fix(startup): bound the initial plugin update so the panel lights sooner

src/display_controller.py

@@ -44,6 +44,20 @@
 # Get logger with consistent configuration
 logger = get_logger(__name__)
 
+# How long startup will wait for plugins to fetch their first data before
+# showing anything. Each plugin's update blocks for up to the executor's 30s
+# timeout and they run one after another, so the uncapped total is the sum of
+# every slow plugin: 82 seconds on the worst boot measured, with a blank panel
+# throughout. Whatever does not finish in time is picked up by the scheduled
+# update tick moments later, with the display already running.
+_INITIAL_UPDATE_BUDGET_SECONDS = 20.0
+
+# The least budget worth starting a plugin with. Below this the plugin is
+# deferred instead: granting it a floor would let the pass run past its
+# deadline, and granting it the true remainder would record a timeout for a
+# slot it never had a chance to use.
+_MIN_INITIAL_UPDATE_TIMEOUT_SECONDS = 2.0
+
 # Vegas mode import (lazy loaded to avoid circular imports)
 _vegas_mode_imported = False
 VegasModeCoordinator = None
@@ -461,7 +475,7 @@ def _controller_config_change(old_config: Dict[str, Any], new_config: Dict[str,
         # Initial data update for plugins (ensures data available on first display)
         logger.info("Performing initial plugin data update...")
         update_start = time.time()
-        self._update_modules()
+        self._update_modules(deadline=update_start + _INITIAL_UPDATE_BUDGET_SECONDS)
         logger.info("Initial plugin update completed in %.3f seconds", time.time() - update_start)
 
         # Initialize Vegas mode coordinator
@@ -817,14 +831,42 @@ def _check_dim_schedule(self) -> int:
             self._cached_target_brightness = normal_brightness  # persist for minute-gate
             return normal_brightness
 
-    def _update_modules(self):
-        """Update all plugin modules."""
+    def _update_modules(self, deadline: Optional[float] = None):
+        """Update all plugin modules.
+
+        Args:
+            deadline: Wall-clock time after which remaining plugins are left
+                for the scheduled update tick instead of being waited on. Each
+                update blocks this thread for up to the executor's timeout, and
+                they run one after another, so without a bound the total is the
+                sum of every slow plugin on the system. Measured at startup on
+                a live rig: 82 seconds, 55 and 26 on the two boots before -- all
+                of it with nothing on the panel.
+        """
         if not self.plugin_manager:
             return
-            
+
         # Update all loaded plugins
         plugins_dict = getattr(self.plugin_manager, 'loaded_plugins', None) or getattr(self.plugin_manager, 'plugins', {})
+        deferred = []
         for plugin_id, plugin_instance in plugins_dict.items():
+            update_timeout = None
+            if deadline is not None:
+                update_timeout = deadline - time.time()
+                if update_timeout < _MIN_INITIAL_UPDATE_TIMEOUT_SECONDS:
+                    # Too little left to be worth starting. Deferring rather
+                    # than granting a floor keeps the budget a real ceiling --
+                    # clamping up to a minimum let a plugin that began with a
+                    # sliver left run on past the deadline -- and a plugin
+                    # handed a slot it cannot use would just be recorded as
+                    # having timed out.
+                    #
+                    # Nothing is lost either way: a plugin that has never
+                    # updated is immediately due, so run_scheduled_updates()
+                    # picks it up within seconds, with the display already
+                    # running.
+                    deferred.append(plugin_id)
+                    continue
             # Check circuit breaker before attempting update
             if hasattr(self.plugin_manager, 'health_tracker') and self.plugin_manager.health_tracker:
                 if self.plugin_manager.health_tracker.should_skip_plugin(plugin_id):
@@ -833,7 +875,13 @@ def _update_modules(self):
 
             # Use PluginExecutor if available for safe execution
             if hasattr(self.plugin_manager, 'plugin_executor'):
-                success = self.plugin_manager.plugin_executor.execute_update(plugin_instance, plugin_id)
+                # The remaining budget is the timeout, so the pass cannot
+                # run past its deadline. Bounding the loop alone did not do
+                # it: the last plugin to start could still block for the
+                # executor's full 30s, which turned a 20s budget into a 31.8s
+                # pass on the rig.
+                success = self.plugin_manager.plugin_executor.execute_update(
+                    plugin_instance, plugin_id, timeout=update_timeout)
                 if success and hasattr(self.plugin_manager, 'plugin_last_update'):
                     self.plugin_manager.plugin_last_update[plugin_id] = time.time()
             else:
@@ -852,6 +900,12 @@ def _update_modules(self):
                     if hasattr(self.plugin_manager, 'health_tracker') and self.plugin_manager.health_tracker:
                         self.plugin_manager.health_tracker.record_failure(plugin_id, exc)
 
+        if deferred:
+            logger.info(
+                "Initial update budget spent; %d plugin(s) left to the update "
+                "tick so the display can start: %s",
+                len(deferred), ", ".join(deferred))
+
     def _tick_plugin_updates_for_vegas(self) -> None:
         """Run scheduled plugin updates and tell Vegas mode which plugins
         actually got fresh data, so it can hot-swap them into the scroll

src/display_manager.py

@@ -25,6 +25,7 @@
 
 import json
 import os
+import socket
 import tempfile
 if os.getenv("EMULATOR", "false") == "true":
     from RGBMatrixEmulator import RGBMatrix, RGBMatrixOptions
@@ -497,6 +498,91 @@ def get_brightness(self) -> int:
             logger.warning(f"[BRIGHTNESS] Matrix does not support brightness property: {e}", exc_info=True)
             return -1
 
+    @staticmethod
+    def _local_ip() -> Optional[str]:
+        """This device's address on the network it routes through, or None.
+
+        Deliberately not `hostname -I` or a systemctl probe for AP mode, which
+        is how the web launcher does it: both spawn processes with multi-second
+        timeouts, and this runs on the startup path the rest of this change
+        exists to shorten. Connecting a UDP socket sends no packets -- it only
+        asks the kernel which source address it would use -- so it costs
+        microseconds and works with the network down, as long as a route
+        exists.
+        """
+        sock = None
+        try:
+            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+            sock.settimeout(0.2)
+            sock.connect(("8.8.8.8", 80))  # nosec B104 - no traffic; selects a route
+            ip = sock.getsockname()[0]
+            return ip if ip and not ip.startswith("127.") else None
+        except OSError:
+            return None
+        finally:
+            if sock is not None:
+                try:
+                    sock.close()
+                except OSError:
+                    pass
+
+    def _fitting_font(self, lines, width):
+        """The largest font from the usual ladder that fits every line."""
+        candidates = [self.font,
+                      ("assets/fonts/4x6-font.ttf", 6)]
+        for candidate in candidates:
+            try:
+                font = candidate
+                if isinstance(candidate, tuple):
+                    font = ImageFont.truetype(candidate[0], candidate[1])
+                if all(self.draw.textlength(t, font=font) <= width for t in lines):
+                    return font
+            except (OSError, ValueError, AttributeError):
+                continue
+        return self.font
+
+    def _draw_startup_banner(self, lines, width: int, height: int) -> None:
+        """Centre `lines` over whatever the test pattern already drew.
+
+        This screen stays on the panel for the whole initial plugin update, and
+        on a headless Pi it is the only place the device's address appears
+        without going looking for it -- so it has to be readable off a wall,
+        not merely present.
+
+        The font is chosen to fit rather than fixed at 8px: "Initializing" is
+        96px in PressStart2P, which ran off the side of a 64px panel even
+        before an address was added. And the pattern is punched out behind the
+        text, because the diagonal runs through the middle of the panel, which
+        is exactly where this sits.
+
+        The text stays blue. It is not decoration: the pattern draws one pure
+        channel per element -- red border, green diagonal, blue text -- so that
+        a glance at the panel says whether led_rgb_sequence is right. Swap the
+        wiring to BGR and the border comes up blue and this text red. Drawing
+        it white would light all three channels and destroy the only blue
+        reference on the screen, which is why it is worth a comment rather
+        than a quiet preference.
+        """
+        if not lines:
+            return
+        font = self._fitting_font(lines, width - 2)
+        line_height = self.draw.textbbox((0, 0), "Ag", font=font)[3] + 1
+        block_height = line_height * len(lines)
+        block_top = max(1, (height - block_height) // 2)
+        block_width = max(self.draw.textlength(t, font=font) for t in lines)
+        block_left = max(0, (width - block_width) // 2)
+
+        self.draw.rectangle(
+            [block_left - 2, block_top - 1,
+             block_left + block_width + 1, block_top + block_height],
+            fill=(0, 0, 0))
+
+        for row, line in enumerate(lines):
+            line_width = self.draw.textlength(line, font=font)
+            self.draw.text(
+                (max(0, (width - line_width) // 2), block_top + row * line_height),
+                line, font=font, fill=(0, 0, 255))
+
     def _draw_test_pattern(self):
         """Draw a test pattern to verify the display is working."""
         try:
@@ -516,8 +602,11 @@ def _draw_test_pattern(self):
             # Draw a diagonal line
             self.draw.line([0, 0, self.matrix.width-1, self.matrix.height-1], fill=(0, 255, 0))
 
-            # Draw some text - changed from "TEST" to "Initializing" with smaller font
-            self.draw.text((10, 10), "Initializing", font=self.font, fill=(0, 0, 255))
+            lines = ["Initializing"]
+            ip = self._local_ip()
+            if ip:
+                lines.append(ip)
+            self._draw_startup_banner(lines, self.matrix.width, self.matrix.height)
 
             # Update the display once after everything is drawn
             self.update_display()