diff options
Diffstat (limited to 'nova')
| -rw-r--r-- | nova/utils.py | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/nova/utils.py b/nova/utils.py index d54b8dfb3..3b403a0d2 100644 --- a/nova/utils.py +++ b/nova/utils.py @@ -39,6 +39,7 @@ import tempfile import threading import time import uuid +import weakref from xml.sax import saxutils from eventlet import corolocal @@ -630,7 +631,7 @@ class InterProcessLock(object): % self.fname) -_semaphores = {} +_semaphores = weakref.WeakValueDictionary() def synchronized(name, external=False): @@ -668,9 +669,13 @@ def synchronized(name, external=False): # NOTE(soren): If we ever go natively threaded, this will be racy. # See http://stackoverflow.com/questions/5390569/dyn # amically-allocating-and-destroying-mutexes + sem = _semaphores.get(name, semaphore.Semaphore()) if name not in _semaphores: - _semaphores[name] = semaphore.Semaphore() - sem = _semaphores[name] + # this check is not racy - we're already holding ref locally + # so GC won't remove the item and there was no IO switch + # (only valid in greenthreads) + _semaphores[name] = sem + LOG.debug(_('Attempting to grab semaphore "%(lock)s" for method ' '"%(method)s"...'), {'lock': name, 'method': f.__name__}) @@ -693,11 +698,6 @@ def synchronized(name, external=False): else: retval = f(*args, **kwargs) - # If no-one else is waiting for it, delete it. - # See note about possible raciness above. - if not sem.balance < 1: - del _semaphores[name] - return retval return inner return wrap |