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<table class="head">
<tr>
<td class="head-ltitle">PTHREAD_SPIN_LOCK(3)</td>
<td class="head-vol">Library Functions Manual</td>
<td class="head-rtitle">PTHREAD_SPIN_LOCK(3)</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">pthread_spin_lock</code>,
<code class="Nm">pthread_spin_trylock</code>,
<code class="Nm">pthread_spin_unlock</code> — <span class="Nd">lock
or unlock a spin lock</span></p>
</section>
<section class="Sh">
<h1 class="Sh" id="LIBRARY"><a class="permalink" href="#LIBRARY">LIBRARY</a></h1>
<p class="Pp"><span class="Lb">POSIX Threads Library (libpthread,
-lpthread)</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">pthread.h</a>></code></p>
<p class="Pp"><var class="Ft">int</var>
<br/>
<code class="Fn">pthread_spin_lock</code>(<var class="Fa" style="white-space: nowrap;">pthread_spinlock_t
*lock</var>);</p>
<p class="Pp"><var class="Ft">int</var>
<br/>
<code class="Fn">pthread_spin_trylock</code>(<var class="Fa" style="white-space: nowrap;">pthread_spinlock_t
*lock</var>);</p>
<p class="Pp"><var class="Ft">int</var>
<br/>
<code class="Fn">pthread_spin_unlock</code>(<var class="Fa" style="white-space: nowrap;">pthread_spinlock_t
*lock</var>);</p>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
<p class="Pp">The
<a class="permalink" href="#pthread_spin_lock"><code class="Fn" id="pthread_spin_lock">pthread_spin_lock</code></a>()
function will acquire <var class="Fa">lock</var> if it is not currently
owned by another thread. If the lock cannot be acquired immediately, it will
spin attempting to acquire the lock (it will not sleep) until it becomes
available.</p>
<p class="Pp" id="pthread_spin_trylock">The
<a class="permalink" href="#pthread_spin_trylock"><code class="Fn">pthread_spin_trylock</code></a>()
function is the same as <code class="Fn">pthread_spin_lock</code>() except
that if it cannot acquire <var class="Fa">lock</var> immediately it will
return with an error.</p>
<p class="Pp" id="pthread_spin_unlock">The
<a class="permalink" href="#pthread_spin_unlock"><code class="Fn">pthread_spin_unlock</code></a>()
function will release <var class="Fa">lock</var>, which must have been
previously locked by a call to <code class="Fn">pthread_spin_lock</code>()
or <code class="Fn">pthread_spin_trylock</code>().</p>
</section>
<section class="Sh">
<h1 class="Sh" id="RETURN_VALUES"><a class="permalink" href="#RETURN_VALUES">RETURN
VALUES</a></h1>
<p class="Pp">If successful, all these functions will return zero. Otherwise, an
error number will be returned to indicate the error.</p>
<p class="Pp">None of these functions will return
<code class="Er">EINTR</code>.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="ERRORS"><a class="permalink" href="#ERRORS">ERRORS</a></h1>
<p class="Pp">The <code class="Fn">pthread_spin_lock</code>(),
<code class="Fn">pthread_spin_trylock</code>() and
<code class="Fn">pthread_spin_unlock</code>() functions will fail if:</p>
<dl class="Bl-tag">
<dt id="EINVAL">[<a class="permalink" href="#EINVAL"><code class="Er">EINVAL</code></a>]</dt>
<dd>The value specified by <var class="Fa">lock</var> is invalid or is not
initialized.</dd>
</dl>
<p class="Pp">The <code class="Fn">pthread_spin_lock</code>() function may fail
if:</p>
<dl class="Bl-tag">
<dt id="EDEADLK">[<a class="permalink" href="#EDEADLK"><code class="Er">EDEADLK</code></a>]</dt>
<dd>The calling thread already owns the lock.</dd>
</dl>
<p class="Pp">The <code class="Fn">pthread_spin_trylock</code>() function will
fail if:</p>
<dl class="Bl-tag">
<dt id="EBUSY">[<a class="permalink" href="#EBUSY"><code class="Er">EBUSY</code></a>]</dt>
<dd>Another thread currently holds <var class="Fa">lock</var>.</dd>
</dl>
<p class="Pp">The <code class="Fn">pthread_spin_unlock</code>() function may
fail if:</p>
<dl class="Bl-tag">
<dt id="EPERM">[<a class="permalink" href="#EPERM"><code class="Er">EPERM</code></a>]</dt>
<dd>The calling thread does not own <var class="Fa">lock</var>.</dd>
</dl>
</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">pthread_spin_destroy(3)</a>,
<a class="Xr">pthread_spin_init(3)</a></p>
</section>
<section class="Sh">
<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1>
<p class="Pp">The <code class="Fn">pthread_spin_lock</code>(),
<code class="Fn">pthread_spin_trylock</code>() and
<code class="Fn">pthread_spin_unlock</code>() functions first appeared in
<span class="Lb">N:M Threading Library (libkse, -lkse)</span> in
<span class="Ux">FreeBSD 5.2</span>, and in <span class="Lb">1:1 Threading
Library (libthr, -lthr)</span> in <span class="Ux">FreeBSD 5.3</span>.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="BUGS"><a class="permalink" href="#BUGS">BUGS</a></h1>
<p class="Pp">The implementation of <code class="Fn">pthread_spin_lock</code>(),
<code class="Fn">pthread_spin_trylock</code>() and
<code class="Fn">pthread_spin_unlock</code>() is expected to conform to
<span class="St">IEEE Std 1003.2 (“POSIX.2”)</span>.</p>
</section>
</div>
<table class="foot">
<tr>
<td class="foot-date">January 22, 2004</td>
<td class="foot-os">FreeBSD 15.0</td>
</tr>
</table>
|
