This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       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.

       See  Section2.9.4,  ThreadScheduling  for  further  details on thread scheduling attributes and their
       default settings.

       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 .

IEEE/The Open Group                                   2017                   PTHREAD_ATTR_GETSCHEDPOLICY(3POSIX)

       The pthread_attr_getschedpolicy() and pthread_attr_setschedpolicy() functions,  respectively,  shall  get
       and set the schedpolicy attribute in the attr argument.

       The  supported values of policy shall include SCHED_FIFO, SCHED_RR, and SCHED_OTHER, which are defined in
       the <sched.h> header. When  threads  executing  with  the  scheduling  policy  SCHED_FIFO,  SCHED_RR,  or
       SCHED_SPORADIC  are  waiting on a mutex, they shall acquire the mutex in priority order when the mutex is
       unlocked.

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

       The pthread_attr_setschedpolicy() function shall fail if:

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

       The pthread_attr_setschedpolicy() function may fail if:

       EINVAL The value of policy is not valid.

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

       Thefollowingsectionsareinformative.

       None.

       None.

       pthread_attr_getschedpolicy,   pthread_attr_setschedpolicy  —  get  and  set  the  schedpolicy  attribute
       (REALTIMETHREADS)

       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.

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

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

pthread_attr_destroy(), pthread_attr_getscope(), pthread_attr_getinheritsched(),
       pthread_attr_getschedparam(), pthread_create()

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

       #include <pthread.h>

       int pthread_attr_getschedpolicy(const pthread_attr_t *restrict attr,
           int *restrict policy);
       int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);