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<title>Boost.Threads, xtime</title>
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<h3><img src="../../../c++boost.gif" alt="C++ Boost" width="277" height="86"></h3>
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<h1 align="center">Boost.Threads</h1>
<h2 align="center">xtime</h2>
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<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">&lt;boost/thread/xtime.hpp&gt;</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>
<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><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">&lt;boost/thread/thread.hpp&gt;</a>
#include <a href="../../../boost/thread/tss.hpp">&lt;boost/thread/xtime.hpp&gt;</a>
int main(int argc, char* argv[])
{
boost::xtime xt;
boost::xtime_get(&amp;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 -->10 September, 2001<!--webbot bot="Timestamp" endspan i-checksum="39328" -->
</p>
<p><i>© Copyright <a href="mailto:williamkempf@hotmail.com">William E. Kempf</a>
2001 all rights reserved.</i></p>
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