From b615417a836bda336ec4259cebcea77ea4c98762 Mon Sep 17 00:00:00 2001 From: Amaury Forgeot d'Arc Date: Mon, 30 Jun 2008 22:42:40 +0000 Subject: #Issue3088 in-progress: Race condition with instances of classes derived from threading.local: When a thread touches such an object for the first time, a new thread-local __dict__ is created, and the __init__ method is run. But a thread switch can occur here; if the other thread touches the same object, it installs another __dict__; when the first thread resumes, it updates the dictionary of the second... This is the deep cause of the failures in test_multiprocessing involving "managers" objects. Also a 2.5 backport candidate. --- Modules/threadmodule.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'Modules') diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c index 81bf288204..a87ddb344d 100644 --- a/Modules/threadmodule.c +++ b/Modules/threadmodule.c @@ -293,7 +293,10 @@ _ldict(localobject *self) } } - else if (self->dict != ldict) { + + /* The call to tp_init above may have caused another thread to run. + Install our ldict again. */ + if (self->dict != ldict) { Py_CLEAR(self->dict); Py_INCREF(ldict); self->dict = ldict; -- cgit v1.2.1