I'm attempting to get a Cython module to raise exceptions that'll be
visible to the calling CPython.
The Cython code in question looks like:
def add_from_fileno(self, fileno, length_to_add):
exception_string = self.add_from_fileno_c(fileno, length_to_add)
if exception_string.startswith("Buffer error"):
raise exceptions.BufferError, exception_string
elif exception_string == '':
pass
else:
raise exceptions.AssertionError, exception_string
cdef add_from_fileno_c(self, fileno, length_to_add):
if self.would_overflow(length_to_add):
return "Buffer error: Would overflow"
# FIXME: We need to do something about EINTR on these 3 read's!
if self.would_add_wrap(length_to_add):
# do the read in two pieces
first_length, second_length =
self.split_to_two_add(length_to_add)
length_added = read(fileno, &self.buffer[self.end],
first_length)
if length_added != first_length:
return "length_added != first_length"
length_added = read(fileno, self.buffer, second_length)
if length_added != second_length:
return "length_added != second_length"
self.end = second_length
else:
# do the read in one piece
length_added = read(fileno, &self.buffer[self.end],
length_to_add)
if length_added != length_to_add:
return "length_added != length_to_add"
self.end += length_to_add
return ''
...and in the caller (CPython code, inheriting from unittest):
def test_fileno_from_file_overflow(self):
file_ = open('input-file', 'w')
file_.write('abc' * 15)
file_.close()
rb = ring_buffer_mod.Ring_buffer(buffer_size = 10)
input_fileno = os.open('input-file', os.O_RDONLY)
for i in xrange(10):
rb.add_from_fileno(input_fileno, 1)
#self.assertRaises(exceptions.BufferError,
rb.add_from_fileno, input_fileno, 1)
try:
rb.add_from_fileno(input_fileno, 1)
except exceptions.BufferError:
pass
All seems fine, except for the exceptions. When I raise an exception in
Cython, I see a message on my terminal (I believe there should be none),
and the calling CPython code doesn't appear to realize that an exception
has been raised. I added the add_from_fileno_c/add_from_file
distinction, because I was hoping that a def would be able to raise an
exception, after finding that cdef's and cpdef's seemed to have problems
with it - but it appears that there's some sort of exception barrier
between Cython and CPython.
I've googled quite a bit, but haven't found much on the topic that
didn't seem kind of hand wavey.
What do I need to do, to raise an exception in Cython, that CPython code
will be able to see?
Thanks!
_______________________________________________
Cython-dev mailing list
[email protected]
http://codespeak.net/mailman/listinfo/cython-dev
