Class UnmanagedMemory

java.lang.Object

org.graalvm.nativeimage.UnmanagedMemory

public final class UnmanagedMemory
extends Object

Contains static methods that allow allocate/free of unmanaged memory, i.e., memory that is not under the control of the garbage collector. In a typical C environment, these are the malloc/free functions of the standard C library, however this class makes no assumptions or guarantees about how the memory is managed. In particular, it is not allowed to free memory returned by these allocation function directly using the standard C library (or vice versa).

Since:

19.0

Method Summary

Modifier and Type	Method	Description
static <T extends PointerBase> T	calloc(int size)	Allocates size bytes of unmanaged memory.
static <T extends PointerBase> T	calloc(UnsignedWord size)	Allocates size bytes of unmanaged memory.
static void	free(PointerBase ptr)	Frees unmanaged memory that was previously allocated using methods of this class.
static <T extends PointerBase> T	malloc(int size)	Allocates size bytes of unmanaged memory.
static <T extends PointerBase> T	malloc(UnsignedWord size)	Allocates size bytes of unmanaged memory.
static <T extends PointerBase> T	realloc(T ptr, UnsignedWord size)	Changes the size of the provided unmanaged memory to size bytes of unmanaged memory.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

malloc

public static <T extends PointerBase> T malloc(UnsignedWord size)

Allocates size bytes of unmanaged memory. The content of the memory is undefined.

This method never returns a null pointer, but instead throws an OutOfMemoryError when allocation fails.

Since:

19.0

malloc

public static <T extends PointerBase> T malloc(int size)

Allocates size bytes of unmanaged memory. The content of the memory is undefined.

This method never returns a null pointer, but instead throws an OutOfMemoryError when allocation fails.

Since:

19.0

calloc

public static <T extends PointerBase> T calloc(UnsignedWord size)

Allocates size bytes of unmanaged memory. The content of the memory is set to 0.

This method never returns a null pointer, but instead throws an OutOfMemoryError when allocation fails.

Since:

19.0

calloc

public static <T extends PointerBase> T calloc(int size)

Allocates size bytes of unmanaged memory. The content of the memory is set to 0.

This method never returns a null pointer, but instead throws an OutOfMemoryError when allocation fails.

Since:

19.0

realloc

public static <T extends PointerBase> T realloc(T ptr,
 UnsignedWord size)

Changes the size of the provided unmanaged memory to size bytes of unmanaged memory. If the new size is larger than the old size, the content of the additional memory is undefined.

This method never returns a null pointer, but instead throws an OutOfMemoryError when allocation fails. In that case, the old data is not deallocated and remains unchanged.

Since:

19.0

free

public static void free(PointerBase ptr)

Frees unmanaged memory that was previously allocated using methods of this class. This method is a no-op if the given pointer is null.

Since:

19.0