static/freebsd/man3/pthread_rwlock_timedwrlock.3 3.html


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<table class="head">
  <tr>
    <td class="head-ltitle">PTHREAD_RWLOCK_TIMEDWRLOCK(3)</td>
    <td class="head-vol">Library Functions Manual</td>
    <td class="head-rtitle">PTHREAD_RWLOCK_TIMEDWRLOCK(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_rwlock_timedwrlock</code> &#x2014;
    <span class="Nd">acquire a read-write lock for writing or give up after a
    specified period</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
    &lt;<a class="In">pthread.h</a>&gt;</code></p>
<p class="Pp"><var class="Ft">int</var>
  <br/>
  <code class="Fn">pthread_rwlock_timedwrlock</code>(<var class="Fa" style="white-space: nowrap;">pthread_rwlock_t
    *restrict rwlock</var>, <var class="Fa" style="white-space: nowrap;">const
    struct timespec *restrict abs_timeout</var>);</p>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
<p class="Pp">This function acquires a write lock on the read-write lock
    <var class="Fa">rwlock</var>. However, if the lock cannot be acquired
    without waiting for another thread to unlock the lock, this wait shall be
    terminated when <var class="Fa">abs_timeout</var> expires.</p>
<p class="Pp" id="pthread_rwlock_timedwrlock">If the thread should be
    interrupted by a signal, the
    <a class="permalink" href="#pthread_rwlock_timedwrlock"><code class="Fn">pthread_rwlock_timedwrlock</code></a>()
    function will be automatically restarted after the thread returns from the
    signal handler.</p>
<p class="Pp">The calling thread may deadlock if at the time the call is made it
    holds <var class="Fa">rwlock</var>. The results are undefined if this
    function is called with an uninitialized read-write lock.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="IMPLEMENTATION_NOTES"><a class="permalink" href="#IMPLEMENTATION_NOTES">IMPLEMENTATION
  NOTES</a></h1>
<p class="Pp">To prevent writer starvation, writers are favored over
  readers.</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, the
    <code class="Fn">pthread_rwlock_timedwrlock</code>() function will return
    zero. Otherwise, an error number will be returned to indicate the error.</p>
<p class="Pp">This function shall not return an error code of
    <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_rwlock_timedwrlock</code>() function
    shall fail if:</p>
<dl class="Bl-tag">
  <dt id="ETIMEDOUT">[<a class="permalink" href="#ETIMEDOUT"><code class="Er">ETIMEDOUT</code></a>]</dt>
  <dd>The lock could not be acquired before the specified timeout expired.</dd>
</dl>
<p class="Pp">The <code class="Fn">pthread_rwlock_timedwrlock</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 holds <var class="Fa">rwlock</var>.</dd>
  <dt id="EINVAL">[<a class="permalink" href="#EINVAL"><code class="Er">EINVAL</code></a>]</dt>
  <dd>The value specified by <var class="Fa">rwlock</var> does not refer to an
      initialized read-write lock object, or the
      <var class="Fa">abs_timeout</var> nanosecond value is less than zero or
      greater than or equal to 1 billion.</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_rwlock_init(3)</a>,
    <a class="Xr">pthread_rwlock_timedrdlock(3)</a>,
    <a class="Xr">pthread_rwlock_unlock(3)</a></p>
</section>
<section class="Sh">
<h1 class="Sh" id="STANDARDS"><a class="permalink" href="#STANDARDS">STANDARDS</a></h1>
<p class="Pp">The <code class="Fn">pthread_rwlock_timedwrlock</code>() function
    is expected to conform to <span class="St">ISO/IEC 9945-1:1996
    (&#x201C;POSIX.1&#x201D;)</span>.</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_rwlock_timedwrlock</code>() function
    first appeared in <span class="Ux">FreeBSD 5.2</span>.</p>
</section>
</div>
<table class="foot">
  <tr>
    <td class="foot-date">August 17, 2018</td>
    <td class="foot-os">FreeBSD 15.0</td>
  </tr>
</table>