OS_InitAlloc

Syntax

#include <nitro/os.h>

void* OS_InitAlloc( OSArenaId id, void* arenaStart, void* arenaEnd, int maxHeaps );

Arguments

id	The arena ID of the arena for which you will initialize the memory allocation system.
*arenaStart*	Address of the arena's lower boundary
*arenaEnd*	Address of the arena's upper boundary
*maxHeap*	The maximum heap number that can be reserved in that arena.

Return Values

After acquiring the region for heap information at the start of the arena, this function returns the arena's actual 32-byte aligned, lower boundary address.

Description

Initializes memory allocation.

This function must be called first before creating a heap that is specified by the arena ID id. For more information about the arena ID value, see OS_InitArena.

An information region for heaps is reserved at the beginning of the arena. The address that is returned after OS_InitAlloc is the arena's lower boundary address (start address) after the region has been reserved. Therefore, set and correct using the OS_Set*ArenaLo function.

Example:

void* nstart;

// In main memory, initialize all of the arena for the heap region 
// Declares that the maximum number of the heap is 3 
nstart = OS_InitAlloc( OS_ARENA_MAIN, OS_GetMainArenaLo(), OS_GetMainArenaHi(), 3 );

// Lower boundary address of the arena
OS_SetMainArenaLo( nstart );

To start over with the setting, it is necessary to clear the memory allocation system information from arena by using the OS_ClearAlloc function.

Revision History

2004/08/30 Added description for OS_ClearAlloc.
2004/07/06 Added an example.
2004/01/06 Initial version.