refactor(companion): Cache configs for shutdown, drop dead setting

companion_manager_stop_timeout() re-read the config file mid-shutdown,
where a since-changed or removed file could raise. Cache the configs at
manager spawn and use them; fall back to a guarded build when no manager
has spawned yet.

Drop companion_manager_reload_timeout: the setting was defined but never
read anywhere. The reload path restarts the single manager via the main
loop and does not bound its wait on this value.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/design/companion-process-manager.md

@@ -182,7 +182,6 @@ companion_restart_delay = 5
 # seconds; used when manager timeout is computed dynamically
 companion_manager_shutdown_buffer = 10
 companion_manager_stop_timeout = None
-companion_manager_reload_timeout = None
 
 companion_control_socket_mode = 0o600
 ```

gunicorn/arbiter.py

@@ -67,6 +67,9 @@ class Arbiter:
         self.master_pid = 0
         self.master_name = "Master"
         self.companion_manager_pid = 0
+        # Configs of the currently running companion manager, cached at spawn so
+        # shutdown can size its wait without re-reading the config file.
+        self._companion_configs = []
 
         cwd = util.getcwd()
 
@@ -697,6 +700,7 @@ class Arbiter:
         pid = os.fork()
         if pid != 0:
             self.companion_manager_pid = pid
+            self._companion_configs = configs
             self.log.info("Companion manager started (pid:%s)", pid)
             return
 
@@ -769,7 +773,15 @@ class Arbiter:
         """
         if self.cfg.companion_manager_stop_timeout is not None:
             return self.cfg.companion_manager_stop_timeout
-        configs = build_companion_configs(self.cfg)
+        # Prefer the configs cached at spawn over re-reading the config file
+        # mid-shutdown, where a since-changed or removed file could raise.
+        configs = self._companion_configs
+        if not configs:
+            try:
+                configs = build_companion_configs(self.cfg)
+            except Exception:
+                self.log.exception("could not read companion config for shutdown")
+                return 0
         if not configs:
             return 0
         slowest = max(config.stop_timeout for config in configs)

gunicorn/config.py

@@ -2723,16 +2723,3 @@ class CompanionManagerStopTimeout(Setting):
         By default it uses the slowest companion ``stop_timeout`` plus a buffer.
         Example: ``companion_manager_stop_timeout = 120``.
         """
-
-
-class CompanionManagerReloadTimeout(Setting):
-    name = "companion_manager_reload_timeout"
-    section = "Companion Processes"
-    validator = validate_pos_int_or_none
-    default = None
-    desc = """\
-        Seconds Gunicorn waits for the manager during reload.
-
-        By default it uses the slowest companion ``reload_timeout`` plus a buffer.
-        Example: ``companion_manager_reload_timeout = 90``.
-        """