From 6f39574ff5eaf3059e2bfeccb02eb7648199cdc6 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Mon, 12 Apr 2021 14:09:27 +0200
Subject: [PATCH] linux-dmabuf-v1: implement wlr_buffer

This allows the DMA-BUF wl_buffer objects to be used directly as
wlr_buffers, without having to use wlr_client_buffer_import.
---
 include/wlr/types/wlr_linux_dmabuf_v1.h |  7 +++-
 types/wlr_linux_dmabuf_v1.c             | 53 ++++++++++++++++++++++---
 2 files changed, 53 insertions(+), 7 deletions(-)

diff --git a/include/wlr/types/wlr_linux_dmabuf_v1.h b/include/wlr/types/wlr_linux_dmabuf_v1.h
index 17e897c3..a2db7fea 100644
--- a/include/wlr/types/wlr_linux_dmabuf_v1.h
+++ b/include/wlr/types/wlr_linux_dmabuf_v1.h
@@ -11,11 +11,16 @@
 
 #include <stdint.h>
 #include <wayland-server-core.h>
+#include <wlr/types/wlr_buffer.h>
 #include <wlr/render/dmabuf.h>
 
 struct wlr_dmabuf_v1_buffer {
-	struct wl_resource *resource;
+	struct wlr_buffer base;
+
+	struct wl_resource *resource; // can be NULL if the client destroyed it
 	struct wlr_dmabuf_attributes attributes;
+
+	struct wl_listener release;
 };
 
 /**
diff --git a/types/wlr_linux_dmabuf_v1.c b/types/wlr_linux_dmabuf_v1.c
index c7d4510e..7b08b350 100644
--- a/types/wlr_linux_dmabuf_v1.c
+++ b/types/wlr_linux_dmabuf_v1.c
@@ -18,13 +18,13 @@ static void buffer_handle_destroy(struct wl_client *client,
 	wl_resource_destroy(resource);
 }
 
-static const struct wl_buffer_interface buffer_impl = {
+static const struct wl_buffer_interface wl_buffer_impl = {
 	.destroy = buffer_handle_destroy,
 };
 
 bool wlr_dmabuf_v1_resource_is_buffer(struct wl_resource *resource) {
 	if (!wl_resource_instance_of(resource, &wl_buffer_interface,
-			&buffer_impl)) {
+			&wl_buffer_impl)) {
 		return false;
 	}
 	return wl_resource_get_user_data(resource) != NULL;
@@ -33,15 +33,50 @@ bool wlr_dmabuf_v1_resource_is_buffer(struct wl_resource *resource) {
 struct wlr_dmabuf_v1_buffer *wlr_dmabuf_v1_buffer_from_buffer_resource(
 		struct wl_resource *resource) {
 	assert(wl_resource_instance_of(resource, &wl_buffer_interface,
-		&buffer_impl));
+		&wl_buffer_impl));
 	return wl_resource_get_user_data(resource);
 }
 
-static void linux_dmabuf_buffer_destroy(struct wlr_dmabuf_v1_buffer *buffer) {
+static const struct wlr_buffer_impl buffer_impl;
+
+static struct wlr_dmabuf_v1_buffer *dmabuf_v1_buffer_from_buffer(
+		struct wlr_buffer *buffer) {
+	assert(buffer->impl == &buffer_impl);
+	return (struct wlr_dmabuf_v1_buffer *)buffer;
+}
+
+static void buffer_destroy(struct wlr_buffer *wlr_buffer) {
+	struct wlr_dmabuf_v1_buffer *buffer =
+		dmabuf_v1_buffer_from_buffer(wlr_buffer);
+	if (buffer->resource != NULL) {
+		wl_resource_set_user_data(buffer->resource, NULL);
+	}
 	wlr_dmabuf_attributes_finish(&buffer->attributes);
+	wl_list_remove(&buffer->release.link);
 	free(buffer);
 }
 
+static bool buffer_get_dmabuf(struct wlr_buffer *wlr_buffer,
+		struct wlr_dmabuf_attributes *attribs) {
+	struct wlr_dmabuf_v1_buffer *buffer =
+		dmabuf_v1_buffer_from_buffer(wlr_buffer);
+	memcpy(attribs, &buffer->attributes, sizeof(buffer->attributes));
+	return true;
+}
+
+static const struct wlr_buffer_impl buffer_impl = {
+	.destroy = buffer_destroy,
+	.get_dmabuf = buffer_get_dmabuf,
+};
+
+static void buffer_handle_release(struct wl_listener *listener, void *data) {
+	struct wlr_dmabuf_v1_buffer *buffer =
+		wl_container_of(listener, buffer, release);
+	if (buffer->resource != NULL) {
+		wl_buffer_send_release(buffer->resource);
+	}
+}
+
 static const struct zwp_linux_buffer_params_v1_interface buffer_params_impl;
 
 static struct wlr_linux_buffer_params_v1 *params_from_resource(
@@ -110,7 +145,8 @@ static void params_add(struct wl_client *client,
 static void buffer_handle_resource_destroy(struct wl_resource *buffer_resource) {
 	struct wlr_dmabuf_v1_buffer *buffer =
 		wlr_dmabuf_v1_buffer_from_buffer_resource(buffer_resource);
-	linux_dmabuf_buffer_destroy(buffer);
+	buffer->resource = NULL;
+	wlr_buffer_drop(&buffer->base);
 }
 
 static bool check_import_dmabuf(struct wlr_linux_dmabuf_v1 *linux_dmabuf,
@@ -247,19 +283,24 @@ static void params_create_common(struct wl_resource *params_resource,
 		wl_resource_post_no_memory(params_resource);
 		goto err_failed;
 	}
+	wlr_buffer_init(&buffer->base, &buffer_impl, attribs.width, attribs.height);
 
 	struct wl_client *client = wl_resource_get_client(params_resource);
 	buffer->resource = wl_resource_create(client, &wl_buffer_interface,
 		1, buffer_id);
 	if (!buffer->resource) {
 		wl_resource_post_no_memory(params_resource);
+		free(buffer);
 		goto err_failed;
 	}
 	wl_resource_set_implementation(buffer->resource,
-		&buffer_impl, buffer, buffer_handle_resource_destroy);
+		&wl_buffer_impl, buffer, buffer_handle_resource_destroy);
 
 	buffer->attributes = attribs;
 
+	buffer->release.notify = buffer_handle_release;
+	wl_signal_add(&buffer->base.events.release, &buffer->release);
+
 	/* send 'created' event when the request is not for an immediate
 	 * import, that is buffer_id is zero */
 	if (buffer_id == 0) {