fix deadlock issue

This commit is contained in:
Thomas Spura 2012-02-25 21:34:30 +01:00
parent e36d6e7112
commit 9bf1f8f3bb
2 changed files with 72 additions and 1 deletions

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@ -0,0 +1,62 @@
# HG changeset patch
# User Charles-François Natali <neologix@free.fr>
# Date 1328209039 -3600
# Node ID c3649173d093ce3bb2f887c1b4c3207196f1f453
# Parent 0b8917fc6db55d371573398c2ae29b120be40a19
Issue #13817: After fork(), reinit the ad-hoc TLS implementation earlier to fix
a random deadlock when fork() is called in a multithreaded process in debug
mode, and make PyOS_AfterFork() more robust.
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -635,6 +635,29 @@ class ThreadJoinOnShutdown(BaseTestCase)
output = "end of worker thread\nend of main thread\n"
self.assertScriptHasOutput(script, output)
+ @unittest.skipUnless(hasattr(os, 'fork'), "needs os.fork()")
+ def test_reinit_tls_after_fork(self):
+ # Issue #13817: fork() would deadlock in a multithreaded program with
+ # the ad-hoc TLS implementation.
+
+ def do_fork_and_wait():
+ # just fork a child process and wait it
+ pid = os.fork()
+ if pid > 0:
+ os.waitpid(pid, 0)
+ else:
+ os._exit(0)
+
+ # start a bunch of threads that will fork() child processes
+ threads = []
+ for i in range(16):
+ t = threading.Thread(target=do_fork_and_wait)
+ threads.append(t)
+ t.start()
+
+ for t in threads:
+ t.join()
+
class ThreadingExceptionTests(BaseTestCase):
# A RuntimeError should be raised if Thread.start() is called
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -976,11 +976,13 @@ void
PyOS_AfterFork(void)
{
#ifdef WITH_THREAD
+ /* PyThread_ReInitTLS() must be called early, to make sure that the TLS API
+ * can be called safely. */
+ PyThread_ReInitTLS();
_PyGILState_Reinit();
PyEval_ReInitThreads();
main_thread = PyThread_get_thread_ident();
main_pid = getpid();
_PyImport_ReInitLock();
- PyThread_ReInitTLS();
#endif
}

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@ -108,7 +108,7 @@ Summary: An interpreted, interactive, object-oriented programming language
Name: %{python}
# Remember to also rebase python-docs when changing this:
Version: 2.7.2
Release: 19%{?dist}
Release: 20%{?dist}
License: Python
Group: Development/Languages
Requires: %{python}-libs%{?_isa} = %{version}-%{release}
@ -601,6 +601,11 @@ Patch147: 00147-add-debug-malloc-stats.patch
# Taken from upstream http://bugs.python.org/issue13007 (rhbz#742242)
Patch148: 00148-gdbm-1.9-magic-values.patch
# Fix deadlock in fork:
# https://bugzilla.redhat.com/show_bug.cgi?id=787712
# http://bugs.python.org/issue13817
Patch151: python-3.2.2-fork-deadlock.patch
# python3.spec's
# Patch149: 00149-backport-issue11254-pycache-bytecompilation-fix.patch
# is not relevant for Python 2
@ -913,6 +918,7 @@ done
%patch147 -p1
%patch148 -p1
# 00149: not for python 2
%patch151 -p1
# This shouldn't be necesarry, but is right now (2.2a3)
@ -1741,6 +1747,9 @@ rm -fr %{buildroot}
# ======================================================
%changelog
* Sat Feb 25 2012 Thomas Spura <tomspur@fedoraproject.org> - 2.7.2-20
- fix deadlock issue (#787712)
* Fri Feb 17 2012 Toshio Kuratomi <toshio@fedoraproject.org> - 2.7.2-19
- Obsolete python-sqlite2