diff options
Diffstat (limited to 'nova/utils.py')
| -rw-r--r-- | nova/utils.py | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/nova/utils.py b/nova/utils.py index 8936614cc..c580e805a 100644 --- a/nova/utils.py +++ b/nova/utils.py @@ -574,10 +574,12 @@ def synchronized(name, external=False): def wrap(f): @functools.wraps(f) def inner(*args, **kwargs): - with _semaphores_semaphore: - if name not in _semaphores: - _semaphores[name] = semaphore.Semaphore() - sem = _semaphores[name] + # NOTE(soren): If we ever go natively threaded, this will be racy. + # See http://stackoverflow.com/questions/5390569/dyn\ + # amically-allocating-and-destroying-mutexes + if name not in _semaphores: + _semaphores[name] = semaphore.Semaphore() + sem = _semaphores[name] LOG.debug(_('Attempting to grab semaphore "%(lock)s" for method ' '"%(method)s"...' % {"lock": name, "method": f.__name__})) @@ -593,8 +595,14 @@ def synchronized(name, external=False): lock = _NoopContextManager() with lock: - return f(*args, **kwargs) + 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 |