Files
pj2/lib/edu/rit/gpu/GpuShortArray.java
2016-04-27 01:07:35 -04:00

182 lines
6.3 KiB
Java

//******************************************************************************
//
// File: GpuShortArray.java
// Package: edu.rit.gpu
// Unit: Class edu.rit.gpu.GpuShortArray
//
// This Java source file is copyright (C) 2014 by Alan Kaminsky. All rights
// reserved. For further information, contact the author, Alan Kaminsky, at
// ark@cs.rit.edu.
//
// This Java source file is part of the Parallel Java 2 Library ("PJ2"). PJ2 is
// free software; you can redistribute it and/or modify it under the terms of
// the GNU General Public License as published by the Free Software Foundation;
// either version 3 of the License, or (at your option) any later version.
//
// PJ2 is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
// A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// A copy of the GNU General Public License is provided in the file gpl.txt. You
// may also obtain a copy of the GNU General Public License on the World Wide
// Web at http://www.gnu.org/licenses/gpl.html.
//
//******************************************************************************
package edu.rit.gpu;
/**
* Class GpuShortArray provides a short integer array GPU variable. This is an
* array of type <TT>short</TT> stored in the GPU's memory and mirrored in the
* CPU's memory.
* <P>
* Class GpuShortArray supports mirroring all of the GPU's data array in the
* CPU's memory, mirroring only a portion of the GPU's data array in the CPU's
* memory, or mirroring none of the GPU's data array. Class GpuShortArray
* provides operations for copying all or portions of the data array from the
* CPU to the GPU or from the GPU to the CPU.
* <P>
* To use a short integer array GPU variable:
* <OL TYPE=1>
* <P><LI>
* Construct an instance of class GpuShortArray by calling either the {@link
* Gpu#getShortArray(int) getShortArray()} method on a {@linkplain Gpu Gpu}
* object or the {@link Module#getShortArray(String,int) getShortArray()} method
* on a {@linkplain Module Module} object, specifying the length of the array
* and (optionally) the length of the array portion mirrored in the CPU.
* <P><LI>
* Set the {@link #item item} field's elements to the desired values. Call the
* {@link #hostToDev() hostToDev()} method to copy the mirrored portion of the
* array from CPU memory to GPU memory.
* <P><LI>
* Pass the GpuShortArray object as an argument of a GPU kernel function call.
* In the GPU code, this becomes a pointer (type <TT>short int*</TT> or
* <TT>unsigned short int*</TT>) to an array of <I>N</I> data elements, where
* <I>N</I> is the length of the array. The GPU code sets the array's elements
* to the desired values.
* <P><LI>
* Call the {@link #devToHost() devToHost()} method to copy the mirrored portion
* of the array from GPU memory to CPU memory. Examine the values of the {@link
* #item item} field's elements.
* </OL>
*
* @author Alan Kaminsky
* @version 03-Apr-2014
*/
public class GpuShortArray
extends GpuArray
{
// Exported data members.
/**
* The mirrored portion of the short integer array in CPU memory.
*/
public final short[] item;
// Hidden constructors.
/**
* Construct a new dynamically allocated GPU short integer array.
*
* @param gpu Gpu object.
* @param len Number of elements in GPU memory.
* @param cpulen Number of elements mirrored in CPU memory.
*
* @exception GpuException
* (unchecked exception) Thrown if a GPU error occurred.
*/
GpuShortArray
(Gpu gpu,
int len,
int cpulen)
{
super (gpu, len, 2L*len, cpulen);
item = new short [cpulen];
}
/**
* Construct a new statically allocated GPU short integer array.
*
* @param gpu Gpu object.
* @param len Number of elements in GPU memory.
* @param cpulen Number of elements mirrored in CPU memory.
* @param dptr Pointer to array in GPU memory.
*
* @exception GpuException
* (unchecked exception) Thrown if a GPU error occurred.
*/
GpuShortArray
(Gpu gpu,
int len,
int cpulen,
long dptr)
{
super (gpu, len, 2L*len, cpulen, dptr);
item = new short [cpulen];
}
// Exported operations.
/**
* Copy the given portion of this GPU array from the host CPU's memory to
* the GPU device's memory. <TT>len</TT> elements starting at index
* <TT>srcindex</TT> in the CPU array are copied to the GPU array starting
* at index <TT>dstindex</TT>.
*
* @param dstindex GPU array starting index.
* @param srcindex CPU array starting index.
* @param len Number of elements to copy.
*
* @exception IndexOutOfBoundsException
* (unchecked exception) Thrown if <TT>dstindex</TT> &lt; 0,
* <TT>srcindex</TT> &lt; 0, <TT>len</TT> &lt; 0, <TT>dstindex+len</TT>
* &gt; <TT>length()</TT>, or <TT>srcindex+len</TT> &gt;
* <TT>cpuLength()</TT>.
* @exception GpuException
* (unchecked exception) Thrown if a GPU error occurred.
*/
public void hostToDev
(int dstindex,
int srcindex,
int len)
{
if (dstindex < 0 || srcindex < 0 || len < 0 ||
dstindex + len > this.len || srcindex + len > cpulen)
throw new IndexOutOfBoundsException();
if (len > 0)
Cuda.cuMemcpyHtoD (gpu.ctx, dptr, dstindex, item, srcindex, len);
}
/**
* Copy the given portion of this GPU array from the GPU device's memory to
* the host CPU's memory. <TT>len</TT> elements copied starting at index
* <TT>srcindex</TT> in the GPU array are copied to the CPU array starting
* at index <TT>dstindex</TT>.
*
* @param dstindex CPU array starting index.
* @param srcindex GPU array starting index.
* @param len Number of elements to copy.
*
* @exception IndexOutOfBoundsException
* (unchecked exception) Thrown if <TT>dstindex</TT> &lt; 0,
* <TT>srcindex</TT> &lt; 0, <TT>len</TT> &lt; 0, <TT>dstindex+len</TT>
* &gt; <TT>cpuLength()</TT>, or <TT>srcindex+len</TT> &gt;
* <TT>length()</TT>.
* @exception GpuException
* (unchecked exception) Thrown if a GPU error occurred.
*/
public void devToHost
(int dstindex,
int srcindex,
int len)
{
if (dstindex < 0 || srcindex < 0 || len < 0 ||
dstindex + len > cpulen || srcindex + len > this.len)
throw new IndexOutOfBoundsException();
if (len > 0)
Cuda.cuMemcpyDtoH (gpu.ctx, item, dstindex, dptr, srcindex, len);
}
}