It seems that Qt does not release unused memory

**wysota** · 25th November 2007, 20:33

Oh, you meant clear()... No, I didn't miss it. The vector goes out of scope and so it gets cleared anyway. But even if I did miss clear, it would only make my app hold an additional of 45000*sizeof(int*) = ~180kB of memory.

**Gopala Krishna** · 25th November 2007, 20:40

Originally Posted by wysota

Oh, you meant clear()... No, I didn't miss it. The vector goes out of scope and so it gets cleared anyway. But even if I did miss clear, it would only make my app hold an additional of 45000*sizeof(int*) = ~180kB of memory.

Sorry , but have a look at the code again. vecs is declared before the outermost for loop so it wont get cleared.

I am not sure how it relates here but deleting an invalid pointer does result in unexpected behavior.

**wysota** · 25th November 2007, 20:48

Yes, I understand your point. But note that I wrote this wasn't the actual code. In the real app I was probably using the index operator to fill the vector, otherwise delete vecs[i] would have crashed the application during the second iteration of the loop (because of trying to delete an unallocated block of memory). And if you read my original post again, you'll see this line:

Originally Posted by wysota

A probable error is not squeezing "vecs" after each iteration, but it shouldn't make it occupy over 2GB of ram (3*15000*sizeof(int) = ~180kB) - at worst it should kill the process on trying to delete an invalid pointer.

**Gopala Krishna** · 25th November 2007, 20:57

Originally Posted by wysota

Yes, I understand your point. But note that I wrote this wasn't the actual code. In the real app I was probably using the index operator to fill the vector, otherwise delete vecs[i] would have crashed the application during the second iteration of the loop (because of trying to delete an unallocated block of memory). And if you read my original post again, you'll see this line:

That is the reason i put this is in one of the post above

Of course you might have just done a cut and paste mistake !

Anyways back to topic

**wysota** · 25th November 2007, 21:02

There was no cut&paste. I had the program written in /tmp which is a ramdisk. And I had to reboot my computer after running the application. Guess the rest