def test_executor():
""" Test the executor """
ex = Executor()
ex2 = Executor()
assert ex is ex2
ex3 = pickle.loads(pickle.dumps(ex))
assert ex3 is ex
assert len(_executor_cache) == 1
assert ex.impl.submit(lambda x: x * 2, 4).result() == 8
ex.shutdown(wait=True)
ex3.shutdown(wait=False)
# Executor should be shutdown at this point
with pytest.raises(RuntimeError):
ex2.impl.submit(lambda x: x * 2, 4)
assert len(_executor_cache) == 1
# Force collection
del ex, ex2, ex3
# Check that callbacks
assert len(_executor_cache) == 0
def __init__(self, factory, *args, **kwargs):
"""
Parameters
----------
factory : callable
Function which creates the CASA table
*args : tuple
Positional arguments passed to factory.
**kwargs : dict
Keyword arguments passed to factory.
__executor_key__ : str, optional
Executor key. Identifies a unique threadpool
in which table operations will be performed.
"""
# Save the arguments as keys for pickling and tokenising
self._factory = factory
self._args = args
self._kwargs = kwargs
# NOTE(sjperkins)
# Copy the kwargs and remove (any) __executor_key__
# This is smelly but we do this to maintain
# key uniqueness derived from
# the *args and **kwargs in the MetaClass
# as well as uniqueness when pickling/unpickling
# A named keyword is possible but
# TableProxy(*args, *kwargs)
# doesn't produce the same unique key as
# TableProxy(*args, ex_key=..., **kwargs)
kwargs = kwargs.copy()
self._ex_key = kwargs.pop("__executor_key__", STANDARD_EXECUTOR)
# Store a reference to the Executor wrapper class
# so that the Executor is retained while this TableProxy
# still lives
self._ex_wrapper = ex = Executor(key=self._ex_key)
self._table_future = table = ex.impl.submit(factory, *args, **kwargs)
weakref.finalize(self, _table_future_finaliser, ex, table, args,
kwargs)
# Reference to the internal ThreadPoolExecutor
self._ex = ex.impl
# Private, should be inaccessible
self._write = False
self._writeable = ex.impl.submit(_iswriteable, table).result()
should_be_writeable = not kwargs.get('readonly', True)
if self._writeable is False and should_be_writeable:
# NOTE(sjperkins)
# This seems to happen if you've opened a WSRT.MS with
# readonly=False, and then you try to open WSRT.MS::SUBTABLE
# with readonly=False.
# Solution is to open WSRT.MS/SUBTABLE to avoid the locking,
# which may introduce it's own set of issues
raise RuntimeError("%s was opened as readonly=False but "
"table.iswritable()==False" % table.name())
def test_executor_keys():
""" Test executor keys """
ex = Executor("foo")
ex2 = Executor("bar")
ex3 = Executor("foo")
ex4 = Executor()
assert len(_executor_cache) == 3
assert ex is not ex2
assert ex is ex3
assert pickle.loads(pickle.dumps(ex)) is ex3
assert pickle.loads(pickle.dumps(ex2)) is not ex3
del ex, ex2, ex3, ex4
assert len(_executor_cache) == 0