Linux: threading fix & optimization

CHANGELOG.md

@@ -5,6 +5,8 @@ See Git checking messages for full history.
 ## 10.0.0 (2024-xx-xx)
 - removed support for Python 3.8
 - added support for Python 3.14
+- Linux: fixed a threadding issue in `.close()` when calling `XCloseDisplay()` (#251)
+- Linux: minor optimization when checking for a X extension status (#251)
 - :heart: contributors: @
 
 ## 9.0.2 (2024-09-01)

src/mss/linux.py

@@ -329,6 +329,14 @@ def __init__(self, /, **kwargs: Any) -> None:
         self._handles.drawable = cast(self._handles.root, POINTER(Display))
 
     def close(self) -> None:
+        # Clean-up
+        if self._handles.display:
+            with lock:
+                self.xlib.XCloseDisplay(self._handles.display)
+            self._handles.display = None
+            self._handles.drawable = None
+            self._handles.root = None
+
         # Remove our error handler
         if self._handles.original_error_handler:
             # It's required when exiting MSS to prevent letting `_error_handler()` as default handler.
@@ -339,34 +347,27 @@ def close(self) -> None:
             self.xlib.XSetErrorHandler(self._handles.original_error_handler)
             self._handles.original_error_handler = None
 
-        # Clean-up
-        if self._handles.display:
-            self.xlib.XCloseDisplay(self._handles.display)
-            self._handles.display = None
-            self._handles.drawable = None
-            self._handles.root = None
-
         # Also empty the error dict
         _ERROR.clear()
 
     def _is_extension_enabled(self, name: str, /) -> bool:
         """Return True if the given *extension* is enabled on the server."""
-        with lock:
-            major_opcode_return = c_int()
-            first_event_return = c_int()
-            first_error_return = c_int()
+        major_opcode_return = c_int()
+        first_event_return = c_int()
+        first_error_return = c_int()
 
-            try:
+        try:
+            with lock:
                 self.xlib.XQueryExtension(
                     self._handles.display,
                     name.encode("latin1"),
                     byref(major_opcode_return),
                     byref(first_event_return),
                     byref(first_error_return),
                 )
-            except ScreenShotError:
-                return False
-            return True
+        except ScreenShotError:
+            return False
+        return True
 
     def _set_cfunctions(self) -> None:
         """Set all ctypes functions and attach them to attributes."""