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diff --git a/static/freebsd/man7/clocks.7 3.html b/static/freebsd/man7/clocks.7 3.html new file mode 100644 index 00000000..a984c8b9 --- /dev/null +++ b/static/freebsd/man7/clocks.7 3.html @@ -0,0 +1,105 @@ +<table class="head"> + <tr> + <td class="head-ltitle">CLOCKS(7)</td> + <td class="head-vol">Miscellaneous Information Manual</td> + <td class="head-rtitle">CLOCKS(7)</td> + </tr> +</table> +<div class="manual-text"> +<section class="Sh"> +<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1> +<p class="Pp"><code class="Nm">clocks</code> — <span class="Nd">various + system timers</span></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> +<p class="Pp"><code class="In">#include + <<a class="In">time.h</a>></code></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> +<p class="Pp"><code class="Dv">HZ</code> is not part of the application + interface in <span class="Ux">BSD</span>.</p> +<p class="Pp">There are many different real and virtual (timekeeping) clocks + with different frequencies:</p> +<ul class="Bl-bullet"> + <li>The scheduling clock. This is a real clock with frequency that happens to + be 100. It is not available to applications.</li> + <li>The statistics clock. This is a real clock with frequency that happens to + be 128. It is not directly available to applications.</li> + <li>The clock reported by <a class="Xr">clock(3)</a>. This is a virtual clock + with a frequency that happens to be 128. Its actual frequency is given by + the macro <code class="Dv">CLOCKS_PER_SEC</code>. Note that + <code class="Dv">CLOCKS_PER_SEC</code> may be floating point. Do not use + <a class="Xr">clock(3)</a> in new programs under + <span class="Ux">FreeBSD</span>. It is feeble compared with + <a class="Xr">getrusage(2)</a>. It is provided for ANSI conformance. It is + implemented by calling <a class="Xr">getrusage(2)</a> and throwing away + information and resolution.</li> + <li id="sysconf">The clock reported by <a class="Xr">times(3)</a>. This is a + virtual clock with a frequency that happens to be 128. Its actual + frequency is given by the macro <code class="Dv">CLK_TCK</code> + (deprecated; do not use) and by + <a class="permalink" href="#sysconf"><code class="Fn">sysconf</code></a>(<var class="Fa">_SC_CLK_TCK</var>) + and by <a class="Xr">sysctl(3)</a>. Note that its frequency may be + different from <code class="Dv">CLOCKS_PER_SEC</code>. Do not use + <a class="Xr">times(3)</a> in new programs under + <span class="Ux">FreeBSD</span>. It is feeble compared with + <a class="Xr">gettimeofday(2)</a> together with + <a class="Xr">getrusage(2)</a>. It is provided for POSIX conformance. It + is implemented by calling <a class="Xr">gettimeofday(2)</a> and + <a class="Xr">getrusage(2)</a> and throwing away information and + resolution.</li> + <li>The profiling clock. This is a real clock with frequency 1024. It is used + mainly by <a class="Xr">moncontrol(3)</a> and <a class="Xr">gprof(1)</a>. + Applications should determine its actual frequency using + <a class="Xr">sysctl(3)</a> or by reading it from the header in the + profiling data file.</li> + <li>The mc146818a clock. This is a real clock with a nominal frequency of + 32768. It is divided down to give the statistic clock and the profiling + clock. It is not available to applications.</li> + <li>The microseconds clock. This is a virtual clock with frequency 1000000. It + is used for most timekeeping in <span class="Ux">BSD</span> and is + exported to applications in <a class="Xr">getrusage(2)</a>, + <a class="Xr">gettimeofday(2)</a>, <a class="Xr">select(2)</a>, + <a class="Xr">getitimer(2)</a>, etc. This is the clock that should + normally be used by <span class="Ux">BSD</span> applications.</li> + <li>The i8254 clock. This is a real clock/timer with a nominal frequency of + 1193182. It has three independent time counters to be used. It is divided + down to give the scheduling clock. It is not available to + applications.</li> + <li>The TSC clock (64-bit register) on fifth-generation or later x86 systems. + This is a real clock with a frequency that is equivalent to the number of + cycles per second of the CPU(s). Its frequency can be found using the + <var class="Va">machdep.tsc_freq</var> sysctl, if it is available. It is + used to interpolate between values of the scheduling clock.</li> + <li>The ACPI clock. This is a real clock/timer with a nominal frequency of + 3579545. It is accessed via a 24 or 32 bit register. Unlike the TSC clock, + it maintains a constant tick rate even when the CPU sleeps or its clock + rate changes. It is not available to applications.</li> +</ul> +<p class="Pp">Summary: if <code class="Dv">HZ</code> is not 1000000 then the + application is probably using the wrong clock.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE + ALSO</a></h1> +<p class="Pp"><a class="Xr">gprof(1)</a>, <a class="Xr">clock_gettime(2)</a>, + <a class="Xr">getitimer(2)</a>, <a class="Xr">getrusage(2)</a>, + <a class="Xr">gettimeofday(2)</a>, <a class="Xr">select(2)</a>, + <a class="Xr">clock(3)</a>, <a class="Xr">moncontrol(3)</a>, + <a class="Xr">times(3)</a></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="AUTHORS"><a class="permalink" href="#AUTHORS">AUTHORS</a></h1> +<p class="Pp">This manual page was written by <span class="An">Jörg + Wunsch</span> after a description posted by <span class="An">Bruce + Evans</span>.</p> +</section> +</div> +<table class="foot"> + <tr> + <td class="foot-date">January 18, 2008</td> + <td class="foot-os">FreeBSD 15.0</td> + </tr> +</table> |