raylib networking: remove locking on UI thread (#36063)

* use callback queue to make this thread safe and remove locks (which lag ui thread?)

* woah this works

* no more lock!

* always run signal handler and store callbacks, like qt

* debug

* more

* okay not for now

* combine _get_connections and _connection_by_ssid, closer to qt and not an explosion of GetSettings dbus calls

* debug

* try this

* skip

* len

* skip hidden networks

* actually slower

* stash

* back to 8929f37d49

* clean up

system/ui/lib/wifi_manager.py

@@ -133,12 +133,12 @@ class WifiManager:
     # State
     self._connecting_to_ssid: str = ""
     self._last_network_update: float = 0.0
+    self._callback_queue: list[Callable] = []
 
     # Callbacks
-    # TODO: implement a callback queue to avoid blocking UI thread
     self._need_auth: Callable[[str], None] | None = None
     self._activated: Callable[[], None] | None = None
-    self._forgotten: Callable[[str], None] | None = None
+    self._forgotten: Callable[[], None] | None = None
     self._networks_updated: Callable[[list[Network]], None] | None = None
     self._disconnected: Callable[[], None] | None = None
 
@@ -154,7 +154,7 @@ class WifiManager:
 
   def set_callbacks(self, need_auth: Callable[[str], None],
                     activated: Callable[[], None] | None,
-                    forgotten: Callable[[str], None],
+                    forgotten: Callable[[], None],
                     networks_updated: Callable[[list[Network]], None],
                     disconnected: Callable[[], None]):
     self._need_auth = need_auth
@@ -163,6 +163,15 @@ class WifiManager:
     self._networks_updated = networks_updated
     self._disconnected = disconnected
 
+  def _enqueue_callback(self, cb: Callable, *args):
+    self._callback_queue.append(lambda: cb(*args))
+
+  def process_callbacks(self):
+    # Call from UI thread to run any pending callbacks
+    to_run, self._callback_queue = self._callback_queue, []
+    for cb in to_run:
+      cb()
+
   def set_active(self, active: bool):
     self._active = active
 
@@ -187,7 +196,6 @@ class WifiManager:
 
     with self._conn_monitor.filter(rule, bufsize=SIGNAL_QUEUE_SIZE) as q:
       while not self._exit:
-        # TODO: always run, and ensure callbacks don't block UI thread
         if not self._active:
           time.sleep(1)
           continue
@@ -204,19 +212,19 @@ class WifiManager:
         if new_state == NMDeviceState.NEED_AUTH and change_reason == NM_DEVICE_STATE_REASON_SUPPLICANT_DISCONNECT and len(self._connecting_to_ssid):
           self.forget_connection(self._connecting_to_ssid, block=True)
           if self._need_auth is not None:
-            self._need_auth(self._connecting_to_ssid)
+            self._enqueue_callback(self._need_auth, self._connecting_to_ssid)
           self._connecting_to_ssid = ""
 
         elif new_state == NMDeviceState.ACTIVATED:
           if self._activated is not None:
             self._update_networks()
-            self._activated()
+            self._enqueue_callback(self._activated)
           self._connecting_to_ssid = ""
 
         elif new_state == NMDeviceState.DISCONNECTED and change_reason != NM_DEVICE_STATE_REASON_NEW_ACTIVATION:
           self._connecting_to_ssid = ""
           if self._disconnected is not None:
-            self._disconnected()
+            self._enqueue_callback(self._disconnected)
 
   def _network_scanner(self):
     self._wait_for_wifi_device()
@@ -324,7 +332,7 @@ class WifiManager:
 
         if self._forgotten is not None:
           self._update_networks()
-          self._forgotten(ssid)
+          self._enqueue_callback(self._forgotten)
 
     if block:
       worker()
@@ -400,7 +408,7 @@ class WifiManager:
     self._networks = networks
 
     if self._networks_updated is not None:
-      self._networks_updated(self._networks)
+      self._enqueue_callback(self._networks_updated, self._networks)
 
   def __del__(self):
     self.stop()

system/ui/widgets/network.py

@@ -1,6 +1,5 @@
 from enum import IntEnum
 from functools import partial
-from threading import Lock
 from typing import cast
 
 import pyray as rl
@@ -50,7 +49,6 @@ class WifiManagerUI(Widget):
     self._networks: list[Network] = []
     self._networks_buttons: dict[str, Button] = {}
     self._forget_networks_buttons: dict[str, Button] = {}
-    self._lock = Lock()
     self._confirm_dialog = ConfirmDialog("", "Forget", "Cancel")
 
     self.wifi_manager.set_callbacks(need_auth=self._on_need_auth,
@@ -71,7 +69,8 @@ class WifiManagerUI(Widget):
       gui_app.texture(icon, ICON_SIZE, ICON_SIZE)
 
   def _render(self, rect: rl.Rectangle):
-    with self._lock:
+    self.wifi_manager.process_callbacks()
+
     if not self._networks:
       gui_label(rect, "Scanning Wi-Fi networks...", 72, alignment=rl.GuiTextAlignment.TEXT_ALIGN_CENTER)
       return
@@ -211,7 +210,6 @@ class WifiManagerUI(Widget):
     self.wifi_manager.forget_connection(network.ssid)
 
   def _on_network_updated(self, networks: list[Network]):
-    with self._lock:
     self._networks = networks
     for n in self._networks:
       self._networks_buttons[n.ssid] = Button(n.ssid, partial(self._networks_buttons_callback, n), font_size=55, text_alignment=TextAlignment.LEFT,
@@ -220,7 +218,6 @@ class WifiManagerUI(Widget):
                                                      font_size=45)
 
   def _on_need_auth(self, ssid):
-    with self._lock:
     network = next((n for n in self._networks if n.ssid == ssid), None)
     if network:
       self.state = UIState.NEEDS_AUTH
@@ -228,17 +225,14 @@ class WifiManagerUI(Widget):
       self._password_retry = True
 
   def _on_activated(self):
-    with self._lock:
     if self.state == UIState.CONNECTING:
       self.state = UIState.IDLE
 
-  def _on_forgotten(self, ssid):
+  def _on_forgotten(self):
-    with self._lock:
     if self.state == UIState.FORGETTING:
       self.state = UIState.IDLE
 
   def _on_disconnected(self):
-    with self._lock:
     if self.state == UIState.CONNECTING:
       self.state = UIState.IDLE