Opened 9 years ago

Closed 8 years ago

#9564 closed defect (duplicate)

libsingular exponentiation can not be interrupted

Reported by: SimonKing Owned by: tba
Priority: critical Milestone: sage-duplicate/invalid/wontfix
Component: c_lib Keywords: KeyboardInterrupt interrupt singular exception cython
Cc: Merged in:
Authors: Reviewers: Nathann Cohen
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description

When trying to get some timings for #7795, I did 

sage: R.<x,y,z> = QQ[]
sage: p = R.random_element()
sage: p
-x^2 + 1/3*x*y + 7/2*y + 2*z
sage: timeit('q=p^(2^10)')

which might be stupid.

Anyway, it was impossible to interrupt the computation with ctrl-C, which I think is a bug.

Change History (7)

comment:1 Changed 9 years ago by jdemeyer

After applying #10018, the interrupt gives a segmentation fault instead of not doing anything at all.

comment:2 Changed 9 years ago by jdemeyer

  • Component changed from commutative algebra to c_lib
  • Owner changed from malb to tba
  • Priority changed from major to critical

comment:3 Changed 9 years ago by jdemeyer

  • Keywords interrupt singular exception cython added; libsingular exponentiation removed

The problem is the following:

When an interrupt is caught, the program acts as if _sig_on returns the value 0. So, when using _sig_on, functions should be declared except 0 and not except -1, which is what the Singular functions do.

The attached patch is purely proof-of-concept showing some improvement (but it doesn't fully fix the problem).

comment:4 Changed 9 years ago by jdemeyer

Note also that what I just said is completely undocumented :-)

comment:5 Changed 9 years ago by jdemeyer

  • Milestone changed from sage-4.6.2 to sage-duplicate/invalid/wontfix
  • Status changed from new to needs_review

Fixed by #9678.

comment:6 Changed 8 years ago by ncohen

Isn't "closed" more fitting that "need_review" in that case ? :-)

Nathann

comment:7 Changed 8 years ago by jdemeyer

  • Resolution set to duplicate
  • Reviewers set to Nathann Cohen
  • Status changed from needs_review to closed
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