Does FastMM detect all memory leaks

Question

Somebody suggested recently ( My program never releases the memory back. Why? ) that my program leaks some memory. I have FastMM set to aggressive and it reports no memory l

Answer 1

There is a lot of good answer already, but one point that wasn't mentionned yet...

There is a lot of "leaks" that won't get detected by most memory leak detector since the memory IS freed, but way after it isn't used anymore. For exemple, object stacked in a TObjectList. Object are put in the object list, but after you are done using them, you don't free them. They will be destroyed when the object list is destroyed too (When application close for exemple, assuming OwnsObject=True). Since the objects are actually freed, objects are not "leaked", but still make your application use more and more memory over time.

FastMM won't report those as it only makes "full run" analysis. To detect those, you need a memory leak detector that allows to do partial runs, that is, analyzing what "leaked" between point A and point B during the execution. AQTime that Eugene mentionned allow that kind of checks. But be aware that is takes a bit of analysis because that will yield many false-positive (Pretty much all "realloc" operations will be marked as a leak).