winewayland.drv: Use a buffer queue for window_surface.

Create a buffer queue to hold the SHM buffers for each window_surface,
to be able to reuse released buffers instead of constantly creating new
ones.

dlls/winewayland.drv/wayland_surface.c

@@ -221,6 +221,9 @@ void wayland_surface_clear_role(struct wayland_surface *surface)
  *          wayland_surface_attach_shm
  *
  * Attaches a SHM buffer to a wayland surface.
+ *
+ * The buffer is marked as unavailable until committed and subsequently
+ * released by the compositor.
  */
 void wayland_surface_attach_shm(struct wayland_surface *surface,
                                 struct wayland_shm_buffer *shm_buffer)
@@ -228,19 +231,34 @@ void wayland_surface_attach_shm(struct wayland_surface *surface,
     TRACE("surface=%p shm_buffer=%p (%dx%d)\n",
           surface, shm_buffer, shm_buffer->width, shm_buffer->height);
 
+    shm_buffer->busy = TRUE;
+    wayland_shm_buffer_ref(shm_buffer);
+
     wl_surface_attach(surface->wl_surface, shm_buffer->wl_buffer, 0, 0);
     wl_surface_damage_buffer(surface->wl_surface, 0, 0,
                              shm_buffer->width, shm_buffer->height);
 }
 
 /**********************************************************************
- *          wayland_shm_buffer_destroy
+ *          wayland_shm_buffer_ref
  *
- * Destroys a SHM buffer.
+ * Increases the reference count of a SHM buffer.
  */
-void wayland_shm_buffer_destroy(struct wayland_shm_buffer *shm_buffer)
+void wayland_shm_buffer_ref(struct wayland_shm_buffer *shm_buffer)
 {
-    TRACE("%p map=%p\n", shm_buffer, shm_buffer->map_data);
+    InterlockedIncrement(&shm_buffer->ref);
+}
+
+/**********************************************************************
+ *          wayland_shm_buffer_unref
+ *
+ * Decreases the reference count of a SHM buffer (and may destroy it).
+ */
+void wayland_shm_buffer_unref(struct wayland_shm_buffer *shm_buffer)
+{
+    if (InterlockedDecrement(&shm_buffer->ref) > 0) return;
+
+    TRACE("destroying %p map=%p\n", shm_buffer, shm_buffer->map_data);
 
     if (shm_buffer->wl_buffer)
         wl_buffer_destroy(shm_buffer->wl_buffer);
@@ -284,6 +302,7 @@ struct wayland_shm_buffer *wayland_shm_buffer_create(int width, int height,
 
     TRACE("%p %dx%d format=%d size=%d\n", shm_buffer, width, height, format, size);
 
+    shm_buffer->ref = 1;
     shm_buffer->width = width;
     shm_buffer->height = height;
     shm_buffer->map_size = size;
@@ -340,6 +359,6 @@ struct wayland_shm_buffer *wayland_shm_buffer_create(int width, int height,
 err:
     if (fd >= 0) close(fd);
     if (handle) NtClose(handle);
-    if (shm_buffer) wayland_shm_buffer_destroy(shm_buffer);
+    if (shm_buffer) wayland_shm_buffer_unref(shm_buffer);
     return NULL;
 }

dlls/winewayland.drv/waylanddrv.h

@@ -107,10 +107,13 @@ struct wayland_surface
 
 struct wayland_shm_buffer
 {
+    struct wl_list link;
     struct wl_buffer *wl_buffer;
     int width, height;
     void *map_data;
     size_t map_size;
+    BOOL busy;
+    LONG ref;
 };
 
 /**********************************************************************
@@ -145,7 +148,8 @@ void wayland_surface_attach_shm(struct wayland_surface *surface,
 
 struct wayland_shm_buffer *wayland_shm_buffer_create(int width, int height,
                                                      enum wl_shm_format format) DECLSPEC_HIDDEN;
-void wayland_shm_buffer_destroy(struct wayland_shm_buffer *shm_buffer) DECLSPEC_HIDDEN;
+void wayland_shm_buffer_ref(struct wayland_shm_buffer *shm_buffer) DECLSPEC_HIDDEN;
+void wayland_shm_buffer_unref(struct wayland_shm_buffer *shm_buffer) DECLSPEC_HIDDEN;
 
 /**********************************************************************
  *          Wayland window surface

dlls/winewayland.drv/window_surface.c

@@ -32,11 +32,20 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(waylanddrv);
 
+struct wayland_buffer_queue
+{
+    struct wl_event_queue *wl_event_queue;
+    struct wl_list buffer_list;
+    int width;
+    int height;
+};
+
 struct wayland_window_surface
 {
     struct window_surface header;
     HWND hwnd;
     struct wayland_surface *wayland_surface;
+    struct wayland_buffer_queue *wayland_buffer_queue;
     RECT bounds;
     void *bits;
     pthread_mutex_t mutex;
@@ -59,11 +68,143 @@ static void buffer_release(void *data, struct wl_buffer *buffer)
 {
     struct wayland_shm_buffer *shm_buffer = data;
     TRACE("shm_buffer=%p\n", shm_buffer);
-    wayland_shm_buffer_destroy(shm_buffer);
+    shm_buffer->busy = FALSE;
+    wayland_shm_buffer_unref(shm_buffer);
 }
 
 static const struct wl_buffer_listener buffer_listener = { buffer_release };
 
+/**********************************************************************
+ *          wayland_buffer_queue_destroy
+ *
+ * Destroys a buffer queue and any contained buffers.
+ */
+static void wayland_buffer_queue_destroy(struct wayland_buffer_queue *queue)
+{
+    struct wayland_shm_buffer *shm_buffer, *next;
+
+    wl_list_for_each_safe(shm_buffer, next, &queue->buffer_list, link)
+    {
+        wl_list_remove(&shm_buffer->link);
+        wl_list_init(&shm_buffer->link);
+        /* Since this buffer may still be busy, attach it to the per-process
+         * wl_event_queue to handle any future buffer release events. */
+        wl_proxy_set_queue((struct wl_proxy *)shm_buffer->wl_buffer,
+                           process_wayland.wl_event_queue);
+        wayland_shm_buffer_unref(shm_buffer);
+    }
+
+    if (queue->wl_event_queue)
+    {
+        /* Dispatch the event queue before destruction to process any
+         * pending buffer release events. This is required after changing
+         * the buffer proxy event queue in the previous step, to avoid
+         * missing any events. */
+        wl_display_dispatch_queue_pending(process_wayland.wl_display,
+                                          queue->wl_event_queue);
+        wl_event_queue_destroy(queue->wl_event_queue);
+    }
+
+    free(queue);
+}
+
+/**********************************************************************
+ *          wayland_buffer_queue_create
+ *
+ * Creates a buffer queue containing buffers with the specified width and height.
+ */
+static struct wayland_buffer_queue *wayland_buffer_queue_create(int width, int height)
+{
+    struct wayland_buffer_queue *queue;
+
+    queue = calloc(1, sizeof(*queue));
+    if (!queue) goto err;
+
+    queue->wl_event_queue = wl_display_create_queue(process_wayland.wl_display);
+    if (!queue->wl_event_queue) goto err;
+    queue->width = width;
+    queue->height = height;
+
+    wl_list_init(&queue->buffer_list);
+
+    return queue;
+
+err:
+    if (queue) wayland_buffer_queue_destroy(queue);
+    return NULL;
+}
+
+/**********************************************************************
+ *          wayland_buffer_queue_get_free_buffer
+ *
+ * Gets a free buffer from the buffer queue. If no free buffers
+ * are available this function blocks until it can provide one.
+ */
+static struct wayland_shm_buffer *wayland_buffer_queue_get_free_buffer(struct wayland_buffer_queue *queue)
+{
+    struct wayland_shm_buffer *shm_buffer;
+
+    TRACE("queue=%p\n", queue);
+
+    while (TRUE)
+    {
+        int nbuffers = 0;
+
+        /* Dispatch any pending buffer release events. */
+        wl_display_dispatch_queue_pending(process_wayland.wl_display,
+                                          queue->wl_event_queue);
+
+        /* Search through our buffers to find an available one. */
+        wl_list_for_each(shm_buffer, &queue->buffer_list, link)
+        {
+            if (!shm_buffer->busy) goto out;
+            nbuffers++;
+        }
+
+        /* Dynamically create up to 3 buffers. */
+        if (nbuffers < 3)
+        {
+            shm_buffer = wayland_shm_buffer_create(queue->width, queue->height,
+                                                   WL_SHM_FORMAT_XRGB8888);
+            if (shm_buffer)
+            {
+                /* Buffer events go to their own queue so that we can dispatch
+                 * them independently. */
+                wl_proxy_set_queue((struct wl_proxy *) shm_buffer->wl_buffer,
+                                   queue->wl_event_queue);
+                wl_buffer_add_listener(shm_buffer->wl_buffer, &buffer_listener,
+                                       shm_buffer);
+                wl_list_insert(&queue->buffer_list, &shm_buffer->link);
+                goto out;
+            }
+            else if (nbuffers < 2)
+            {
+                /* If we failed to allocate a new buffer, but we have at least two
+                 * buffers busy, there is a good chance the compositor will
+                 * eventually release one of them, so dispatch events and wait
+                 * below. Otherwise, give up and return a NULL buffer. */
+                ERR(" => failed to acquire buffer\n");
+                return NULL;
+            }
+        }
+
+        /* We don't have any buffers available, so block waiting for a buffer
+         * release event. */
+        if (wl_display_dispatch_queue(process_wayland.wl_display,
+                                      queue->wl_event_queue) == -1)
+        {
+            return NULL;
+        }
+    }
+
+out:
+    TRACE(" => %p %dx%d map=[%p, %p)\n",
+          shm_buffer, shm_buffer->width, shm_buffer->height, shm_buffer->map_data,
+          (unsigned char*)shm_buffer->map_data + shm_buffer->map_size);
+
+    return shm_buffer;
+}
+
 /***********************************************************************
  *           wayland_window_surface_lock
  */
@@ -119,33 +260,30 @@ static void wayland_window_surface_set_region(struct window_surface *window_surf
 static void wayland_window_surface_flush(struct window_surface *window_surface)
 {
     struct wayland_window_surface *wws = wayland_window_surface_cast(window_surface);
-    struct wayland_shm_buffer *shm_buffer;
+    struct wayland_shm_buffer *shm_buffer = NULL;
     BOOL flushed = FALSE;
 
     wayland_window_surface_lock(window_surface);
 
     if (IsRectEmpty(&wws->bounds)) goto done;
 
-    if (!wws->wayland_surface)
+    if (!wws->wayland_surface || !wws->wayland_buffer_queue)
     {
-        ERR("missing wayland surface, returning\n");
+        ERR("missing wayland surface=%p or buffer_queue=%p, returning\n",
+            wws->wayland_surface, wws->wayland_buffer_queue);
         goto done;
     }
 
     TRACE("surface=%p hwnd=%p surface_rect=%s bounds=%s\n", wws, wws->hwnd,
           wine_dbgstr_rect(&wws->header.rect), wine_dbgstr_rect(&wws->bounds));
 
-    shm_buffer = wayland_shm_buffer_create(wws->info.bmiHeader.biWidth,
-                                           abs(wws->info.bmiHeader.biHeight),
-                                           WL_SHM_FORMAT_XRGB8888);
+    shm_buffer = wayland_buffer_queue_get_free_buffer(wws->wayland_buffer_queue);
     if (!shm_buffer)
     {
-        ERR("failed to create Wayland SHM buffer, returning\n");
+        ERR("failed to acquire Wayland SHM buffer, returning\n");
         goto done;
     }
 
-    wl_buffer_add_listener(shm_buffer->wl_buffer, &buffer_listener, shm_buffer);
-
     memcpy(shm_buffer->map_data, wws->bits, shm_buffer->map_size);
 
     pthread_mutex_lock(&wws->wayland_surface->mutex);
@@ -158,7 +296,6 @@ static void wayland_window_surface_flush(struct window_surface *window_surface)
     else
     {
         TRACE("Wayland surface not configured yet, not flushing\n");
-        wayland_shm_buffer_destroy(shm_buffer);
     }
     pthread_mutex_unlock(&wws->wayland_surface->mutex);
     wl_display_flush(process_wayland.wl_display);
@@ -178,6 +315,8 @@ static void wayland_window_surface_destroy(struct window_surface *window_surface
     TRACE("surface=%p\n", wws);
 
     pthread_mutex_destroy(&wws->mutex);
+    if (wws->wayland_buffer_queue)
+        wayland_buffer_queue_destroy(wws->wayland_buffer_queue);
     free(wws->bits);
     free(wws);
 }
@@ -254,5 +393,18 @@ void wayland_window_surface_update_wayland_surface(struct window_surface *window
 
     wws->wayland_surface = wayland_surface;
 
+    /* We only need a buffer queue if we have a surface to commit to. */
+    if (wws->wayland_surface && !wws->wayland_buffer_queue)
+    {
+        wws->wayland_buffer_queue =
+            wayland_buffer_queue_create(wws->info.bmiHeader.biWidth,
+                                        abs(wws->info.bmiHeader.biHeight));
+    }
+    else if (!wws->wayland_surface && wws->wayland_buffer_queue)
+    {
+        wayland_buffer_queue_destroy(wws->wayland_buffer_queue);
+        wws->wayland_buffer_queue = NULL;
+    }
+
     wayland_window_surface_unlock(window_surface);
 }