RtAllocateLocalMemoryEx

RtAllocateLocalMemoryEx allocates memory from the external memory allocation space (MSpace) of the current process. RtAllocateLocalMemoryEx allows you to allocate memory without zero-initializing the memory region.

Syntax

PVOID RtAllocateLocalMemoryEx(
    [in]    ULONG Size,
    [in]    ULONG Flags
);

Parameters

[in] Size

An unsigned long specifying the number of bytes to allocate.

[in] Flags

The memory allocation option. This parameter can be one or more of the following values:

Return Value

If the function succeeds, it returns a pointer to the memory. If the function fails, it returns a NULL pointer.

Remarks

RtAllocateLocalMemoryEx is a deterministic memory allocation call and can be called in a shutdown handler, provided the MSpace contains the requested memory.

Note: If the MSpace’s local pool has not been created yet or if the amount of free memory in the pool is not enough for the requested Size, there is Windows interaction involved in an RtAllocateLocalMemoryEx call and the deterministic feature is lost. To avoid that, call RtQueryProcessMSpace first to make sure there is enough free memory in the MSpace.

Note: If the MSpace’s local pool has not been created yet, RtAllocateLocalMemoryEx will initialize the pool with a size equal to the greater value of the Size parameter or the minimum size threshold configured via wRTOS Settings. If the amount of free memory in the pool is not enough for the requested Size, RtAllocateLocalMemoryEx will implicitly expand the pool with a size equal to the max{ MSpacePoolExpandSize, Size }. You can disable this implicitly expand feature overall through wRTOS Settings or individually by using RtssRun /e with nExpandSize equal to 0.

See Also:

• RtExpandMSpace
• RtQueryProcessMSpace
• RtShrinkMSpace