[mutter/wip/carlosg/x11less-preparations: 11/13] wayland: Split Xwayland initialization in 2 steps

[Carlos Garnacho <carlosg src gnome org>]

commit 354a363df8d6c0c976be7f4b2e8b97531a10cb8a
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Dec 10 14:24:43 2018 +0100

    wayland: Split Xwayland initialization in 2 steps
    
    It is now separated into meta_xwayland_start(), which picks an unused
    display and sets up the sockets, and meta_xwayland_init_xserver(), which
    does the actual exec of Xwayland and MetaX11Display initialization.
    
    This differentiation will be useful when Mutter is able to launch Xwayland
    lazily, currently the former calls into the latter.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/420

 src/wayland/meta-wayland-private.h |  1 +
 src/wayland/meta-xwayland.c        | 22 +++++++++++++++-------
 2 files changed, 16 insertions(+), 7 deletions(-)
---
diff --git a/src/wayland/meta-wayland-private.h b/src/wayland/meta-wayland-private.h
index 31a7fc748..f2410be4c 100644
--- a/src/wayland/meta-wayland-private.h
+++ b/src/wayland/meta-wayland-private.h
@@ -48,6 +48,7 @@ typedef struct
   char *lock_file;
   int abstract_fd;
   int unix_fd;
+  struct wl_display *wayland_display;
   struct wl_client *client;
   struct wl_resource *xserver_resource;
   char *display_name;
diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c
index 90fdd222b..955f18e65 100644
--- a/src/wayland/meta-xwayland.c
+++ b/src/wayland/meta-xwayland.c
@@ -465,9 +465,8 @@ on_displayfd_ready (int          fd,
   return G_SOURCE_REMOVE;
 }
 
-gboolean
-meta_xwayland_start (MetaXWaylandManager *manager,
-                     struct wl_display   *wl_display)
+static gboolean
+meta_xwayland_init_xserver (MetaXWaylandManager *manager)
 {
   int xwayland_client_fd[2];
   int displayfd[2];
@@ -476,9 +475,6 @@ meta_xwayland_start (MetaXWaylandManager *manager,
   GSubprocessFlags flags;
   GError *error = NULL;
 
-  if (!choose_xdisplay (manager))
-    goto out;
-
   /* We want xwayland to be a wayland client so we make a socketpair to setup a
    * wayland protocol connection. */
   if (socketpair (AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, xwayland_client_fd) < 0)
@@ -537,7 +533,8 @@ meta_xwayland_start (MetaXWaylandManager *manager,
   g_subprocess_wait_async (manager->proc, manager->xserver_died_cancellable,
                            xserver_died, NULL);
   g_unix_fd_add (displayfd[0], G_IO_IN, on_displayfd_ready, manager);
-  manager->client = wl_client_create (wl_display, xwayland_client_fd[0]);
+  manager->client = wl_client_create (manager->wayland_display,
+                                      xwayland_client_fd[0]);
 
   /* We need to run a mainloop until we know xwayland has a binding
    * for our xserver interface at which point we can assume it's
@@ -556,6 +553,17 @@ out:
   return started;
 }
 
+gboolean
+meta_xwayland_start (MetaXWaylandManager *manager,
+                     struct wl_display   *wl_display)
+{
+  if (!choose_xdisplay (manager))
+    return FALSE;
+
+  manager->wayland_display = wl_display;
+  return meta_xwayland_init_xserver (manager);
+}
+
 static void
 on_x11_display_closing (MetaDisplay *display)
 {