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<title>sem_destroy()-Destroy Unnamed Semaphore</title>
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<h2>sem_destroy()--Destroy Unnamed Semaphore</h2>
<div class="box" style="width: 70%;">
<br>
&nbsp;&nbsp;Syntax<br>
<pre>
#include &lt;semaphore.h&gt;
int sem_destroy(sem_t * <em>sem</em>);
</pre>
<br>
&nbsp;&nbsp;Service Program Name: QP0ZPSEM<br>
<!-- iddvc RMBR -->
<br>
&nbsp;&nbsp;Default Public Authority: *USE<br>
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<br>
&nbsp;&nbsp;Threadsafe: Yes<br>
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<br>
</div>
<p>The <strong>sem_destroy()</strong> function destroys an unnamed semaphore
that was previously initialized using <strong>sem_init()</strong> or <strong>
sem_init_np()</strong>. Any threads that have blocked from calling <strong>
sem_wait()</strong> or <strong>sem_wait_np()</strong> on the semaphore will
unblock and return an [EINVAL] or [EDESTROYED] error.</p>
<br>
<h3>Parameters</h3>
<dl>
<dt><strong><em>sem</em></strong></dt>
<dd>(Input) A pointer to an initialized unnamed semaphore. The semaphore is
destroyed.</dd>
</dl>
<br>
<h3>Authorities</h3>
<p>None</p>
<br>
<h3>Return Value</h3>
<table cellpadding="5">
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<tr>
<td align="left" valign="top"><em>0</em></td>
<td align="left" valign="top"><strong>sem_destroy()</strong> was
successful.</td>
</tr>
<tr>
<td align="left" valign="top"><em>-1</em></td>
<td align="left" valign="top"><strong>sem_destroy()</strong> was not
successful. The <em>errno</em> variable is set to indicate the error.</td>
</tr>
</table>
<br>
<br>
<h3>Error Conditions</h3>
<p>If <strong>sem_destroy()</strong> is not successful, <em>errno</em>
usually indicates one of the following errors. Under some conditions, <em>
errno</em> could indicate an error other than those listed here.</p>
<dl>
<dt><em>[EBUSY]</em></dt>
<dd>
<p>Resource busy.</p>
<p>An attempt was made to use a system resource that is not available at this
time.</p>
<p>The semaphore is being destroyed by another thread.</p>
</dd>
<dt><em>[EINVAL]</em></dt>
<dd>
<p>The value specified for the argument is not correct.</p>
<p>A function was passed incorrect argument values, or an operation was
attempted on an object and the operation specified is not supported for that
type of object.</p>
<p>An argument value is not valid, out of range, or NULL.</p>
<p>The <em>sem</em> parameter is not a valid semaphore.</p>
</dd>
</dl>
<br>
<h3>Error Messages</h3>
<p>None.</p>
<br>
<h3>Related Information</h3>
<ul>
<li>The &lt;<strong>semaphore.h</strong>&gt; file (see <a href="unix13.htm">
Header Files for UNIX-Type Functions</a>)<br>
<br>
</li>
<li><a href="ipcsemge.htm">sem_getvalue()</a>--Get Semaphore Value<br>
<br>
</li>
<li><a href="ipcsemi.htm">sem_init()</a>--Initialize Unnamed Semaphore<br>
<br>
</li>
<li><a href="ipcsemin.htm">sem_init_np()</a>--Initialize Unnamed Semaphore with
Maximum Value<br>
<br>
</li>
<li><a href="ipcsemp.htm">sem_post()</a>--Post to Semaphore<br>
<br>
</li>
<li><a href="ipcsempn.htm">sem_post_np()</a>--Post Value to Semaphore<br>
<br>
</li>
<li><a href="ipcsemtr.htm">sem_trywait()</a>--Try to Decrement Semaphore<br>
<br>
</li>
<li><a href="ipcsemun.htm">sem_unlink()</a>--Unlink Named Semaphore<br>
<br>
</li>
<li><a href="ipcsemw.htm">sem_wait()</a>--Wait for Semaphore<br>
<br>
</li>
<li><a href="ipcsemwn.htm">sem_wait_np()</a>--Wait for Semaphore with
Timeout</li>
</ul>
<br>
<h3>Example</h3>
<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
for information pertaining to code examples.</p>
<p>The following example initializes an unnamed semaphore, my_semaphore, that
will be used by threads of the current process and sets its value to 10. The
semaphore is then destroyed using <strong>sem_destroy()</strong>.</p>
<pre>
#include &lt;semaphore.h&gt;
main() {
sem_t my_semaphore;
int rc;
rc = sem_init(&amp;my_semaphore, 0, 10);
rc = sem_destroy(&amp;my_semaphore);
}
</pre>
<br>
<hr>
API introduced: V4R4
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