diff options
| -rw-r--r-- | Lib/test/test_threading_local.py | 26 | ||||
| -rw-r--r-- | Misc/NEWS | 4 | ||||
| -rw-r--r-- | Modules/threadmodule.c | 5 |
3 files changed, 34 insertions, 1 deletions
diff --git a/Lib/test/test_threading_local.py b/Lib/test/test_threading_local.py index b7dd538..8642141 100644 --- a/Lib/test/test_threading_local.py +++ b/Lib/test/test_threading_local.py @@ -42,6 +42,32 @@ class ThreadingLocalTest(unittest.TestCase): deadlist = [weak for weak in weaklist if weak() is None] self.assert_(len(deadlist) in (n-1, n), (n, len(deadlist))) + def test_derived(self): + # Issue 3088: if there is a threads switch inside the __init__ + # of a threading.local derived class, the per-thread dictionary + # is created but not correctly set on the object. + # The first member set may be bogus. + import time + class Local(threading.local): + def __init__(self): + time.sleep(0.01) + local = Local() + + def f(i): + local.x = i + # Simply check that the variable is correctly set + self.assertEqual(local.x, i) + + threads= [] + for i in range(10): + t = threading.Thread(target=f, args=(i,)) + t.start() + threads.append(t) + + for t in threads: + t.join() + + def test_main(): suite = unittest.TestSuite() suite.addTest(DocTestSuite('_threading_local')) @@ -10,6 +10,10 @@ What's New in Python 2.6 beta 2? Core and Builtins ----------------- +- Issue #3088: Corrected a race condition in classes derived from + threading.local: the first member set by a thread could be saved in + another thread's dictionary. + - Issue #3004: Minor change to slice.indices(): the start and stop arguments are now treated identically, making the behaviour easier to describe and understand. For example, slice(None, -10, diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c index 81bf288..a87ddb3 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; |