queue pending buffers for wayland shm clients

due to how deferred rendering works, it's possible for a client to
send a second buffer before enlightenment has rendered the first one.
in this situation, it seems that the best solution is to queue successive
buffers (frames) and pop the queue after each render

ref T2784

diff --git a/src/bin/e_pixmap.c b/src/bin/e_pixmap.c
index 178c00c..958bda0 100644 (file)
--- a/src/bin/e_pixmap.c
+++ b/src/bin/e_pixmap.c
@@ -37,6 +37,7 @@ struct _E_Pixmap
 #ifdef HAVE_WAYLAND
    E_Comp_Wl_Buffer *buffer;
    E_Comp_Wl_Buffer_Ref buffer_ref;
+   Eina_List *buffers;
    struct wl_listener buffer_destroy_listener;
    void *data;
    Eina_Rectangle opaque;
@@ -49,6 +50,13 @@ struct _E_Pixmap
 };
 
 #ifdef HAVE_WAYLAND
+typedef struct E_Pixmap_Pending_Buffer
+{
+   E_Comp_Wl_Buffer *buffer;
+   E_Pixmap *cp;
+   struct wl_listener destroy_listener;
+} E_Pixmap_Pending_Buffer;
+
 static void 
 _e_pixmap_cb_buffer_destroy(struct wl_listener *listener, void *data EINA_UNUSED)
 {
@@ -58,6 +66,42 @@ _e_pixmap_cb_buffer_destroy(struct wl_listener *listener, void *data EINA_UNUSED
    cp->data = NULL;
    cp->buffer_destroy_listener.notify = NULL;
 }
+
+static void
+_e_pixmap_cb_pending_buffer_destroy(struct wl_listener *listener, void *data EINA_UNUSED)
+{
+   E_Pixmap_Pending_Buffer *ref;
+
+   ref = container_of(listener, E_Pixmap_Pending_Buffer, destroy_listener);
+   ref->cp->buffers = eina_list_remove(ref->cp->buffers, ref);
+   free(ref);
+}
+
+static Eina_Bool
+_e_pixmap_wl_image_refresh(E_Pixmap *cp, E_Comp_Wl_Buffer *buffer)
+{
+   struct wl_shm_buffer *shm_buffer;
+
+   shm_buffer = wl_shm_buffer_get(buffer->resource);
+   if (!shm_buffer)
+     {
+        WRN("Cannot get shm buffer from buffer resource");
+        return EINA_FALSE;
+     }
+   e_comp_wl_buffer_reference(&cp->buffer_ref, buffer);
+
+   if (cp->buffer_destroy_listener.notify)
+     {
+        wl_list_remove(&cp->buffer_destroy_listener.link);
+        cp->buffer_destroy_listener.notify = NULL;
+     }
+
+   cp->buffer_destroy_listener.notify = _e_pixmap_cb_buffer_destroy;
+   wl_signal_add(&buffer->destroy_signal, &cp->buffer_destroy_listener);
+   cp->data = wl_shm_buffer_get_data(shm_buffer);
+   return EINA_TRUE;
+}
+
 #endif
 
 static void
@@ -81,6 +125,8 @@ _e_pixmap_clear(E_Pixmap *cp, Eina_Bool cache)
       case E_PIXMAP_TYPE_WL:
 #ifdef HAVE_WAYLAND
         e_pixmap_image_clear(cp, cache);
+        while (cp->buffers)
+          e_pixmap_image_clear(cp, cache);
 #endif
         break;
       default: 
@@ -530,7 +576,7 @@ e_pixmap_resource_get(E_Pixmap *cp)
         return NULL;
      }
 #ifdef HAVE_WAYLAND
-   return cp->buffer;
+   return cp->buffer_ref.buffer ?: cp->buffer;
 #endif
    return NULL;
 }
@@ -650,6 +696,16 @@ e_pixmap_image_clear(E_Pixmap *cp, Eina_Bool cache)
           }
         e_comp_wl_buffer_reference(&cp->buffer_ref, NULL);
         cp->data = NULL;
+        if (!cp->buffers) break;
+        {
+           E_Pixmap_Pending_Buffer *ref;
+
+           ref = eina_list_data_get(cp->buffers);
+           cp->buffers = eina_list_remove_list(cp->buffers, cp->buffers);
+           wl_list_remove(&ref->destroy_listener.link);
+           _e_pixmap_wl_image_refresh(cp, ref->buffer);
+           free(ref);
+        }
 #endif
         break;
       default:
@@ -688,31 +744,20 @@ e_pixmap_image_refresh(E_Pixmap *cp)
 #ifdef HAVE_WAYLAND
         {
            E_Comp_Wl_Buffer *buffer = cp->buffer;
-           struct wl_shm_buffer *shm_buffer;
-
-           shm_buffer = wl_shm_buffer_get(buffer->resource);
-           if (!shm_buffer)
-             {
-                WRN("Cannot get shm buffer from buffer resource");
-                return EINA_FALSE;
-             }
            if (cp->buffer_ref.buffer && (cp->buffer_ref.buffer != buffer))
              {
-                /* FIXME: wtf? */
+                E_Pixmap_Pending_Buffer *ref;
+
+                ref = calloc(1, sizeof(E_Pixmap_Pending_Buffer));
+                cp->buffers = eina_list_append(cp->buffers, ref);
+                ref->destroy_listener.notify = _e_pixmap_cb_pending_buffer_destroy;
+                wl_signal_add(&buffer->destroy_signal, &ref->destroy_listener);
+                ref->buffer = buffer;
+                ref->cp = cp;
+                return EINA_TRUE;
              }
            else if (cp->buffer_ref.buffer) return EINA_TRUE;
-           e_comp_wl_buffer_reference(&cp->buffer_ref, buffer);
-
-           if (cp->buffer_destroy_listener.notify)
-             {
-                wl_list_remove(&cp->buffer_destroy_listener.link);
-                cp->buffer_destroy_listener.notify = NULL;
-             }
-
-           cp->buffer_destroy_listener.notify = _e_pixmap_cb_buffer_destroy;
-           wl_signal_add(&buffer->destroy_signal, &cp->buffer_destroy_listener);
-           cp->data = wl_shm_buffer_get_data(shm_buffer);
-           return EINA_TRUE;
+           return _e_pixmap_wl_image_refresh(cp, buffer);
         }
 #endif
         break;