### _uaddmem -- Add Memory to a Heap

Format

>     #include <umalloc.h>
>     Heap_t _uaddmem(Heap_t heap, void *block, size_t size, int clean);

Language Level: Extension
_uaddmem adds a block of memory of size bytes into the specified user heap (created with _ucreate).

For OS/2, you can use an OS/2 API like DosAllocMem or by allocating it statically.

Before calling _uaddmem, you must first get the block from the operating system, typically, for Windows, by using a Win32 API like VirtualAlloc or by allocating it statically.

If the memory block has been initialized to 0, specify _BLOCK_CLEAN for the clean parameter. If not, specify !_BLOCK_CLEAN. (This information makes calloc and _ucalloc more efficient).

Note: Memory returned by DosAllocMem, on OS/2, is initialized to 0.

Note: On Windows, memory returned by VirtualAlloc is initialized to 0.

For fixed-size heaps, you must return all the blocks you added with _uaddmem to the system. (For expandable heaps, these blocks are returned by your release_fn when you call _udestroy.)

Note: For every block of memory you add, a small number of bytes from it are used to store internal information. To reduce the total amount of overhead, it is better to add a few large blocks of memory than many small blocks.

Return Value
_uaddmem returns a pointer to the heap the memory was added to. If the heap specified is not valid, _uaddmem returns NULL.

Example

Memory Management

_ucreate -- Create a Memory Heap
_udestroy -- Destroy a Heap
_uheapmin -- Release Unused Memory in User Heap
<umalloc.h>