59 lines
1.4 KiB
Python
59 lines
1.4 KiB
Python
|
import threading
|
||
|
|
|
||
|
|
import scipy._lib.decorator
|
||
|
|
|
||
|
|
|
||
|
|
__all__ = ['ReentrancyError', 'ReentrancyLock', 'non_reentrant']
|
||
|
|
|
||
|
|
|
||
|
|
class ReentrancyError(RuntimeError):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
class ReentrancyLock:
|
||
|
|
"""
|
||
|
|
Threading lock that raises an exception for reentrant calls.
|
||
|
|
|
||
|
|
Calls from different threads are serialized, and nested calls from the
|
||
|
|
same thread result to an error.
|
||
|
|
|
||
|
|
The object can be used as a context manager or to decorate functions
|
||
|
|
via the decorate() method.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, err_msg):
|
||
|
|
self._rlock = threading.RLock()
|
||
|
|
self._entered = False
|
||
|
|
self._err_msg = err_msg
|
||
|
|
|
||
|
|
def __enter__(self):
|
||
|
|
self._rlock.acquire()
|
||
|
|
if self._entered:
|
||
|
|
self._rlock.release()
|
||
|
|
raise ReentrancyError(self._err_msg)
|
||
|
|
self._entered = True
|
||
|
|
|
||
|
|
def __exit__(self, type, value, traceback):
|
||
|
|
self._entered = False
|
||
|
|
self._rlock.release()
|
||
|
|
|
||
|
|
def decorate(self, func):
|
||
|
|
def caller(func, *a, **kw):
|
||
|
|
with self:
|
||
|
|
return func(*a, **kw)
|
||
|
|
return scipy._lib.decorator.decorate(func, caller)
|
||
|
|
|
||
|
|
|
||
|
|
def non_reentrant(err_msg=None):
|
||
|
|
"""
|
||
|
|
Decorate a function with a threading lock and prevent reentrant calls.
|
||
|
|
"""
|
||
|
|
def decorator(func):
|
||
|
|
msg = err_msg
|
||
|
|
if msg is None:
|
||
|
|
msg = "%s is not re-entrant" % func.__name__
|
||
|
|
lock = ReentrancyLock(msg)
|
||
|
|
return lock.decorate(func)
|
||
|
|
return decorator
|