Package ai.rapids.cudf

Class DeviceMemoryBuffer

java.lang.Object

ai.rapids.cudf.MemoryBuffer

ai.rapids.cudf.BaseDeviceMemoryBuffer

ai.rapids.cudf.DeviceMemoryBuffer

All Implemented Interfaces:

AutoCloseable

public class DeviceMemoryBuffer
extends BaseDeviceMemoryBuffer

This class represents data in some form on the GPU. Closing this object will effectively release the memory held by the buffer. Note that because of pooling in RMM or reference counting if a buffer is sliced it may not actually result in the memory being released.

Nested Class Summary

Nested classes/interfaces inherited from class ai.rapids.cudf.MemoryBuffer

MemoryBuffer.EventHandler, MemoryBuffer.MemoryBufferCleaner

Field Summary

Fields inherited from class ai.rapids.cudf.MemoryBuffer

address, cleaner, closed, id, length, refCount

Method Summary

Modifier and Type	Method	Description
static DeviceMemoryBuffer	allocate(long bytes)	Allocate memory for use on the GPU.
static DeviceMemoryBuffer	allocate(long bytes, Cuda.Stream stream)	Allocate memory for use on the GPU.
static DeviceMemoryBuffer	fromRmm(long address, long lengthInBytes, long rmmBufferAddress)	Wrap an existing RMM allocation in a device memory buffer.
final DeviceMemoryBuffer	slice(long offset, long len)	Slice off a part of the device buffer.

Methods inherited from class ai.rapids.cudf.BaseDeviceMemoryBuffer

copyFromDeviceBufferAsync, copyFromHostBuffer, copyFromHostBuffer, copyFromHostBuffer, copyFromHostBuffer, copyFromHostBuffer, copyFromHostBufferAsync, copyFromHostBufferAsync, sliceWithCopy

Methods inherited from class ai.rapids.cudf.MemoryBuffer

addressOutOfBoundsCheck, close, copyFromMemoryBuffer, copyFromMemoryBufferAsync, getAddress, getEventHandler, getLength, getRefCount, incRefCount, noWarnLeakExpected, setEventHandler, toString

Methods inherited from class java.lang.Object

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

Method Details

fromRmm

public static DeviceMemoryBuffer fromRmm(long address,
 long lengthInBytes,
 long rmmBufferAddress)

Wrap an existing RMM allocation in a device memory buffer. The RMM allocation will be freed when the resulting device memory buffer instance frees its memory resource (i.e.: when its reference count goes to zero).

Parameters:

address - device address of the RMM allocation

lengthInBytes - length of the RMM allocation in bytes

rmmBufferAddress - host address of the rmm::device_buffer that owns the device memory

Returns:

new device memory buffer instance that wraps the existing RMM allocation

allocate

public static DeviceMemoryBuffer allocate(long bytes)

Allocate memory for use on the GPU. You must close it when done.

Parameters:

bytes - size in bytes to allocate

Returns:

the buffer

allocate

public static DeviceMemoryBuffer allocate(long bytes,
 Cuda.Stream stream)

Allocate memory for use on the GPU. You must close it when done.

Parameters:

bytes - size in bytes to allocate

stream - The stream in which to synchronize this command

Returns:

the buffer

slice

public final DeviceMemoryBuffer slice(long offset,
 long len)

Slice off a part of the device buffer. Note that this is a zero copy operation and all slices must be closed along with the original buffer before the memory is released to RMM. So use this with some caution.

Specified by:

slice in class MemoryBuffer

Parameters:

offset - where to start the slice at.

len - how many bytes to slice

Returns:

a device buffer that will need to be closed independently from this buffer.