1sched.h(0P)                POSIX Programmer's Manual               sched.h(0P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

13       sched.h — execution scheduling
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SYNOPSIS

16       #include <sched.h>
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DESCRIPTION

19       The <sched.h> header shall  define  the  pid_t  type  as  described  in
20       <sys/types.h>.
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22       The  <sched.h>  header  shall  define  the  time_t type as described in
23       <sys/types.h>.
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25       The <sched.h> header shall define the timespec structure  as  described
26       in <time.h>.
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28       The  <sched.h>  header  shall  define  the sched_param structure, which
29       shall include the scheduling parameters required for implementation  of
30       each supported scheduling policy. This structure shall include at least
31       the following member:
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33           int       sched_priority        Process or thread execution scheduling priority.
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35       The sched_param structure defined in <sched.h> shall include  the  fol‐
36       lowing members in addition to those specified above:
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38           int             sched_ss_low_priority Low scheduling priority for
39                                                 sporadic server.
40           struct timespec sched_ss_repl_period  Replenishment period for
41                                                 sporadic server.
42           struct timespec sched_ss_init_budget  Initial budget for sporadic server.
43           int             sched_ss_max_repl     Maximum pending replenishments for
44                                                 sporadic server.
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46       Each process or thread is controlled by an associated scheduling policy
47       and priority. Associated with each policy is  a  priority  range.  Each
48       policy definition specifies the minimum priority range for that policy.
49       The priority ranges for each policy may overlap the priority ranges  of
50       other policies.
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52       Four  scheduling  policies  are  defined;  others may be defined by the
53       implementation. The four standard policies are indicated by the  values
54       of the following symbolic constants:
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56       SCHED_FIFO    First in-first out (FIFO) scheduling policy.
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58       SCHED_RR      Round robin scheduling policy.
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60       SCHED_SPORADIC
61                     Sporadic server scheduling policy.
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63       SCHED_OTHER   Another scheduling policy.
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65       The values of these constants are distinct.
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67       The following shall be declared as functions and may also be defined as
68       macros. Function prototypes shall be provided.
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70           int    sched_get_priority_max(int);
71           int    sched_get_priority_min(int);
72           int    sched_getparam(pid_t, struct sched_param *);
73           int    sched_getscheduler(pid_t);
74           int    sched_rr_get_interval(pid_t, struct timespec *);
75           int    sched_setparam(pid_t, const struct sched_param *);
76           int    sched_setscheduler(pid_t, int, const struct sched_param *);
77           int    sched_yield(void);
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79       Inclusion of the <sched.h> header may make visible all symbols from the
80       <time.h> header.
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82       The following sections are informative.
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APPLICATION USAGE

85       None.
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RATIONALE

88       None.
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FUTURE DIRECTIONS

91       None.
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SEE ALSO

94       <sys_types.h>, <time.h>
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96       The System Interfaces volume of POSIX.1‐2008, sched_get_priority_max(),
97       sched_getparam(),    sched_getscheduler(),     sched_rr_get_interval(),
98       sched_setparam(), sched_setscheduler(), sched_yield()
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101       Portions  of  this text are reprinted and reproduced in electronic form
102       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
103       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
104       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
105       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
106       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  In  the
107       event of any discrepancy between this version and the original IEEE and
108       The Open Group Standard, the original IEEE and The Open Group  Standard
109       is  the  referee document. The original Standard can be obtained online
110       at http://www.unix.org/online.html .
111
112       Any typographical or formatting errors that appear  in  this  page  are
113       most likely to have been introduced during the conversion of the source
114       files to man page format. To report such errors,  see  https://www.ker‐
115       nel.org/doc/man-pages/reporting_bugs.html .
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119IEEE/The Open Group                  2013                          sched.h(0P)
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