Details
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Bug
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Resolution: Unresolved
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P2: Important
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None
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6.5.3
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None
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Linux/Other display system
Description
QBinaryJson::toBinaryData appears to leak memory each time it is called. Here is my test program:
#include <QJsonDocument>
#include <QJsonObject>
#include <QBinaryJson>
#include <QCoreApplication>
void test()
{
static const auto obj = QJsonObject{
{ QStringLiteral("hi"), QStringLiteral("there") },
{ QStringLiteral("foo"), QStringLiteral("bar") },
{ QStringLiteral("123"), QStringLiteral("456") }
};
static const auto doc = QJsonDocument{obj};
const auto ba = QBinaryJson::toBinaryData(doc);
Q_ASSERT(!ba.isEmpty());
}
int main(int argc, char* argv[])
{
QCoreApplication app(argc, argv);
for (int i = 0; i < 100000; i++)
test();
return 0;
}
and here is the valgrind report:
$ valgrind --leak-check=full ./test ==1619140== Memcheck, a memory error detector ==1619140== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al. ==1619140== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info ==1619140== Command: ./test ==1619140== ==1619140== ==1619140== HEAP SUMMARY: ==1619140== in use at exit: 8,819,404 bytes in 100,022 blocks ==1619140== total heap usage: 1,200,115 allocs, 1,100,093 frees, 60,900,054 bytes allocated ==1619140== ==1619140== 88 bytes in 1 blocks are possibly lost in loss record 18 of 25 ==1619140== at 0x48407B4: malloc (vg_replace_malloc.c:381) ==1619140== by 0x487AAA5: ??? (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x487C502: ??? (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x487A58C: QBinaryJson::toRawData(QJsonDocument const&, int*) (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x487A5ED: QBinaryJson::toBinaryData(QJsonDocument const&) (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x109618: test() (test.cpp:17) ==1619140== by 0x109816: main (test.cpp:27) ==1619140== ==1619140== 8,799,824 bytes in 99,998 blocks are definitely lost in loss record 25 of 25 ==1619140== at 0x48407B4: malloc (vg_replace_malloc.c:381) ==1619140== by 0x487AAA5: ??? (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x487C502: ??? (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x487A58C: QBinaryJson::toRawData(QJsonDocument const&, int*) (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x487A5ED: QBinaryJson::toBinaryData(QJsonDocument const&) (in /home/hamish/dev/Qt6.5.3/6.5.3/gcc_64/lib/libQt6Core5Compat.so.6.5.3) ==1619140== by 0x109618: test() (test.cpp:17) ==1619140== by 0x109816: main (test.cpp:27) ==1619140== ==1619140== LEAK SUMMARY: ==1619140== definitely lost: 8,799,824 bytes in 99,998 blocks ==1619140== indirectly lost: 0 bytes in 0 blocks ==1619140== possibly lost: 88 bytes in 1 blocks ==1619140== still reachable: 19,492 bytes in 23 blocks ==1619140== suppressed: 0 bytes in 0 blocks ==1619140== Reachable blocks (those to which a pointer was found) are not shown. ==1619140== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==1619140== ==1619140== For lists of detected and suppressed errors, rerun with: -s ==1619140== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)
The amount leaked seems to be related to the size of the value to be converted. It leaks more or less if I add/remove more keys from the object. If I increase the loop iterations it leaks more proportionally.