malloc() vs. HeapAlloc()

c++ winapi malloc
TCS picture TCS · Nov 22, 2011 · Viewed 41.3k times · Source

What is the difference between malloc() and HeapAlloc()? As far as I understand malloc allocates memory from the heap, just as HeapAlloc, right?

So what is the difference?

Thanks!

Answer

Luis Miguel Huapaya picture Luis Miguel Huapaya · Jan 4, 2012

Actually, malloc() (and other C runtime heap functions) are module dependant, which means that if you call malloc() in code from one module (i.e. a DLL), then you should call free() within code of the same module or you could suffer some pretty bad heap corruption (and this has been well documented). Using HeapAlloc() with GetProcessHeap() instead of malloc(), including overloading new and delete operators to make use of such, allow you to pass dynamically allocated objects between modules and not have to worry about memory corruption if memory is allocated in code of one module and freed in code of another module once the pointer to a block of memory has been passed across to an external module.

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