Memory is not full released after deleting all QPushButtons in QTApp

[asimfile]

i am creating a program containing QPushButtons, the Problem is when i am adding QPushButtons memory(RAM) increasing but when i deleted all added buttons memory is not fully releasing.

void TempTest ::addSLOT()
{
  li= new QList<QPushButton*>;
  for(int i=0;i<50000;i++)
   {
     QPushButton *p = new QPushButton;
     p->setText("sample");
     p->setFixedSize(100,100);
     li->append(p);
   }
}
void TempTest ::removeSLOT()
{
  while(li->count())
   {
     QPushButton*p= li->at(0);
     li->removeAt(0);
     delete p;
   }
   delete li;
}

1.initialy memory is 2.0 mb

2.after adding memory increased to 49.3 mb

3.after deleting memory decreased to 4.1 mb

there is 2.1 mb of RAM it never released

[BjornW]

How do you check memory consumption? Afaik, all memory may not be returned immediately to the OS.

If you run your example multiple times, do you see a steady increase by 2 MB for each iteration?

[asimfile]

thanks for replying @BjornW
further if i repeat same process -
again add and delete Buttons - 4.4 mb
again add and delete Buttons - 4.9 mb
again add and delete Buttons - 4.6 mb
again add and delete Buttons - 4.4 mb
again add and delete Buttons - 5.4 mb
again add and delete Buttons - 4.9 mb
again add and delete Buttons - 4.6 mb

[kshegunov]

See my answer here.

[asimfile]

@kshegunov thanks for reply , i have read your link and it seems OS is resposible for memory loss.

[kshegunov]

@asimfile said in Memory is not full released after deleting all QPushButtons in QTApp:

it seems OS is resposible for memory loss

You misunderstood. The OS is responsible for memory management. C++ is a stack based language (following ASM's push and pop), everything you allocate on the heap is managed by the OS's heap manager - that's its purpose (small wonder the heap allocation in C is a function). In any case, if you need to make sure you don't leak things, just use a code analyzer.