我試圖將UDisks2與Qt應用程序接口,並讀取自定義屬性使程序崩潰。嘗試獲取自定義類型的DBus屬性時發生致命錯誤
對於SMART屬性,一切都OK了(包括custom properties),但是當我嘗試讀取RAID設備的屬性ActiveDevices我收到了Qt的致命錯誤和應用程序崩潰
下面是一個測試程序,它說明行爲:
#include <QApplication>
#include <QDBusMetaType>
#include <QDBusConnection>
#include <QDBusInterface>
#include <QDebug>
//create the structure as defined in
// http://udisks.freedesktop.org/docs/latest/gdbus-org.freedesktop.UDisks2.MDRaid.html#gdbus-property-org-freedesktop-UDisks2-MDRaid.ActiveDevices
struct MDRaidMember {
QDBusObjectPath block;
qint32 slot;
QStringList state;
qint64 numReadErrors;
QVariantMap expansion;
};
Q_DECLARE_METATYPE(MDRaidMember)
//marshalling operator
QDBusArgument &operator<<(QDBusArgument &argument, const MDRaidMember& raidMember)
{
argument.beginStructure();
argument << raidMember.block;
argument << raidMember.slot;
argument << raidMember.state;
argument << raidMember.numReadErrors;
argument << raidMember.expansion;
argument.endStructure();
return argument;
}
//unmarshall operator
const QDBusArgument &operator>>(const QDBusArgument &argument, MDRaidMember& raidMember)
{
argument.beginStructure();
argument >> raidMember.block;
argument >> raidMember.slot;
argument >> raidMember.state;
argument >> raidMember.numReadErrors;
argument >> raidMember.expansion;
argument.endStructure();
return argument;
}
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
//register the type, everything looks fine
qDebug() << qRegisterMetaType<MDRaidMember>("MDRaidMember");
qDebug() << qDBusRegisterMetaType<MDRaidMember>();
QDBusInterface iface("org.freedesktop.UDisks2",
"/org/freedesktop/UDisks2/mdraid/9aec6784_86ec37d4_8c1c6add_4dc9fe81",
"org.freedesktop.UDisks2.MDRaid",
QDBusConnection::systemBus());
//read some properties
qDebug() << iface.property("UUID");
qDebug() << iface.property("ActiveDevices"); //crash the test program!
return app.exec();
}
執行此代碼生成以下輸出
1057
1057
QVariant(QString, "9aec6784:86ec37d4:8c1c6add:4dc9fe81")
Cannot construct placeholder type QDBusRawType
zsh: abort (core dumped) ./app/test_members
任何人遇到這種情況?我沒有把它和我的代碼聯繫起來,因爲如果自定義類型沒有被聲明(只保留函數的內容),結果是一樣的。
我面對完全相同的問題進行UDisks2。 – Orient 2017-11-16 06:08:24