2004-11-03 13:51:07 +00:00
|
|
|
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
|
2007-06-20 22:33:04 +00:00
|
|
|
.TH "PTHREAD_GETSCHEDPARAM" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
|
2004-11-03 13:51:07 +00:00
|
|
|
.\" pthread_getschedparam
|
2007-09-20 06:03:25 +00:00
|
|
|
.SH PROLOG
|
|
|
|
This manual page is part of the POSIX Programmer's Manual.
|
|
|
|
The Linux implementation of this interface may differ (consult
|
|
|
|
the corresponding Linux manual page for details of Linux behavior),
|
|
|
|
or the interface may not be implemented on Linux.
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH NAME
|
|
|
|
pthread_getschedparam, pthread_setschedparam \- dynamic thread scheduling
|
|
|
|
parameters access (\fBREALTIME
|
|
|
|
THREADS\fP)
|
|
|
|
.SH SYNOPSIS
|
|
|
|
.LP
|
|
|
|
\fB#include <pthread.h>
|
|
|
|
.br
|
|
|
|
.sp
|
|
|
|
int pthread_getschedparam(pthread_t\fP \fIthread\fP\fB, int *restrict\fP
|
|
|
|
\fIpolicy\fP\fB,
|
|
|
|
.br
|
|
|
|
\ \ \ \ \ \ struct sched_param *restrict\fP \fIparam\fP\fB);
|
|
|
|
.br
|
|
|
|
int pthread_setschedparam(pthread_t\fP \fIthread\fP\fB, int\fP \fIpolicy\fP\fB,
|
|
|
|
.br
|
|
|
|
\ \ \ \ \ \ const struct sched_param *\fP\fIparam\fP\fB); \fP
|
|
|
|
\fB
|
|
|
|
.br
|
|
|
|
\fP
|
|
|
|
.SH DESCRIPTION
|
|
|
|
.LP
|
|
|
|
The \fIpthread_getschedparam\fP() and \fIpthread_setschedparam\fP()
|
|
|
|
functions shall, respectively, get and set the scheduling
|
|
|
|
policy and parameters of individual threads within a multi-threaded
|
|
|
|
process to be retrieved and set. For SCHED_FIFO and SCHED_RR,
|
|
|
|
the only required member of the \fBsched_param\fP structure is the
|
|
|
|
priority \fIsched_priority\fP. For SCHED_OTHER, the affected
|
|
|
|
scheduling parameters are implementation-defined.
|
|
|
|
.LP
|
|
|
|
The \fIpthread_getschedparam\fP() function shall retrieve the scheduling
|
|
|
|
policy and scheduling parameters for the thread whose
|
|
|
|
thread ID is given by \fIthread\fP and shall store those values in
|
|
|
|
\fIpolicy\fP and \fIparam\fP, respectively. The priority
|
|
|
|
value returned from \fIpthread_getschedparam\fP() shall be the value
|
|
|
|
specified by the most recent \fIpthread_setschedparam\fP(),
|
|
|
|
\fIpthread_setschedprio\fP(), or \fIpthread_create\fP() call affecting
|
|
|
|
the target thread. It shall not reflect any temporary
|
|
|
|
adjustments to its priority as a result of any priority inheritance
|
|
|
|
or ceiling functions. The \fIpthread_setschedparam\fP()
|
|
|
|
function shall set the scheduling policy and associated scheduling
|
|
|
|
parameters for the thread whose thread ID is given by
|
|
|
|
\fIthread\fP to the policy and associated parameters provided in \fIpolicy\fP
|
|
|
|
and \fIparam\fP, respectively.
|
|
|
|
.LP
|
|
|
|
The \fIpolicy\fP parameter may have the value SCHED_OTHER, SCHED_FIFO,
|
|
|
|
or SCHED_RR. The scheduling parameters for the
|
|
|
|
SCHED_OTHER policy are implementation-defined. The SCHED_FIFO and
|
|
|
|
SCHED_RR policies shall have a single scheduling parameter,
|
|
|
|
\fIpriority\fP.
|
|
|
|
.LP
|
|
|
|
If _POSIX_THREAD_SPORADIC_SERVER is defined, then the \fIpolicy\fP
|
|
|
|
argument may have the value SCHED_SPORADIC, with the exception
|
|
|
|
for the \fIpthread_setschedparam\fP() function that if the scheduling
|
|
|
|
policy was not SCHED_SPORADIC at the time of the call, it is
|
|
|
|
implementation-defined whether the function is supported; in other
|
|
|
|
words, the implementation need not allow the application to
|
|
|
|
dynamically change the scheduling policy to SCHED_SPORADIC. The sporadic
|
|
|
|
server scheduling policy has the associated parameters
|
|
|
|
\fIsched_ss_low_priority\fP, \fIsched_ss_repl_period\fP, \fIsched_ss_init_budget\fP,
|
|
|
|
\fIsched_priority\fP, and
|
|
|
|
\fIsched_ss_max_repl\fP. The specified \fIsched_ss_repl_period\fP
|
|
|
|
shall be greater than or equal to the specified
|
|
|
|
\fIsched_ss_init_budget\fP for the function to succeed; if it is not,
|
|
|
|
then the function shall fail. The value of
|
|
|
|
\fIsched_ss_max_repl\fP shall be within the inclusive range [1, {SS_REPL_MAX}]
|
|
|
|
for the function to succeed; if not, the function
|
|
|
|
shall fail.
|
|
|
|
.LP
|
|
|
|
If the \fIpthread_setschedparam\fP() function fails, the scheduling
|
|
|
|
parameters shall not be changed for the target thread.
|
|
|
|
.SH RETURN VALUE
|
|
|
|
.LP
|
|
|
|
If successful, the \fIpthread_getschedparam\fP() and \fIpthread_setschedparam\fP()
|
|
|
|
functions shall return zero; otherwise, an
|
|
|
|
error number shall be returned to indicate the error.
|
|
|
|
.SH ERRORS
|
|
|
|
.LP
|
|
|
|
The \fIpthread_getschedparam\fP() function may fail if:
|
|
|
|
.TP 7
|
|
|
|
.B ESRCH
|
|
|
|
The value specified by \fIthread\fP does not refer to an existing
|
|
|
|
thread.
|
|
|
|
.sp
|
|
|
|
.LP
|
|
|
|
The \fIpthread_setschedparam\fP() function may fail if:
|
|
|
|
.TP 7
|
|
|
|
.B EINVAL
|
|
|
|
The value specified by \fIpolicy\fP or one of the scheduling parameters
|
|
|
|
associated with the scheduling policy \fIpolicy\fP is
|
|
|
|
invalid.
|
|
|
|
.TP 7
|
|
|
|
.B ENOTSUP
|
|
|
|
An attempt was made to set the policy or scheduling parameters to
|
|
|
|
an unsupported value.
|
|
|
|
.TP 7
|
|
|
|
.B ENOTSUP
|
|
|
|
An attempt was made to dynamically change the scheduling policy to
|
|
|
|
SCHED_SPORADIC, and the implementation does not support this
|
|
|
|
change.
|
|
|
|
.TP 7
|
|
|
|
.B EPERM
|
|
|
|
The caller does not have the appropriate permission to set either
|
|
|
|
the scheduling parameters or the scheduling policy of the
|
|
|
|
specified thread.
|
|
|
|
.TP 7
|
|
|
|
.B EPERM
|
|
|
|
The implementation does not allow the application to modify one of
|
|
|
|
the parameters to the value specified.
|
|
|
|
.TP 7
|
|
|
|
.B ESRCH
|
|
|
|
The value specified by \fIthread\fP does not refer to a existing thread.
|
|
|
|
.sp
|
|
|
|
.LP
|
|
|
|
These functions shall not return an error code of [EINTR].
|
|
|
|
.LP
|
|
|
|
\fIThe following sections are informative.\fP
|
|
|
|
.SH EXAMPLES
|
|
|
|
.LP
|
|
|
|
None.
|
|
|
|
.SH APPLICATION USAGE
|
|
|
|
.LP
|
|
|
|
None.
|
|
|
|
.SH RATIONALE
|
|
|
|
.LP
|
|
|
|
None.
|
|
|
|
.SH FUTURE DIRECTIONS
|
|
|
|
.LP
|
|
|
|
None.
|
|
|
|
.SH SEE ALSO
|
|
|
|
.LP
|
2007-09-20 17:56:19 +00:00
|
|
|
\fIpthread_setschedprio\fP(), \fIsched_getparam\fP(), \fIsched_getscheduler\fP(),
|
|
|
|
the Base
|
2004-11-03 13:51:07 +00:00
|
|
|
Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<pthread.h>\fP, \fI<sched.h>\fP
|
|
|
|
.SH COPYRIGHT
|
|
|
|
Portions of this text are reprinted and reproduced in electronic form
|
|
|
|
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
|
|
|
|
-- Portable Operating System Interface (POSIX), The Open Group Base
|
|
|
|
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
|
|
|
|
Electrical and Electronics Engineers, Inc and The Open Group. In the
|
|
|
|
event of any discrepancy between this version and the original IEEE and
|
|
|
|
The Open Group Standard, the original IEEE and The Open Group Standard
|
|
|
|
is the referee document. The original Standard can be obtained online at
|
|
|
|
http://www.opengroup.org/unix/online.html .
|