def target(result_queue, precision_changed, continue_event):
# Change the context in a background thread. Put computed
# precisions on a results queue for testing in the main thread.
# We use events to pause execution of the background thread
# so that we can effectively test that the main thread is
# unaffected at that point.
try:
result_queue.put(("PREC", getcontext().precision))
with precision(20):
result_queue.put(("PREC", getcontext().precision))
precision_changed.set()
if not continue_event.wait(timeout=SAFETY_TIMEOUT):
raise RuntimeError("continue_event not received")
result_queue.put(("PREC", getcontext().precision))
except BaseException as e:
result_queue.put(("EXC", str(e)))
result_queue.put(("DONE", ))
def test_with(self):
# check use of contexts in with statements
c = Context(emin=-123, emax=456, precision=1729,
subnormalize=True, rounding=mpfr.MPFR_RNDU)
d = Context(emin=0, emax=10585, precision=20,
subnormalize=False, rounding=mpfr.MPFR_RNDD)
with c:
# check nested with
with d:
self.assertEqual(getcontext().precision, d.precision)
self.assertEqual(getcontext().emin, d.emin)
self.assertEqual(getcontext().emax, d.emax)
self.assertEqual(getcontext().subnormalize, d.subnormalize)
self.assertEqual(getcontext().rounding, d.rounding)
# check context is restored on normal exit
self.assertEqual(getcontext().precision, c.precision)
self.assertEqual(getcontext().emin, c.emin)
self.assertEqual(getcontext().emax, c.emax)
self.assertEqual(getcontext().subnormalize, c.subnormalize)
self.assertEqual(getcontext().rounding, c.rounding)
# check context is restored on abnormal exit, and that exceptions
# raised within the with block are propagated
try:
with d:
raise ValueError
except ValueError:
pass
else:
self.fail('ValueError not propagated from with block')
self.assertEqual(getcontext().precision, c.precision)
self.assertEqual(getcontext().emin, c.emin)
self.assertEqual(getcontext().emax, c.emax)
self.assertEqual(getcontext().subnormalize, c.subnormalize)
self.assertEqual(getcontext().rounding, c.rounding)
def test_with(self):
# check use of contexts in with statements
c = Context(emin=-123,
emax=456,
precision=1729,
subnormalize=True,
rounding=mpfr.MPFR_RNDU)
d = Context(emin=0,
emax=10585,
precision=20,
subnormalize=False,
rounding=mpfr.MPFR_RNDD)
with c:
# check nested with
with d:
self.assertEqual(getcontext().precision, d.precision)
self.assertEqual(getcontext().emin, d.emin)
self.assertEqual(getcontext().emax, d.emax)
self.assertEqual(getcontext().subnormalize, d.subnormalize)
self.assertEqual(getcontext().rounding, d.rounding)
# check context is restored on normal exit
self.assertEqual(getcontext().precision, c.precision)
self.assertEqual(getcontext().emin, c.emin)
self.assertEqual(getcontext().emax, c.emax)
self.assertEqual(getcontext().subnormalize, c.subnormalize)
self.assertEqual(getcontext().rounding, c.rounding)
# check context is restored on abnormal exit, and that exceptions
# raised within the with block are propagated
try:
with d:
raise ValueError
except ValueError:
pass
else:
self.fail('ValueError not propagated from with block')
self.assertEqual(getcontext().precision, c.precision)
self.assertEqual(getcontext().emin, c.emin)
self.assertEqual(getcontext().emax, c.emax)
self.assertEqual(getcontext().subnormalize, c.subnormalize)
self.assertEqual(getcontext().rounding, c.rounding)
def test_rounding_contexts(self):
with RoundTiesToEven:
self.assertEqual(getcontext().rounding, ROUND_TIES_TO_EVEN)
with RoundTowardPositive:
self.assertEqual(getcontext().rounding, ROUND_TOWARD_POSITIVE)
with RoundTowardNegative:
self.assertEqual(getcontext().rounding, ROUND_TOWARD_NEGATIVE)
with RoundTiesToEven:
self.assertEqual(getcontext().rounding, ROUND_TIES_TO_EVEN)
with RoundAwayFromZero:
self.assertEqual(getcontext().rounding, ROUND_AWAY_FROM_ZERO)
# Rounding contexts should not affect existing settings for
# precision, exponents, etc.
original_contexts = [
Context(
precision=234,
emin=-9999,
emax=9999,
subnormalize=True,
rounding=ROUND_TOWARD_NEGATIVE,
),
Context(
precision=5,
emin=-10,
emax=10,
subnormalize=False,
rounding=ROUND_AWAY_FROM_ZERO,
),
]
rounding_contexts = [
RoundTiesToEven,
RoundTowardPositive,
RoundTowardNegative,
RoundTowardZero,
RoundAwayFromZero,
]
for original_context in original_contexts:
for rounding_context in rounding_contexts:
with original_context:
with rounding_context:
self.assertEqual(
getcontext().precision,
original_context.precision,
)
self.assertEqual(
getcontext().emin,
original_context.emin,
)
self.assertEqual(
getcontext().emax,
original_context.emax,
)
self.assertEqual(
getcontext().subnormalize,
original_context.subnormalize,
)
self.assertEqual(
getcontext().rounding,
rounding_context.rounding,
)
def test_context_initialised_in_background_thread(self):
# Regression test for mdickinson/bigfloat#78.
# Timeout for blocking waits, so that a badly written test or
# an unexpected failure mode doesn't cause the whole test suite
# to block.
SAFETY_TIMEOUT = 10.0
def target(result_queue, precision_changed, continue_event):
# Change the context in a background thread. Put computed
# precisions on a results queue for testing in the main thread.
# We use events to pause execution of the background thread
# so that we can effectively test that the main thread is
# unaffected at that point.
try:
result_queue.put(("PREC", getcontext().precision))
with precision(20):
result_queue.put(("PREC", getcontext().precision))
precision_changed.set()
if not continue_event.wait(timeout=SAFETY_TIMEOUT):
raise RuntimeError("continue_event not received")
result_queue.put(("PREC", getcontext().precision))
except BaseException as e:
result_queue.put(("EXC", str(e)))
result_queue.put(("DONE", ))
result_queue = queue.Queue()
precision_changed = threading.Event()
continue_event = threading.Event()
default_precision = DefaultContext.precision
self.assertEqual(getcontext().precision, default_precision)
thread = threading.Thread(
target=target,
args=(result_queue, precision_changed, continue_event),
)
thread.start()
try:
precision_changed.wait(timeout=SAFETY_TIMEOUT)
# At this point, the precision in the background thread has
# been changed, but our precision should be unaltered.
self.assertEqual(getcontext().precision, default_precision)
continue_event.set()
finally:
thread.join()
# Collect messages from the background thread.
messages = []
while True:
message = result_queue.get(timeout=SAFETY_TIMEOUT)
if message[0] == "DONE":
break
messages.append(message)
self.assertEqual(
messages,
[
("PREC", DefaultContext.precision),
("PREC", 20),
("PREC", DefaultContext.precision),
],
)
def test_rounding_contexts(self):
with RoundTiesToEven:
self.assertEqual(getcontext().rounding, ROUND_TIES_TO_EVEN)
with RoundTowardPositive:
self.assertEqual(getcontext().rounding, ROUND_TOWARD_POSITIVE)
with RoundTowardNegative:
self.assertEqual(getcontext().rounding, ROUND_TOWARD_NEGATIVE)
with RoundTiesToEven:
self.assertEqual(getcontext().rounding, ROUND_TIES_TO_EVEN)
with RoundAwayFromZero:
self.assertEqual(getcontext().rounding, ROUND_AWAY_FROM_ZERO)
# Rounding contexts should not affect existing settings for
# precision, exponents, etc.
original_contexts = [
Context(
precision=234,
emin=-9999,
emax=9999,
subnormalize=True,
rounding=ROUND_TOWARD_NEGATIVE,
),
Context(
precision=5,
emin=-10,
emax=10,
subnormalize=False,
rounding=ROUND_AWAY_FROM_ZERO,
),
]
rounding_contexts = [
RoundTiesToEven,
RoundTowardPositive,
RoundTowardNegative,
RoundTowardZero,
RoundAwayFromZero,
]
for original_context in original_contexts:
for rounding_context in rounding_contexts:
with original_context:
with rounding_context:
self.assertEqual(
getcontext().precision,
original_context.precision,
)
self.assertEqual(
getcontext().emin,
original_context.emin,
)
self.assertEqual(
getcontext().emax,
original_context.emax,
)
self.assertEqual(
getcontext().subnormalize,
original_context.subnormalize,
)
self.assertEqual(
getcontext().rounding,
rounding_context.rounding,
)
