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<title>pthread_attr_init()--Initialize Thread Attributes Object</title>
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<h2>pthread_attr_init()--Initialize Thread Attributes Object</h2>
<div class="box" style="width: 50%;">
<br>
&nbsp;&nbsp;Syntax:
<pre>
#include &lt;pthread.h&gt;
int pthread_attr_init(pthread_attr_t *attr);
</pre>
&nbsp;&nbsp;Service Program Name: QP0WPTHR<br>
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<br>
&nbsp;&nbsp;Default Public Authority: *USE<br>
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&nbsp;&nbsp;Threadsafe: Yes<br>
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&nbsp;&nbsp;Signal Safe: Yes<br>
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<p>The <strong>pthread_attr_init</strong>() function initializes a thread
attributes object to the default thread attributes. The thread attributes
object can be used in a call to <strong>pthread_create</strong>() to specify
attributes of the new thread.</p>
<br>
<h3>Authorities and Locks</h3>
<p>None.</p>
<br>
<h3>Parameters</h3>
<dl>
<dt><strong>attr</strong></dt>
<dd>(Input/Output) The address of the thread attributes object to be
initialized</dd>
</dl>
<br>
<h3>Return Value</h3>
<dl>
<dt><strong>0</strong></dt>
<dd><strong>pthread_attr_init</strong>() was successful.</dd>
<dt><strong>value</strong></dt>
<dd><strong>pthread_attr_init</strong>() was not successful. <em>value</em> is
set to indicate the error condition.</dd>
</dl>
<br>
<h3>Error Conditions</h3>
<p>If <strong>pthread_attr_init</strong>() was not successful, the error
condition returned usually indicates one of the following errors. Under some
conditions, the value returned could indicate an error other than those listed
here.</p>
<dl>
<dt><em>[EINVAL]</em></dt>
<dd><p>The value specified for the argument is not correct.</p></dd>
</dl>
<br>
<h3>Related Information</h3>
<ul>
<li>The &lt;<strong>pthread.h</strong>&gt; header file. See <a href=
"rzah4hed.htm">Header files for Pthread functions</a>.<br><br></li>
<li><a href="users_g5.htm">pthread_attr_destroy()--Destroy Thread Attributes
Object</a><br><br></li>
<li><a href="users_14.htm">pthread_create()</a>--Create Thread</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>
<pre>
#define _MULTI_THREADED
#include &lt;pthread.h&gt;
#include &lt;stdio.h&gt;
#include "check.h"
void *threadfunc(void *parm)
{
printf("Thread created using an default attributes\n");
return NULL;
}
int main(int argc, char **argv)
{
pthread_t thread;
int rc=0;
pthread_attr_t pta;
printf("Enter Testcase - %s\n", argv[0]);
printf("Create a thread attributes object\n");
rc = pthread_attr_init(&amp;pta);
checkResults("pthread_attr_init()\n", rc);
printf("Create a thread using the attributes object\n");
rc = pthread_create(&amp;thread, &amp;pta, threadfunc, NULL);
checkResults("pthread_create()\n", rc);
printf("Create a thread using the default attributes\n");
rc = pthread_create(&amp;thread, NULL, threadfunc, NULL);
checkResults("pthread_create()\n", rc);
printf("Destroy thread attributes object\n");
rc = pthread_attr_destroy(&amp;pta);
checkResults("pthread_attr_destroy()\n", rc);
/* sleep() is not a very robust way to wait for the thread */
sleep(5);
printf("Main completed\n");
return 0;
}
</pre>
<p><strong>Output:</strong></p>
<pre>
Enter Testcase - QP0WTEST/TAINI0
Create a thread attributes object
Create a thread using the attributes object
Create a thread using the default attributes
Destroy thread attributes object
Thread created using an default attributes
Thread created using an default attributes
Main completed
</pre>
<br>
<hr>
API introduced: V4R3
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