DeviceMemoryBuffer#

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.

Method Summary

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

Fields inherited from class ai.rapids.cudf.MemoryBuffer: address, cleaner, closed, id, length, refCount

Methods inherited from class ai.rapids.cudf.MemoryBuffer: addressOutOfBoundsCheck, close, copyFromMemoryBuffer, copyFromMemoryBufferAsync, getAddress, getEventHandler, getLength, getRefCount, incRefCount, noWarnLeakExpected, setEventHandler, toString

Methods inherited from class ai.rapids.cudf.BaseDeviceMemoryBuffer: copyFromDeviceBufferAsync, copyFromHostBuffer, copyFromHostBufferAsync, sliceWithCopy

Methods

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.

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.

Static Methods

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

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

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