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| <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN" |
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| <refentry> |
| <refentryinfo> |
| <keywordset> |
| <keyword>clSetKernelArg</keyword> |
| </keywordset> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle> |
| clSetKernelArg |
| </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="clSetKernelArg"> |
| <refname> |
| clSetKernelArg |
| </refname> |
| |
| <refpurpose> |
| Used to set the argument value for a specific argument of a kernel. |
| </refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv xmlns:xlink="http://www.w3.org/1999/xlink"><title></title> |
| <funcsynopsis> |
| <funcprototype> |
| <funcdef> |
| <link xlink:href="scalarDataTypes.html">cl_int</link> |
| <function>clSetKernelArg</function> |
| </funcdef> |
| |
| <paramdef><link xlink:href="abstractDataTypes.html">cl_kernel</link><parameter>kernel</parameter></paramdef> |
| <paramdef><link xlink:href="scalarDataTypes.html">cl_uint</link><parameter>arg_index</parameter></paramdef> |
| <paramdef><link xlink:href="scalarDataTypes.html">size_t</link><parameter>arg_size</parameter></paramdef> |
| <paramdef>const <link xlink:href="scalarDataTypes.html">void</link><parameter>*arg_value</parameter></paramdef> |
| </funcprototype> |
| </funcsynopsis> |
| </refsynopsisdiv> |
| |
| |
| <!-- ================================ PARAMETERS --> |
| <!-- For each <varlistentry />, place the parameter name in <term /><varname />, then the definition in |
| <listitem /><para />. When refering to anything |
| that has a page in this system, use <citerefentry /><refentrytitle /> to make it a link. |
| --> |
| |
| <refsect1 id="parameters"> |
| <title>Parameters</title> |
| <variablelist> |
| <varlistentry> |
| <term> |
| <varname>kernel</varname> |
| </term> |
| <listitem> |
| <para> |
| A valid kernel object. |
| </para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term> |
| <varname>arg_index</varname> |
| </term> |
| |
| <listitem> |
| <para> |
| The argument index. Arguments to the kernel are referred by indices that go from 0 for the leftmost argument to <emphasis>n</emphasis> - 1, where <emphasis>n</emphasis> is the total number of arguments declared by a kernel. |
| </para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term> |
| <varname>arg_value</varname> |
| </term> |
| |
| <listitem> |
| |
| <para> |
| A pointer to data that should be used as the argument value for argument specified |
| by <varname>arg_index</varname>. The argument data pointed to by <varname>arg_value</varname> is copied and the <varname>arg_value</varname> pointer can therefore be reused by the application after <function>clSetKernelArg</function> returns. The argument value specified is the value used by all API calls that enqueue <varname>kernel</varname> (<citerefentry><refentrytitle>clEnqueueNDRangeKernel</refentrytitle></citerefentry> and |
| <citerefentry><refentrytitle>clEnqueueTask</refentrytitle></citerefentry>) until the argument value is changed by a call to <function>clSetKernelArg</function> for <varname>kernel</varname>. |
| </para> |
| |
| <para> |
| If the argument is a memory object (buffer or image), the <varname>arg_value</varname> entry will be a |
| pointer to the appropriate buffer or image object. The memory object must be created with the context |
| associated with the kernel object. A NULL value can also be specified if the argument is a buffer |
| object in which case a NULL value will be used as the value for the argument declared as a |
| pointer to <varname>__global</varname> or <varname>__constant</varname> memory in the kernel. If the |
| argument is declared with the <varname>__local</varname> qualifier, the <varname>arg_value</varname> |
| entry must be NULL. If the argument is of type <varname>sampler_t</varname>, the <varname>arg_value</varname> |
| entry must be a pointer to the sampler object. |
| </para> |
| <para> |
| If the argument is declared to be a pointer of a built-in or user defined type with |
| the <varname>__global</varname> or <varname>__constant</varname> qualifier, the memory object specified as |
| argument value must be a buffer object (or NULL). If the argument is declared with the <varname>__constant</varname> |
| qualifier, the size in bytes of the memory object cannot exceed CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE and the |
| number of arguments declared with the <varname>__constant</varname> qualifier cannot exceed |
| CL_DEVICE_MAX_CONSTANT_ARGS. |
| </para> |
| |
| <para> |
| The memory object specified as argument value must be a 2D image object if the argument is |
| declared to be of type <varname>image2d_t</varname>. The memory object specified as argument value must |
| be a 3D image object if argument is declared to be of type <varname>image3d_t</varname>. |
| </para> |
| <para> |
| For all other kernel arguments, the <varname>arg_value</varname> entry must be a pointer to the actual |
| data to be used as argument value. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <varname> |
| arg_size |
| </varname> |
| </term> |
| |
| <listitem> |
| <para> |
| Specifies the size of the argument value. If the argument is a memory object, the size is |
| the size of the buffer or image object type. For arguments declared with the <varname>__local</varname> |
| qualifier, the size specified will be the size in bytes of the buffer that must be allocated |
| for the <varname>__local</varname> argument. If the argument is of type <varname>sampler_t</varname>, |
| the <varname>arg_size</varname> value must be equal to <code>sizeof(cl_sampler)</code>. For all other |
| arguments, the size will be the size of argument type. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| |
| <!-- ================================ NOTES --> |
| <!-- Use <function /> to refer ONLY to the function that this page describes. All other functions should use |
| <citerefentry /><refentrytitle /> to make it a link. Use <varname /> for parameters. Use <constant /> for |
| constants (or anything to be set in monospace, non-bold type. --> |
| |
| <refsect1 id="notes"><title>Notes</title> |
| <para> |
| A kernel object does not update the reference count for objects such as memory, sampler |
| objects specified as argument values by <function>clSetKernelArg</function>. Users may not rely on a kernel object |
| to retain objects specified as argument values to the kernel. |
| </para> |
| <para> |
| Implementations shall not allow cl_kernel objects to hold reference counts to cl_kernel arguments, because no |
| mechanism is provided for the user to tell the kernel to release that ownership right. If the kernel holds ownership |
| rights on kernel args, that would make it impossible for the user to tell with certainty when he may safely release |
| user allocated resources associated with OpenCL objects such as the cl_mem backing store used with |
| <constant>CL_MEM_USE_HOST_PTR</constant>. |
| </para> |
| <para> |
| An OpenCL API call is considered to be thread-safe if the internal state as |
| managed by OpenCL remains consistent when called simultaneously by multiple host threads. |
| OpenCL API calls that are thread-safe allow an application to call these functions in multiple |
| host threads without having to implement mutual exclusion across these host threads i.e. they are |
| also re-entrant-safe. |
| </para> |
| <para> |
| All OpenCL API calls are thread-safe except <function>clSetKernelArg</function>, which is safe to call |
| from any host thread, and is safe to call re-entrantly so long as concurrent calls operate on |
| different cl_kernel objects. However, the behavior of the cl_kernel object is undefined if |
| <function>clSetKernelArg</function> is called from multiple host threads on the same cl_kernel object at the same |
| time. |
| </para> |
| <para> |
| There is an inherent race condition in the design of OpenCL that occurs between setting a kernel argument and |
| using the kernel with <citerefentry><refentrytitle>clEnqueueNDRangeKernel</refentrytitle></citerefentry> or <citerefentry><refentrytitle>clEnqueueTask</refentrytitle></citerefentry>. Another host thread might change the kernel |
| arguments between when a host thread sets the kernel arguments and then enqueues the kernel, causing the wrong |
| kernel arguments to be enqueued. Rather than attempt to share cl_kernel objects among multiple host threads, |
| applications are strongly encouraged to make additional cl_kernel objects for kernel functions for each host thread. |
| </para> |
| </refsect1> |
| |
| |
| <!-- ================================ ERRORS --> |
| |
| |
| <refsect1 id="errors"><title>Errors</title> |
| <para> |
| <function>clSetKernelArg</function> returns <errorname>CL_SUCCESS</errorname> if the function is |
| executed successfully. Otherwise, it returns one of the following errors: |
| </para> |
| <itemizedlist mark="disc"> |
| <listitem> |
| <errorname>CL_INVALID_KERNEL</errorname> if <varname>kernel</varname> is not a valid kernel object. |
| </listitem> |
| <listitem> |
| <errorname>CL_INVALID_ARG_INDEX</errorname> if <varname>arg_index</varname> is not a valid argument index. |
| </listitem> |
| <listitem> |
| <errorname>CL_INVALID_ARG_VALUE</errorname> if <varname>arg_value</varname> specified is NULL for an argument that is not |
| declared with the <varname>__local</varname> qualifier or vice-versa. |
| </listitem> |
| <listitem> |
| <errorname>CL_INVALID_MEM_OBJECT</errorname> for an argument declared to be a memory object when the |
| specified <varname>arg_value</varname> is not a valid memory object. |
| </listitem> |
| <listitem> |
| <errorname>CL_INVALID_SAMPLER</errorname> for an argument declared to be of type <varname>sampler_t</varname> when |
| the specified <varname>arg_value</varname> is not a valid sampler object. |
| </listitem> |
| <listitem> |
| <errorname>CL_INVALID_ARG_SIZE</errorname> if <varname>arg_size</varname> does not match the size of the |
| data type for an argument that is not a memory object or if the argument is a memory object |
| and <varname>arg_size</varname> != <constant>sizeof(cl_mem)</constant> or if <varname>arg_size</varname> is zero |
| and the argument is declared with the <citerefentry href="local"><refentrytitle>__local</refentrytitle></citerefentry> |
| qualifier or if the argument is a sampler and <varname>arg_size</varname> != <constant>sizeof(cl_sampler)</constant>. |
| </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> |
| __kernel void |
| image_filter (int n, int m, |
| __constant float *filter_weights, |
| __read_only image2d_t src_image, |
| __write_only image2d_t dst_image) |
| { |
| ... |
| } |
| </entry> |
| </row> |
| </tbody> |
| </tgroup> |
| </informaltable> |
| <para> |
| Argument index values for <constant>image_filter</constant> will be 0 for n, 1 for m, 2 for |
| <constant>filter_weights</constant>, 3 for <constant>src_image</constant> and 4 for <constant>dst_image</constant>. |
| </para> |
| </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="clSetKernelArg">OpenCL Specification</olink> |
| </para> |
| </refsect1> |
| |
| |
| <!-- ================================ ALSO SEE --> |
| |
| |
| <refsect1 id="seealso"><title>Also see</title> |
| <para> |
| <citerefentry><refentrytitle>clCreateKernel</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clCreateKernelsInProgram</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clReleaseKernel</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clRetainKernel</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clGetKernelInfo</refentrytitle></citerefentry>, |
| <citerefentry><refentrytitle>clGetKernelWorkGroupInfo</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> |
| |