wayland: Add wl_drm listener immediately upon bind

Events on wl_drm could get lost if the listener is bound only after
the roundtrip is complete. While it is correct that to get all wl_drm
events at most two roundtrips are required, in fact one roundtrip may
be enough if another thread flushes and reads from the connection
in parallel to the initial libva wl_registry roundtrip. It is thus too
late to call wl_drm_add_listener after the roundtrip.

Fixes: #101

diff --git a/va/wayland/va_wayland_drm.c b/va/wayland/va_wayland_drm.c
index 552f243..d8c4ec9 100644 (file)
--- a/va/wayland/va_wayland_drm.c
+++ b/va/wayland/va_wayland_drm.c
@@ -154,7 +154,8 @@ registry_handle_global(
     uint32_t            version
 )
 {
-    struct va_wayland_drm_context *wl_drm_ctx = data;
+    VADisplayContextP const pDisplayContext = data;
+    struct va_wayland_drm_context * const wl_drm_ctx = pDisplayContext->opaque;
 
     if (strcmp(interface, "wl_drm") == 0) {
         /* bind to at most version 2, but also support version 1 if
@@ -164,6 +165,13 @@ registry_handle_global(
         wl_drm_ctx->drm =
             wl_registry_bind(wl_drm_ctx->registry, name, &wl_drm_interface,
                              (version < 2) ? version : 2);
+
+        if (wl_drm_ctx->drm
+            && wl_drm_add_listener(wl_drm_ctx->drm, &drm_listener, pDisplayContext) != 0) {
+            va_wayland_error("could not add listener to wl_drm");
+            wl_drm_destroy(wl_drm_ctx->drm);
+            wl_drm_ctx->drm = NULL;
+        }
     }
 }
 
@@ -259,7 +267,7 @@ va_wayland_drm_create(VADisplayContextP pDisplayContext)
         va_wayland_error("could not create wl_registry");
         goto end;
     }
-    if (wl_registry_add_listener(wl_drm_ctx->registry, &registry_listener, wl_drm_ctx) != 0) {
+    if (wl_registry_add_listener(wl_drm_ctx->registry, &registry_listener, pDisplayContext) != 0) {
         va_wayland_error("could not add listener to wl_registry");
         goto end;
     }
@@ -273,11 +281,6 @@ va_wayland_drm_create(VADisplayContextP pDisplayContext)
     /* Do not print an error, the compositor might just not support wl_drm */
     if (!wl_drm_ctx->drm)
         goto end;
-
-    if (wl_drm_add_listener(wl_drm_ctx->drm, &drm_listener, pDisplayContext) != 0) {
-        va_wayland_error("could not add listener to wl_drm");
-        goto end;
-    }
     if (!wayland_roundtrip_queue(ctx->native_dpy, wl_drm_ctx->queue))
         goto end;
     if (drm_state->fd < 0) {