Re: [Bug-apl] Segmentation fault causes GNU APL version 1.5-1 AMD64 to exit

[Juergen Sauermann]

Hi Blake, as of now I suspect the problem is not a too small ⎕WA, but a too large automatic variable on the stack. General problem in *nix-like OSes is that they (in practice) never run out of space but begin swapping instead. And we already have ⎕SYL where you can limit the number of ravel elements available to APL. You can also set space limits with the ulimit command (a bash built-in). But none of the above has worked for reproducing the fault. /// Jürgen On 01/02/2016 03:36 PM, Blake McBride wrote: Hi Juergen, Just a thought, perhaps you can change a parameter in GNU APL (for local testing purposes only) to force a small ⎕wa so that you can simulate the problem and do so more quickly. Thanks. Blake On Sat, Jan 2, 2016 at 7:55 AM, Juergen Sauermann <juergen.sauerm...@t-online.de> wrote: Hi, I am currently trying to reproduce the fault, but was not yet able to. Like in Blake's case, 1500x1500 worked on my machine. I am currently trying 4000x4000 but that hasn't finished yet (takes ages). The _expression_ that I am using is:  ⌹?(Q,Q←4000)⍴10 Rick, I suppose you can reproduce the fault more easily. Please try the following: 1. in the GNU APL src directory, start gdb with GNU APL: gdb ./apl run ⌹?(Q,Q←1500)⍴10 2. after the segfault has occurred, print the backtrace (still in gdb): bt Thanks a lot, Jürgen On 01/02/2016 02:39 PM, Blake McBride wrote: Just for reference, I tried your example with the head of the source code repository, and I got: $ apl       a←1500 1500⍴?(1500×1500)⍴10       ⎕wa 732487680       b←⌹a       )off However, since your  ⎕wa was substantially less than mine, it may be that you ran out of RAM and I didn't. Also, what version of the GNU APL source code did you start with?  (The repository head is highly recommended.) Hope this helps. Blake McBride On Fri, Jan 1, 2016 at 2:03 PM, Rick Mayforth <gri...@msn.com> wrote: The following sequence caused the fault. APL exits. The interpreter is running under Debian 8 in a VMWare virtual machine with 2GB RAM & 880MB swap space. One would expect a WS FULL or some other APL error in this instance rather than a forced exit, no? a←1500 1500 ⍴ ?(1500×1500)⍴10       ⎕wa 193433600       b←⌹a Segmentation fault