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compute/doc/reference/algorithm/copy.xml
Kyle Lutz 4ab37ada07 Add system-wide default command queue
This adds a system-wide default command queue. This queue is
accessible via the new static system::default_queue() method.
The default command queue is created for the default compute
device in the default context and is analogous to the default
stream in CUDA.

This changes how algorithms operate when invoked without an
explicit command queue. Previously, each algorithm had two
overloads, the first expected a command queue to be explicitly
passed and the second would create and use a temporary command
queue. Now, all algorithms take a command queue argument which
has a default value equal to system::default_queue().

This fixes a number of race-conditions and performance issues
througout the library associated with create, using, and
destroying many separate command queues.
2013-05-15 20:59:56 -04:00

118 lines
4.2 KiB
XML

<?xml version="1.0" encoding="utf-8"?>
<header name="boost/compute/algorithm/copy.hpp">
<namespace name="boost">
<namespace name="compute">
<!-- boost::compute::copy(first, last, result, queue) -->
<function name="copy">
<template>
<template-type-parameter name="InputIterator"/>
<template-type-parameter name="OutputIterator"/>
</template>
<type>OutputIterator</type>
<parameter name="first">
<paramtype>InputIterator</paramtype>
</parameter>
<parameter name="last">
<paramtype>InputIterator</paramtype>
</parameter>
<parameter name="result">
<paramtype>OutputIterator</paramtype>
</parameter>
<parameter name="queue">
<paramtype>command_queue &amp;</paramtype>
<default>
<methodname>system::default_queue()</methodname>
</default>
</parameter>
<returns>
An iterator pointing to the end of the result range.
</returns>
<description>
<para>
Copies the values from the range [<code>first</code>,
<code>last</code>) to the range beginning at <code>result</code>.
</para>
<para>
The copy() function is one of the few Boost.Compute algorithms
which can take both device and host iterators as arguments. For
example, to copy values from a vector on the host to a vector on
the device:
<programlisting>
std::vector&lt;int&gt; host_vector = ...
<classname>boost::compute::vector</classname>&lt;int&gt; device_vector = ...
// copy all values in host_vector to device_vector
<functionname>boost::compute::copy</functionname>(host_vector.begin(),
host_vector.end(),
device_vector.begin());
</programlisting>
</para>
<para>
The generic <code>copy()</code> function can be used for a variety
of data transfer tasks and provides a standard interface to the
following OpenCL functions:
<itemizedlist>
<listitem><code>clEnqueueReadBuffer()</code></listitem>
<listitem><code>clEnqueueWriteBuffer()</code></listitem>
<listitem><code>clEnqueueCopyBuffer()</code></listitem>
</itemizedlist>
Unlike the aforementioned OpenCL functions, <code>copy()</code>
will also work with non-contiguous data-structures (e.g.
<code>std::list&lt;T&gt;</code>) as well as with "fancy"
iterators (e.g. <classname>transform_iterator</classname>).
</para>
<para>
See also: <functionname>copy_n()</functionname>,
<functionname>copy_if()</functionname>,
<functionname>copy_async()</functionname>
</para>
</description>
</function>
<!-- boost::compute::copy_async(first, last, result, queue) -->
<function name="copy_async">
<template>
<template-type-parameter name="InputIterator"/>
<template-type-parameter name="OutputIterator"/>
</template>
<type><classname>future</classname>&lt;OutputIterator&gt;</type>
<parameter name="first">
<paramtype>InputIterator</paramtype>
</parameter>
<parameter name="last">
<paramtype>InputIterator</paramtype>
</parameter>
<parameter name="result">
<paramtype>OutputIterator</paramtype>
</parameter>
<parameter name="queue">
<paramtype>command_queue &amp;</paramtype>
<default>
<methodname>system::default_queue()</methodname>
</default>
</parameter>
<returns>
A <classname>future</classname> containing an iterator pointing to
the end of the result range.
</returns>
<description>
<para>
Copies the values from the range [<code>first</code>,
<code>last</code>) to the range beginning at <code>result</code>.
The copy is performed asynchronously.
</para>
</description>
</function>
</namespace>
</namespace>
</header>