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| <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN" |
| "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd"> |
| <refentry> |
| <refentryinfo> |
| <keywordset> |
| <keyword>clCreateSubBuffer</keyword> |
| </keywordset> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle> |
| clCreateSubBuffer |
| </refentrytitle> |
| |
| <refmiscinfo> |
| <copyright> |
| <year>2007-2010</year> |
| <holder>The Khronos Group Inc. |
| Permission is hereby granted, free of charge, to any person obtaining a |
| copy of this software and/or associated documentation files (the |
| "Materials"), to deal in the Materials without restriction, including |
| without limitation the rights to use, copy, modify, merge, publish, |
| distribute, sublicense, and/or sell copies of the Materials, and to |
| permit persons to whom the Materials are furnished to do so, subject to |
| the condition that this copyright notice and permission notice shall be included |
| in all copies or substantial portions of the Materials.</holder> |
| </copyright> |
| </refmiscinfo> |
| <manvolnum>3</manvolnum> |
| |
| </refmeta> |
| |
| |
| <!-- ================================ SYNOPSIS --> |
| |
| <refnamediv id="clCreateSubBuffer"> |
| <refname> |
| clCreateSubBuffer |
| </refname> |
| |
| <refpurpose> |
| Creates a buffer object (referred to as a sub-buffer object) from an existing |
| buffer object. |
| </refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv xmlns:xlink="http://www.w3.org/1999/xlink"><title></title> |
| <funcsynopsis> |
| <funcprototype> |
| <funcdef> |
| <link xlink:href="abstractDataTypes.html">cl_mem</link> <function>clCreateSubBuffer</function> |
| </funcdef> |
| |
| <paramdef><link xlink:href="abstractDataTypes.html">cl_mem</link><parameter>buffer</parameter></paramdef> |
| <paramdef><link xlink:href="enums.html#cl_mem_flags">cl_mem_flags</link><parameter>flags</parameter></paramdef> |
| <paramdef><link xlink:href="enums.html#cl_buffer_create_type">cl_buffer_create_type</link><parameter>buffer_create_type</parameter></paramdef> |
| <paramdef>const <link xlink:href="scalarDataTypes.html">void</link><parameter>*buffer_create_info</parameter></paramdef> |
| <paramdef><link xlink:href="scalarDataTypes.html">cl_int</link><parameter>*errcode_ret</parameter></paramdef> |
| |
| </funcprototype> |
| </funcsynopsis> |
| </refsynopsisdiv> |
| |
| |
| <!-- ================================ PARAMETERS --> |
| |
| <refsect1 id="parameters"> |
| <title>Parameters</title> |
| <variablelist> |
| |
| <varlistentry> |
| <term><varname>buffer</varname></term> |
| <listitem> |
| <para>A valid object. Cannot be a sub-buffer object.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <varname>flags</varname> |
| </term> |
| <listitem> |
| <para> <!-- parameter description --> |
| A bit-field that is used to specify allocation and usage information about the image memory |
| object being created. The |
| following table describes the possible values for <varname>flags</varname>: |
| </para> |
| |
| <informaltable frame="all"> |
| <tgroup cols="2" align="left" colsep="1" rowsep="1"> |
| <colspec colname="col1" colnum="1" /> |
| <thead> |
| <row> |
| <entry>cl_mem_flags</entry> |
| <entry>Description</entry> |
| </row> |
| </thead> |
| <tbody> |
| |
| <row> |
| <entry><constant>CL_MEM_READ_WRITE</constant></entry> |
| <entry> |
| This flag specifies that the memory object will be read and |
| written by a kernel. This is the default. |
| </entry> |
| </row> |
| |
| <row> |
| <entry><constant>CL_MEM_WRITE_ONLY</constant></entry> |
| <entry> |
| <para>This flags specifies that the memory object will be written |
| but not read by a kernel.</para> |
| <para>Reading from a buffer or image object created with |
| <constant>CL_MEM_WRITE_ONLY</constant> inside a kernel is undefined.</para> |
| </entry> |
| </row> |
| |
| <row> |
| <entry><constant>CL_MEM_READ_ONLY</constant></entry> |
| <entry> |
| <para>This flag specifies that the memory object is a read-only |
| memory object when used inside a kernel.</para> |
| <para>Writing to a buffer or image object created with |
| <constant>CL_MEM_READ_ONLY</constant> inside a kernel is undefined.</para> |
| </entry> |
| </row> |
| |
| <row> |
| <entry><constant>CL_MEM_USE_HOST_PTR</constant></entry> |
| <entry> |
| <para>This flag is valid only if <varname>host_ptr</varname> is not NULL. If |
| specified, it indicates that the application wants the |
| OpenCL implementation to use memory referenced by |
| <varname>host_ptr</varname> as the storage bits for the memory object.</para> |
| <para>OpenCL implementations are allowed to cache the buffer |
| contents pointed to by <varname>host_ptr</varname> in device memory. This |
| cached copy can be used when kernels are executed on a |
| device.</para> |
| <para>The result of OpenCL commands that operate on multiple |
| buffer objects created with the same <varname>host_ptr</varname> or |
| overlapping host regions is considered to be undefined.</para> |
| </entry> |
| </row> |
| |
| <row> |
| <entry><constant>CL_MEM_ALLOC_HOST_PTR</constant></entry> |
| <entry> |
| <para>This flag specifies that the application wants the OpenCL |
| implementation to allocate memory from host accessible |
| memory.</para> |
| <para> |
| <constant>CL_MEM_ALLOC_HOST_PTR</constant> and |
| <constant>CL_MEM_USE_HOST_PTR</constant> are mutually exclusive.</para> |
| </entry> |
| </row> |
| |
| <row> |
| <entry><constant>CL_MEM_COPY_HOST_PTR</constant></entry> |
| <entry> |
| <para> |
| This flag is valid only if <varname>host_ptr</varname> is not NULL. If |
| specified, it indicates that the application wants the |
| OpenCL implementation to allocate memory for the |
| memory object and copy the data from memory referenced |
| by <varname>host_ptr</varname>. |
| </para> |
| <para> |
| <constant>CL_MEM_COPY_HOST_PTR</constant> and |
| <constant>CL_MEM_USE_HOST_PTR</constant> are mutually exclusive. |
| </para> |
| <para> |
| <constant>CL_MEM_COPY_HOST_PTR</constant> can be used with |
| <constant>CL_MEM_ALLOC_HOST_PTR</constant> to initialize the contents of |
| the cl_mem object allocated using host-accessible (e.g. |
| PCIe) memory. |
| </para> |
| </entry> |
| </row> |
| </tbody> |
| </tgroup> |
| </informaltable> |
| </listitem> |
| </varlistentry> |
| <!-- END PARAMETER TABLE --> |
| |
| <varlistentry> |
| <term><varname>buffer_create_type</varname> and <varname>buffer_create_info</varname></term> |
| <listitem> |
| <para>The type of buffer object to be created. The supported value for <varname>buffer_create_type</varname> is CL_BUFFER_CREATE_TYPE_REGION, which create a buffer object that represents a specific region in <varname>buffer</varname>. <varname>buffer_create_info</varname> is a pointer to the following structure:</para> |
| <literallayout> |
| typedef struct _cl_buffer_region { |
| size_t origin; |
| size_t size; |
| } cl_buffer_region; |
| </literallayout> |
| |
| <para>(<varname>origin, size</varname>) defines the offset and size in bytes in <varname>buffer</varname>.</para> |
| |
| <para>If <varname>buffer</varname> is created with CL_MEM_USE_HOST_PTR, the <varname>host_ptr</varname> associated with the buffer object returned is <varname>host_ptr</varname> + <varname>origin</varname>.</para> |
| |
| <para>The buffer object returned references the data store allocated for <varname>buffer</varname> and points to a specific region given by (<varname>origin, size</varname>) in this data store.</para> |
| |
| <para>CL_INVALID_VALUE is returned in <varname>errcode_ret</varname> if the region specified by (<varname>origin, size</varname>) is out of bounds in <varname>buffer</varname>.</para> |
| |
| <para>CL_MISALIGNED_SUB_BUFFER_OFFSET is returned in <varname>errcode_ret</varname> if there are no devices in context associated with <varname>buffer</varname> for which the <varname>origin</varname> value is aligned to the CL_DEVICE_MEM_BASE_ADDR_ALIGN value.</para> |
| |
| |
| |
| |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>errcode_ret</varname></term> |
| <listitem> |
| <para> <!-- parameter description --> |
| Returns an appropriate error code. If <varname>errcode_ret</varname> is NULL, no error code is returned. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| |
| <!-- ================================ NOTES --> |
| <refsect1 id="notes"><title>Notes</title> |
| <para> |
| The implementation may return the same <citerefentry href="abstractDataTypes"><refentrytitle>cl_mem</refentrytitle></citerefentry> object with the reference count incremented |
| appropriately for multiple calls to <function>clCreateSubBuffer</function> that use the same values for <varname>buffer</varname>, <varname>flags</varname>, <varname>buffer_create_type</varname> and <varname>buffer_create_info</varname> points to the same descriptor or descriptors that |
| describe values that are exactly the same. |
| </para> |
| <para> |
| The result of OpenCL commands that read from and write to multiple sub-buffer objects created |
| using <function>clCreateSubBuffer</function> with the same buffer object but represent overlapping regions in the |
| buffer object is undefined. The result of OpenCL commands that read from and write to a buffer |
| object and its sub-buffer object(s) created using <function>clCreateSubBuffer</function> with the same buffer object |
| is undefined. OpenCL commands that only read from multiple sub-buffer objects created using |
| <function>clCreateSubBuffer</function> with the same buffer object but represent overlapping regions in the buffer |
| object or read from a buffer object and its sub-buffer objects should work as defined. |
| </para> |
| </refsect1> |
| |
| |
| <!-- ================================ ERRORS --> |
| |
| <refsect1 id="errors"><title>Errors</title> |
| <para> |
| Returns a valid non-zero buffer object and <varname>errcode_ret</varname> is set to <errorname>CL_SUCCESS</errorname> if |
| the buffer object is created successfully. Otherwise, it returns one of the following error in <varname>errcode_ret</varname>: |
| </para> |
| |
| <itemizedlist mark="disc"> |
| <listitem> |
| <errorname>CL_INVALID_MEM_OBJECT</errorname> if <varname>buffer</varname> is not a valid buffer object or is a sub-buffer object. |
| </listitem> |
| |
| <listitem> |
| <errorname>CL_INVALID_VALUE</errorname> if values specified in <varname>flags</varname> are not valid; or if value specified in <varname>buffer_create_type</varname> is not valid; or if value(s) specified in <varname>buffer_create_info</varname> (for a given <varname>buffer_create_type</varname>) is not valid or if <varname>buffer_create_info</varname> is NULL. |
| </listitem> |
| |
| <listitem> |
| <errorname>CL_OUT_OF_RESOURCES</errorname> if there is a failure to allocate resources required by the |
| OpenCL implementation on the device. |
| </listitem> |
| <listitem> |
| <errorname>CL_OUT_OF_HOST_MEMORY</errorname> if there is a failure to allocate resources required by the |
| OpenCL implementation on the host. |
| </listitem> |
| </itemizedlist> |
| </refsect1> |
| |
| |
| <!-- ================================ EXAMPLE --> |
| <!-- DO NOT DELETE IN CASE AN EXAMPLE IS ADDED IN THE FUTURE --> |
| <!-- |
| <refsect2 id="example1"> |
| <title> |
| Example |
| </title> |
| |
| <informaltable frame="none"> |
| <tgroup cols="1" align="left" colsep="0" rowsep="0"> |
| <colspec colname="col1" colnum="1" /> |
| <tbody> |
| <row> |
| <entry> |
| Example goes here - it will be set in "code" type with white space preserved. |
| </entry> |
| </row> |
| </tbody> |
| </tgroup> |
| </informaltable> |
| </refsect2> |
| --> |
| |
| |
| <!-- ================================ SPECIFICATION --> |
| <!-- Set the "uri" attribute in the <olink /> element to the "named destination" for the PDF page |
| --> |
| <refsect1 id="specification"><title>Specification</title> |
| <para> |
| <imageobject> |
| <imagedata fileref="pdficon_small1.gif" format="gif" /> |
| </imageobject> |
| |
| |
| <olink uri="clCreateSubBuffer">OpenCL Specification</olink> |
| </para> |
| </refsect1> |
| |
| |
| <!-- ================================ ALSO SEE --> |
| |
| |
| <refsect1 id="seealso"><title>Also see</title> |
| <para> |
| <citerefentry><refentrytitle>clCreateBuffer</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clEnqueueReadBuffer</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clEnqueueWriteBuffer</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clEnqueueCopyBuffer</refentrytitle></citerefentry> |
| </para> |
| </refsect1> |
| |
| <!-- ================================ COPYRIGHT --> |
| <!-- Content included from copyright.inc.xsl --> |
| |
| <refsect3 id="Copyright"><title></title> |
| <imageobject> |
| <imagedata fileref="KhronosLogo.jpg" format="jpg" /> |
| </imageobject> |
| <para /> |
| </refsect3> |
| |
| </refentry> |
| |