Add EAGER_MAX_TIME and EAGER_MAX_CALLBACKS constants for the default settings

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: asvetlov

Lib/asyncio/constants.py

@@ -33,6 +33,11 @@
 # Default timeout for joining the threads in the threadpool
 THREAD_JOIN_TIMEOUT = 300
 
+# Default limits of eager callback processing per event loop iteration,
+# used by EventLoopSettings.DEFAULT.
+EAGER_MAX_TIME = 1e-4  # seconds
+EAGER_MAX_CALLBACKS = 100
+
 # Maximum number of callbacks run during eager processing between checks
 # of the eager_max_time deadline.  A batch also ends where the callbacks
 # scheduled during it begin, so for chains of callbacks the deadline is

Lib/asyncio/events.py

@@ -27,6 +27,7 @@
 import sys
 import threading
 
+from . import constants
 from . import format_helpers
 
 
@@ -271,8 +272,9 @@ def __post_init__(self):
             raise ValueError("eager_max_callbacks must be non-negative")
 
 
-EventLoopSettings.DEFAULT = EventLoopSettings(eager_max_time=1e-4,
-                                              eager_max_callbacks=100)
+EventLoopSettings.DEFAULT = EventLoopSettings(
+    eager_max_time=constants.EAGER_MAX_TIME,
+    eager_max_callbacks=constants.EAGER_MAX_CALLBACKS)
 
 
 class AbstractEventLoop: