How to increase heap size allocated to a process??

[risa]

I did HANDLE hHeap = GetProcessHeap(); which gives me the handle to the heap of the process then i did
DWORD dsize = 468178553;
(near pointer)PBYTE pBuffer = (LPBYTE)HeapAlloc(hHeap, 0, size);
but here i got pBuffer as NULL and then i did
_stprintf( (TCHAR*)pBuffer,"", , ,);
here my program crashes.............may be its bcoz the heap memory is less than
dsize(468178553)................how to solve this.........do i need to use a far pointer(LPBYTE).....plz help..

[vijayan121]

> here my program crashes.............may be its bcoz the heap memory is less
yes. to specify a larger process default heap size for your executable image, use the /HEAP linker switch. http://msdn2.microsoft.com/en-us/library/f90ybzkh.aspx
to allocate 468 MB of memory, the heap is not a good choice. use VirtualAlloc instead. http://msdn2.microsoft.com/en-us/library/aa366887(VS.85).aspx

[risa]

Thank you..... i will try out ...........

[risa]

DWORD dsize = 468178553;
PBYTE pBuffer=(PBYTE)::VirtualAlloc(NULL,dsize ,MEM_COMMIT,PAGE_READWRITE);

but still its crashing.......i hav 1GB of RAM and my virtual memory settings are:
initial size (1024MB)
Max size(1509MB)
Curently allocated(4044MB)
Wht shld i do?

[vijayan121]

Curently allocated(4044MB)! if you are on a 32-bit machine, the address space is almost exhausted; you certinly won't get another 400 MB+ memory.

are you allocating this memory just once in your program?
if not are you freeing yhe allocated memory (VirtualFree with MEM_RELEASE) after use?

[mitrmkar]

What do you mean by 'crashing'?
Is it so that VirtualAlloc returns NULL and you are still using the pBuffer?
Or something else?

[risa]

yes.............virtualalloc() is returning NULL hence when used in pBuffer it crashes...........i want to allocate more than 400MB upto say 1GB.