| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>Platform-Specific Implementation Notes</title> |
| <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> |
| <link rel="home" href="../../boost_asio.html" title="Boost.Asio"> |
| <link rel="up" href="../overview.html" title="Overview"> |
| <link rel="prev" href="ssl.html" title="SSL"> |
| <link rel="next" href="../using.html" title="Using Boost.Asio"> |
| </head> |
| <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> |
| <table cellpadding="2" width="100%"><tr> |
| <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> |
| <td align="center"><a href="../../../../index.html">Home</a></td> |
| <td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> |
| <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> |
| <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> |
| <td align="center"><a href="../../../../more/index.htm">More</a></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="ssl.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../using.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_asio.overview.implementation"></a><a class="link" href="implementation.html" title="Platform-Specific Implementation Notes">Platform-Specific |
| Implementation Notes</a> |
| </h3></div></div></div> |
| <p> |
| This section lists platform-specific implementation details, such as the |
| default demultiplexing mechanism, the number of threads created internally, |
| and when threads are created. |
| </p> |
| <a name="boost_asio.overview.implementation.linux_kernel_2_4"></a><h5> |
| <a name="id775193"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.linux_kernel_2_4">Linux |
| Kernel 2.4</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for demultiplexing. |
| This means that the number of file descriptors in the process cannot |
| be permitted to exceed <code class="computeroutput"><span class="identifier">FD_SETSIZE</span></code>. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">select</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.linux_kernel_2_6"></a><h5> |
| <a name="id775520"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.linux_kernel_2_6">Linux |
| Kernel 2.6</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">epoll</span></code> for demultiplexing. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">epoll</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.solaris"></a><h5> |
| <a name="id775833"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.solaris">Solaris</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="literal">/dev/poll</code> for demultiplexing. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="literal">/dev/poll</code> is performed in one |
| of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.qnx_neutrino"></a><h5> |
| <a name="id776134"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.qnx_neutrino">QNX Neutrino</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for demultiplexing. |
| This means that the number of file descriptors in the process cannot |
| be permitted to exceed <code class="computeroutput"><span class="identifier">FD_SETSIZE</span></code>. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">select</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.mac_os_x"></a><h5> |
| <a name="id776457"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.mac_os_x">Mac OS X</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">kqueue</span></code> for demultiplexing. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">kqueue</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.freebsd"></a><h5> |
| <a name="id776768"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.freebsd">FreeBSD</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">kqueue</span></code> for demultiplexing. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">kqueue</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.aix"></a><h5> |
| <a name="id777080"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.aix">AIX</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for demultiplexing. |
| This means that the number of file descriptors in the process cannot |
| be permitted to exceed <code class="computeroutput"><span class="identifier">FD_SETSIZE</span></code>. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">select</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.hp_ux"></a><h5> |
| <a name="id777403"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.hp_ux">HP-UX</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for demultiplexing. |
| This means that the number of file descriptors in the process cannot |
| be permitted to exceed <code class="computeroutput"><span class="identifier">FD_SETSIZE</span></code>. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">select</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.tru64"></a><h5> |
| <a name="id777727"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.tru64">Tru64</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for demultiplexing. |
| This means that the number of file descriptors in the process cannot |
| be permitted to exceed <code class="computeroutput"><span class="identifier">FD_SETSIZE</span></code>. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">select</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="number">64</span><span class="special">,</span><span class="identifier">IOV_MAX</span><span class="special">)</span></code> buffers may be transferred in a single |
| operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.windows_95__98_and_me"></a><h5> |
| <a name="id778049"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.windows_95__98_and_me">Windows |
| 95, 98 and Me</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for demultiplexing. |
| </li></ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using <code class="computeroutput"><span class="identifier">select</span></code> |
| is performed in one of the threads that calls <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| For sockets, at most 16 buffers may be transferred in a single operation. |
| </li></ul></div> |
| <a name="boost_asio.overview.implementation.windows_nt__2000__xp__2003_and_vista"></a><h5> |
| <a name="id778332"></a> |
| <a class="link" href="implementation.html#boost_asio.overview.implementation.windows_nt__2000__xp__2003_and_vista">Windows |
| NT, 2000, XP, 2003 and Vista</a> |
| </h5> |
| <p> |
| Demultiplexing mechanism: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Uses overlapped I/O and I/O completion ports for all asynchronous socket |
| operations except for asynchronous connect. |
| </li> |
| <li class="listitem"> |
| Uses <code class="computeroutput"><span class="identifier">select</span></code> for emulating |
| asynchronous connect. |
| </li> |
| </ul></div> |
| <p> |
| Threads: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Demultiplexing using I/O completion ports is performed in all threads |
| that call <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">poll_one</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used for the <code class="computeroutput"><span class="identifier">select</span></code> |
| demultiplexing. This thread is created on the first call to <code class="computeroutput"><span class="identifier">async_connect</span><span class="special">()</span></code>. |
| </li> |
| <li class="listitem"> |
| An additional thread per <code class="computeroutput"><span class="identifier">io_service</span></code> |
| is used to emulate asynchronous host resolution. This thread is created |
| on the first call to either <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">udp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">async_resolve</span><span class="special">()</span></code>. |
| </li> |
| </ul></div> |
| <p> |
| Scatter-Gather: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| For sockets, at most 64 buffers may be transferred in a single operation. |
| </li> |
| <li class="listitem"> |
| For stream-oriented handles, only one buffer may be transferred in a |
| single operation. |
| </li> |
| </ul></div> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2003 - 2010 Christopher M. Kohlhoff<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
| </p> |
| </div></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="ssl.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../using.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |
