def test_set_and_retrieve_func(self):
def fn(*args):
pass
sys.settrace(fn)
try:
assert sys.gettrace() is fn
finally:
sys.settrace(None)
python类gettrace()的实例源码
def test_set_and_retrieve_none(self):
sys.settrace(None)
assert sys.gettrace() is None
def test_set_and_retrieve_func(self):
def fn(*args):
pass
sys.settrace(fn)
try:
assert sys.gettrace() is fn
finally:
sys.settrace(None)
def test_frame_tstate_tracing(self):
# Issue #14432: Crash when a generator is created in a C thread that is
# destroyed while the generator is still used. The issue was that a
# generator contains a frame, and the frame kept a reference to the
# Python state of the destroyed C thread. The crash occurs when a trace
# function is setup.
def noop_trace(frame, event, arg):
# no operation
return noop_trace
def generator():
while 1:
yield "generator"
def callback():
if callback.gen is None:
callback.gen = generator()
return next(callback.gen)
callback.gen = None
old_trace = sys.gettrace()
sys.settrace(noop_trace)
try:
# Install a trace function
threading.settrace(noop_trace)
# Create a generator in a C thread which exits after the call
_testcapi.call_in_temporary_c_thread(callback)
# Call the generator in a different Python thread, check that the
# generator didn't keep a reference to the destroyed thread state
for test in range(3):
# The trace function is still called here
callback()
finally:
sys.settrace(old_trace)
def test_set_and_retrieve_none(self):
sys.settrace(None)
assert sys.gettrace() is None
def test_set_and_retrieve_func(self):
def fn(*args):
pass
sys.settrace(fn)
try:
assert sys.gettrace() is fn
finally:
sys.settrace(None)
def test_frame_tstate_tracing(self):
# Issue #14432: Crash when a generator is created in a C thread that is
# destroyed while the generator is still used. The issue was that a
# generator contains a frame, and the frame kept a reference to the
# Python state of the destroyed C thread. The crash occurs when a trace
# function is setup.
def noop_trace(frame, event, arg):
# no operation
return noop_trace
def generator():
while 1:
yield "generator"
def callback():
if callback.gen is None:
callback.gen = generator()
return next(callback.gen)
callback.gen = None
old_trace = sys.gettrace()
sys.settrace(noop_trace)
try:
# Install a trace function
threading.settrace(noop_trace)
# Create a generator in a C thread which exits after the call
_testcapi.call_in_temporary_c_thread(callback)
# Call the generator in a different Python thread, check that the
# generator didn't keep a reference to the destroyed thread state
for test in range(3):
# The trace function is still called here
callback()
finally:
sys.settrace(old_trace)
def no_tracing(func):
"""Decorator to temporarily turn off tracing for the duration of a test."""
if not hasattr(sys, 'gettrace'):
return func
else:
@functools.wraps(func)
def wrapper(*args, **kwargs):
original_trace = sys.gettrace()
try:
sys.settrace(None)
return func(*args, **kwargs)
finally:
sys.settrace(original_trace)
return wrapper
def __init__(self, run=True, *, _frame=1):
"""
set _frame to 2 if you are inherting from ConditionalBlock and
__enter__() is nested. Set _frame to N+1 for N levels of nesting.
See `DebugBlock.__enter__`
"""
self.run = run
self.old_sys_trace = sys.gettrace()
self._frame = _frame
def no_tracing(func):
"""Decorator to temporarily turn off tracing for the duration of a test."""
if not hasattr(sys, 'gettrace'):
return func
else:
@functools.wraps(func)
def wrapper(*args, **kwargs):
original_trace = sys.gettrace()
try:
sys.settrace(None)
return func(*args, **kwargs)
finally:
sys.settrace(original_trace)
return wrapper
def __enter__(self):
self.real_stdin = sys.stdin
sys.stdin = _FakeInput(self.input)
self.orig_trace = sys.gettrace() if hasattr(sys, 'gettrace') else None
def testLocalsClass_WithTrace(self):
# Issue23728: after the trace function returns, the locals()
# dictionary is used to update all variables, this used to
# include free variables. But in class statements, free
# variables are not inserted...
import sys
self.addCleanup(sys.settrace, sys.gettrace())
sys.settrace(lambda a,b,c:None)
x = 12
class C:
def f(self):
return x
self.assertEqual(x, 12) # Used to raise UnboundLocalError
def get_sys_gettrace(self):
return sys.gettrace()
def no_tracing(func):
"""Decorator to temporarily turn off tracing for the duration of a test."""
if not hasattr(sys, 'gettrace'):
return func
else:
@functools.wraps(func)
def wrapper(*args, **kwargs):
original_trace = sys.gettrace()
try:
sys.settrace(None)
return func(*args, **kwargs)
finally:
sys.settrace(original_trace)
return wrapper
def test_set_and_retrieve_none(self):
sys.settrace(None)
assert sys.gettrace() is None
def test_set_and_retrieve_func(self):
def fn(*args):
pass
sys.settrace(fn)
try:
assert sys.gettrace() is fn
finally:
sys.settrace(None)
def setUp(self):
self.addCleanup(sys.settrace, sys.gettrace())
def test_exception_arguments(self):
def f():
x = 0
# this should raise an error
x.no_such_attr
def g(frame, event, arg):
if (event == 'exception'):
type, exception, trace = arg
self.assertIsInstance(exception, Exception)
return g
existing = sys.gettrace()
try:
sys.settrace(g)
try:
f()
except AttributeError:
# this is expected
pass
finally:
sys.settrace(existing)
# 'Jump' tests: assigning to frame.f_lineno within a trace function
# moves the execution position - it's how debuggers implement a Jump
# command (aka. "Set next statement").
def setUp(self):
self.addCleanup(sys.settrace, sys.gettrace())
sys.settrace(None)
def setUp(self):
self.my_py_filename = fix_ext_py(__file__)
self.addCleanup(sys.settrace, sys.gettrace())
