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| <refentry> |
| <refentryinfo> |
| <keywordset> |
| <keyword>clSetKernelArg</keyword> |
| </keywordset> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle> |
| clSetKernelArg |
| </refentrytitle> |
| |
| <refmiscinfo> |
| <copyright> |
| <year>2007-2011</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" xmlns:xlink="http://www.w3.org/1999/xlink"> |
| <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, image or image array), the |
| <varname>arg_value</varname> entry will be a pointer to the appropriate |
| buffer, image or image array object. The memory object must be created |
| with the context associated with the kernel object. If the argument |
| is a buffer object, the <varname>arg_value</varname> pointer can be |
| NULL or point to a NULL value in which case a NULL value will be used |
| as the value for the argument declared as a pointer to <citerefentry |
| href="global"><refentrytitle>__global</refentrytitle></citerefentry> |
| or <citerefentry |
| href="constant"><refentrytitle>__constant</refentrytitle></citerefentry> |
| memory in the kernel. If the argument is declared with the <citerefentry |
| href="local"><refentrytitle>__local</refentrytitle></citerefentry> |
| qualifier, the <varname>arg_value</varname> entry must be NULL. If the |
| argument is of type sampler_t, 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 scalar or vector |
| type, or a user defined structure type in the global or constant address |
| space, the memory object specified as argument value must be a buffer |
| object (or NULL). If the argument is declared with the <citerefentry |
| href="constant"><refentrytitle>__constant</refentrytitle></citerefentry> |
| qualifier, the size in bytes of the memory object cannot |
| exceed <constant>CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE</constant> |
| and the number of arguments declared as pointers to <citerefentry |
| href="constant"><refentrytitle>__constant</refentrytitle></citerefentry> |
| memory cannot exceed <constant>CL_DEVICE_MAX_CONSTANT_ARGS</constant>. |
| </para> |
| |
| <para> |
| The memory object specified as argument value must be a 2D image object if the argument is |
| declared to be of type <link xlink:href="abstractDataTypes.html">image2d_t</link>. The memory object |
| specified as argument value must be a 3D image object if argument is declared to be of type |
| <link xlink:href="abstractDataTypes.html">image3d_t</link>. The memory object specified as |
| argument value must be a 1D image object if the argument is declared to be of type |
| <link xlink:href="abstractDataTypes.html">image1d_t</link>. The memory object specified as |
| argument value must be a 1D image buffer object if the argument is declared to be of type |
| <link xlink:href="abstractDataTypes.html">image1d_buffer_t</link>. |
| The memory object specified as argument value must be a 1D image array object if argument |
| is declared to be of type <link xlink:href="abstractDataTypes.html">image1d_array_t</link>. |
| The memory object specified as argument value must be a 2D image array object if argument is |
| declared to be of type <link xlink:href="abstractDataTypes.html">image2d_array_t</link>. |
| </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 <citerefentry |
| href="local"><refentrytitle>__local</refentrytitle></citerefentry> |
| qualifier, the size specified will be the size in bytes |
| of the buffer that must be allocated for the <citerefentry |
| href="local"><refentrytitle>__local</refentrytitle></citerefentry> |
| argument. If the argument is of type <type>sampler_t</type>, |
| 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> |
| <!-- from the spec's glossary --> An OpenCL API call is considered to be |
| <emphasis>thread-safe</emphasis> if the internal state as managed by OpenCL remains |
| consistent when called simultaneously by multiple <emphasis>host</emphasis> threads. |
| OpenCL API calls that are <emphasis>thread-safe</emphasis> allow an application to |
| call these functions in multiple <emphasis>host</emphasis> threads without having to |
| implement mutual exclusion across these <emphasis>host</emphasis> threads i.e. they |
| are also re-entrant-safe. |
| </para> |
| |
| <para> |
| <!-- core spec p. 354, section A.2 --> All OpenCL API calls are thread-safe except |
| <function>clSetKernelArg</function>. <function>clSetKernelArg</function> 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. Please note that there |
| are additional limitations as to which OpenCL APIs may be called from OpenCL callback |
| functions -- please see section 5.9. |
| </para> |
| |
| <para> |
| <!-- core spec p. 354, section A.2 --> 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 not a valid value. |
| </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_INVALID_ARG_VALUE</errorname> if the argument is an image declared |
| with the <constant>read_only</constant> qualifier and <varname>arg_value</varname> |
| refers to an image object created with <varname>cl_mem_flags</varname> of |
| <constant>CL_MEM_WRITE</constant> or if the image argument is declared with |
| the <constant>write_only</constant> qualifier and <varname>arg_value</varname> |
| refers to an image object created with <varname>cl_mem_flags</varname> of |
| <constant>CL_MEM_READ</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 <constant>n</constant>, 1 for <constant>m</constant>, 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> |
| |
| <!-- 17-Oct-2011 --> |
| </refentry> |
| |
