>> Hello Shriramana,
>>
>>
>> On Fri, 12 May 2006 13:41:12 +0530 "Shriramana Sharma"
>> <samjnaa@xxxxxxxxx> wrote:
>>
>> > One of my programs, which was working quite well till now, suddenly
>> > gives me the error:
>> >
>> > *** glibc detected *** double free or corruption (top): 0x0808a338
>> > ***
>> > Aborted
>> >
>> > It is a pure C program compiled with GCC 4.02 -- I do not understand
>> > why it does not work suddenly. Please tell me what the above error
>> > can
>> > be.
>>
>> Would be nice to run it from gdb, in order to get the backtrace when
>> it
>> crashes. This should help you understand where and why :).
>
> Additionally, you can try valgrind, which reports typical programming
> errors like calling free() twice on the same object.
>
> \Steve
> -
Steve,
I just saw that utility the other day. It looks interesting. How do you
typically use it? or grindcall-grindval? Do you know of a good tutorial
you could point me/us to?
Nate,
The easiest way to use valgrind is to pass it the "apparently faulty"
program including all arguments using the --tool switch:
graegerts@kenji:~/vmware/haiku> valgrind --tool=memcheck ls -la
Afterwards a summary is printed:
==11048== Memcheck, a memory error detector for x86-linux.
==11048== Copyright (C) 2002-2004, and GNU GPL'd, by Julian Seward et al.
==11048== Using valgrind-2.2.0, a program supervision framework for
x86-linux.
==11048== Copyright (C) 2000-2004, and GNU GPL'd, by Julian Seward et al.
==11048== For more details, rerun with: -v
==11048==
[lengthy file listing omitted]
==11048==
==11048== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 23 from 1)
==11048== malloc/free: in use at exit: 14901 bytes in 21 blocks.
==11048== malloc/free: 446 allocs, 425 frees, 48474 bytes allocated.
==11048== For a detailed leak analysis, rerun with: --leak-check=yes
==11048== For counts of detected errors, rerun with: -v
graegerts@kenji:~/vmware/haiku>
By entering "valgrind" in the console a list of available tools is
listed, all of them obeying the --help switch:
% valgrind
valgrind: Missing --tool option
Available tools:
helgrind
addrcheck
cachegrind
memcheck
callgrind
corecheck
lackey
none
massif
% valgrind --tool=memcheck --help
The valgrind homepage (http://valgrind.org) is a good starting point
for documentation and description of related concepts. Hope that was
helpful.
Bye
\Steve
-
Very helpful. And speedy. :)
Thanks. That is what I assumed it might be like. I will have to do some
learning about that tool and others like it. I am looking down the road,
knowing that I have a memory leak to track down soon in a project I have
been asked to fix.
Thanks again,
Nate
-
: send the line "unsubscribe linux-c-programming" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
