280 lines
11 KiB
HTML
280 lines
11 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
|
||
<HTML>
|
||
<HEAD>
|
||
<META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=utf-8">
|
||
<TITLE>PTHREAD_ATTR_INIT(3) manual page</TITLE>
|
||
<META NAME="GENERATOR" CONTENT="OpenOffice.org 1.1.3 (Linux)">
|
||
<META NAME="CREATED" CONTENT="20050504;10092900">
|
||
<META NAME="CHANGED" CONTENT="20050505;16540200">
|
||
<!-- manual page source format generated by PolyglotMan v3.2, -->
|
||
<!-- available at http://polyglotman.sourceforge.net/ -->
|
||
</HEAD>
|
||
<BODY LANG="en-GB" BGCOLOR="#ffffff" DIR="LTR">
|
||
<H4>POSIX Threads for Windows – REFERENCE - <A HREF="http://sources.redhat.com/pthreads-win32">Pthreads-w32</A></H4>
|
||
<P><A HREF="index.html">Reference Index</A></P>
|
||
<P><A HREF="#toc">Table of Contents</A></P>
|
||
<H2><A HREF="#toc0" NAME="sect0">Name</A></H2>
|
||
<P>pthread_attr_init, pthread_attr_destroy,
|
||
pthread_attr_setdetachstate, pthread_attr_getdetachstate,
|
||
pthread_attr_setschedparam, pthread_attr_getschedparam,
|
||
pthread_attr_setschedpolicy, pthread_attr_getschedpolicy,
|
||
pthread_attr_setinheritsched, pthread_attr_getinheritsched,
|
||
pthread_attr_setscope, pthread_attr_getscope - thread creation
|
||
attributes
|
||
</P>
|
||
<H2><A HREF="#toc1" NAME="sect1">Synopsis</A></H2>
|
||
<P><B>#include <pthread.h></B>
|
||
</P>
|
||
<P><B>int pthread_attr_init(pthread_attr_t *</B><I>attr</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_destroy(pthread_attr_t *</B><I>attr</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_setdetachstate(pthread_attr_t *</B><I>attr</I><B>,
|
||
int </B><I>detachstate</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_getdetachstate(const pthread_attr_t *</B><I>attr</I><B>,
|
||
int *</B><I>detachstate</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_setschedpolicy(pthread_attr_t *</B><I>attr</I><B>,
|
||
int </B><I>policy</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_getschedpolicy(const pthread_attr_t *</B><I>attr</I><B>,
|
||
int *</B><I>policy</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_setschedparam(pthread_attr_t *</B><I>attr</I><B>,
|
||
const struct sched_param *</B><I>param</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_getschedparam(const pthread_attr_t *</B><I>attr</I><B>,
|
||
struct sched_param *</B><I>param</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_setinheritsched(pthread_attr_t *</B><I>attr</I><B>,
|
||
int </B><I>inherit</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_getinheritsched(const pthread_attr_t *</B><I>attr</I><B>,
|
||
int *</B><I>inherit</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_setscope(pthread_attr_t *</B><I>attr</I><B>,
|
||
int </B><I>scope</I><B>);</B>
|
||
</P>
|
||
<P><B>int pthread_attr_getscope(const pthread_attr_t *</B><I>attr</I><B>,
|
||
int *</B><I>scope</I><B>);</B>
|
||
</P>
|
||
<H2><A HREF="#toc2" NAME="sect2">Description</A></H2>
|
||
<P>Setting attributes for threads is achieved by filling a thread
|
||
attribute object <I>attr</I> of type <B>pthread_attr_t</B>, then
|
||
passing it as second argument to <A HREF="pthread_create.html"><B>pthread_create</B>(3)</A>
|
||
. Passing <B>NULL</B> is equivalent to passing a thread attribute
|
||
object with all attributes set to their default values.
|
||
</P>
|
||
<P><B>pthread_attr_init</B> initializes the thread attribute object
|
||
<I>attr</I> and fills it with default values for the attributes. (The
|
||
default values are listed below for each attribute.)
|
||
</P>
|
||
<P>Each attribute <I>attrname</I> (see below for a list of all
|
||
attributes) can be individually set using the function
|
||
<B>pthread_attr_set</B><I>attrname</I> and retrieved using the
|
||
function <B>pthread_attr_get</B><I>attrname.</I>
|
||
</P>
|
||
<P><B>pthread_attr_destroy</B> destroys a thread attribute object,
|
||
which must not then be reused until it is reinitialized.
|
||
</P>
|
||
<P>Attribute objects are consulted only when creating a new thread.
|
||
The same attribute object can be used for creating several threads.
|
||
Modifying an attribute object after a call to <B>pthread_create</B>
|
||
does not change the attributes of the thread previously created.
|
||
</P>
|
||
<P>The following thread attributes are supported:
|
||
</P>
|
||
<H3><A HREF="#toc3" NAME="sect3">detachstate</A></H3>
|
||
<P>Control whether the thread is created in the joinable state (value
|
||
<B>PTHREAD_CREATE_JOINABLE</B>) or in the detached state (
|
||
<B>PTHREAD_CREATE_DETACHED</B>).
|
||
</P>
|
||
<P>Default value: <B>PTHREAD_CREATE_JOINABLE</B>.
|
||
</P>
|
||
<P>In the joinable state, another thread can synchronize on the
|
||
thread termination and recover its termination code using
|
||
<A HREF="pthread_join.html"><B>pthread_join</B>(3)</A> . When a
|
||
joinable thread terminates, some of the thread resources are kept
|
||
allocated, and released only when another thread performs
|
||
<A HREF="pthread_join.html"><B>pthread_join</B>(3)</A> on that
|
||
thread.
|
||
</P>
|
||
<P>In the detached state, the thread's resources are released
|
||
immediately when it terminates. <A HREF="pthread_join.html"><B>pthread_join</B>(3)</A>
|
||
cannot be used to synchronize on the thread termination.
|
||
</P>
|
||
<P>A thread created in the joinable state can later be put in the
|
||
detached thread using <A HREF="pthread_detach.html"><B>pthread_detach</B>(3)</A>
|
||
.
|
||
</P>
|
||
<H3><A HREF="#toc4" NAME="sect4">schedpolicy</A></H3>
|
||
<P>Select the scheduling policy for the thread: one of <B>SCHED_OTHER</B>
|
||
(regular, non-real-time scheduling), <B>SCHED_RR</B> (real-time,
|
||
round-robin) or <B>SCHED_FIFO</B> (real-time, first-in first-out).
|
||
</P>
|
||
<P><B>Pthreads-w32</B> only supports <B>SCHED_OTHER</B> - attempting
|
||
to set one of the other policies will return an error ENOTSUP.</P>
|
||
<P>Default value: <B>SCHED_OTHER</B>.
|
||
</P>
|
||
<P><B>Pthreads-w32</B> only supports <B>SCHED_OTHER</B> - attempting
|
||
to set one of the other policies will return an error ENOTSUP.</P>
|
||
<P>The scheduling policy of a thread can be changed after creation
|
||
with <A HREF="pthread_setschedparam.html"><B>pthread_setschedparam</B>(3)</A>
|
||
.
|
||
</P>
|
||
<H3><A HREF="#toc5" NAME="sect5">schedparam</A></H3>
|
||
<P>Contain the scheduling parameters (essentially, the scheduling
|
||
priority) for the thread.</P>
|
||
<P><B>Pthreads-w32</B> supports the priority levels defined by the
|
||
Windows system it is running on. Under Windows, thread priorities are
|
||
relative to the process priority class, which must be set via the
|
||
Windows W32 API.</P>
|
||
<P>Default value: priority is 0 (Win32 level <B>THREAD_PRIORITY_NORMAL</B>).
|
||
</P>
|
||
<P>The scheduling priority of a thread can be changed after creation
|
||
with <A HREF="pthread_setschedparam.html"><B>pthread_setschedparam</B>(3)</A>
|
||
.
|
||
</P>
|
||
<H3><A HREF="#toc6" NAME="sect6">inheritsched</A></H3>
|
||
<P>Indicate whether the scheduling policy and scheduling parameters
|
||
for the newly created thread are determined by the values of the
|
||
<I>schedpolicy</I> and <I>schedparam</I> attributes (value
|
||
<B>PTHREAD_EXPLICIT_SCHED</B>) or are inherited from the parent
|
||
thread (value <B>PTHREAD_INHERIT_SCHED</B>).
|
||
</P>
|
||
<P>Default value: <B>PTHREAD_EXPLICIT_SCHED</B>.
|
||
</P>
|
||
<H3><A HREF="#toc7" NAME="sect7">scope</A></H3>
|
||
<P>Define the scheduling contention scope for the created thread. The
|
||
only value supported in the <B>Pthreads-w32</B> implementation is
|
||
<B>PTHREAD_SCOPE_SYSTEM</B>, meaning that the threads contend for CPU
|
||
time with all processes running on the machine. The other value
|
||
specified by the standard, <B>PTHREAD_SCOPE_PROCESS</B>, means that
|
||
scheduling contention occurs only between the threads of the running
|
||
process.</P>
|
||
<P><B>Pthreads-w32</B> only supports <B>PTHREAD_SCOPE_SYSTEM</B>.</P>
|
||
<P>Default value: <B>PTHREAD_SCOPE_SYSTEM</B>.
|
||
</P>
|
||
<H2><A HREF="#toc8" NAME="sect8">Return Value</A></H2>
|
||
<P>All functions return 0 on success and a non-zero error code on
|
||
error. On success, the <B>pthread_attr_get</B><I>attrname</I>
|
||
functions also store the current value of the attribute <I>attrname</I>
|
||
in the location pointed to by their second argument.
|
||
</P>
|
||
<H2><A HREF="#toc9" NAME="sect9">Errors</A></H2>
|
||
<P>The <B>pthread_attr_setdetachstate</B> function returns the
|
||
following error codes on error:
|
||
</P>
|
||
<DL>
|
||
<DL>
|
||
<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EINVAL</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
the specified <I>detachstate</I> is not one of
|
||
<B>PTHREAD_CREATE_JOINABLE</B> or <B>PTHREAD_CREATE_DETACHED</B>.
|
||
</DD></DL>
|
||
</DL>
|
||
<P>
|
||
The <B>pthread_attr_setschedparam</B> function returns the following
|
||
error codes on error:
|
||
</P>
|
||
<DL>
|
||
<DL>
|
||
<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EINVAL</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
the priority specified in <I>param</I> is outside the range of
|
||
allowed priorities for the scheduling policy currently in <I>attr</I>
|
||
(1 to 99 for <B>SCHED_FIFO</B> and <B>SCHED_RR</B>; 0 for
|
||
<B>SCHED_OTHER</B>).
|
||
</DD></DL>
|
||
</DL>
|
||
<P>
|
||
The <B>pthread_attr_setschedpolicy</B> function returns the following
|
||
error codes on error:
|
||
</P>
|
||
<DL>
|
||
<DL>
|
||
<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EINVAL</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
the specified <I>policy</I> is not one of <B>SCHED_OTHER</B>,
|
||
<B>SCHED_FIFO</B>, or <B>SCHED_RR</B>.
|
||
</DD><DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
<B>ENOTSUP</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
<I>policy</I> is not <B>SCHED_OTHER</B>, the only value supported
|
||
by <B>Pthreads-w32</B>.</DD></DL>
|
||
</DL>
|
||
<P>
|
||
The <B>pthread_attr_setinheritsched</B> function returns the
|
||
following error codes on error:
|
||
</P>
|
||
<DL>
|
||
<DL>
|
||
<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EINVAL</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
the specified <I>inherit</I> is not one of <B>PTHREAD_INHERIT_SCHED</B>
|
||
or <B>PTHREAD_EXPLICIT_SCHED</B>.
|
||
</DD></DL>
|
||
</DL>
|
||
<P>
|
||
The <B>pthread_attr_setscope</B> function returns the following error
|
||
codes on error:
|
||
</P>
|
||
<DL>
|
||
<DL>
|
||
<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EINVAL</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
the specified <I>scope</I> is not one of <B>PTHREAD_SCOPE_SYSTEM</B>
|
||
or <B>PTHREAD_SCOPE_PROCESS</B>.
|
||
</DD><DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
<B>ENOTSUP</B>
|
||
</DT><DD STYLE="margin-right: 1cm; margin-bottom: 0.5cm">
|
||
the specified <I>scope</I> is <B>PTHREAD_SCOPE_PROCESS</B> (not
|
||
supported by <B>Pthreads-w32</B>).
|
||
</DD></DL>
|
||
</DL>
|
||
<H2>
|
||
<A HREF="#toc10" NAME="sect10">Author</A></H2>
|
||
<P>Xavier Leroy <Xavier.Leroy@inria.fr>
|
||
</P>
|
||
<P>Modified by Ross Johnson for use with <A HREF="http://sources.redhat.com/pthreads-win32">Pthreads-w32</A>.</P>
|
||
<H2><A HREF="#toc11" NAME="sect11">See Also</A></H2>
|
||
<P><A HREF="pthread_create.html"><B>pthread_create</B>(3)</A> ,
|
||
<A HREF="pthread_join.html"><B>pthread_join</B>(3)</A> ,
|
||
<A HREF="pthread_detach.html"><B>pthread_detach</B>(3)</A> ,
|
||
<A HREF="pthread_setschedparam.html"><B>pthread_setschedparam</B>(3)</A>
|
||
.
|
||
</P>
|
||
<HR>
|
||
<P><A NAME="toc"></A><B>Table of Contents</B></P>
|
||
<UL>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect0" NAME="toc0">Name</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect1" NAME="toc1">Synopsis</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect2" NAME="toc2">Description</A>
|
||
</P>
|
||
<UL>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect3" NAME="toc3">detachstate</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect4" NAME="toc4">schedpolicy</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect5" NAME="toc5">schedparam</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect6" NAME="toc6">inheritsched</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect7" NAME="toc7">scope</A>
|
||
</P>
|
||
</UL>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect8" NAME="toc8">Return
|
||
Value</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect9" NAME="toc9">Errors</A>
|
||
</P>
|
||
<LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect10" NAME="toc10">Author</A>
|
||
</P>
|
||
<LI><P><A HREF="#sect11" NAME="toc11">See Also</A>
|
||
</P>
|
||
</UL>
|
||
</BODY>
|
||
</HTML>
|