#18897: Memory leak in eigenvalues method
---------------------------+------------------------
Reporter: slabbe | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.8
Component: memleak | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
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Description changed by slabbe:
Old description:
> This method, inspired from the code of Nils Bruin posted in the sage-
> devel post [https://groups.google.com/d/msg/sage-
> devel/Jqi5f60j_lY/M7esZcJliZoJ Memory leaks on matrix creation?], shows
> some leak in the eigenvalues method for 4x4 and 5x5 integer matrices.
> Examples are below.
>
> {{{
> #!python
> def test(L, dim):
> import gc
> from collections import Counter
> gc.collect()
> pre={id(c) for c in gc.get_objects()}
> for _ in range(100):
> matrix(dim, L).eigenvalues()
> gc.collect()
> post=Counter(type(o) for o in gc.get_objects() if id(o) not in pre)
> return [(k,v) for (k,v) in post.iteritems() if v>10]
> }}}
>
> An example with no leak::
> {{{
> #!python
> sage: L = [1,0,0,1,0,0,1,1,0,0,0,1,2,0,0,1,0,0,2,0,0,0,0,0,1]
> sage: test(L, 5)
> []
> }}}
> Five forgotten polynomials::
> {{{
> #!python
> sage: L = [1,1,0,1,0,1,2,1,1,0,0,1,2,0,0,1,1,0,2,0,0,0,0,0,1]
> sage: test(L, 5)
> [(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
> }}}
> Twelve forgotten polynomials::
>
> {{{
> #!python
> sage: L = [0,1,2,0,0,2,1,2,1,1,1,0,1,1,2,1,1,1,2,0,0,2,0,2,0]
> sage: test(L, 5)
> [(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>,
> 1200)]
> }}}
> A 4 by 4 matrix with five forgotten polynomials::
> {{{
> #!python
> sage: L = [0, 2, 0, 2, 2, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1]
> sage: test(L, 4)
> [(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
> }}}
>
> Random ones::
>
> {{{
> #!python
> sage: test([randint(0,100) for _ in range(9)], 3)
> []
> sage: test([randint(0,100) for _ in range(16)], 4)
> [(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
> sage: test([randint(0,2) for _ in range(25)], 5)
> [(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
> sage: test([randint(0,2) for _ in range(25)], 5)
> [(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>,
> 1200)]
> sage: test([randint(0,2) for _ in range(25)], 5)
> []
> }}}
New description:
This method, inspired from the code of Nils Bruin posted in the sage-devel
post [https://groups.google.com/d/msg/sage-devel/Jqi5f60j_lY/M7esZcJliZoJ
Memory leaks on matrix creation?], shows some leak in the eigenvalues
method for integer matrices of order larger or equal to 4. Examples are
below.
{{{
#!python
def test(L, dim):
import gc
from collections import Counter
gc.collect()
pre={id(c) for c in gc.get_objects()}
for _ in range(100):
matrix(dim, L).eigenvalues()
gc.collect()
post=Counter(type(o) for o in gc.get_objects() if id(o) not in pre)
return [(k,v) for (k,v) in post.iteritems() if v>10]
}}}
An example with no leak::
{{{
#!python
sage: L = [1,0,0,1,0,0,1,1,0,0,0,1,2,0,0,1,0,0,2,0,0,0,0,0,1]
sage: test(L, 5)
[]
}}}
Five forgotten polynomials::
{{{
#!python
sage: L = [1,1,0,1,0,1,2,1,1,0,0,1,2,0,0,1,1,0,2,0,0,0,0,0,1]
sage: test(L, 5)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
}}}
Twelve forgotten polynomials::
{{{
#!python
sage: L = [0,1,2,0,0,2,1,2,1,1,1,0,1,1,2,1,1,1,2,0,0,2,0,2,0]
sage: test(L, 5)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 1200)]
}}}
A 4 by 4 matrix with five forgotten polynomials::
{{{
#!python
sage: L = [0, 2, 0, 2, 2, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1]
sage: test(L, 4)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
}}}
Random ones::
{{{
#!python
sage: test([randint(0,100) for _ in range(9)], 3)
[]
sage: test([randint(0,100) for _ in range(16)], 4)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
sage: test([randint(0,2) for _ in range(25)], 5)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 500)]
sage: test([randint(0,2) for _ in range(25)], 5)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 1200)]
sage: test([randint(0,2) for _ in range(25)], 5)
[]
sage: test([randint(0,100) for _ in range(36)], 6)
[(<type 'sage.rings.polynomial.polynomial_compiled.univar_pd'>, 1400)]
}}}
--
--
Ticket URL: <http://trac.sagemath.org/ticket/18897#comment:1>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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