Re: [Valgrind-users] Info message

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In data mercoledì 15 dicembre 2021 10:15:51 CET, David Chapman ha scritto:
Ok. Thanks

> On 12/15/2021 12:34 AM, Domenico Panella wrote:
> > Hi ,
> > 
> > I'm getting this message when I run :
> > 
> > valgrind --leak-check=full ./MyProg
> > 
> > ==4189== HEAP SUMMARY:
> > ==4189==     in use at exit: 192 bytes in 12 blocks
> > ==4189==   total heap usage: 21 allocs, 9 frees, 3,513 bytes allocated
> > ==4189==
> > ==4189== LEAK SUMMARY:
> > ==4189==    definitely lost: 0 bytes in 0 blocks
> > ==4189==    indirectly lost: 0 bytes in 0 blocks
> > ==4189==      possibly lost: 0 bytes in 0 blocks
> > ==4189==    still reachable: 192 bytes in 12 blocks
> > ==4189==         suppressed: 0 bytes in 0 blocks
> > ==4189== Reachable blocks (those to which a pointer was found) are not
> > shown. ==4189== To see them, rerun with: --leak-check=full
> > --show-leak-kinds=all ==4189==
> > ==4189== For lists of detected and suppressed errors, rerun with: -s
> > ==4189== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
> > 
> > I don't see errors but some still reachable blocks.
> > Now, If i run :
> > 
> > valgrind --leak-check=full --show-leak-kinds=all -s ./MyProg
> > 
> > ==7209== HEAP SUMMARY:
> > ==7209==     in use at exit: 192 bytes in 12 blocks
> > ==7209==   total heap usage: 21 allocs, 9 frees, 3,513 bytes allocated
> > ==7209==
> > ==7209== 48 bytes in 6 blocks are still reachable in loss record 1 of 2
> > ==7209==    at 0x48437B5: malloc (in
> > /usr/libexec/valgrind/vgpreload_memcheck- amd64-linux.so)
> > ==7209==    by 0x4D9FC20: ??? (in /usr/lib64/libgcrypt.so.20.3.4)
> > ==7209==    by 0x4D2235C: ??? (in /usr/lib64/libgcrypt.so.20.3.4)
> > ==7209==    by 0x4D197E7: ??? (in /usr/lib64/libgcrypt.so.20.3.4)
> > ==7209==    by 0x4012A6D: call_init (in /usr/lib64/ld-linux-x86-64.so.2)
> > ==7209==    by 0x4012B6B: _dl_init (in /usr/lib64/ld-linux-x86-64.so.2)
> > ==7209==    by 0x40030C9: ??? (in /usr/lib64/ld-linux-x86-64.so.2)
> > ==7209==
> > ==7209== 144 bytes in 6 blocks are still reachable in loss record 2 of 2
> > ==7209==    at 0x48437B5: malloc (in
> > /usr/libexec/valgrind/vgpreload_memcheck- amd64-linux.so)
> > ==7209==    by 0x4D9FC20: ??? (in /usr/lib64/libgcrypt.so.20.3.4)
> > ==7209==    by 0x4D2235C: ??? (in /usr/lib64/libgcrypt.so.20.3.4)
> > ==7209==    by 0x4D197DA: ??? (in /usr/lib64/libgcrypt.so.20.3.4)
> > ==7209==    by 0x4012A6D: call_init (in /usr/lib64/ld-linux-x86-64.so.2)
> > ==7209==    by 0x4012B6B: _dl_init (in /usr/lib64/ld-linux-x86-64.so.2)
> > ==7209==    by 0x40030C9: ??? (in /usr/lib64/ld-linux-x86-64.so.2)
> > ==7209==
> > ==7209== LEAK SUMMARY:
> > ==7209==    definitely lost: 0 bytes in 0 blocks
> > ==7209==    indirectly lost: 0 bytes in 0 blocks
> > ==7209==    possibly lost: 0 bytes in 0 blocks
> > ==7209==    still reachable: 192 bytes in 12 blocks
> > ==7209==    suppressed: 0 bytes in 0 blocks
> > ==7209==
> > ==7209== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
> > 
> > Could you help me to understand if I'm wronging something ?
> 
> A system library (in this case libgcrypt.so) is allocating memory but
> not releasing it (keeping the memory for the life of the program). 
> There are pointers to those memory blocks, so strictly speaking they are
> not lost memory.  Even this is not the fault of your code, so don't
> worry about it.  Your code does not have a memory leak.