def queue(self):
QueuingContext.append(self, owns=tuple(self.obs))
for o in self.obs:
try:
QueuingContext.update_info(o, owner=self)
except AttributeError:
pass
return self
def __enter__(self):
if not QueuingContext.recording():
# if the tape is the first active queuing context
# monkeypatch the operations to support the new queuing context
with contextlib.ExitStack() as stack:
for mock in mock_operations():
stack.enter_context(mock)
self._stack = stack.pop_all()
QueuingContext.append(self)
return super().__enter__()
def __enter__(self):
QuantumTape._lock.acquire()
try:
if not QueuingContext.recording():
# if the tape is the first active queuing context
# monkeypatch the operations to support the new queuing context
with contextlib.ExitStack() as stack:
for mock in mock_operations():
stack.enter_context(mock)
self._stack = stack.pop_all()
QueuingContext.append(self)
return super().__enter__()
except Exception as _:
QuantumTape._lock.release()
raise
def __exit__(self, exception_type, exception_value, traceback):
super().__exit__(exception_type, exception_value, traceback)
if not QueuingContext.recording():
# remove the monkeypatching
self._stack.__exit__(exception_type, exception_value, traceback)
self._process_queue()
def test_get_info_none(self):
"""Test that get_info returns None if there is no active queuing context"""
A = qml.RZ(0.5, wires=1)
with AnnotatedQueue() as q:
q.append(A, inv=True)
assert QueuingContext.get_info(A) is None
def mock_queuing_context(monkeypatch):
"""A mock instance of the abstract QueuingContext class."""
with monkeypatch.context() as m:
m.setattr(QueuingContext, "__abstractmethods__", frozenset())
m.setattr(
QueuingContext,
"_append",
lambda self, operator: self.queue.append(operator),
)
m.setattr(
QueuingContext,
"_remove",
lambda self, operator: self.queue.remove(operator),
)
context = QueuingContext()
context.queue = []
yield context
def __exit__(self, exception_type, exception_value, traceback):
try:
super().__exit__(exception_type, exception_value, traceback)
if not QueuingContext.recording():
# remove the monkeypatching
self._stack.__exit__(exception_type, exception_value, traceback)
self._process_queue()
finally:
QuantumTape._lock.release()
def test_update_info(self):
"""Test that update_info correctly updates an annotation"""
A = qml.RZ(0.5, wires=1)
with AnnotatedQueue() as q:
q.append(A, inv=True)
assert QueuingContext.get_info(A) == {"inv": True}
assert q._get_info(A) == {"inv": True}
q._update_info(A, inv=False, owner=None)
assert q._get_info(A) == {"inv": False, "owner": None}
def three_mock_queuing_contexts(monkeypatch):
"""A list of three mock instances of the abstract QueuingContext class."""
with monkeypatch.context() as m:
m.setattr(QueuingContext, "__abstractmethods__", frozenset())
m.setattr(
QueuingContext,
"_append",
lambda self, operator: self.queue.append(operator),
)
m.setattr(
QueuingContext,
"_remove",
lambda self, operator: self.queue.remove(operator),
)
contexts = [QueuingContext() for _ in range(3)]
for context in contexts:
context.queue = []
yield contexts
def test_remove_no_context(self):
"""Test that remove does not fail when no context is present."""
QueuingContext.remove(qml.PauliZ(0))
def test_append_no_context(self):
"""Test that append does not fail when no context is present."""
QueuingContext.append(qml.PauliZ(0))