Wrong pointer inside the function, why?

[Max_a]

Creating thread to sort an arrey.
When i'm trying to use anything from the struct inside the function i got smt wrong
@
struct t_arg // My struct for arguments
{
int begin;
int end;
} *tmp_struct;

void * sort(void* arg) //here i got smt wrong
{
struct t_arg tmp_arg = *(struct t_arg *) arg;
int begin = tmp_arg.begin; int end = tmp_arg.end;
for(int j = begin; j < end; j++)
for(int i = begin; end-1 < 19; i++)
{
if(mass[i] > mass[i+1])
{
int tmp = mass[i]; mass[i] = mass[i+1];
mass[i+1] = tmp;
} sum = tmp_arg.end;
}

return NULL;

}
void MainWindow::on_pushButton_clicked() //Button Start
{
pthread_t thread;
tmp_struct = new struct t_arg;
n_qthreads = ui->comboBox->currentText().toInt(); n_e_quantity = ui->spinBox->value();
mass = new int[n_e_quantity];
for(int i = 0; i < n_e_quantity; i++)
{
mass[i] = rand()0 + 40;
}
tmp_struct->begin = 0;
tmp_struct->end = n_e_quantity;

pthread_create(&thread, NULL, &sort, &tmp_struct);

ui->textBrowser->insertPlainText(QString::number(tmp_struct->end)); //here always correct

}
void MainWindow::on_pushButton_3_clicked()
{
ui->textBrowser->insertPlainText( "From sort == "); // here i got 0 or smt else, but not end or begin
ui->textBrowser->insertPlainText(QString::number(sum));
ui->textBrowser->insertPlainText( "\n\n");

}
@

[Binary91]

They way you are passing the struct to your function is not C++ conform.
Try the following:
@
struct t_arg // My struct for arguments
{
int begin;
int end;
} *tmp_struct;

void * sort(t_arg* arg) //here i got smt wrong
{
t_arg* tmp_arg = arg;
//...

return NULL;

}@

Also, I don't understand the following in your function MainWindow::on_pushButton_clicked():
@
tmp_struct = new struct t_arg;
// ...
pthread_create(&thread, NULL, &sort, &tmp_struct); // tmp_struct is already a pointer, so there's no need to reference it...
@

I recommend you to check your code and correct your pointer management...