aboutsummaryrefslogtreecommitdiff
path: root/backend/headless/backend.c
blob: 49c2c8bac9f74e1f123e2ddd989d66ce1c02352c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <drm_fourcc.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <wlr/interfaces/wlr_input_device.h>
#include <wlr/interfaces/wlr_output.h>
#include <wlr/render/wlr_renderer.h>
#include <wlr/util/log.h>
#include <xf86drm.h>
#include "backend/headless.h"
#include "render/drm_format_set.h"
#include "util/signal.h"

struct wlr_headless_backend *headless_backend_from_backend(
		struct wlr_backend *wlr_backend) {
	assert(wlr_backend_is_headless(wlr_backend));
	return (struct wlr_headless_backend *)wlr_backend;
}

static bool backend_start(struct wlr_backend *wlr_backend) {
	struct wlr_headless_backend *backend =
		headless_backend_from_backend(wlr_backend);
	wlr_log(WLR_INFO, "Starting headless backend");

	struct wlr_headless_output *output;
	wl_list_for_each(output, &backend->outputs, link) {
		wl_event_source_timer_update(output->frame_timer, output->frame_delay);
		wlr_output_update_enabled(&output->wlr_output, true);
		wlr_signal_emit_safe(&backend->backend.events.new_output,
			&output->wlr_output);
	}

	struct wlr_headless_input_device *input_device;
	wl_list_for_each(input_device, &backend->input_devices,
			wlr_input_device.link) {
		wlr_signal_emit_safe(&backend->backend.events.new_input,
			&input_device->wlr_input_device);
	}

	backend->started = true;
	return true;
}

static void backend_destroy(struct wlr_backend *wlr_backend) {
	struct wlr_headless_backend *backend =
		headless_backend_from_backend(wlr_backend);
	if (!wlr_backend) {
		return;
	}

	wl_list_remove(&backend->display_destroy.link);
	wl_list_remove(&backend->parent_renderer_destroy.link);

	struct wlr_headless_output *output, *output_tmp;
	wl_list_for_each_safe(output, output_tmp, &backend->outputs, link) {
		wlr_output_destroy(&output->wlr_output);
	}

	struct wlr_headless_input_device *input_device, *input_device_tmp;
	wl_list_for_each_safe(input_device, input_device_tmp,
			&backend->input_devices, wlr_input_device.link) {
		wlr_input_device_destroy(&input_device->wlr_input_device);
	}

	wlr_backend_finish(wlr_backend);

	close(backend->drm_fd);
	free(backend);
}

static struct wlr_renderer *backend_get_renderer(
		struct wlr_backend *wlr_backend) {
	struct wlr_headless_backend *backend =
		headless_backend_from_backend(wlr_backend);
	if (backend->parent_renderer != NULL) {
		return backend->parent_renderer;
	} else {
		return wlr_backend->renderer;
	}
}

static int backend_get_drm_fd(struct wlr_backend *wlr_backend) {
	struct wlr_headless_backend *backend =
		headless_backend_from_backend(wlr_backend);
	return backend->drm_fd;
}

static uint32_t get_buffer_caps(struct wlr_backend *wlr_backend) {
	return WLR_BUFFER_CAP_DATA_PTR
		| WLR_BUFFER_CAP_DMABUF
		| WLR_BUFFER_CAP_SHM;
}

static const struct wlr_backend_impl backend_impl = {
	.start = backend_start,
	.destroy = backend_destroy,
	.get_renderer = backend_get_renderer,
	.get_drm_fd = backend_get_drm_fd,
	.get_buffer_caps = get_buffer_caps,
};

static void handle_display_destroy(struct wl_listener *listener, void *data) {
	struct wlr_headless_backend *backend =
		wl_container_of(listener, backend, display_destroy);
	backend_destroy(&backend->backend);
}

static void handle_renderer_destroy(struct wl_listener *listener, void *data) {
	struct wlr_headless_backend *backend =
		wl_container_of(listener, backend, parent_renderer_destroy);
	backend_destroy(&backend->backend);
}

static bool backend_init(struct wlr_headless_backend *backend,
		struct wl_display *display, struct wlr_renderer *renderer) {
	wlr_backend_init(&backend->backend, &backend_impl);

	backend->display = display;
	wl_list_init(&backend->outputs);
	wl_list_init(&backend->input_devices);
	wl_list_init(&backend->parent_renderer_destroy.link);

	if (renderer == NULL) {
		renderer = wlr_renderer_autocreate(&backend->backend);
		if (!renderer) {
			wlr_log(WLR_ERROR, "Failed to create renderer");
			return false;
		}
		backend->backend.renderer = renderer;
	} else {
		backend->parent_renderer = renderer;
		backend->parent_renderer_destroy.notify = handle_renderer_destroy;
		wl_signal_add(&renderer->events.destroy, &backend->parent_renderer_destroy);
	}

	backend->display_destroy.notify = handle_display_destroy;
	wl_display_add_destroy_listener(display, &backend->display_destroy);

	return true;
}

static int open_drm_render_node(void) {
	uint32_t flags = 0;
	int devices_len = drmGetDevices2(flags, NULL, 0);
	if (devices_len < 0) {
		wlr_log(WLR_ERROR, "drmGetDevices2 failed: %s", strerror(-devices_len));
		return -1;
	}
	drmDevice **devices = calloc(devices_len, sizeof(drmDevice *));
	if (devices == NULL) {
		wlr_log_errno(WLR_ERROR, "Allocation failed");
		return -1;
	}
	devices_len = drmGetDevices2(flags, devices, devices_len);
	if (devices_len < 0) {
		free(devices);
		wlr_log(WLR_ERROR, "drmGetDevices2 failed: %s", strerror(-devices_len));
		return -1;
	}

	int fd = -1;
	for (int i = 0; i < devices_len; i++) {
		drmDevice *dev = devices[i];
		if (dev->available_nodes & (1 << DRM_NODE_RENDER)) {
			const char *name = dev->nodes[DRM_NODE_RENDER];
			wlr_log(WLR_DEBUG, "Opening DRM render node '%s'", name);
			fd = open(name, O_RDWR | O_CLOEXEC);
			if (fd < 0) {
				wlr_log_errno(WLR_ERROR, "Failed to open '%s'", name);
				goto out;
			}
			break;
		}
	}
	if (fd < 0) {
		wlr_log(WLR_ERROR, "Failed to find any DRM render node");
	}

out:
	for (int i = 0; i < devices_len; i++) {
		drmFreeDevice(&devices[i]);
	}
	free(devices);

	return fd;
}

struct wlr_backend *wlr_headless_backend_create(struct wl_display *display) {
	wlr_log(WLR_INFO, "Creating headless backend");

	struct wlr_headless_backend *backend =
		calloc(1, sizeof(struct wlr_headless_backend));
	if (!backend) {
		wlr_log(WLR_ERROR, "Failed to allocate wlr_headless_backend");
		return NULL;
	}

	backend->drm_fd = open_drm_render_node();
	if (backend->drm_fd < 0) {
		wlr_log(WLR_ERROR, "Failed to open DRM render node");
	}

	if (!backend_init(backend, display, NULL)) {
		goto error_init;
	}

	return &backend->backend;

error_init:
	close(backend->drm_fd);
	free(backend);
	return NULL;
}

struct wlr_backend *wlr_headless_backend_create_with_renderer(
		struct wl_display *display, struct wlr_renderer *renderer) {
	wlr_log(WLR_INFO, "Creating headless backend with parent renderer");

	struct wlr_headless_backend *backend =
		calloc(1, sizeof(struct wlr_headless_backend));
	if (!backend) {
		wlr_log(WLR_ERROR, "Failed to allocate wlr_headless_backend");
		return NULL;
	}

	int drm_fd = wlr_renderer_get_drm_fd(renderer);
	if (drm_fd < 0) {
		wlr_log(WLR_ERROR, "Failed to get DRM device FD from parent renderer");
		backend->drm_fd = -1;
	} else {
		backend->drm_fd = fcntl(drm_fd, F_DUPFD_CLOEXEC, 0);
		if (backend->drm_fd < 0) {
			wlr_log_errno(WLR_ERROR, "fcntl(F_DUPFD_CLOEXEC) failed");
		}
	}

	if (!backend_init(backend, display, renderer)) {
		goto error_init;
	}

	return &backend->backend;

error_init:
	close(backend->drm_fd);
	free(backend);
	return NULL;
}

bool wlr_backend_is_headless(struct wlr_backend *backend) {
	return backend->impl == &backend_impl;
}