On Tue, May 1, 2012 at 10:35 AM, raymond.hettinger <python-checkins@python.org> wrote:

http://hg.python.org/cpython/rev/b3aeaef6c315 changeset:   76675:b3aeaef6c315 user:        Raymond Hettinger <python@rcn.com> date:        Mon Apr 30 14:14:28 2012 -0700 summary:  Handle a possible race condition

files:  Lib/functools.py |  6 ++++++  1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/Lib/functools.py b/Lib/functools.py --- a/Lib/functools.py +++ b/Lib/functools.py @@ -241,6 +241,12 @@                         return result                 result = user_function(*args, **kwds)                 with lock: +                    if key in cache: +                        # getting here means that this same key was added to the +                        # cache while the lock was released.  since the link +                        # update is already done, we need only return the +                        # computed result and update the count of misses. +                        pass                     if currsize < maxsize:                         # put result in a new link at the front of the queue                         last = root[PREV]

To get the desired effect, I believe you also need s/if currsize/elif currsize/ Cheers, Nick. -- Nick Coghlan   |   ncoghlan@gmail.com   |   Brisbane, Australia