Merge pull request #815 from troycurtisjr/xinitthreads

Call XInitThreads() before any other GUI code initializes.

ulauncher/config.py

@@ -16,6 +16,7 @@
 from gettext import gettext
 from xdg.BaseDirectory import xdg_config_home, xdg_cache_home, xdg_data_dirs, xdg_data_home
 
+
 DATA_DIR = os.path.join(xdg_data_home, 'ulauncher')
 # Use ulauncher_cache dir because of the WebKit bug
 # https://bugs.webkit.org/show_bug.cgi?id=151646
@@ -61,23 +62,6 @@ def get_data_path():
     return abs_data_path
 
 
-def is_wayland():
-    return os.environ.get('XDG_SESSION_TYPE', '').lower() == 'wayland'
-
-
-def is_wayland_compatibility_on():
-    """
-    In this mode user won't be able to set app hotkey via preferences
-    Set hotkey in OS Settings > Devices > Keyboard > Add Hotkey > Command: ulauncher-toggle
-    GDK_BACKEND is typically unset in Wayland sessions to allow GTK apps to self-select
-    """
-    return is_wayland() and (gdk_backend() == '' or gdk_backend().lower().startswith('wayland'))
-
-
-def gdk_backend():
-    return os.environ.get('GDK_BACKEND', '')
-
-
 @lru_cache()
 def get_options():
     """Support for command line options"""

ulauncher/main.py

@@ -4,6 +4,10 @@
 import logging
 import time
 from threading import Event
+# This xinit import must happen before any GUI libraries are initialized.
+# pylint: disable=wrong-import-position,wrong-import-order,ungrouped-imports,unused-import
+import ulauncher.utils.xinit  # noqa: F401
+
 import gi
 
 # Fixes issue #488
@@ -16,9 +20,9 @@
 import dbus.service
 from dbus.mainloop.glib import DBusGMainLoop
 
-from ulauncher.config import (get_version, get_options, is_wayland, is_wayland_compatibility_on,
-                              gdk_backend, CACHE_DIR, CONFIG_DIR, DATA_DIR)
+from ulauncher.config import get_version, get_options, CACHE_DIR, CONFIG_DIR, DATA_DIR
 from ulauncher.utils.decorator.run_async import run_async
+from ulauncher.utils.wayland import is_wayland, is_wayland_compatibility_on
 from ulauncher.ui.windows.UlauncherWindow import UlauncherWindow
 from ulauncher.ui.AppIndicator import AppIndicator
 from ulauncher.utils.Settings import Settings
@@ -86,17 +90,6 @@ def main():
     """
     Main function that starts everything
     """
-    if is_wayland() and gdk_backend().lower() != 'x11' and not is_wayland_compatibility_on():
-        warn = """
-                    [!]
-        Looks like you are in Wayland session
-        Please run Ulauncher with env var
-        GDK_BACKEND set to 'x11' like this:
-
-        GDK_BACKEND=x11 ulauncher
-        """
-        print(warn, file=sys.stderr)
-        sys.exit(1)
 
     # start DBus loop
     DBusGMainLoop(set_as_default=True)

ulauncher/ui/windows/PreferencesUlauncherDialog.py

@@ -33,12 +33,13 @@
 from ulauncher.utils.decorator.glib_idle_add import glib_idle_add
 from ulauncher.utils.mypy_extensions import TypedDict
 from ulauncher.utils.decorator.run_async import run_async
+from ulauncher.utils.wayland import is_wayland
 from ulauncher.utils.Settings import Settings
 from ulauncher.utils.Router import Router, get_url_params
 from ulauncher.utils.AutostartPreference import AutostartPreference
 from ulauncher.ui.AppIndicator import AppIndicator
 from ulauncher.search.shortcuts.ShortcutsDb import ShortcutsDb
-from ulauncher.config import get_data_file, get_options, get_version, is_wayland, EXTENSIONS_DIR
+from ulauncher.config import get_data_file, get_options, get_version, EXTENSIONS_DIR
 
 
 logger = logging.getLogger(__name__)

ulauncher/ui/windows/UlauncherWindow.py

@@ -18,7 +18,7 @@
 from ulauncher.ui.ResultItemWidget import ResultItemWidget  # noqa: F401
 from ulauncher.ui.SmallResultItemWidget import SmallResultItemWidget   # noqa: F401
 
-from ulauncher.config import get_data_file, is_wayland_compatibility_on, get_options
+from ulauncher.config import get_data_file, get_options
 from ulauncher.ui.ItemNavigation import ItemNavigation
 from ulauncher.search.Search import Search
 from ulauncher.search.apps.AppStatDb import AppStatDb
@@ -32,6 +32,7 @@
 from ulauncher.utils.image_loader import load_image
 from ulauncher.utils.version_cmp import gtk_version_is_gte
 from ulauncher.utils.desktop.notification import show_notification
+from ulauncher.utils.wayland import is_wayland_compatibility_on
 from ulauncher.utils.Theme import Theme, load_available_themes
 from ulauncher.search.apps.app_watcher import start as start_app_watcher
 from ulauncher.search.Query import Query

ulauncher/utils/wayland.py

@@ -0,0 +1,24 @@
+"""
+Module for detecting different states with respect to Wayland.
+
+These functions are in a standalone module to minimize the dependencies so that
+ulauncher.utils.xinit can safely use it.
+"""
+import os
+
+
+def is_wayland():
+    return os.environ.get('XDG_SESSION_TYPE', '').lower() == 'wayland'
+
+
+def is_wayland_compatibility_on():
+    """
+    In this mode user won't be able to set app hotkey via preferences
+    Set hotkey in OS Settings > Devices > Keyboard > Add Hotkey > Command: ulauncher-toggle
+    GDK_BACKEND is typically unset in Wayland sessions to allow GTK apps to self-select
+    """
+    return is_wayland() and (gdk_backend() == '' or gdk_backend().lower().startswith('wayland'))
+
+
+def gdk_backend():
+    return os.environ.get('GDK_BACKEND', '')

ulauncher/utils/xinit.py

@@ -0,0 +1,20 @@
+"""
+Simple module to call XInitThreads() to properly support multi-threaded X11 applications.
+"""
+from ulauncher.utils.wayland import is_wayland_compatibility_on
+
+
+if not is_wayland_compatibility_on():
+    from ctypes import cdll
+
+    # Using libX11.so.6 may seem a bit hard-coded, but a quick search on the Internet indicates
+    # discussion of this ABI version back to before 2009, 12 years prior to when this code was added.
+    # Also, with most of the development focus on Wayland, the chance of a ABI version bump in X11 is
+    # exceptionally small. Therefore, no additional fancy discovery methods are necessary.
+    x11 = cdll.LoadLibrary("libX11.so.6")
+
+    # In order to use any X11 calls from multiple threads, the X11 library must be initialized to use
+    # mutex protection. XInitThreads() sets this up and must be called before any other X11
+    # initialization is performed. Since this always needs to be called before other imports anyway,
+    # this module does the init at module import time.
+    x11.XInitThreads()