HeapSize

The HeapSize function returns the size, in bytes, of a memory block allocated from a heap by the HeapAlloc or HeapReAlloc function.

DWORD HeapSize(

HANDLE hHeap, // handle to the heap
DWORD dwFlags, // heap size control flags
LPCVOID lpMem // pointer to memory to return size for
);  

Parameters

hHeap

Specifies the heap in which the memory block resides. This handle is returned by the HeapCreate or GetProcessHeap function.

dwFlags

Specifies several controllable aspects of accessing the memory block. Only one flag is currently defined; however, all other flag values are reserved for future use. Specifying this flag will override the corresponding flag specified in the flOptions parameter when the heap was created by using the HeapCreate function:

Value Meaning
HEAP_NO_SERIALIZE Specifies that mutual exclusion will not be used while the function is accessing the heap. For more information about HEAP_NO_SERIALIZE, see the Remarks for HeapCreate.

lpaam

Points to the memory block whose size the function will obtain. This is a pointer returned by the HeapAlloc or HeapReAlloc function.

Return Values

If the function succeeds, the return value is the size, in bytes, of the allocated memory block.

If the function fails, the return value is 0xFFFFFFFF. The function does not call SetLastError. An application cannot call GetLastError for extended error information.

See Also

GetProcessHeap, HeapAlloc, HeapCreate, HeapDestroy, HeapFree, HeapReAlloc, SetLastError