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<title>Boost.Threads, xtime</title>
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<table summary="header" border="0" cellpadding="7" cellspacing="0"
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<tr>
<td valign="top" width="300">
<h3><img src="../../../c++boost.gif" alt="C++ Boost" width=
"277" height="86"></h3>
</td>
<td valign="top">
<h1 align="center">Boost.Threads</h1>
<h2 align="center">xtime</h2>
</td>
</tr>
</table>
<hr>
<p><a href="#Introduction">Introduction</a><br>
<a href="#Header">Header</a><br>
<a href="#Synopsis">Synopsis</a><br>
<a href="#Reference">Reference</a><br>
<a href="#Example">Example</a></p>
<h2><a name="Introduction">Introduction</a></h2>
<p>The <code>xtime</code> type is used to represent a point on some
time scale or a duration in time. This type may be proposed for the C
standard by Markus Kuhn. <b>Boost.Threads</b> provides only a very
minimal implementation of this proposal and it's expected that a
full implementation will be provided in Boost as a separate library, at
which time <b>Boost.Threads</b> will deprecate its implementation.</p>
<h2><a name="Header">Header</a></h2>
<pre>
#include <a href=
"../../../boost/thread/xtime.hpp"><boost/thread/xtime.hpp></a>
</pre>
<h2><a name="Synopsis">Synopsis</a></h2>
<pre>
namespace boost {
enum
{
TIME_UTC=1,
};
struct xtime
{
#if defined(BOOST_NO_INT64_T)
int_fast32_t sec;
#else
int_fast64_t sec;
#endif
int_fast32_t nsec;
};
int xtime_get(struct xtime* xtp, int clock_type);
} // namespace boost
</pre>
<h2><a name="Reference">Reference</a></h2>
<hr>
<h3>TIME_UTC</h3>
<p>The clock type for Coordinated Universal Time (UTC). The epoch for
this clock type is 1970-01-01 00:00:00. This is the only clock type
supported by <b>Boost.Threads</b>.</p>
<hr>
<h3>xtime</h3>
<pre>
struct xtime
{
#if defined(BOOST_NO_INT64_T)
int_fast32_t sec;
#else
int_fast64_t sec;
#endif
int_fast32_t nsec;
};
</pre>
<p><b>sec</b> represents the whole seconds that have passed since the
epoch.</p>
<p><b>nsec</b> represents the nanoseconds since <code>sec.</code></p>
<hr>
<h3>xtime_get</h3>
<pre>
int xtime_get(struct xtime* xtp, int clock_type);
</pre>
<p><b>Postcondition:</b> <code>xtp</code> represents the current point
in time as a duration since the epoch specified by the <code>
clock_type</code>.</p>
<p><b>Returns:</b> <code>clock_type</code> if successful, otherwise
0.</p>
<p><b>Notes:</b> The resolution is implementation specific. For many
implementations the best resolution of time is far more than one
nanosecond, and even when the resolution is reasonably good, the
latency of a call to <code>xtime_get()</code> may be significant. For
maximum portability, avoid durations of less than one second.</p>
<hr>
<h2><a name="Example">Example Usage</a></h2>
<pre>
#include <a href=
"../../../boost/thread/thread.hpp"><boost/thread/thread.hpp></a>
#include <a href=
"../../../boost/thread/tss.hpp"><boost/thread/xtime.hpp></a>
int main(int argc, char* argv[])
{
boost::xtime xt;
boost::xtime_get(&xt, boost::TIME_UTC);
xt.sec += 1;
boost::thread::sleep(xt); // Sleep for 1 second
}
</pre>
<hr>
<p>Revised
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->05 November, 2001<!--webbot bot="Timestamp" endspan i-checksum="39359" --></p>
<p><i>© Copyright <a href="mailto:williamkempf@hotmail.com">
William E. Kempf</a> 2001 all rights reserved.</i></p>
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