¿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 las cosas internas de Qt. ¿Alguien podría compartir un archivo de supresión valgrind adecuado para aplicaciones Qt?

Gracias !

P.ej.

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

devoluciones:

$ 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

- muestra accesible muestra memoria que no se ha filtrado, aunque 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 debes usar la opción --gen-suppressions de valgrind para generar esas supresiones para ti.

Answer 2

El registro de valgrind anterior reporta 0 fugas, es decir, no hay errores.

Answer 3

still reachable: 744 bytes in 7 blocks

Si liberas QObject o? ¿Sigues teniendo 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 libere la memoria, y siempre es agradable saber que tiene control sobre lo que está asignado y desasignado. (para que no termines con pérdidas de memoria reales ...)