# IBM Visualization Data Explorer Programmer's Reference

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### DXAllocate, DXAllocateZero, DXAllocateLocal, DXAllocateLocalZero, DXAllocateLocalOnly, DXAllocateLocalOnlyZero

Function Allocate global or local memory.

Syntax

    #include <dx/dx.h>
    Pointer DXAllocate(unsigned int n)
    Pointer DXAllocateZero(unsigned int n)
    Pointer DXAllocateLocal(unsigned int n)
    Pointer DXAllocateLocalZero(unsigned int n)
    Pointer DXAllocateLocalOnly(unsigned int n)
    Pointer DXAllocateLocalOnlyZero(unsigned int n)

.

Functional Details For all of these routines, `n` must be greater than zero.

`DXAllocate` | Allocates `n` bytes of memory in global memory.
`DXAllocateZero` | Allocates and clears `n` bytes of global memory.
`DXAllocateLocal` | On platforms with per-processor local memory (such as multiprocessor workstations), allocates `n` bytes of memory in local memory.
`DXAllocateLocalZero` | Allocates `n` bytes in local memory and zeros the allocated memory.
`DXAllocateLocal`, `DXAllocateLocalZero` | If `n` bytes of local memory are not available, allocate them from global memory.
`DXAllocateLocalOnly`, `DXAllocateLocalOnlyZero` | Allocate local memory only.

On platforms without per-processor local memory (such as all currently supported workstations), `DXAllocateLocal` is identical to `DXAllocate`.

Although local is usually faster than global access, local memory should be used only for Objects within a task or for parts of a module not in a task Group: Objects in local memory cannot be shared between processors. Objects that are the output of a module must be in global memory.

Note: Memory allocated by any routine listed here should be freed (with DXFree) when it is no longer needed.

Return Value Returns a pointer to the allocated memory or returns `NULL` and sets an error code.

See Also `DXAbortTaskGroup, DXAddTask, DXCreateTaskGroup, DXExecuteTaskGroup, DXFree, DXPrintAlloc, DXReAllocate`

13.3 , "Memory Allocation".

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