Hi all,

Question 1:
I have a nasty bug: an unknown function is overwriting some memory. The bug appears later in other functions (destroyed heap and objects). For example: the GetMem allocates memory which partly was never freed. To find the evil function I want to check the complete heap (allocated mem) from time to time to see when the error appears. I think the heaptrc unit can add marks at the head and the tail of each allocated mem and do some little checks every time memory is allocated/freed. But how can I check ALL structures (allocated+freed memory blocks) at once?

I set:

initialization
  HeapTrc.QuickTrace:=true;
  HeapTrc.HaltOnError:=true;
  HeapTrc.KeepReleased:=false;
  HeapTrc.add_tail:=true;
  HeapTrc.UseCRC:=true;
writeln('heap tracing ...');
end.
Question 2:
If I set 'KeepReleased:=true' I got a Segmentation fault right before the 'writeln' statement. Why that?

Mattias Gaertner

I think that if you recompile the heaptrc unit with -dEXTRA, this will happen every time you allocate/release memory.

BTW: I don't know about your second question, but you should "quicktrace" to false if you want more thorough debugging

Jonas

Thx, it works.
But it is far too slow because I have millions of mem blocks and thus it is not useful for debugging. If I have a single function to check all allocated/freed mem blocks at once I could binary search the bug.

Somebody knows of such a function?

Mattias

for
debugging.

If I have a single function to check all allocated/freed mem blocks at once I could

binary
search the bug.

Somebody knows of such a function?

There is none yet. I know that the heaptrc unit can use some extensions like:
- Trace only from a start to end instead of everything
- Checking if the heap is still correct every X getmem calls