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 .