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.

NAME

       pthread_attr_getschedparam,  pthread_attr_setschedparam  —  get  and  set  the  schedparam
       attribute

SYNOPSIS

       #include <pthread.h>

       int pthread_attr_getschedparam(const pthread_attr_t *restrict attr,
           struct sched_param *restrict param);
       int pthread_attr_setschedparam(pthread_attr_t *restrict attr,
           const struct sched_param *restrict param);

DESCRIPTION

       The pthread_attr_getschedparam() and pthread_attr_setschedparam() functions, respectively,
       shall  get  and set the scheduling parameter attributes in the attr argument. The contents
       of the param structure are defined  in  the  <sched.h>  header.  For  the  SCHED_FIFO  and
       SCHED_RR policies, the only required member of param is sched_priority.

       For   the  SCHED_SPORADIC  policy,  the  required  members  of  the  param  structure  are
       sched_priority,  sched_ss_low_priority,  sched_ss_repl_period,  sched_ss_init_budget,  and
       sched_ss_max_repl.   The  specified  sched_ss_repl_period must be greater than or equal to
       the specified sched_ss_init_budget for the function to succeed; if it  is  not,  then  the
       function  shall  fail.  The value of sched_ss_max_repl shall be within the inclusive range
       [1,{SS_REPL_MAX}] for the function to succeed; if not, the function  shall  fail.   It  is
       unspecified whether the sched_ss_repl_period and sched_ss_init_budget values are stored as
       provided by this function or are rounded to align with the resolution of the  clock  being
       used.

       The   behavior   is   undefined   if   the   value  specified  by  the  attr  argument  to
       pthread_attr_getschedparam()  or  pthread_attr_setschedparam()  does  not  refer   to   an
       initialized thread attributes object.

RETURN VALUE

       If successful, the pthread_attr_getschedparam() and pthread_attr_setschedparam() functions
       shall return zero; otherwise, an error number shall be returned to indicate the error.

ERRORS

       The pthread_attr_setschedparam() function shall fail if:

       ENOTSUP
              An attempt was made to set the attribute to an unsupported value.

       The pthread_attr_setschedparam() function may fail if:

       EINVAL The value of param is not valid.

       These functions shall not return an error code of [EINTR].

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       After these attributes have  been  set,  a  thread  can  be  created  with  the  specified
       attributes  using  pthread_create().   Using  these  routines  does not affect the current
       running thread.

RATIONALE

       If  an  implementation  detects  that  the  value  specified  by  the  attr  argument   to
       pthread_attr_getschedparam()   or   pthread_attr_setschedparam()  does  not  refer  to  an
       initialized thread attributes object, it is recommended that the function should fail  and
       report an [EINVAL] error.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_attr_destroy(), pthread_attr_getscope(), pthread_attr_getinheritsched(),
       pthread_attr_getschedpolicy(), pthread_create()

       The Base Definitions volume of POSIX.1‐2017, <pthread.h>, <sched.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1-2017,  Standard  for  Information Technology -- Portable Operating System Interface
       (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C)  2018  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 .

       Any typographical or formatting errors that appear in this page are most  likely  to  have
       been  introduced  during  the conversion of the source files to man page format. To report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .