Staging
v0.6.0
v0.6.0
test_callbacks.py
import unittest
from ctypes import *
import _ctypes_test
class Callbacks(unittest.TestCase):
functype = CFUNCTYPE
## def tearDown(self):
## import gc
## gc.collect()
def callback(self, *args):
self.got_args = args
return args[-1]
def check_type(self, typ, arg):
PROTO = self.functype.__func__(typ, typ)
result = PROTO(self.callback)(arg)
if typ == c_float:
self.assertAlmostEqual(result, arg, places=5)
else:
self.assertEqual(self.got_args, (arg,))
self.assertEqual(result, arg)
PROTO = self.functype.__func__(typ, c_byte, typ)
result = PROTO(self.callback)(-3, arg)
if typ == c_float:
self.assertAlmostEqual(result, arg, places=5)
else:
self.assertEqual(self.got_args, (-3, arg))
self.assertEqual(result, arg)
################
def test_byte(self):
self.check_type(c_byte, 42)
self.check_type(c_byte, -42)
def test_ubyte(self):
self.check_type(c_ubyte, 42)
def test_short(self):
self.check_type(c_short, 42)
self.check_type(c_short, -42)
def test_ushort(self):
self.check_type(c_ushort, 42)
def test_int(self):
self.check_type(c_int, 42)
self.check_type(c_int, -42)
def test_uint(self):
self.check_type(c_uint, 42)
def test_long(self):
self.check_type(c_long, 42)
self.check_type(c_long, -42)
def test_ulong(self):
self.check_type(c_ulong, 42)
def test_longlong(self):
self.check_type(c_longlong, 42)
self.check_type(c_longlong, -42)
def test_ulonglong(self):
self.check_type(c_ulonglong, 42)
def test_float(self):
# only almost equal: double -> float -> double
import math
self.check_type(c_float, math.e)
self.check_type(c_float, -math.e)
def test_double(self):
self.check_type(c_double, 3.14)
self.check_type(c_double, -3.14)
def test_longdouble(self):
self.check_type(c_longdouble, 3.14)
self.check_type(c_longdouble, -3.14)
def test_char(self):
self.check_type(c_char, b"x")
self.check_type(c_char, b"a")
# disabled: would now (correctly) raise a RuntimeWarning about
# a memory leak. A callback function cannot return a non-integral
# C type without causing a memory leak.
## def test_char_p(self):
## self.check_type(c_char_p, "abc")
## self.check_type(c_char_p, "def")
def test_pyobject(self):
o = ()
from sys import getrefcount as grc
for o in (), [], object():
initial = grc(o)
# This call leaks a reference to 'o'...
self.check_type(py_object, o)
before = grc(o)
# ...but this call doesn't leak any more. Where is the refcount?
self.check_type(py_object, o)
after = grc(o)
self.assertEqual((after, o), (before, o))
def test_unsupported_restype_1(self):
# Only "fundamental" result types are supported for callback
# functions, the type must have a non-NULL stgdict->setfunc.
# POINTER(c_double), for example, is not supported.
prototype = self.functype.__func__(POINTER(c_double))
# The type is checked when the prototype is called
self.assertRaises(TypeError, prototype, lambda: None)
def test_unsupported_restype_2(self):
prototype = self.functype.__func__(object)
self.assertRaises(TypeError, prototype, lambda: None)
try:
WINFUNCTYPE
except NameError:
pass
else:
class StdcallCallbacks(Callbacks):
functype = WINFUNCTYPE
################################################################
class SampleCallbacksTestCase(unittest.TestCase):
def test_integrate(self):
# Derived from some then non-working code, posted by David Foster
dll = CDLL(_ctypes_test.__file__)
# The function prototype called by 'integrate': double func(double);
CALLBACK = CFUNCTYPE(c_double, c_double)
# The integrate function itself, exposed from the _ctypes_test dll
integrate = dll.integrate
integrate.argtypes = (c_double, c_double, CALLBACK, c_long)
integrate.restype = c_double
def func(x):
return x**2
result = integrate(0.0, 1.0, CALLBACK(func), 10)
diff = abs(result - 1./3.)
self.assertTrue(diff < 0.01, "%s not less than 0.01" % diff)
################################################################
if __name__ == '__main__':
unittest.main()