Opened 11 years ago

Closed 2 years ago

#8904 closed defect (invalid)

libsingular: memory leak in Matrix.act_on_polynomial

Reported by: SimonKing Owned by: tbd
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: memleak Keywords: libsingular act_on_polynomial memleak
Cc: malb Merged in:
Authors: Reviewers: Frédéric Chapoton, Simon King
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description

There is a memory leak that occurs when mapping a multivariate polynomial using a matrix:

sage: R.<a,b>  =  QQ[]
sage: M = Matrix([[0,1],[1,0]])
sage: n = 0
sage: p = R.random_element()
sage: q = M.act_on_polynomial(p)
sage: mem = get_memory_usage()
sage: while(1):
....:     n+=1
....:     q = M.act_on_polynomial(p)
....:     if get_memory_usage()>mem:
....:         mem = get_memory_usage()
....:         print mem,n
....:
801.04296875 2
801.54296875 2011
802.04296875 4738
802.54296875 7406
803.04296875 10091
803.54296875 12809
804.04296875 15495
804.54296875 18171
805.04296875 20873
805.54296875 23561
806.04296875 26251
...

This does not occur if one maps the polynomial by a proper morphism:

sage: f = R.hom([M.act_on_polynomial(t) for t in R.gens()],R)
sage: while(1):
....:     n+=1
....:     q = f(p)
....:     if get_memory_usage()>mem:
....:         mem = get_memory_usage()
....:         print mem,n
....:

Change History (7)

comment:1 Changed 8 years ago by jdemeyer

  • Milestone changed from sage-5.11 to sage-5.12

comment:2 Changed 7 years ago by vbraun_spam

  • Milestone changed from sage-6.1 to sage-6.2

comment:3 Changed 7 years ago by vbraun_spam

  • Milestone changed from sage-6.2 to sage-6.3

comment:4 Changed 7 years ago by vbraun_spam

  • Milestone changed from sage-6.3 to sage-6.4

comment:5 follow-up: Changed 3 years ago by chapoton

  • Milestone changed from sage-6.4 to sage-duplicate/invalid/wontfix
  • Status changed from new to needs_review

no longer an issue in 8.3.beta2

comment:6 in reply to: ↑ 5 Changed 3 years ago by SimonKing

  • Reviewers set to Frédéric Chapoton, Simon King
  • Status changed from needs_review to positive_review

Replying to chapoton:

no longer an issue in 8.3.beta2

I can confirm. So, positive review with both of us as reviewers, I guess.

comment:7 Changed 2 years ago by embray

  • Resolution set to invalid
  • Status changed from positive_review to closed

Presuming these are all correctly reviewed as either duplicate, invalid, or wontfix.

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