xref: /relibc/pthreads-emb/sched.h (revision 714af18cbe52336f4ff71fe91bfb035d5efaef7d)

/*
 * Module: sched.h
 *
 * Purpose:
 *      Provides an implementation of POSIX realtime extensions
 *      as defined in
 *
 *              POSIX 1003.1b-1993      (POSIX.1b)
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
 *      Copyright(C) 2008 Jason Schmidlapp
 *
 *      Contact Email: jschmidlapp@users.sourceforge.net
 *
 *
 *      Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
 *      Copyright(C) 2008 Jason Schmidlapp
 *
 *      Contact Email: jschmidlapp@users.sourceforge.net
 *
 *
 *      Based upon Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 *
 *      Contact Email: rpj@callisto.canberra.edu.au
 *
 *      The original list of contributors to the Pthreads-win32 project
 *      is contained in the file CONTRIBUTORS.ptw32 included with the
 *      source code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation; either
 *      version 2 of the License, or (at your option) any later version.
 *
 *      This library is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *      Lesser General Public License for more details.
 *
 *      You should have received a copy of the GNU Lesser General Public
 *      License along with this library in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */
#ifndef _SCHED_H
#define _SCHED_H

#include <pte_types.h>

#undef PTE_LEVEL

#if defined(_POSIX_SOURCE)
#define PTE_LEVEL 0
/* Early POSIX */
#endif

#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 199309
#undef PTE_LEVEL
#define PTE_LEVEL 1
/* Include 1b, 1c and 1d */
#endif

#if defined(INCLUDE_NP)
#undef PTE_LEVEL
#define PTE_LEVEL 2
/* Include Non-Portable extensions */
#endif

#define PTE_LEVEL_MAX 3

#if !defined(PTE_LEVEL)
#define PTE_LEVEL PTE_LEVEL_MAX
/* Include everything */
#endif

/*
 *
 */

/* Thread scheduling policies */

enum
{
  SCHED_OTHER = 0,
  SCHED_FIFO,
  SCHED_RR,
  SCHED_MIN   = SCHED_OTHER,
  SCHED_MAX   = SCHED_RR
};

struct sched_param
  {
    int sched_priority;
  };

#ifdef __cplusplus
extern "C"
  {
#endif                          /* __cplusplus */

    int sched_yield (void);

    int sched_get_priority_min (int policy);

    int sched_get_priority_max (int policy);

    int sched_setscheduler (pid_t pid, int policy);

    /*
     * Note that this macro returns ENOTSUP rather than
     * ENOSYS as might be expected. However, returning ENOSYS
     * should mean that sched_get_priority_{min,max} are
     * not implemented as well as sched_rr_get_interval.
     * This is not the case, since we just don't support
     * round-robin scheduling. Therefore I have chosen to
     * return the same value as sched_setscheduler when
     * SCHED_RR is passed to it.
     */
#define sched_rr_get_interval(_pid, _interval) \
  ( errno = ENOTSUP, (int) -1 )


#ifdef __cplusplus
  }                               /* End of extern "C" */
#endif                          /* __cplusplus */

#undef PTE_LEVEL
#undef PTE_LEVEL_MAX

#endif                          /* !_SCHED_H */