#14059: Fix refcount/deallocation of integers
-------------------------+--------------------------------------------------
Reporter: SimonKing | Owner: rlm
Type: defect | Status: new
Priority: blocker | Milestone: sage-5.7
Component: memleak | Keywords:
Work issues: | Report Upstream: N/A
Reviewers: | Authors:
Merged in: | Dependencies:
Stopgaps: |
-------------------------+--------------------------------------------------
In #2435, the deallocation function in sage/rings/integer.pyx became as
follows:
{{{
#!python
cdef void fast_tp_dealloc(PyObject* o):
# If there is room in the pool for a used integer object,
# then put it in rather than deallocating it.
global integer_pool, integer_pool_count
if integer_pool_count < integer_pool_size:
# Here we free any extra memory used by the mpz_t by
# setting it to a single limb.
if (<__mpz_struct *>( <char *>o + mpz_t_offset))._mp_alloc > 10:
_mpz_realloc(<mpz_t *>( <char *>o + mpz_t_offset), 10)
# It's cheap to zero out an integer, so do it here.
(<__mpz_struct *>( <char *>o + mpz_t_offset))._mp_size = 0
# And add it to the pool.
integer_pool[integer_pool_count] = o
integer_pool_count += 1
return
# Again, we move to the mpz_t and clear it. See above, why this is
evil.
# The clean version of this line would be:
# mpz_clear(<mpz_t>(<char *>o + mpz_t_offset))
mpz_free((<__mpz_struct *>( <char *>o + mpz_t_offset) )._mp_d, 0)
# Free the object. This assumes that Py_TPFLAGS_HAVE_GC is not
# set. If it was set another free function would need to be
# called.
PyObject_FREE(o)
}}}
The purpose of #2435 was to fix a memory leak introduced in #1337.
Problem: One has to manually incref `ONE`, which I find a bit suspicious.
When I build sage-5.7.beta2 in debug version (as by #13864), Sage crashes
at exit, while attempting `PyObject_FREE(o)`. I will attach backtraces in
comments.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14059>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.
