[C++/WinAPI] Checking number of allocated memory

[jagi]

Hi. How can I check number of memory, allocated by malloc() function ?

[sean]

malloc accepts as it's only parameter, a value provided by you to tell it how much space to allocate. It will return a pointer to that location. If it fails to allocate the amount of space you told it to, it will return NULL. Short of scanning that space in memory for the end of your data, that is the only way I can think of to check how much space was allocated. If this isn't what you're looking for, try and give us a little more detail as to what it is that you are trying to do.

malloc() is part of the standard C library (also part of the standard C++ library - which you appear to be using). Because this particular question does not refer to the Windows API, I am moving this thread to the C++ board.

[Kybo_Ren]

This works for Visual C++:

//MemoryLeaks.h
#ifndef MEMORY_LEAKS_01_H
#define MEMORY_LEAKS_01_H
#define CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>


class CMemory_alloc
{
public:
   CMemory_alloc()
   {   };
  
   CMemory_alloc(long num)
   {    _CrtSetBreakAlloc(num);   };
   //if they want to break on whatever allocation.  this makes it easy
   
   ~CMemory_alloc()
   {	_CrtDumpMemoryLeaks();   };
   //dumps leaks

};//this will report memory leaks accurately as long 
//as the object of this class is declared as the very first thing in the file

#endif

To use it, include this file in your project, and declare a CMemory_alloc object as the very first global var in your program. If there are any memory leaks when you run it from the IDE, they will be reported in the output window. Note that this ONLY works for Visual C++.

I got sample code from the MSDN and made this class. It's been pretty useful to me