Hi Bill,

Thanks for trying! I tried the new APK but the following script still
crashes for me:

NB. bug: the following crashes J with bus error
max=: 100
padrifshort=: ]`(max (,,[) ])@.(>&#)
ts =: 0 1 0 0 0 1 0 0 0, (7 9$9$0 1), (0 0 0 1 0 0 0 1 0)
NB. crash
NB. try=: [: ( [+2 <./\ padrifshort)&.>/\@|. [: </. 0 (<0 0)} ]
NB. try=: [: ( [+2 <./\ padrifshort)&.>/\@|. [: </. ]
NB. try=: [: (2 <./\ padrifshort)&.>/\@|. [: </. ]
NB. try=: [: (2 <./\ padrifshort)&.>/\ [: </. ]
NB. try=: [: (2 <./\ ])&.>/\ [: </. ]
NB. try=: [: (2 >./\ ])&.>/\ [: </. ]
NB. try=: [: (2 <./\ ])&.>/\ </.
try=: [: (2 <./\ ])&.>/\ </.
NB. fine
NB. try=: [: (>&#)&.>/\ [: </. ]
NB. try=: [: (padrifshort)&.>/\ [: </. ]
NB. try=: [: (2 <./\ ])&.>/ [: </. ]
NB. try=: [: (2 #\ ])&.>/\ [: </. ]
try ts

~/.../J/aoc2021 $ jcon
   JVERSION
Engine: j903/j32/android
Release-a: commercial/2022-01-07T10:45:28
Library: 9.03.08
Platform: Android 32 (armeabi-v7a)
Installer: unknown
InstallPath: /mnt/sdcard/Android/data/com.jsoftware.j.android/files
Contact: www.jsoftware.com
   load 'bug.ijs'
Bus error

Thanks,
Jan-Pieter

On Fri, Jan 7, 2022, 03:55 bill lam <[email protected]> wrote:

> There was a minor update and I tested it on 32-bit raspberry and the try ts
> didn't crash.
>
> I uploaded an updated jandroid.apk. please download and try again.
> tool>check for new version should also work this  time.
>
> On Fri, Jan 7, 2022 at 10:01 AM Jan-Pieter Jacobs <
> [email protected]> wrote:
>
> > Hi Bill,
> >
> > Are
> >
> > max =: 100
> > tss =: 0 1 0 0 0 , (3 5$5$0 1), (0 0 0 1 0 )
> >
> > small enough?
> > In this case "try ts" still crashes. In case it's useful, I reducing the
> > "try" verb as well, with the following results:
> >
> > max=: 100
> > padrifshort=: ]`(max (,,[) ])@.(>&#)
> > ts =: 0 1 0 0 0 1 0 0 0, (7 9$9$0 1), (0 0 0 1 0 0 0 1 0)
> >
> > NB. all of the below crash with bus error
> > NB. try=: [: ( [+2 <./\ padrifshort)&.>/\@|. [: </. 0 (<0 0)} ]
> > NB. try=: [: ( [+2 <./\ padrifshort)&.>/\@|. [: </. ]
> > NB. try=: [: (2 <./\ padrifshort)&.>/\@|. [: </. ]
> > NB. try=: [: (2 <./\ padrifshort)&.>/\ [: </. ]
> > NB. try=: [: (2 <./\ ])&.>/\ [: </. ]
> > NB. try=: [: (2 >./\ ])&.>/\ [: </. ]
> > NB. try=: [: (2 <./\ ])&.>/\ </.
> > try=: [: (2 <./\ ])&.>/\ </.
> >
> > NB. the following do not crash
> > NB. try=: [: (>&#)&.>/\ [: </. ]
> > NB. try=: [: (padrifshort)&.>/\ [: </. ]
> > NB. try=: [: (2 <./\ ])&.>/ [: </. ]
> > NB. try=: [: (2 #\ ])&.>/\ [: </. ]
> > try ts
> >
> > I hope this helps.
> >
> > Jan-Pieter
> >
> > On Thu, Jan 6, 2022, 23:18 bill lam <[email protected]> wrote:
> >
> > > It's likely a 32-bit arm unaligned memory access issue. Can you check
> if
> > it
> > > will also crash for a small max and ts ?
> > >
> > > On Fri, 7 Jan 2022 at 3:39 AM Jan-Pieter Jacobs <
> > > [email protected]>
> > > wrote:
> > >
> > > > I was trying to debug my implementation of Dijkstra's algorithm and
> ran
> > > > into this J crash:
> > > >
> > > > (AoC Day 15 spoiler ahead -- well sort off, the solution is not
> > entirely
> > > > correct, hence the debugging :p)
> > > >
> > > > ts is a snaking path of 0's from 0 0 to 9 9, and try1 (should)
> > implement
> > > > Dijkstra's algorithm for finding a path with a minimal sum of the
> nodes
> > > > crossed. Something in my implementation is wrong (hints welcome), but
> > > the J
> > > > bug turned up when I wanted to debug this approach by adding a \ to
> > keep
> > > > intermediate results, which causes a bus error:
> > > >
> > > >    try=: [: ([ + 2 <./\ padrifshort)&.>/\@|. [: </. 0 (<0 0)} ]
> > > >    ts =: 0 1 0 0 0 1 0 0 0, (7 9$9$0 1), (0 0 0 1 0 0 0 1 0)
> > > >    try1=: [: ([ + 2 <./\ padrifshort)&.>/@|. [: </. 0 (<0 0)} ]
> > > >    max=: 2e9
> > > >    padrifshort=: ]`(max (,,[) ])@.(>&#)
> > > >    try1 ts NB. "works" no crash, but result is wrong.
> > > > ┌─┐
> > > > │2│
> > > > └─┘
> > > >    try ts
> > > > Bus error
> > > > NB. J crashed.
> > > >
> > > > For an explanation of the code, see (
> > > >
> > http://www.jsoftware.com/pipermail/programming/2022-January/059538.html
> > > ).
> > > >
> > > > My J version:
> > > >    JVERSION
> > > > Engine: j903/j32/android
> > > > Release-a: commercial/2021-12-17T11:10:19
> > > > Library: 9.03.08
> > > > Platform: Android 32 (armeabi-v7a)
> > > > Installer: unknown
> > > > InstallPath: /mnt/sdcard/Android/data/com.jsoftware.j.android/files
> > > > Contact: www.jsoftware.com
> > > >
> > > > Jan-Pieter
> > > >
> ----------------------------------------------------------------------
> > > > For information about J forums see
> http://www.jsoftware.com/forums.htm
> > > >
> > > ----------------------------------------------------------------------
> > > For information about J forums see http://www.jsoftware.com/forums.htm
> > >
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> >
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to