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delphifastmm

How much memory your program takes? (FastMM vs Borland MM)


I have seen recently a strange behavior in my program. After creating large amounts of objects (500MB of RAM) then releasing them, the program's memory footprint does not return to its original size. It still shows a footprint of 160MB (Private working set).

Normal behavior?

Borland's memory manager does not behave like this, so if possible please confirm (or infirm) this is a normal behavior for FastMM: If you have a handy program in which you create a rather complex MDI child (containing several controls/objects), can you create in a loop 250 instances of that MDI child in memory (at the same time) then release them all and check the memory footprint. Please make sure that you consume at least 200-300MB or RAM with those MDI childs.

Especially those that still using Delphi 7 can see the difference by temporary disabling FastMM.

Thanks


If anybody is interested, especially if you want some proof this is not a memory leak (I hope it is not a mem leak in my code - this is also one of the points of this post: to check if it is my fault), here are the original discussions:

My program never releases the memory back. Why?
How to convince the memory manager to release unused memory


Solution

  • SOLVED

    To confirm that this behavior is generated by FastMM (as suggested by Barry Kelly) I created a second program that allocated A LOT of RAM. As soon as Windows ran out of RAM, my program memory utilization returned to its original value.

    Problem solved. Special thanks to Barry Kelly, the only person that pointed to the real "problem".