Hi,
Cython generators aren’t closed on dealloc and this can lead to cleanup code
not being ran (see example below). I couldn’t find any reference to this issue
on the trac or the wiki and therefore wanted to report it. If this is a know
issue please disregard this post.
I believe this can easily be corrected by adding the following line to the top
of each generator dealloc function:
if (p->resume_label != -1) __Pyx_Generator_Close(o);
This explicitly closes the generator unless it’s already finished. For testing
I manually added this code to the generated C file and it worked as expected.
-Matt
Example:
I found this issue in the following code that relies upon a finally block to
free memory. If not explicitly closed, the cleanup code is never executed and
memory is leaked.
############################################
# generate_primes.pyx
from libc.stdlib cimport malloc, realloc, free
def generate_primes(unsigned int initial_buffer_size=64):
cdef unsigned int test_number, i, N_primes, N_allocated
cdef unsigned int *primes
N_primes = 0
N_allocated = initial_buffer_size
primes = <unsigned int*>malloc(N_allocated * sizeof(unsigned int))
if not primes: raise MemoryError
test_number = 2
try:
while 1:
# is the current value of test_number prime?
# i.e. is it not divisible by any of the already seen primes
i = 0
while i<N_primes and test_number % primes[i] != 0:
i += 1
if i == N_primes:
yield test_number
# grow primes array if needed
if N_primes == N_allocated:
N_allocated = N_allocated + 64
primes = <unsigned int*>realloc(primes, N_allocated *
sizeof(unsigned int))
if not primes: raise MemoryError
primes[N_primes] = test_number
N_primes += 1
test_number += 1
finally:
print 'clean up'
free(primes)
###############################################
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