Benjamin Lambert <benlamb...@cmu.edu> writes:
> Hi there,

> I've been a bit puzzled the last few days about a memory fault I've
> been getting.  It turns out to be the control stack getting exhausted,
> but the error I have been getting is simply a "memory fault".  I
> thought I should share this, in case it's possible to print that the
> error is a control stack problem, rather than the more vague "memory
> fault" error.

> It took me a while of adding numerous print-outs to my code to find the error, but it turned out to be coming from this form, which appends a list of lists:
> (apply 'append list-of-lists)

> Before I discovered that it was a control stack size issue (which SBCL on my Mac is now showing), I tried this instead, which doesn't cause the error:
> (apply 'concatenate 'list list-of-lists)

> The list of lists is length 100,000.  So, it's easy to reproduce this with (or increase the 100,000 to be big enough to fill the control stack):
> (apply 'append (make-list 100000 :initial-element '()))

> It makes sense that this would exhaust the stack.  (I am aware of how to increase the stack size with --control-stack-size).

> On Linux (and sometimes on Mac), I get the error:
> CORRUPTION WARNING in SBCL pid 16130(tid 140737353885424):
> Memory fault at f293d040 (pc=0x100050d041, sp=0x7ffff293d040)
> The integrity of this image is possibly compromised.
> Exiting.

> Previously, I was getting the same error on Mac, but now I'm getting a control stack exhausted error:
> fatal error encountered in SBCL pid 91825:
> Control stack exhausted

> This is SBCL 1.0.55 on Mac, and 1.1.0 on Linux (x86-64).

> So, I suppose my questions are:

> 1)  Does it make sense that APPEND exhausts the stack, but CONCATENATE doesn't?

> 2)  Is it possible to catch the error and report it as "control stack exhausted" rather than simply as a "memory fault"?

> Thanks,
> Ben

Benjamin Lambert <benlamb...@cmu.edu> writes:
> Hi there,

> I've been a bit puzzled the last few days about a memory fault I've
> been getting.  It turns out to be the control stack getting exhausted,
> but the error I have been getting is simply a "memory fault".  I
> thought I should share this, in case it's possible to print that the
> error is a control stack problem, rather than the more vague "memory
> fault" error.

> It took me a while of adding numerous print-outs to my code to find the error, but it turned out to be coming from this form, which appends a list of lists:
> (apply 'append list-of-lists)

> Before I discovered that it was a control stack size issue (which SBCL on my Mac is now showing), I tried this instead, which doesn't cause the error:
> (apply 'concatenate 'list list-of-lists)

> The list of lists is length 100,000.  So, it's easy to reproduce this with (or increase the 100,000 to be big enough to fill the control stack):
> (apply 'append (make-list 100000 :initial-element '()))

> It makes sense that this would exhaust the stack.  (I am aware of how to increase the stack size with --control-stack-size).

> On Linux (and sometimes on Mac), I get the error:
> CORRUPTION WARNING in SBCL pid 16130(tid 140737353885424):
> Memory fault at f293d040 (pc=0x100050d041, sp=0x7ffff293d040)
> The integrity of this image is possibly compromised.
> Exiting.

> Previously, I was getting the same error on Mac, but now I'm getting a control stack exhausted error:
> fatal error encountered in SBCL pid 91825:
> Control stack exhausted

> This is SBCL 1.0.55 on Mac, and 1.1.0 on Linux (x86-64).

> So, I suppose my questions are:

> 1)  Does it make sense that APPEND exhausts the stack, but CONCATENATE doesn't?

> 2)  Is it possible to catch the error and report it as "control stack exhausted" rather than simply as a "memory fault"?

>> 2)  Is it possible to catch the error and report it as "control stack exhausted" rather than simply as a "memory fault"?
> And as to the error you're seeing, there's a bug ticket:
> https://bugs.launchpad.net/sbcl/+bug/484143

> --
> With best regards, Stas.

On Sat, Oct 20, 2012 at 12:31 AM, Benjamin Lambert <benlamb...@cmu.edu> wrote:
>>> 2)  Is it possible to catch the error and report it as "control stack exhausted" rather than simply as a "memory fault"?
>> And as to the error you're seeing, there's a bug ticket:
>> https://bugs.launchpad.net/sbcl/+bug/484143

> Ahh, I see.  Thanks Stas.  And thanks especially about the tip to use REDUCE rather than APPLY!  Now why didn't I think of that...  duh.