GAPError: Error, reached the pre-set memory limit (change it with the -o command line option)

[guenterrote]

"GAPError: Error, reached the pre-set memory limit
(change it with the -o command line option)"

A) intercept this error message and provide meaningful info for
unsuspecting users. (at least for notebook interface,
i don't know about commandline) Something like this:

"1) you can simply repeat the calculation, and it will
use a larger memory limit."
(I found this by googling, and it works)
"2) Beware however that an excessive memory consumption might slow down other processes
on the computer."

B) How is the user supposed to "change it" with a command-line option?

Maybe a way to set this can be provided

(The current status is a nuisance: I had a lengthy calculation with
subgroups in a loop. First it stopped with the "o flag" message after
30 seconds. On restart, after 1 minute or so. Eventually
I had to restart it a few times. It about took 15 minutes.
Half of it was wasted because I had the restart from scratch.
(and I had to watch whether it was proceeding.)

Depends on #34041

CC: @dimpase

Component: group theory

Keywords: options for GAP

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/31205

[guenterrote]

comment:1

Proposal:
Intercept this error message, and extend it by a more informative error message:

---

"There are two options.

a) If you are in an interactive session, you can run the command again. GAP with retry with twice
as much memory as before.

b) You can start a new sage session, or a new batch run, and set the memory limit in advance
with the set_gap_memory_pool_size(size_in_bytes) function of the sage.interfaces.gap module, before running any commands that involve GAP.
(The standard memory pool size can be found with the function get_gap_memory_pool_size().)

Beware however that an excessive memory consumption might slow down other processes
or even stall the computer completely.

---

I don't know if there is any situation where the "-o command line option" message
makes sense. If not, it should be replaced, and not extended.

---

How is the standard limit determined?
(The current test case says "# random output".)

sage: from sage.interfaces.gap import get_gap_memory_pool_size
sage: get_gap_memory_pool_size()
262144000

I get different results on different computers, and it decreases on successive calls.

[guenterrote]

Author: Günter Rote

[DaveWitteMorris]

comment:2

Related ticket: #14779. (duplicate?)

[mkoeppe]

comment:3

Moving to 9.4, as 9.3 has been released.

[mkoeppe]

Dependencies: #34041

[mkoeppe]

comment:7

Taken care of by #34041, I think

[dimpase]

Reviewer: Dima Pasechnik

[mkoeppe]

Changed author from Günter Rote to none