From: Tim Peters <tim.peters@gmail.com>
Date: Sat, 16 Feb 2002 07:26:27 +0000 (+0000)
Subject: SF bug #516372:  test_thread: unhandled exc. in thread
X-Git-Tag: v2.3c1~6666
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=20882dd1742310c8cf6858354ecb150810adb95c;p=python

SF bug #516372:  test_thread: unhandled exc. in thread
Fix exit races in test_thread.py and test_threaded_import.py.
I suspect the bug is provokable only under Linux (where child threads
seem to get lots of cycles before they get killed after the main thread
exits), or on multi-processor machines running other OSes.
Bugfix candidate.
---

diff --git a/Lib/test/test_thread.py b/Lib/test/test_thread.py
index 02da94e75d..a45fb2fd5b 100644
--- a/Lib/test/test_thread.py
+++ b/Lib/test/test_thread.py
@@ -97,10 +97,14 @@ def task2(ident):
         if verbose:
             print 'task', ident, 'leaving barrier', i
     mutex.acquire()
-    running = running - 1
-    if running == 0:
-        done.release()
+    running -= 1
+    # Must release mutex before releasing done, else the main thread can
+    # exit and set mutex to None as part of global teardown; then
+    # mutex.release() raises AttributeError.
+    finished = running == 0
     mutex.release()
+    if finished:
+        done.release()
 
 print '\n*** Barrier Test ***'
 if done.acquire(0):
diff --git a/Lib/test/test_threaded_import.py b/Lib/test/test_threaded_import.py
index e022c5fe92..d9f3d70573 100644
--- a/Lib/test/test_threaded_import.py
+++ b/Lib/test/test_threaded_import.py
@@ -17,9 +17,13 @@ def task():
     x = random.randrange(1, 3)
     critical_section.acquire()
     N -= 1
-    if N == 0:
-        done.release()
+    # Must release critical_section before releasing done, else the main
+    # thread can exit and set critical_section to None as part of global
+    # teardown; then critical_section.release() raises AttributeError.
+    finished = N == 0
     critical_section.release()
+    if finished:
+        done.release()
 
 # Tricky:  When regrtest imports this module, the thread running regrtest
 # grabs the import lock and won't let go of it until this module returns.