man-pages/man3/pthread_attr_setstack.3.html
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<H1>PTHREAD_ATTR_SETSTACK</H1>
Section: Linux Programmer's Manual (3)<BR>Updated: 2017-09-15<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
pthread_attr_setstack, pthread_attr_getstack - set/get stack
attributes in thread attributes object
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<PRE>
<B>#include &lt;<A HREF="file:///usr/include/pthread.h">pthread.h</A>&gt;</B>
<B>int pthread_attr_setstack(pthread_attr_t *</B><I>attr</I><B>,</B>
<B> void *</B><I>stackaddr</I><B>, size_t </B><I>stacksize</I><B>);</B>
<B>int pthread_attr_getstack(const pthread_attr_t *</B><I>attr</I><B>,</B>
<B> void **</B><I>stackaddr</I><B>, size_t *</B><I>stacksize</I><B>);</B>
Compile and link with <I>-pthread</I>.
</PRE>
<P>
Feature Test Macro Requirements for glibc (see
<B><A HREF="/cgi-bin/man/man2html?7+feature_test_macros">feature_test_macros</A></B>(7)):
<P>
<B>pthread_attr_getstack</B>(),
<B>pthread_attr_setstack</B>():
<DL COMPACT><DT id="1"><DD>
_POSIX_C_SOURCE&nbsp;&gt;=&nbsp;200112L
</DL>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
The
<B>pthread_attr_setstack</B>()
function sets the stack address and stack size attributes of the
thread attributes object referred to by
<I>attr</I>
to the values specified in
<I>stackaddr</I>
and
<I>stacksize</I>,
respectively.
These attributes specify the location and size of the stack that should
be used by a thread that is created using the thread attributes object
<I>attr</I>.
<P>
<I>stackaddr</I>
should point to the lowest addressable byte of a buffer of
<I>stacksize</I>
bytes that was allocated by the caller.
The pages of the allocated buffer should be both readable and writable.
<P>
The
<B>pthread_attr_getstack</B>()
function returns the stack address and stack size attributes of the
thread attributes object referred to by
<I>attr</I>
in the buffers pointed to by
<I>stackaddr</I>
and
<I>stacksize</I>,
respectively.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
On success, these functions return 0;
on error, they return a nonzero error number.
<A NAME="lbAF">&nbsp;</A>
<H2>ERRORS</H2>
<B>pthread_attr_setstack</B>()
can fail with the following error:
<DL COMPACT>
<DT id="2"><B>EINVAL</B>
<DD>
<I>stacksize</I>
is less than
<B>PTHREAD_STACK_MIN</B>
(16384) bytes.
On some systems, this error may also occur if
<I>stackaddr</I>
or
<I>stackaddr&nbsp;+&nbsp;stacksize</I>
is not suitably aligned.
</DL>
<P>
POSIX.1 also documents an
<B>EACCES</B>
error if the stack area described by
<I>stackaddr</I>
and
<I>stacksize</I>
is not both readable and writable by the caller.
<A NAME="lbAG">&nbsp;</A>
<H2>VERSIONS</H2>
These functions are provided by glibc since version 2.2.
<A NAME="lbAH">&nbsp;</A>
<H2>ATTRIBUTES</H2>
For an explanation of the terms used in this section, see
<B><A HREF="/cgi-bin/man/man2html?7+attributes">attributes</A></B>(7).
<TABLE BORDER>
<TR VALIGN=top><TD><B>Interface</B></TD><TD><B>Attribute</B></TD><TD><B>Value</B><BR></TD></TR>
<TR VALIGN=top><TD>
<B>pthread_attr_setstack</B>(),
<B>pthread_attr_getstack</B>()
</TD><TD>Thread safety</TD><TD>MT-Safe<BR></TD></TR>
</TABLE>
<A NAME="lbAI">&nbsp;</A>
<H2>CONFORMING TO</H2>
POSIX.1-2001, POSIX.1-2008.
<A NAME="lbAJ">&nbsp;</A>
<H2>NOTES</H2>
These functions are provided for applications that must ensure that
a thread's stack is placed in a particular location.
For most applications, this is not necessary,
and the use of these functions should be avoided.
(Use
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setstacksize">pthread_attr_setstacksize</A></B>(3)
if an application simply requires a stack size other than the default.)
<P>
When an application employs
<B>pthread_attr_setstack</B>(),
it takes over the responsibility of allocating the stack.
Any guard size value that was set using
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setguardsize">pthread_attr_setguardsize</A></B>(3)
is ignored.
If deemed necessary,
it is the application's responsibility to allocate a guard area
(one or more pages protected against reading and writing)
to handle the possibility of stack overflow.
<P>
The address specified in
<I>stackaddr</I>
should be suitably aligned:
for full portability, align it on a page boundary
(<I>sysconf(_SC_PAGESIZE)</I>).
<B><A HREF="/cgi-bin/man/man2html?3+posix_memalign">posix_memalign</A></B>(3)
may be useful for allocation.
Probably,
<I>stacksize</I>
should also be a multiple of the system page size.
<P>
If
<I>attr</I>
is used to create multiple threads, then the caller must change the
stack address attribute between calls to
<B><A HREF="/cgi-bin/man/man2html?3+pthread_create">pthread_create</A></B>(3);
otherwise, the threads will attempt to use the same memory area
for their stacks, and chaos will ensue.
<A NAME="lbAK">&nbsp;</A>
<H2>EXAMPLE</H2>
See
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_init">pthread_attr_init</A></B>(3).
<A NAME="lbAL">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?2+mmap">mmap</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?2+mprotect">mprotect</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?3+posix_memalign">posix_memalign</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_init">pthread_attr_init</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setguardsize">pthread_attr_setguardsize</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setstackaddr">pthread_attr_setstackaddr</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setstacksize">pthread_attr_setstacksize</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_create">pthread_create</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?7+pthreads">pthreads</A></B>(7)
<A NAME="lbAM">&nbsp;</A>
<H2>COLOPHON</H2>
This page is part of release 5.05 of the Linux
<I>man-pages</I>
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="3"><A HREF="#lbAB">NAME</A><DD>
<DT id="4"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="5"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="6"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="7"><A HREF="#lbAF">ERRORS</A><DD>
<DT id="8"><A HREF="#lbAG">VERSIONS</A><DD>
<DT id="9"><A HREF="#lbAH">ATTRIBUTES</A><DD>
<DT id="10"><A HREF="#lbAI">CONFORMING TO</A><DD>
<DT id="11"><A HREF="#lbAJ">NOTES</A><DD>
<DT id="12"><A HREF="#lbAK">EXAMPLE</A><DD>
<DT id="13"><A HREF="#lbAL">SEE ALSO</A><DD>
<DT id="14"><A HREF="#lbAM">COLOPHON</A><DD>
</DL>
<HR>
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Time: 00:05:53 GMT, March 31, 2021
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