¿Alguien está usando valgrind y Qt?

Question

Estoy tratando de depurar una gran compilación de aplicaciones usando Qt/C++ y valgrind está reportando una gran cantidad de pérdida de memoria de cosas internas de Qt. ¿Alguien podría compartir un archivo de supresión de valgrind adecuado para aplicaciones Qt?

Gracias!

Por ejemplo.

#include <qobject.h> 
int main() 
{ 
    QObject o; 
    return 0; 
} 

devuelve:

 
$ valgrind --leak-check=full --show-reachable=yes ./leak 
==12655== Memcheck, a memory error detector 
==12655== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al. 
==12655== Using Valgrind-3.5.0-Debian and LibVEX; rerun with -h for copyright info 
==12655== Command: ./leak 
==12655== 
==12655== 
==12655== HEAP SUMMARY: 
==12655==  in use at exit: 744 bytes in 7 blocks 
==12655== total heap usage: 28 allocs, 21 frees, 1,640 bytes allocated 
==12655== 
==12655== 16 bytes in 1 blocks are still reachable in loss record 1 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x6203124: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== 96 bytes in 1 blocks are still reachable in loss record 2 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x62030FC: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== 96 bytes in 1 blocks are still reachable in loss record 3 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x62041CD: QWaitCondition::QWaitCondition() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6200EAF: ??? (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62010A0: ??? (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6203132: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== 120 bytes in 1 blocks are still reachable in loss record 4 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x61FE681: QMutex::QMutex(QMutex::RecursionMode) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6200DC8: QThreadData::QThreadData(int) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x620310C: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== 120 bytes in 1 blocks are still reachable in loss record 5 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x61FE681: QMutex::QMutex(QMutex::RecursionMode) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6200DE9: QThreadData::QThreadData(int) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x620310C: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== 120 bytes in 1 blocks are still reachable in loss record 6 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x61FE681: QMutex::QMutex(QMutex::RecursionMode) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6200E77: ??? (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62010A0: ??? (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6203132: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== 176 bytes in 1 blocks are still reachable in loss record 7 of 7 
==12655== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220) 
==12655== by 0x6201092: ??? (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x6203132: QThreadData::current() (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x62FC4BC: QObject::QObject(QObject*) (in /usr/lib/libQtCore.so.4.5.2) 
==12655== by 0x4008D2: main (in /tmp/Qt/bin/leak) 
==12655== 
==12655== LEAK SUMMARY: 
==12655== definitely lost: 0 bytes in 0 blocks 
==12655== indirectly lost: 0 bytes in 0 blocks 
==12655==  possibly lost: 0 bytes in 0 blocks 
==12655== still reachable: 744 bytes in 7 blocks 
==12655==   suppressed: 0 bytes in 0 blocks 
==12655== 
==12655== For counts of detected and suppressed errors, rerun with: -v 
==12655== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 8 from 8) 

Answer 1

--show-alcanzatable muestra la memoria que no se ha filtrado, a pesar de que valgrind lo llama un registro de pérdida. Su aplicación de prueba no pierde ninguna memoria.

No necesita ninguna supresión de valgrind para este caso en particular. Para otros, tal vez, pero debería usar valgrind's --gen-supresiones opción para generar esas supresiones para usted.

Answer 2

El registro de valgrind anteriormente informes 0 fugas, es decir, hay son sin errores.

Answer 3

still reachable: 744 bytes in 7 blocks 

Si suelta QObject o? ¿Todavía tienes el mismo resultado?

Actualización: Solo para aclarar, esta memoria será liberada por el sistema operativo cuando cierre la aplicación (para que no sea una fuga).

Sin embargo, por su propio bien, siempre es bueno escribir un destructor que libera la memoria, y siempre se siente bien saber que tiene control sobre lo que se asigna y desasignado. (para que no termine con fugas de memoria reales ...)