan func())}, nil
	65	+	}
	66	+
	67	+	// AddSocketFD serves clients on an already bound, listening unix socket.
	68	+	func (d *Display) AddSocketFD(fd int) error {
	69	+	if wlDisplayAddSocketFD(d.c, int32(fd)) != 0 {
	70	+	return fmt.Errorf("purego-libwayland: wl_display_add_socket_fd(%d) failed", fd)
	71	+	}
	72	+	return nil
	73	+	}
	74	+
	75	+	func (d Display) CreateGlobal(iface Interface, version int32, bindFn BindFunc) error {
	76	+	live.nextBind++
	77	+	token := live.nextBind
	78	+	live.binds[token] = bindFn
	79	+	if wlGlobalCreate(d.c, iface.c, version, token, cbBind) == 0 {
	80	+	delete(live.binds, token)
	81	+	return fmt.Errorf("purego-libwayland: wl_global_create(%s) failed", iface.Name)
	82	+	}
	83	+	return nil
	84	+	}
	85	+
	86	+	// Run dispatches libwayland on one OS-locked goroutine until ctx is done.
	87	+	func (d *Display) Run(ctx context.Context) error {
	88	+	runtime.LockOSThread()
	89	+	defer runtime.UnlockOSThread()
	90	+	for {
	91	+	select {
	92	+	case <-ctx.Done():
	93	+	wlDisplayDestroyClients(d.c)
	94	+	wlDisplayDestroy(d.c)
	95	+	return nil
	96	+	case fn := <-d.calls:
	97	+	fn()
	98	+	default:
	99	+	}
	100	+	if wlEventLoopDispatch(d.loop, 5) < 0 {
	101	+	return errors.New("purego-libwayland: wl_event_loop_dispatch failed")
	102	+	}
	103	+	wlDisplayFlushClients(d.c)
	104	+	}
	105	+	}
	106	+
	107	+	// Do runs fn on the display goroutine and waits for it.
	108	+	func (d *Display) Do(fn func()) {
	109	+	done := make(chan struct{})
	110	+	d.calls <- func() { fn(); close(done) }
	111	+	<-done
	112	+	}
	113	+
	114	+	// LiveResources reports resources not yet destroyed. Display goroutine only.
	115	+	func LiveResources() int { return len(live.resources) }
	116	+
	117	+	func (c Client) CreateResource(iface Interface, version int32, id uint32, h Handler) (Resource, error) {
	118	+	rc := wlResourceCreate(c.c, iface.c, version, id)
	119	+	if rc == 0 {
	120	+	return nil, fmt.Errorf("purego-libwayland: wl_resource_create(%s) failed", iface.Name)
	121	+	}
	122	+	r := &Resource{c: rc, iface: iface, handler: h}
	123	+	live.resources[rc] = r
	124	+	wlResourceSetDispatcher(rc, cbDispatcher, implMarker(), 0, cbDestroy)
	125	+	return r, nil
	126	+	}
	127	+
	128	+	func (r *Resource) ID() uint32 { return wlResourceGetID(r.c) }
	129	+	func (r *Resource) Version() int32 { return wlResourceGetVersion(r.c) }
	130	+	func (r *Resource) Client() Client { return Client{wlResourceGetClient(r.c)} }
	131	+	func (r *Resource) Destroy() { wlResourceDestroy(r.c) }
	132	+	func (r Resource) Iface() Interface { return r.iface }
	133	+
	134	+	// PostEvent sends an event. String and array arguments are not supported yet.
	135	+	func (r *Resource) PostEvent(opcode uint32, args ...Arg) {
	136	+	var p unsafe.Pointer
	137	+	if len(args) > 0 {
	138	+	p = unsafe.Pointer(&args[0])
	139	+	}
	140	+	wlResourcePostEventArr(r.c, opcode, p)
	141	+	runtime.KeepAlive(args)
	142	+	}
	143	+
	144	+	// implMarker is a non-nil implementation pointer. libwayland only passes it
	145	+	// back to our dispatcher.
	146	+	func implMarker() uintptr {
	147	+	if marker == 0 {
	148	+	_, marker = tables.alloc(8)
	149	+	}
	150	+	return marker
	151	+	}
	152	+
	153	+	var marker uintptr
	154	+
	155	+	// --- C callbacks (display goroutine) ---
	156	+
	157	+	func dispatch(_ uintptr, target uintptr, opcode uint32, msg unsafe.Pointer, args unsafe.Pointer) int32 {
	158	+	r := live.resources[target]
	159	+	if r == nil \|\| r.handler == nil {
	160	+	return 0
	161	+	}
	162	+	n := argCount(msgSignature(msg))
	163	+	var a []Arg
	164	+	if n > 0 {
	165	+	a = append([]Arg(nil), unsafe.Slice((*Arg)(args), n)...)
	166	+	}
	167	+	r.handler(r, opcode, a)
	168	+	return 0
	169	+	}
	170	+
	171	+	func destroyed(res uintptr) {
	172	+	r := live.resources[res]
	173	+	delete(live.resources, res)
	174	+	if r != nil && r.OnDestroy != nil {
	175	+	r.OnDestroy()
	176	+	}
	177	+	}
	178	+
	179	+	func bind(client uintptr, data uintptr, version uint32, id uint32) {
	180	+	if fn := live.binds[data]; fn != nil {
	181	+	fn(Client{client}, version, id)
	182	+	}
	183	+	}
	184	+
	185	+	// msgSignature reads wl_message.signature.
	186	+	func msgSignature(msg unsafe.Pointer) string {
	187	+	p := (unsafe.Pointer)(unsafe.Add(msg, 8))
	188	+	n := 0
	189	+	for (byte)(unsafe.Add(p, n)) != 0 {
	190	+	n++
	191	+	}
	192	+	return string(unsafe.Slice((*byte)(p), n))
	193	+	}
	194	+
	195	+	// argCount counts arguments in a libwayland signature ("?oii", "2n", ...).
	196	+	func argCount(sig string) int {
	197	+	n := 0
	198	+	for _, ch := range sig {
	199	+	if ch != '?' && (ch < '0' \|\| ch > '9') {
	200	+	n++
	201	+	}
	202	+	}
	203	+	return n
	204	+	}

A server/interface.go +92 -0

@@ -0,0 +1,92 @@
	1	+	package server
	2	+
	3	+	// Message describes one request or event. Signature uses the libwayland
	4	+	// format ("n", "?oii", ...). Types holds one entry per argument; entries are
	5	+	// non-nil only for typed new_id and object arguments.
	6	+	type Message struct {
	7	+	Name string
	8	+	Signature string
	9	+	Types []*Interface
	10	+	}
	11	+
	12	+	// Interface describes a protocol interface. Build it once with
	13	+	// NewInterfaces; its C table lives for the process lifetime.
	14	+	type Interface struct {
	15	+	Name string
	16	+	Version int32
	17	+	Requests []Message
	18	+	Events []Message
	19	+
	20	+	c uintptr // struct wl_interface*
	21	+	}
	22	+
	23	+	// C layout (LP64):
	24	+	//
	25	+	// struct wl_message { const char name; const char signature; const struct wl_interface **types; } // 24 bytes
	26	+	// struct wl_interface { const char name; int version; int method_count; const struct wl_message methods;
	27	+	// int event_count; const struct wl_message *events; } // 40 bytes
	28	+	const (
	29	+	sizeMessage = 24
	30	+	sizeInterface = 40
	31	+	)
	32	+
	33	+	var tables *arena
	34	+
	35	+	// NewInterfaces writes C tables for a set of interfaces that may reference
	36	+	// each other. It must be called before any interface is used.
	37	+	func NewInterfaces(ifaces ...*Interface) error {
	38	+	if err := load(); err != nil {
	39	+	return err
	40	+	}
	41	+	if tables == nil {
	42	+	a, err := newArena(1 << 20)
	43	+	if err != nil {
	44	+	return err
	45	+	}
	46	+	tables = a
	47	+	}
	48	+	a := tables
	49	+	// Pass 1: reserve every wl_interface so cross references resolve.
	50	+	offs := make([]int, len(ifaces))
	51	+	for i, it := range ifaces {
	52	+	offs[i], it.c = a.alloc(sizeInterface)
	53	+	}
	54	+	// Pass 2: fill messages and headers.
	55	+	for i, it := range ifaces {
	56	+	o := offs[i]
	57	+	a.putPtr(o, a.cstring(it.Name))
	58	+	a.putI32(o+8, it.Version)
	59	+	a.putI32(o+12, int32(len(it.Requests)))
	60	+	a.putPtr(o+16, writeMessages(a, it.Requests))
	61	+	a.putI32(o+24, int32(len(it.Events)))
	62	+	a.putPtr(o+32, writeMessages(a, it.Events))
	63	+	}
	64	+	return nil
	65	+	}
	66	+
	67	+	func writeMessages(a *arena, msgs []Message) uintptr {
	68	+	if len(msgs) == 0 {
	69	+	return 0
	70	+	}
	71	+	off, addr := a.alloc(sizeMessage * len(msgs))
	72	+	for i, m := range msgs {
	73	+	var types uintptr
	74	+	if len(m.Types) > 0 {
	75	+	toff, taddr := a.alloc(8 * len(m.Types))
	76	+	for j, t := range m.Types {
	77	+	if t != nil {
	78	+	if t.c == 0 {
	79	+	panic("purego-libwayland: interface " + t.Name + " referenced before NewInterfaces")
	80	+	}
	81	+	a.putPtr(toff+8*j, t.c)
	82	+	}
	83	+	}
	84	+	types = taddr
	85	+	}
	86	+	mo := off + i*sizeMessage
	87	+	a.putPtr(mo, a.cstring(m.Name))
	88	+	a.putPtr(mo+8, a.cstring(m.Signature))
	89	+	a.putPtr(mo+16, types)
	90	+	}
	91	+	return addr
	92	+	}

@@ -0,0 +1,92 @@
	1	+	package server
	2	+
	3	+	// Message describes one request or event. Signature uses the libwayland
	4	+	// format ("n", "?oii", ...). Types holds one entry per argument; entries are
	5	+	// non-nil only for typed new_id and object arguments.
	6	+	type Message struct {
	7	+	Name string
	8	+	Signature string
	9	+	Types []*Interface
	10	+	}
	11	+
	12	+	// Interface describes a protocol interface. Build it once with
	13	+	// NewInterfaces; its C table lives for the process lifetime.
	14	+	type Interface struct {
	15	+	Name string
	16	+	Version int32
	17	+	Requests []Message
	18	+	Events []Message
	19	+
	20	+	c uintptr // struct wl_interface*
	21	+	}
	22	+
	23	+	// C layout (LP64):
	24	+	//
	25	+	// struct wl_message { const char name; const char signature; const struct wl_interface **types; } // 24 bytes
	26	+	// struct wl_interface { const char name; int version; int method_count; const struct wl_message methods;
	27	+	// int event_count; const struct wl_message *events; } // 40 bytes
	28	+	const (
	29	+	sizeMessage = 24
	30	+	sizeInterface = 40
	31	+	)
	32	+
	33	+	var tables *arena
	34	+
	35	+	// NewInterfaces writes C tables for a set of interfaces that may reference
	36	+	// each other. It must be called before any interface is used.
	37	+	func NewInterfaces(ifaces ...*Interface) error {
	38	+	if err := load(); err != nil {
	39	+	return err
	40	+	}
	41	+	if tables == nil {
	42	+	a, err := newArena(1 << 20)
	43	+	if err != nil {
	44	+	return err
	45	+	}
	46	+	tables = a
	47	+	}
	48	+	a := tables
	49	+	// Pass 1: reserve every wl_interface so cross references resolve.
	50	+	offs := make([]int, len(ifaces))
	51	+	for i, it := range ifaces {
	52	+	offs[i], it.c = a.alloc(sizeInterface)
	53	+	}
	54	+	// Pass 2: fill messages and headers.
	55	+	for i, it := range ifaces {
	56	+	o := offs[i]
	57	+	a.putPtr(o, a.cstring(it.Name))
	58	+	a.putI32(o+8, it.Version)
	59	+	a.putI32(o+12, int32(len(it.Requests)))
	60	+	a.putPtr(o+16, writeMessages(a, it.Requests))
	61	+	a.putI32(o+24, int32(len(it.Events)))
	62	+	a.putPtr(o+32, writeMessages(a, it.Events))
	63	+	}
	64	+	return nil
	65	+	}
	66	+
	67	+	func writeMessages(a *arena, msgs []Message) uintptr {
	68	+	if len(msgs) == 0 {
	69	+	return 0
	70	+	}
	71	+	off, addr := a.alloc(sizeMessage * len(msgs))
	72	+	for i, m := range msgs {
	73	+	var types uintptr
	74	+	if len(m.Types) > 0 {
	75	+	toff, taddr := a.alloc(8 * len(m.Types))
	76	+	for j, t := range m.Types {
	77	+	if t != nil {
	78	+	if t.c == 0 {
	79	+	panic("purego-libwayland: interface " + t.Name + " referenced before NewInterfaces")
	80	+	}
	81	+	a.putPtr(toff+8*j, t.c)
	82	+	}
	83	+	}
	84	+	types = taddr
	85	+	}
	86	+	mo := off + i*sizeMessage
	87	+	a.putPtr(mo, a.cstring(m.Name))
	88	+	a.putPtr(mo+8, a.cstring(m.Signature))
	89	+	a.putPtr(mo+16, types)
	90	+	}
	91	+	return addr
	92	+	}

A server/lib.go +79 -0

@@ -0,0 +1,79 @@
	1	+	package server
	2	+
	3	+	import (
	4	+	"fmt"
	5	+	"sync"
	6	+	"unsafe"
	7	+
	8	+	"github.com/bnema/purego"
	9	+	)
	10	+
	11	+	// libwayland-server entry points. Only non-varargs functions are bound.
	12	+	var (
	13	+	wlDisplayCreate func() uintptr
	14	+	wlDisplayDestroy func(display uintptr)
	15	+	wlDisplayDestroyClients func(display uintptr)
	16	+	wlDisplayAddSocketFD func(display uintptr, fd int32) int32
	17	+	wlDisplayGetEventLoop func(display uintptr) uintptr
	18	+	wlDisplayFlushClients func(display uintptr)
	19	+	wlEventLoopDispatch func(loop uintptr, timeout int32) int32
	20	+	wlEventLoopGetFD func(loop uintptr) int32
	21	+	wlGlobalCreate func(display, iface uintptr, version int32, data uintptr, bind uintptr) uintptr
	22	+	wlResourceCreate func(client, iface uintptr, version int32, id uint32) uintptr
	23	+	wlResourceSetDispatcher func(resource, dispatcher, impl, data, destroy uintptr)
	24	+	wlResourcePostEventArr func(resource uintptr, opcode uint32, args unsafe.Pointer)
	25	+	wlResourcePostError func(resource uintptr, code uint32, msg uintptr)
	26	+	wlResourceDestroy func(resource uintptr)
	27	+	wlResourceGetID func(resource uintptr) uint32
	28	+	wlResourceGetClient func(resource uintptr) uintptr
	29	+	wlResourceGetVersion func(resource uintptr) int32
	30	+	)
	31	+
	32	+	var (
	33	+	loadOnce sync.Once
	34	+	loadErr error
	35	+
	36	+	// Shared C callbacks. purego callbacks are never freed, so there is one
	37	+	// of each for the whole process.
	38	+	cbDispatcher uintptr
	39	+	cbDestroy uintptr
	40	+	cbBind uintptr
	41	+	)
	42	+
	43	+	func load() error {
	44	+	loadOnce.Do(func() {
	45	+	lib, err := purego.Dlopen("libwayland-server.so.0", purego.RTLD_NOW\|purego.RTLD_GLOBAL)
	46	+	if err != nil {
	47	+	loadErr = fmt.Errorf("purego-libwayland: open libwayland-server.so.0: %w", err)
	48	+	return
	49	+	}
	50	+	defer func() {
	51	+	if r := recover(); r != nil {
	52	+	loadErr = fmt.Errorf("purego-libwayland: %v", r)
	53	+	}
	54	+	}()
	55	+	reg := func(fptr any, name string) { purego.RegisterLibFunc(fptr, lib, name) }
	56	+	reg(&wlDisplayCreate, "wl_display_create")
	57	+	reg(&wlDisplayDestroy, "wl_display_destroy")
	58	+	reg(&wlDisplayDestroyClients, "wl_display_destroy_clients")
	59	+	reg(&wlDisplayAddSocketFD, "wl_display_add_socket_fd")
	60	+	reg(&wlDisplayGetEventLoop, "wl_display_get_event_loop")
	61	+	reg(&wlDisplayFlushClients, "wl_display_flush_clients")
	62	+	reg(&wlEventLoopDispatch, "wl_event_loop_dispatch")
	63	+	reg(&wlEventLoopGetFD, "wl_event_loop_get_fd")
	64	+	reg(&wlGlobalCreate, "wl_global_create")
	65	+	reg(&wlResourceCreate, "wl_resource_create")
	66	+	reg(&wlResourceSetDispatcher, "wl_resource_set_dispatcher")
	67	+	reg(&wlResourcePostEventArr, "wl_resource_post_event_array")
	68	+	reg(&wlResourcePostError, "wl_resource_post_error")
	69	+	reg(&wlResourceDestroy, "wl_resource_destroy")
	70	+	reg(&wlResourceGetID, "wl_resource_get_id")
	71	+	reg(&wlResourceGetClient, "wl_resource_get_client")
	72	+	reg(&wlResourceGetVersion, "wl_resource_get_version")
	73	+
	74	+	cbDispatcher = purego.NewCallback(dispatch)
	75	+	cbDestroy = purego.NewCallback(destroyed)
	76	+	cbBind = purego.NewCallback(bind)
	77	+	})
	78	+	return loadErr
	79	+	}

@@ -0,0 +1,79 @@
	1	+	package server
	2	+
	3	+	import (
	4	+	"fmt"
	5	+	"sync"
	6	+	"unsafe"
	7	+
	8	+	"github.com/bnema/purego"
	9	+	)
	10	+
	11	+	// libwayland-server entry points. Only non-varargs functions are bound.
	12	+	var (
	13	+	wlDisplayCreate func() uintptr
	14	+	wlDisplayDestroy func(display uintptr)
	15	+	wlDisplayDestroyClients func(display uintptr)
	16	+	wlDisplayAddSocketFD func(display uintptr, fd int32) int32
	17	+	wlDisplayGetEventLoop func(display uintptr) uintptr
	18	+	wlDisplayFlushClients func(display uintptr)
	19	+	wlEventLoopDispatch func(loop uintptr, timeout int32) int32
	20	+	wlEventLoopGetFD func(loop uintptr) int32
	21	+	wlGlobalCreate func(display, iface uintptr, version int32, data uintptr, bind uintptr) uintptr
	22	+	wlResourceCreate func(client, iface uintptr, version int32, id uint32) uintptr
	23	+	wlResourceSetDispatcher func(resource, dispatcher, impl, data, destroy uintptr)
	24	+	wlResourcePostEventArr func(resource uintptr, opcode uint32, args unsafe.Pointer)
	25	+	wlResourcePostError func(resource uintptr, code uint32, msg uintptr)
	26	+	wlResourceDestroy func(resource uintptr)
	27	+	wlResourceGetID func(resource uintptr) uint32
	28	+	wlResourceGetClient func(resource uintptr) uintptr
	29	+	wlResourceGetVersion func(resource uintptr) int32
	30	+	)
	31	+
	32	+	var (
	33	+	loadOnce sync.Once
	34	+	loadErr error
	35	+
	36	+	// Shared C callbacks. purego callbacks are never freed, so there is one
	37	+	// of each for the whole process.
	38	+	cbDispatcher uintptr
	39	+	cbDestroy uintptr
	40	+	cbBind uintptr
	41	+	)
	42	+
	43	+	func load() error {
	44	+	loadOnce.Do(func() {
	45	+	lib, err := purego.Dlopen("libwayland-server.so.0", purego.RTLD_NOW\|purego.RTLD_GLOBAL)
	46	+	if err != nil {
	47	+	loadErr = fmt.Errorf("purego-libwayland: open libwayland-server.so.0: %w", err)
	48	+	return
	49	+	}
	50	+	defer func() {
	51	+	if r := recover(); r != nil {
	52	+	loadErr = fmt.Errorf("purego-libwayland: %v", r)
	53	+	}
	54	+	}()
	55	+	reg := func(fptr any, name string) { purego.RegisterLibFunc(fptr, lib, name) }
	56	+	reg(&wlDisplayCreate, "wl_display_create")
	57	+	reg(&wlDisplayDestroy, "wl_display_destroy")
	58	+	reg(&wlDisplayDestroyClients, "wl_display_destroy_clients")
	59	+	reg(&wlDisplayAddSocketFD, "wl_display_add_socket_fd")
	60	+	reg(&wlDisplayGetEventLoop, "wl_display_get_event_loop")
	61	+	reg(&wlDisplayFlushClients, "wl_display_flush_clients")
	62	+	reg(&wlEventLoopDispatch, "wl_event_loop_dispatch")
	63	+	reg(&wlEventLoopGetFD, "wl_event_loop_get_fd")
	64	+	reg(&wlGlobalCreate, "wl_global_create")
	65	+	reg(&wlResourceCreate, "wl_resource_create")
	66	+	reg(&wlResourceSetDispatcher, "wl_resource_set_dispatcher")
	67	+	reg(&wlResourcePostEventArr, "wl_resource_post_event_array")
	68	+	reg(&wlResourcePostError, "wl_resource_post_error")
	69	+	reg(&wlResourceDestroy, "wl_resource_destroy")
	70	+	reg(&wlResourceGetID, "wl_resource_get_id")
	71	+	reg(&wlResourceGetClient, "wl_resource_get_client")
	72	+	reg(&wlResourceGetVersion, "wl_resource_get_version")
	73	+
	74	+	cbDispatcher = purego.NewCallback(dispatch)
	75	+	cbDestroy = purego.NewCallback(destroyed)
	76	+	cbBind = purego.NewCallback(bind)
	77	+	})
	78	+	return loadErr
	79	+	}