render/vulkan: add upload thread

TODO:

- Update blocking stage submission as well
- Allow multiple data ptr accesses
- Stop abusing FDs for multi-thread queue

include/render/vulkan.h

@@ -1,6 +1,7 @@
 #ifndef RENDER_VULKAN_H
 #define RENDER_VULKAN_H
 
+#include <pthread.h>
 #include <stdint.h>
 #include <string.h>
 #include <stdbool.h>
@@ -270,6 +271,12 @@ struct wlr_vk_renderer {
 	// Pool of command buffers
 	struct wlr_vk_command_buffer command_buffers[VULKAN_COMMAND_BUFFERS_CAP];
 
+	struct {
+		pthread_t thread;
+		int worker_fd, control_fd;
+		struct wl_event_source *event_source;
+	} upload;
+
 	struct {
 		struct wlr_vk_command_buffer *cb;
 		uint64_t last_timeline_point;
@@ -301,6 +308,17 @@ struct wlr_vk_texture_view {
 	struct wlr_vk_descriptor_pool *ds_pool;
 };
 
+struct wlr_vk_upload_task {
+	struct wlr_buffer *buffer;
+	VkDeviceMemory memory;
+	uint64_t timeline_point;
+	char *dst;
+	const char *src;
+	uint32_t src_stride, dst_size;
+	pixman_region32_t region;
+	const struct wlr_pixel_format_info *format_info;
+};
+
 struct wlr_vk_pipeline *setup_get_or_create_pipeline(
 	struct wlr_vk_render_format_setup *setup,
 	const struct wlr_vk_pipeline_key *key);
@@ -312,7 +330,8 @@ struct wlr_vk_texture_view *vulkan_texture_get_or_create_view(
 	const struct wlr_vk_pipeline_layout *layout);
 
 // Creates a vulkan renderer for the given device.
-struct wlr_renderer *vulkan_renderer_create_for_device(struct wlr_vk_device *dev);
+struct wlr_renderer *vulkan_renderer_create_for_device(struct wlr_vk_device *dev,
+	struct wl_event_loop *loop);
 
 // stage utility - for uploading/retrieving data
 // Gets an command buffer in recording state which is guaranteed to be
@@ -382,6 +401,9 @@ bool vulkan_read_pixels(struct wlr_vk_renderer *vk_renderer,
 	uint32_t width, uint32_t height, uint32_t src_x, uint32_t src_y,
 	uint32_t dst_x, uint32_t dst_y, void *data);
 
+bool vulkan_init_upload_worker(struct wlr_vk_renderer *renderer,
+	struct wl_event_loop *loop);
+
 // State (e.g. image texture) associated with a surface.
 struct wlr_vk_texture {
 	struct wlr_texture wlr_texture;

include/wlr/render/vulkan.h

@@ -18,7 +18,8 @@ struct wlr_vk_image_attribs {
 	VkFormat format;
 };
 
-struct wlr_renderer *wlr_vk_renderer_create_with_drm_fd(int drm_fd);
+struct wlr_renderer *wlr_vk_renderer_create_with_drm_fd(
+	struct wl_event_loop *loop, int drm_fd);
 
 VkInstance wlr_vk_renderer_get_instance(struct wlr_renderer *renderer);
 VkPhysicalDevice wlr_vk_renderer_get_physical_device(struct wlr_renderer *renderer);

render/vulkan/meson.build

@@ -46,6 +46,7 @@ wlr_files += files(
 )
 
 wlr_deps += dep_vulkan
+wlr_deps += dependency('threads')
 features += { 'vulkan-renderer': true }
 
 subdir('shaders')

render/vulkan/renderer.c

@@ -369,6 +369,7 @@ bool vulkan_submit_stage_wait(struct wlr_vk_renderer *renderer) {
 		return false;
 	}
 
+	// TODO
 	VkTimelineSemaphoreSubmitInfoKHR timeline_submit_info = {
 		.sType = VK_STRUCTURE_TYPE_TIMELINE_SEMAPHORE_SUBMIT_INFO_KHR,
 		.signalSemaphoreValueCount = 1,
@@ -2153,7 +2154,8 @@ error:
 	return NULL;
 }
 
-struct wlr_renderer *vulkan_renderer_create_for_device(struct wlr_vk_device *dev) {
+struct wlr_renderer *vulkan_renderer_create_for_device(struct wlr_vk_device *dev,
+		struct wl_event_loop *loop) {
 	struct wlr_vk_renderer *renderer;
 	VkResult res;
 	if (!(renderer = calloc(1, sizeof(*renderer)))) {
@@ -2210,6 +2212,10 @@ struct wlr_renderer *vulkan_renderer_create_for_device(struct wlr_vk_device *dev
 		goto error;
 	}
 
+	if (!vulkan_init_upload_worker(renderer, loop)) {
+		goto error;
+	}
+
 	return &renderer->wlr_renderer;
 
 error:
@@ -2217,7 +2223,8 @@ error:
 	return NULL;
 }
 
-struct wlr_renderer *wlr_vk_renderer_create_with_drm_fd(int drm_fd) {
+struct wlr_renderer *wlr_vk_renderer_create_with_drm_fd(struct wl_event_loop *loop,
+		int drm_fd) {
 	wlr_log(WLR_INFO, "The vulkan renderer is only experimental and "
 		"not expected to be ready for daily use");
 	wlr_log(WLR_INFO, "Run with VK_INSTANCE_LAYERS=VK_LAYER_KHRONOS_validation "
@@ -2252,7 +2259,7 @@ struct wlr_renderer *wlr_vk_renderer_create_with_drm_fd(int drm_fd) {
 		return NULL;
 	}
 
-	return vulkan_renderer_create_for_device(dev);
+	return vulkan_renderer_create_for_device(dev, loop);
 }
 
 VkInstance wlr_vk_renderer_get_instance(struct wlr_renderer *renderer) {

render/vulkan/texture.c

@@ -2,9 +2,11 @@
 #include <assert.h>
 #include <drm_fourcc.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/socket.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <wlr/render/wlr_texture.h>
@@ -70,13 +72,150 @@ static void copy_pixels(char *vmap, const char *vdata, uint32_t tex_width,
 	assert((uint32_t)(map - vmap) == size);
 }
 
+static bool read_upload_task(struct wlr_vk_upload_task *task, int fd) {
+	while (true) {
+		errno = 0;
+		ssize_t n = read(fd, task, sizeof(*task));
+		if (errno == EINTR) {
+			continue;
+		}
+		if (n == sizeof(*task)) {
+			return true;
+		} else if (n < 0) {
+			wlr_log_errno(WLR_ERROR, "read() failed");
+		} else if (n > 0) {
+			wlr_log(WLR_ERROR, "Unexpected partial read");
+		}
+		return false;
+	}
+}
+
+static bool write_upload_task(const struct wlr_vk_upload_task *task, int fd) {
+	while (true) {
+		errno = 0;
+		ssize_t n = write(fd, task, sizeof(*task));
+		if (errno == EINTR) {
+			continue;
+		}
+		if (n == sizeof(*task)) {
+			return true;
+		} else if (n < 0) {
+			wlr_log_errno(WLR_ERROR, "write() failed");
+		} else if (n > 0) {
+			wlr_log(WLR_ERROR, "Unexpected partial write");
+		}
+		return false;
+	}
+}
+
+static void process_upload_task(struct wlr_vk_renderer *renderer,
+		struct wlr_vk_upload_task *task) {
+	copy_pixels(task->dst, task->src, task->buffer->width, task->src_stride,
+		task->dst_size, &task->region, task->format_info);
+
+	VkSemaphoreSignalInfoKHR signal_info = {
+		.sType = VK_STRUCTURE_TYPE_SEMAPHORE_SIGNAL_INFO_KHR,
+		.semaphore = renderer->upload_timeline_semaphore,
+		.value = task->timeline_point,
+	};
+	VkResult res = renderer->dev->api.vkSignalSemaphoreKHR(renderer->dev->dev, &signal_info);
+	if (res != VK_SUCCESS) {
+		wlr_vk_error("vkMapMemory", res);
+	}
+}
+
+static void *run_uploads(void *data) {
+	struct wlr_vk_renderer *renderer = data;
+
+	while (true) {
+		struct wlr_vk_upload_task task = {0};
+		if (!read_upload_task(&task, renderer->upload.worker_fd)) {
+			break;
+		}
+		process_upload_task(renderer, &task);
+		if (!write_upload_task(&task, renderer->upload.worker_fd)) {
+			break;
+		}
+	}
+
+	close(renderer->upload.worker_fd);
+	return NULL;
+}
+
+static void handle_upload_task_complete(struct wlr_vk_renderer *renderer,
+		struct wlr_vk_upload_task *task) {
+	wlr_buffer_end_data_ptr_access(task->buffer);
+	wlr_buffer_unlock(task->buffer);
+	pixman_region32_fini(&task->region);
+}
+
+static int handle_upload_fd_event(int fd, uint32_t mask, void *data) {
+	struct wlr_vk_renderer *renderer = data;
+
+	if (mask & WL_EVENT_ERROR) {
+		wlr_log(WLR_ERROR, "Upload worker FD error");
+		return 0;
+	}
+	if (mask & WL_EVENT_HANGUP) {
+		return 0;
+	}
+
+	if (mask & WL_EVENT_READABLE) {
+		struct wlr_vk_upload_task task = {0};
+		if (!read_upload_task(&task, fd)) {
+			return 0;
+		}
+		handle_upload_task_complete(renderer, &task);
+	}
+
+	return 0;
+}
+
+bool vulkan_init_upload_worker(struct wlr_vk_renderer *renderer,
+		struct wl_event_loop *loop) {
+	int sockets[2];
+	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockets) != 0) {
+		wlr_log_errno(WLR_ERROR, "pipe() failed");
+		return false;
+	}
+	renderer->upload.worker_fd = sockets[0];
+	renderer->upload.control_fd = sockets[1];
+
+	renderer->upload.event_source = wl_event_loop_add_fd(loop,
+		renderer->upload.control_fd, WL_EVENT_READABLE,
+		handle_upload_fd_event, renderer);
+	if (renderer->upload.event_source == NULL) {
+		wlr_log(WLR_ERROR, "wl_event_loop_add_fd() failed");
+		goto error_fds;
+	}
+
+	// Block all signals in the new thread: let the main thread handle these
+	sigset_t saved_sigset, new_sigset;
+	sigfillset(&new_sigset);
+	pthread_sigmask(SIG_BLOCK, &new_sigset, &saved_sigset);
+	int ret = pthread_create(&renderer->upload.thread, NULL, run_uploads, renderer);
+	pthread_sigmask(SIG_SETMASK, &saved_sigset, NULL);
+	if (ret != 0) {
+		wlr_log_errno(WLR_ERROR, "pthread_create() failed");
+		goto error_event_source;
+	}
+
+	return true;
+
+error_event_source:
+	wl_event_source_remove(renderer->upload.event_source);
+error_fds:
+	close(renderer->upload.worker_fd);
+	close(renderer->upload.control_fd);
+	return false;
+}
+
 // Will transition the texture to shaderReadOnlyOptimal layout for reading
 // from fragment shader later on
-static bool write_pixels(struct wlr_vk_texture *texture,
+static bool start_upload(struct wlr_vk_texture *texture, struct wlr_buffer *buffer,
 		uint32_t stride, const pixman_region32_t *region, const void *vdata,
 		VkImageLayout old_layout, VkPipelineStageFlags src_stage,
 		VkAccessFlags src_access) {
-	VkResult res;
 	struct wlr_vk_renderer *renderer = texture->renderer;
 
 	const struct wlr_pixel_format_info *format_info = drm_get_pixel_format_info(texture->format->drm);
@@ -144,19 +283,20 @@ static bool write_pixels(struct wlr_vk_texture *texture,
 		buf_off += height * packed_stride;
 	}
 
-	char *dst = (char *)span.buffer->map + span.alloc.start;
-	copy_pixels(dst, vdata, texture->wlr_texture.width,
-		stride, bsize, region, format_info);
-
-	VkSemaphoreSignalInfoKHR signal_info = {
-		.sType = VK_STRUCTURE_TYPE_SEMAPHORE_SIGNAL_INFO_KHR,
-		.semaphore = renderer->upload_timeline_semaphore,
-		.value = timeline_point,
+	struct wlr_vk_upload_task task = {
+		.buffer = wlr_buffer_lock(buffer),
+		.memory = span.buffer->memory,
+		.timeline_point = timeline_point,
+		.dst = (char *)span.buffer->map + span.alloc.start,
+		.src = vdata,
+		.src_stride = stride,
+		.dst_size = bsize,
+		.format_info = format_info,
 	};
-	res = renderer->dev->api.vkSignalSemaphoreKHR(renderer->dev->dev, &signal_info);
-	if (res != VK_SUCCESS) {
+	pixman_region32_init(&task.region);
+	pixman_region32_copy(&task.region, region);
+	if (!write_upload_task(&task, renderer->upload.control_fd)) {
 		free(copies);
-		wlr_vk_error("vkMapMemory", res);
 		return false;
 	}
 
@@ -199,19 +339,21 @@ static bool vulkan_texture_update_from_buffer(struct wlr_texture *wlr_texture,
 		return false;
 	}
 
-	bool ok = true;
-
 	if (format != texture->format->drm) {
-		ok = false;
-		goto out;
+		goto error;
 	}
 
-	ok = write_pixels(texture, stride, damage, data, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
-		VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, VK_ACCESS_SHADER_READ_BIT);
+	if (!start_upload(texture, buffer, stride, damage, data,
+			VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
+			VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, VK_ACCESS_SHADER_READ_BIT)) {
+		goto error;
+	}
 
-out:
+	return true;
+
+error:
 	wlr_buffer_end_data_ptr_access(buffer);
-	return ok;
+	return false;
 }
 
 void vulkan_texture_destroy(struct wlr_vk_texture *texture) {
@@ -407,7 +549,8 @@ static void texture_set_format(struct wlr_vk_texture *texture,
 }
 
 static struct wlr_texture *vulkan_texture_from_pixels(
-		struct wlr_vk_renderer *renderer, uint32_t drm_fmt, uint32_t stride,
+		struct wlr_vk_renderer *renderer, struct wlr_buffer *buffer,
+		uint32_t drm_fmt, uint32_t stride,
 		uint32_t width, uint32_t height, const void *data) {
 	VkResult res;
 	VkDevice dev = renderer->dev->dev;
@@ -480,7 +623,8 @@ static struct wlr_texture *vulkan_texture_from_pixels(
 
 	pixman_region32_t region;
 	pixman_region32_init_rect(&region, 0, 0, width, height);
-	if (!write_pixels(texture, stride, &region, data, VK_IMAGE_LAYOUT_UNDEFINED,
+	if (!start_upload(texture, buffer, stride, &region, data,
+			VK_IMAGE_LAYOUT_UNDEFINED,
 			VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT, 0)) {
 		goto error;
 	}
@@ -816,8 +960,10 @@ struct wlr_texture *vulkan_texture_from_buffer(struct wlr_renderer *wlr_renderer
 	} else if (wlr_buffer_begin_data_ptr_access(buffer,
 			WLR_BUFFER_DATA_PTR_ACCESS_READ, &data, &format, &stride)) {
 		struct wlr_texture *tex = vulkan_texture_from_pixels(renderer,
-			format, stride, buffer->width, buffer->height, data);
-		wlr_buffer_end_data_ptr_access(buffer);
+			buffer, format, stride, buffer->width, buffer->height, data);
+		if (tex == NULL) {
+			wlr_buffer_end_data_ptr_access(buffer);
+		}
 		return tex;
 	} else {
 		return NULL;

render/wlr_renderer.c

@@ -267,7 +267,7 @@ static struct wlr_renderer *renderer_autocreate(struct wlr_backend *backend, int
 			log_creation_failure(is_auto, "Cannot create Vulkan renderer: no DRM FD available");
 		} else {
 #if WLR_HAS_VULKAN_RENDERER
-			renderer = wlr_vk_renderer_create_with_drm_fd(drm_fd);
+			renderer = wlr_vk_renderer_create_with_drm_fd(loop, drm_fd);
 #else
 			wlr_log(WLR_ERROR, "Cannot create Vulkan renderer: disabled at compile-time");
 #endif