As dynamic libraries to use class variables?

[Mikee]

I think that need to do reference class variable. But this code isn't working

void StrategyCod(/*MainWindow * main*/)
{
    long long &NBar1 =MainWindow.NBar;
    qDebug()<<"Library work2";//<<w.NBar;
}

How can i do reference?

[mrjj]

@Mikee

via the parameter ( main or what u called it)

void StrategyCod(MainWindow * main) {
    qDebug()<<"Library work2"<<main->NBar;
}

if NBAr is wrong, then something else is wrong. not the function
it might be you call StrategyCod BEFORE setting it in mainwindow or
something like that.

[Mikee]

I checked:
library:
void StrategyCod(double Parametr)

{
    MainWindow *w;
    qDebug()<<"Library work2"<<Parametr<<w->NBar;
}

main.cpp:

QLibrary MyLib("C:\\Qt\\project\\build-StrategyCod-Desktop_Qt_5_9_2_MinGW_32bit-Debug\\debug\\StrategyCod");  
    MyLib.load();
    typedef void (*MyPrototype)();
    MyPrototype StrategyCod = (MyPrototype) MyLib.resolve("StrategyCod");
    qDebug()<<w.NBar;  //NBar=0 is hear 
    StrategyCod();  //NBar=5943858560 is hear 
    MyLib.unload();

Maybe here typedef void (*MyPrototype)(); need append void (*MyPrototype)(class); ?

[mrjj]

@Mikee
Yes it must all match.

typedef void (*MyPrototype)();

means pointer to function takes no parameters
which is untrue.

[Mikee]

But what to do with NBar?

void StrategyCod()
{
    MainWindow *w;
    qDebug()<<"Library work2"<<w->NBar;
  
}

[jsulm]

@Mikee

typedef void (*MyPrototype)(MainWindow *w);

[Mikee]

I have done this and it's working

 QLibrary MyLib("C:\\Qt\\project\\build-StrategyCod-Desktop_Qt_5_9_2_MinGW_32bit-Debug\\debug\\StrategyCod");  
    MyLib.load();
    typedef void (*MyPrototype)(MainWindow *);
    MyPrototype StrategyCod = (MyPrototype) MyLib.resolve("StrategyCod");
    StrategyCod(&w);  
    qDebug()<<"q1"<< q1;
    MyLib.unload();

Thank you

[mrjj]

Congrats :)

[Mikee]

I have are new problem.

qDebug()<<NBar;

return NBar=1064,

qDebug()<<"Library work2"<< Parametr<<w->NBar;

return NBar=0
In class MainWindow:

void MainWindow::on_ButtonRuneOne_clicked()//запуск стратегии на одном ядре
{
    bool ok;
    double d = QInputDialog::getDouble(this, tr("ParametrForStrategy"),
                                           tr("double:"), 37.56, -100000, 100000, 6, &ok);
    if (ok) {ParametrForStrategyCod=d; }

    QLibrary MyLib("C:\\Qt\\project\\build-StrategyCod-Desktop_Qt_5_9_2_MinGW_32bit-Debug\\debug\\StrategyCod");  
    MyLib.load();
    typedef void (*MyPrototype)(double,MainWindow *);
    MyPrototype StrategyCod = (MyPrototype) MyLib.resolve("StrategyCod");
    MainWindow w;
    qDebug()<<NBar;
    StrategyCod(ParametrForStrategyCod,&w);  /
    MyLib.unload();
}

In library:

void StrategyCod(double Parametr, MainWindow *w)
{
    qDebug()<<"Library work2"<< Parametr<<w->NBar;
}

But in main.cpp it works good. How can I fix problem with link of object class?

[SGaist]

You're passing w to your method which is not the current MainWindow object you are calling StrategyCod from.

Pass this to the method.

On a side note, you are doing some pretty convoluted stuff here for what seems to be a pretty simple task. I'd encourage you to re-think a bit the design of your application.

[Mikee]

Thank you. I wrote it like this

StrategyCod(ParametrForStrategyCod,this); 

and it works

[Mikee]

How can I create lamda function in the slot of the class?

       QVector <double> Perebor1;
       for (double i=d1;i<=d2;i=i+d3) 
       {
           Perebor1.append(i);
       }
       QLibrary MyLib("C:\\Qt\\project\\build-StrategyCod-Desktop_Qt_5_9_2_MinGW_32bit-Debug\\debug\\StrategyCod");  
       MyLib.load();
       typedef void (*MyPrototype)(double,MainWindow *);
       MyPrototype StrategyCod = (MyPrototype) MyLib.resolve("StrategyCod");
       //StrategyCod(ParametrForStrategyCod,this);  
       QFuture<void> Perebor2 = QtConcurrent::map(Perebor1,[&](const double& d){ StrategyCod(d,this);}); 
       MyLib.unload();

[Mikee]

And if I do, the function does not work.

void StrategyCod(double Parametr, MainWindow *w)
{
    qDebug()<<"Library work2"<< Parametr<<w->NBar;
    w->NBar=2000;
}

error:
Invalid parameter passed to C runtime function.
Invalid parameter passed to C runtime function.

[mrjj]

Well if Perebor2 still runs when you do MyLib.unload()
its not so nice for it...

[Mikee]

How to wait for all Perebor2?
How to change w->NBar throw StrategyCod? If I do it in one thred

void StrategyCod(double Parametr, MainWindow *w)
{
    qDebug()<<"Library work2"<< Parametr<<w->NBar;
    w->NBar=2000;
}

it compiles, but when it works errors appears:
ASSERT failure in QVector<T>::operator[]: "index out of range", file ....\Qt5.9.2\5.9.2\mingw53_32\include/QtCore/qvector.h, line 430
Invalid parameter passed to C runtime function.
Invalid parameter passed to C runtime function.

[mrjj]

@Mikee
Dont wait for it.
Just move the MyLib.unload(); to a better place.

also if you have

void mainwindow::somefunction {
QVector <double> Perebor1;
for (double i=d1;i<=d2;i=i+d3)
{
Perebor1.append(i);
}
QLibrary MyLib("C:\Qt\project\build-StrategyCod-Desktop_Qt_5_9_2_MinGW_32bit-Debug\debug\StrategyCod");
MyLib.load();
typedef void (*MyPrototype)(double,MainWindow *);
MyPrototype StrategyCod = (MyPrototype) MyLib.resolve("StrategyCod");
//StrategyCod(ParametrForStrategyCod,this);
QFuture<void> Perebor2 = QtConcurrent::map(Perebor1,[&](const double& d){ StrategyCod(d,this);});
MyLib.unload();
} // Perebor1 is deleted here.

Perebor1 also dies as its a local
so make them member variables of the class
and structure code better.

[Mikee]

`Perebor in class ,MainWindow. It doesn't work. Errors are the same.
``
for (double i=d1;i<=d2;i=i+d3)
{
Perebor.append(i);
}

   QLibrary MyLib("C:\\Qt\\project\\build-StrategyCod-Desktop_Qt_5_9_2_MinGW_32bit-Debug\\debug\\StrategyCod");  
   MyLib.load();
   typedef void (*MyPrototype)(double,MainWindow *);
   MyPrototype StrategyCod = (MyPrototype) MyLib.resolve("StrategyCod");
   //StrategyCod(ParametrForStrategyCod,this);  
   //QFuture<void> Perebor2 = QtConcurrent::map(Perebor1,[&](const double& d){ StrategyCod(d,this);});  
   QFuture<void> Perebor2 = QtConcurrent::map(Perebor,[&](const double& d){ StrategyCod(d,this);});

[mrjj]

What about Perebor2 ?
Wont it suffer the same and run out of scope ?

[Mikee]

No. It's okey with Perebor2. Function StrategyCod2 is in class MainWindow works correctly.

for (double i=d1;i<=d2;i=i+d3) 
       {
           Perebor.append(i);
       }

       QFuture<void> Perebor2 = QtConcurrent::map(Perebor,[this](const double& d){ StrategyCod2(d);});

[mrjj]

@Mikee
Ok for
QLibrary MyLib;
docs says
QLibrary::~QLibrary()

Destroys the QLibrary object.
Unless unload() was called explicitly, the library stays in memory until the application terminates.

so that seems ok.

Im not sure what line gives the
"Invalid parameter passed to C runtime function."

You should use the debugger to find out.