From: Guido van Rossum <guido@python.org>
Date: Mon, 20 Aug 2007 15:18:04 +0000 (+0000)
Subject: Add a hack (originally devised in a slightly different form by Thomas Wouters)
X-Git-Tag: v2.6a1~1475
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=54ec61ea6e0e5eab62309f1c238af19dda77b607;p=python

Add a hack (originally devised in a slightly different form by Thomas Wouters)
to prevent spurious tracebacks when a daemon thread's cleanup happens to wake
up when the world around it has already been destroyed.
---

diff --git a/Lib/threading.py b/Lib/threading.py
index 5fc149dc33..7b07265670 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -446,6 +446,26 @@ class Thread(_Verbose):
             self.__target(*self.__args, **self.__kwargs)
 
     def __bootstrap(self):
+        # Wrapper around the real bootstrap code that ignores
+        # exceptions during interpreter cleanup.  Those typically
+        # happen when a daemon thread wakes up at an unfortunate
+        # moment, finds the world around it destroyed, and raises some
+        # random exception *** while trying to report the exception in
+        # __bootstrap_inner() below ***.  Those random exceptions
+        # don't help anybody, and they confuse users, so we suppress
+        # them.  We suppress them only when it appears that the world
+        # indeed has already been destroyed, so that exceptions in
+        # __bootstrap_inner() during normal business hours are properly
+        # reported.  Also, we only suppress them for daemonic threads;
+        # if a non-daemonic encounters this, something else is wrong.
+        try:
+            self.__bootstrap_inner()
+        except:
+            if self.__daemonic and _sys is None:
+                return
+            raise
+
+    def __bootstrap_inner(self):
         try:
             self.__started = True
             _active_limbo_lock.acquire()