mirror of
https://github.com/python/cpython
synced 2024-10-08 02:29:43 +00:00
Merged revisions 64601 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk ........ r64601 | amaury.forgeotdarc | 2008-06-30 17:42:40 -0500 (Mon, 30 Jun 2008) | 11 lines #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. ........
This commit is contained in:
parent
ec19d95f51
commit
8a250aeb21
|
@ -42,6 +42,32 @@ def _local_refs(self, n):
|
|||
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'))
|
||||
|
|
|
@ -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;
|
||||
|
|
Loading…
Reference in a new issue