bus error, resize vector

[imutate]

I get a bus (or is it buss) error when I resize a vector

typedef std::vector<dou bledblvec;
n = 127;
dblvec rv;
rv.resize(n); // error happens here

Any clues ? I can post more info if required ?

[Daniel T.]

im*****@hotmail .co.uk wrote:

I get a bus (or is it buss) error when I resize a vector

typedef std::vector<dou bledblvec;
n = 127;
dblvec rv;
rv.resize(n); // error happens here

Any clues ? I can post more info if required ?

The below code works perfectly. Try posting the code that actually
produced the error.

#include <vector>

int main()
{
typedef std::vector<dou bledblvec;
int n = 127;
dblvec rv;
rv.resize(n); // error happens here
}

--
There are two things that simply cannot be doubted, logic and perception.
Doubt those, and you no longer*have anyone to discuss your doubts with,
nor any ability to discuss them.

[imutate]

Daniel T. wrote:

The below code works perfectly. Try posting the code that actually
produced the error.

Indeed. How can I do that the whole thing is too large to post, but
why is it relevant. As I said I can post more but why ?

DEBUG_LOG("fn1" );
rv.resize(n); // error happens here
DEBUG_LOG("fn2" );

I know the error happens at rv.resize(n) because I don't get the output
from the second DEBUG_LOG.

[Roland Pibinger]

On 29 Sep 2006 11:36:55 -0700, im*****@hotmail .co.uk wrote:

>Daniel T. wrote:

>The below code works perfectly. Try posting the code that actually
produced the error.

Indeed. How can I do that the whole thing is too large to post, but
why is it relevant. As I said I can post more but why ?

DEBUG_LOG("fn1 ");
rv.resize(n) ; // error happens here
DEBUG_LOG("fn2 ");

I know the error happens at rv.resize(n) because I don't get the output
from the second DEBUG_LOG.

A bus error usually stems from misaligned objects, not from the code
you posted. Do you use a custom memory allocator?

[imutate]

Roland Pibinger wrote:

A bus error usually stems from misaligned objects, not from the code
you posted. Do you use a custom memory allocator?

Do you mean like malloc, alloc etc and C++ new ?
No I am not using any of those or third party. I am only using reserve
and resize. Actually I am not using reserve on this particular
variable. I just tried it and it also failed.

DEBUG_LOG("fn0" );
rv.reserve(n); // error happens here now
DEBUG_LOG("fn1" );
rv.resize(n); DEBUG_LOG("fn2" );

[Howard]

<im*****@hotmai l.co.ukwrote in message
news:11******** *************@e 3g2000cwe.googl egroups.com...

>I get a bus (or is it buss) error when I resize a vector

typedef std::vector<dou bledblvec;
n = 127;
dblvec rv;
rv.resize(n); // error happens here

Any clues ? I can post more info if required ?

Probably a bus error. A buss error occurs when you make a mistake kissing
someone. :-)

Seriously, the problem may stem from earlier, apparently unrelated code.
Using uninitialized variables or using objects which have been deleted or
writing past the bounds of an array are examples of problems which can often
cause errors to occur later in the code. The code above, by itself, looks
fine.

-Howard

[imutate]

Howard wrote:

Probably a bus error. A buss error occurs when you make a mistake kissing
someone. :-)

lol, it is a good word.
http://en.wikipedia.org/wiki/Buss

Seriously, the problem may stem from earlier, apparently unrelated code.
Using uninitialized variables or using objects which have been deleted or
writing past the bounds of an array are examples of problems which can often
cause errors to occur later in the code. The code above, by itself, looks
fine.

-Howard

So as I'm mostly using std vectors, one of these is likely to be the
culprit.
Thanks

[Daniel T.]

im*****@hotmail .co.uk wrote:

Daniel T. wrote:

>The below code works perfectly. Try posting the code that actually
produced the error.

Indeed. How can I do that the whole thing is too large to post, but
why is it relevant. As I said I can post more but why ?

Because if you don't post the code that is actually causing the problem,
then no one can help you. BTW, don't post the whole thing. Start pairing
it down until you have the smallest example possible that still exhibits
the error. Nine times out of ten just trying to do that will help you
find the problem on your own.

DEBUG_LOG("fn1" );
rv.resize(n); // error happens here
DEBUG_LOG("fn2" );

I know the error happens at rv.resize(n) because I don't get the output
from the second DEBUG_LOG.

resize is not broken. Some code that you wrote is causing the problem.
What type is 'n'?

--
There are two things that simply cannot be doubted, logic and perception.
Doubt those, and you no longer*have anyone to discuss your doubts with,
nor any ability to discuss them.

[imutate]

Daniel T. wrote:

resize is not broken. Some code that you wrote is causing the problem.

Yes, maybe I need to learn to use some kind of debugger to traceback
the problem.

What type is 'n'?

it is passed in as an int as in
void fn(.. , int n, ..)

I changed this to "const int &n" instead (this code is older code that
I started when I knew less) , but no that did not solve the problem.

[Larry Smith]

im*****@hotmail .co.uk wrote:

Daniel T. wrote:

>resize is not broken. Some code that you wrote is causing the problem.

Yes, maybe I need to learn to use some kind of debugger to traceback
the problem.

>What type is 'n'?

it is passed in as an int as in
void fn(.. , int n, ..)

I changed this to "const int &n" instead (this code is older code that
I started when I knew less) , but no that did not solve the problem.

Are you checking that 'n' is not zero, and not negative?
How large might 'n' be?

If you're validating 'n' before using it, then I'd
look elswhere - something is probably trashing memory,
causing this failure as a side effect.