Add build option for enabling screencopy-dmabuf

include/buffer.h

@@ -17,6 +17,7 @@
 #pragma once
 
 #include "sys/queue.h"
+#include "config.h"
 
 #include <unistd.h>
 #include <stdbool.h>
@@ -29,7 +30,9 @@ struct gbm_bo;
 enum wv_buffer_type {
 	WV_BUFFER_UNSPEC = 0,
 	WV_BUFFER_SHM,
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	WV_BUFFER_DMABUF,
+#endif
 };
 
 struct wv_buffer {

meson.build

@@ -41,7 +41,7 @@ libm = cc.find_library('m', required: false)
 librt = cc.find_library('rt', required: false)
 
 pixman = dependency('pixman-1')
-gbm = dependency('gbm')
+gbm = dependency('gbm', required: get_option('screencopy-dmabuf'))
 drm = dependency('libdrm')
 xkbcommon = dependency('xkbcommon')
 wayland_client = dependency('wayland-client')
@@ -116,6 +116,10 @@ elif cc.has_function('SYS_memfd_create', prefix : '#include <sys/syscall.h>')
 	config.set('HAVE_MEMFD', true)
 endif
 
+if gbm.found() and not get_option('screencopy-dmabuf').disabled()
+	config.set('ENABLE_SCREENCOPY_DMABUF', true)
+endif
+
 configure_file(
 	output: 'config.h',
 	configuration: config,

meson_options.txt

@@ -0,0 +1,2 @@
+option('screencopy-dmabuf', type: 'feature', value: 'disabled',
+	description: 'Enable GPU-side screencopy (experimental)')

src/buffer.c

@@ -30,6 +30,7 @@
 #include "sys/queue.h"
 #include "buffer.h"
 #include "pixels.h"
+#include "config.h"
 
 extern struct wl_shm* wl_shm;
 extern struct zwp_linux_dmabuf_v1* zwp_linux_dmabuf;
@@ -42,8 +43,10 @@ enum wv_buffer_type wv_buffer_get_available_types(void)
 	if (wl_shm)
 		type |= WV_BUFFER_SHM;
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	if (zwp_linux_dmabuf && gbm_device)
 		type |= WV_BUFFER_DMABUF;
+#endif
 
 	return type;
 }
@@ -99,6 +102,7 @@ failure:
 	return NULL;
 }
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 static struct wv_buffer* wv_buffer_create_dmabuf(int width, int height,
 		uint32_t fourcc)
 {
@@ -152,6 +156,7 @@ bo_failure:
 	free(self);
 	return NULL;
 }
+#endif
 
 struct wv_buffer* wv_buffer_create(enum wv_buffer_type type, int width,
 		int height, int stride, uint32_t fourcc)
@@ -159,8 +164,10 @@ struct wv_buffer* wv_buffer_create(enum wv_buffer_type type, int width,
 	switch (type) {
 	case WV_BUFFER_SHM:
 		return wv_buffer_create_shm(width, height, stride, fourcc);
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	case WV_BUFFER_DMABUF:
 		return wv_buffer_create_dmabuf(width, height, fourcc);
+#endif
 	case WV_BUFFER_UNSPEC:;
 	}
 
@@ -175,12 +182,14 @@ static void wv_buffer_destroy_shm(struct wv_buffer* self)
 	free(self);
 }
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 static void wv_buffer_destroy_dmabuf(struct wv_buffer* self)
 {
 	wl_buffer_destroy(self->wl_buffer);
 	gbm_bo_destroy(self->bo);
 	free(self);
 }
+#endif
 
 void wv_buffer_destroy(struct wv_buffer* self)
 {
@@ -191,15 +200,18 @@ void wv_buffer_destroy(struct wv_buffer* self)
 	case WV_BUFFER_SHM:
 		wv_buffer_destroy_shm(self);
 		return;
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	case WV_BUFFER_DMABUF:
 		wv_buffer_destroy_dmabuf(self);
 		return;
+#endif
 	case WV_BUFFER_UNSPEC:;
 	}
 
 	abort();
 }
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 static int wv_buffer_map_dmabuf(struct wv_buffer* self)
 {
 	if (self->bo_map_handle)
@@ -215,34 +227,41 @@ static int wv_buffer_map_dmabuf(struct wv_buffer* self)
 	self->bo_map_handle = NULL;
 	return -1;
 }
+#endif
 
 int wv_buffer_map(struct wv_buffer* self)
 {
 	switch (self->type) {
 	case WV_BUFFER_SHM:
 		return 0;
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	case WV_BUFFER_DMABUF:
 		return wv_buffer_map_dmabuf(self);
+#endif
 	case WV_BUFFER_UNSPEC:;
 	}
 
 	abort();
 }
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 static void wv_buffer_unmap_dmabuf(struct wv_buffer* self)
 {
 	if (self->bo_map_handle)
 		gbm_bo_unmap(self->bo, self->bo_map_handle);
 	self->bo_map_handle = NULL;
 }
+#endif
 
 void wv_buffer_unmap(struct wv_buffer* self)
 {
 	switch (self->type) {
 	case WV_BUFFER_SHM:
 		return;
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	case WV_BUFFER_DMABUF:
 		return wv_buffer_unmap_dmabuf(self);
+#endif
 	case WV_BUFFER_UNSPEC:;
 
 	}
@@ -327,12 +346,13 @@ static bool wv_buffer_pool_match_buffer(struct wv_buffer_pool* pool,
 			return false;
 
 		/* fall-through */
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	case WV_BUFFER_DMABUF:
 		if (pool->width != buffer->width
 		    || pool->height != buffer->height
 		    || pool->format != buffer->format)
 			return false;
-
+#endif
 		return true;
 	case WV_BUFFER_UNSPEC:
 		abort();

src/main.c

@@ -34,8 +34,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <gbm.h>
-#include <xf86drm.h>
 
 #include "wlr-screencopy-unstable-v1.h"
 #include "wlr-virtual-pointer-unstable-v1.h"
@@ -55,6 +53,11 @@
 #include "damage-refinery.h"
 #include "usdt.h"
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
+#include <gbm.h>
+#include <xf86drm.h>
+#endif
+
 #define DEFAULT_ADDRESS "127.0.0.1"
 #define DEFAULT_PORT 5900
 
@@ -229,6 +232,7 @@ static void registry_remove(void* data, struct wl_registry* registry,
 	}
 }
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 static int find_render_node(char *node, size_t maxlen) {
 	bool r = -1;
 	drmDevice *devices[64];
@@ -248,6 +252,26 @@ static int find_render_node(char *node, size_t maxlen) {
 	return r;
 }
 
+static int init_render_node(int* fd)
+{
+	char render_node[256];
+	if (find_render_node(render_node, sizeof(render_node)) < 0)
+		return -1;
+
+	*fd = open(render_node, O_RDWR);
+	if (*fd < 0)
+		return -1;
+
+	gbm_device = gbm_create_device(*fd);
+	if (!gbm_device) {
+		close(*fd);
+		return -1;
+	}
+
+	return 0;
+}
+#endif
+
 void wayvnc_destroy(struct wayvnc* self)
 {
 	output_list_destroy(&self->outputs);
@@ -739,7 +763,7 @@ int main(int argc, char* argv[])
 	int max_rate = 30;
 
 	static const char* shortopts = "C:o:k:s:rf:hpV";
-	int drm_fd = -1;
+	int drm_fd MAYBE_UNUSED = -1;
 
 	static const struct option longopts[] = {
 		{ "config", required_argument, NULL, 'C' },
@@ -883,17 +907,11 @@ int main(int argc, char* argv[])
 	out->on_dimension_change = on_output_dimension_change;
 	out->userdata = &self;
 
-	char render_node[256];
-	if (find_render_node(render_node, sizeof(render_node)) < 0)
-		goto failure;
-
-	drm_fd = open(render_node, O_RDWR);
-	if (drm_fd < 0)
-		goto failure;
-
-	gbm_device = gbm_create_device(drm_fd);
-	if (!gbm_device)
-		goto failure;
+#ifdef ENABLE_SCREENCOPY_DMABUF
+	if (init_render_node(&drm_fd) < 0) {
+		log_error("Failed to initialise DRM render node. No GPU acceleration will be available.\n");
+	}
+#endif
 
 	struct aml* aml = aml_new();
 	if (!aml)
@@ -948,7 +966,12 @@ int main(int argc, char* argv[])
 		zwp_linux_dmabuf_v1_destroy(zwp_linux_dmabuf);
 	if (self.screencopy.manager)
 		screencopy_destroy(&self.screencopy);
-	gbm_device_destroy(gbm_device);
+#ifdef ENABLE_SCREENCOPY_DMABUF
+	if (gbm_device) {
+		gbm_device_destroy(gbm_device);
+		close(drm_fd);
+	}
+#endif
 	wayvnc_destroy(&self);
 	aml_unref(aml);
 
@@ -960,9 +983,12 @@ capture_failure:
 nvnc_failure:
 main_loop_failure:
 failure:
-	gbm_device_destroy(gbm_device);
+#ifdef ENABLE_SCREENCOPY_DMABUF
+	if (gbm_device)
+		gbm_device_destroy(gbm_device);
 	if (drm_fd >= 0)
 		close(drm_fd);
+#endif
 	wayvnc_destroy(&self);
 	return 1;
 }

src/screencopy.c

@@ -32,6 +32,7 @@
 #include "time-util.h"
 #include "usdt.h"
 #include "pixels.h"
+#include "config.h"
 
 #define DELAY_SMOOTHER_TIME_CONSTANT 0.5 // s
 
@@ -63,6 +64,9 @@ static void screencopy_linux_dmabuf(void* data,
 #ifdef ENABLE_SCREENCOPY_DMABUF
 	struct screencopy* self = data;
 
+	if (!(wv_buffer_get_available_types() & WV_BUFFER_DMABUF))
+		return;
+
 	self->have_linux_dmabuf = true;
 	self->dmabuf_width = width;
 	self->dmabuf_height = height;
@@ -77,13 +81,16 @@ static void screencopy_buffer_done(void* data,
 	uint32_t width, height, stride, fourcc;
 	enum wv_buffer_type type = WV_BUFFER_UNSPEC;
 
+#ifdef ENABLE_SCREENCOPY_DMABUF
 	if (self->have_linux_dmabuf) {
 		width = self->dmabuf_width;
 		height = self->dmabuf_height;
 		stride = 0;
 		fourcc = self->fourcc;
 		type = WV_BUFFER_DMABUF;
-	} else {
+	} else
+#endif
+	{
 		width = self->wl_shm_width;
 		height = self->wl_shm_height;
 		stride = self->wl_shm_stride;