[fpc-devel] Possible memory leak in cthread.

Peter Popov ppopov99 at gmail.com
Wed Aug 5 22:28:58 CEST 2009


Since you mentioned cprt0, you could try checking the order of  
initialization of libc and libgcc. This may have something to do with it,  
see also http://bugs.freepascal.org/view.php?id=14265

Peter


On Wed, 05 Aug 2009 07:19:56 -0500, Jonas Maebe  
<jonas.maebe at elis.ugent.be> wrote:

>
> On 05 Aug 2009, at 13:55, Wimpie Nortje wrote:
>
>> program memleak;
>>
>> {$mode objfpc}{$H+}
>>
>> uses
>> cthreads;
>>
>> begin
>> end.
>>
>> If I run the program using valgrind I get the following output:
>> ==1944==    Invalid free() / delete /  
>> delete[]                                                              
>> ==1944==    at 0x4025DFA: free (vg_replace_malloc.c:323)              
>> ==1944==    by 0x4171664: (within /lib/tls/i686/cmov/libc-2.9.so)
>> ==1944==    by 0x4020422: _vgnU_freeres (vg_preloaded.c:60)
>> ==1944==    by 0x40E5B23: _Exit (in /lib/tls/i686/cmov/libc-2.9.so)
>> ==1944==    by 0x405C77C: (below main) (in /lib/tls/i686/cmov/ 
>> libc-2.9.so)
>> ==1944==  Address 0xffffffff is not stack'd, malloc'd or (recently)  
>> free'd
>
> This invalid free is probably the reason for the memory leak.
>
> It even happens for this program:
>
> {$linklib c}
> begin
> end.
>
> There is probably some error in FPC's startup code (the code in fpc/ 
> rtl/linux/i386/cprt0.as) which doesn't initialise some libc pointer. You  
> should indeed report a bug about this.
>
> To Graeme and Michael: heaptrc is useless/irrelevant to analyse memory  
> leaks reported inside libc. Such errors can always be due to wrong usage  
> of the C library from within FPC code.
>
>
> Jonas
> _______________________________________________
> fpc-devel maillist  -  fpc-devel at lists.freepascal.org
> http://lists.freepascal.org/mailman/listinfo/fpc-devel



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