#11521: Memleak when resolving the action of Integers on an Elliptic Curve
------------------------+---------------------------------------------------
Reporter: jpflori | Owner: robertwb
Type: defect | Status: needs_work
Priority: major | Milestone: sage-4.8
Component: coercion | Keywords: sd35
Work_issues: | Upstream: N/A
Reviewer: | Author: Simon King
Merged: | Dependencies: #11900 #715
------------------------+---------------------------------------------------
Comment(by jpflori):
I guess you're solution should be the right one because resetting the
coercion cache solves the problem, so dealing with it should be enough for
the example in the ticket description.
Only one copy gets cached in _action_hash because the curves are equal
(==) but not identical (is). However, if one uses (really) different
curves, one of each gets also cached in _action_hash
Here is small piece of code to test the effect of clearing different
caches (the code to clear the ZZ cache is left as an exercise, anyway we
should use weakrefs there):
{{{
sage: import gc, inspect
sage: load /usr/share/shared/objgraph.py # or whatever you should type to
use objgraph
sage: from sage.schemes.elliptic_curves.ell_finite_field import
EllipticCurve_finite_field
sage: K = GF(1<<60, 't')
sage: j = K.random_element()
sage: for i in xrange(100):
....: E = EllipticCurve(j=j); P = E.random_point(); 2*P; del P; del E;
....:
sage: gc.collect()
68
sage: L = [x for x in gc.get_objects() if isintance(x,
EllipticCurve_finite_field)]
sage: len(L)
100
sage: del L
sage: get_coercion_model().reset_cache()
sage: gc.collect()
6172
sage: L = [x for x in gc.get_objects() if isintance(x,
EllipticCurve_finite_field)]
sage: len(L)
1
sage: del L
sage: ZZ.del_hash()
sage: gc.collect()
56
sage: L = [x for x in gc.get_objects() if isintance(x,
EllipticCurve_finite_field)]
sage: len(L)
0
sage: del L
sage: for i in xrange(100):
....: E = EllipticCurve(j=K.random_element()); P = E.random_point();
2*P; del P; del E;
....:
sage: gc.collect()
174
sage: L = [x for x in gc.get_objects() if isintance(x,
EllipticCurve_finite_field)]
sage: len(L)
100
sage: del L
sage: get_coercion_model().reset_cache()
sage: gc.collect()
738
sage: L = [x for x in gc.get_objects() if isintance(x,
EllipticCurve_finite_field)]
sage: len(L) # _action_hash
100
sage: del L
sage: ZZ.del_hash()
sage: gc.collect()
5742
sage: L = [x for x in gc.get_objects() if isintance(x,
EllipticCurve_finite_field)]
sage: len(L) # mmm got one left!!! not sure where it comes from yet...
1
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11521#comment:81>
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 post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
