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PTHREAD_SETSCHEDPRIO(3P)   POSIX Programmer's Manual  PTHREAD_SETSCHEDPRIO(3P)
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_setschedprio -- dynamic  thread  scheduling  parameters  access
       (REALTIME THREADS)
SYNOPSIS
       #include <pthread.h>
       int pthread_setschedprio(pthread_t thread, int prio);
DESCRIPTION
       The  pthread_setschedprio()  function shall set the scheduling priority
       for the thread whose thread ID is given by thread to the value given by
       prio.   See  Scheduling Policies for a description on how this function
       call affects the ordering of the thread in the thread list for its  new
       priority.
       If  the  pthread_setschedprio() function fails, the scheduling priority
       of the target thread shall not be changed.
RETURN VALUE
       If successful, the pthread_setschedprio() function shall  return  zero;
       otherwise, an error number shall be returned to indicate the error.
ERRORS
       The pthread_setschedprio() function may fail if:
       EINVAL The  value  of  prio is invalid for the scheduling policy of the
              specified thread.
       EPERM  The caller does not  have  appropriate  privileges  to  set  the
              scheduling priority of the specified thread.
       The  pthread_setschedprio()  function shall not return an error code of
       [EINTR].
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       The pthread_setschedprio() function provides a way for  an  application
       to temporarily raise its priority and then lower it again, without hav-
       ing the undesired side-effect of yielding to other threads of the  same
       priority.  This is necessary if the application is to implement its own
       strategies for bounding priority inversion, such  as  priority  inheri-
       tance  or priority ceilings. This capability is especially important if
       the implementation does not support the Thread Priority  Protection  or
       Thread Priority Inheritance options, but even if those options are sup-
       ported it is needed if the application is to bound priority inheritance
       for other resources, such as semaphores.
       The  standard  developers  considered that while it might be preferable
       conceptually to solve this problem by modifying  the  specification  of
       pthread_setschedparam(),  it  was  too  late  to make such a change, as
       there may be implementations that would need to be changed.  Therefore,
       this new function was introduced.
       If  an  implementation  detects use of a thread ID after the end of its
       lifetime, it is recommended that the function should fail and report an
       [ESRCH] error.
FUTURE DIRECTIONS
       None.
SEE ALSO
       Scheduling Policies, pthread_getschedparam()
       The Base Definitions volume of POSIX.1-2008, <pthread.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  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.unix.org/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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013             PTHREAD_SETSCHEDPRIO(3P)