1.\" Copyright (c) 1998 HD Associates, Inc.
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\" notice, this list of conditions and the following disclaimer in the
11.\" documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
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25.\" $FreeBSD: head/lib/libc/sys/sched_get_priority_max.2 131504 2004-07-02 23:52:20Z ru $
26.\"
27.Dd March 12, 1998
28.Dt SCHED_GET_PRIORITY_MAX 2
29.Os
30.Sh NAME
31.Nm sched_get_priority_max ,
32.Nm sched_get_priority_min ,
33.Nm sched_rr_get_interval
34.Nd get scheduling parameter limits
35.Sh LIBRARY
36.Lb libc
37.Sh SYNOPSIS
38.In sched.h
39.Ft int
40.Fn sched_get_priority_max "int policy"
41.Ft int
42.Fn sched_get_priority_min "int policy"
43.Ft int
44.Fn sched_rr_get_interval "pid_t pid" "struct timespec *interval"
45.Sh DESCRIPTION
46The
47.Fn sched_get_priority_max
48and
49.Fn sched_get_priority_min
50system calls return the appropriate maximum or minimum, respectively,
51for the scheduling policy specified by
52.Fa policy .
53The
54.Fn sched_rr_get_interval
55system call updates the
56.Fa timespec
57structure referenced by the
58.Fa interval
59argument to contain the current execution time limit (i.e., time
60quantum) for the process specified by
61.Fa pid .
62If
63.Fa pid
64is zero, the current execution time limit for the calling process is
65returned.
66.Pp
67The value of
68.Fa policy
69should be one of the scheduling policy values defined in
70.Fa <sched.h> :
71.Bl -tag -width [SCHED_OTHER]
72.It Bq Er SCHED_FIFO
73First-in-first-out fixed priority scheduling with no round robin scheduling;
74.It Bq Er SCHED_OTHER
75The standard time sharing scheduler;
76.It Bq Er SCHED_RR
77Round-robin scheduling across same priority processes.
78.El
79.Sh RETURN VALUES
80If successful, the
81.Fn sched_get_priority_max
82and
83.Fn sched_get_priority_min
84system calls shall return the appropriate maximum or minimum values,
85respectively.
86If unsuccessful, they shall return a value of -1 and set
87.Fa errno
88to indicate the error.
89.Pp
90.Rv -std sched_rr_get_interval
91.Sh ERRORS
92On failure
93.Va errno
94will be set to the corresponding value:
95.Bl -tag -width Er
96.It Bq Er EINVAL
97The value of the
98.Fa policy
99argument does not represent a defined scheduling policy.
100.It Bq Er ENOSYS
101The
102.Fn sched_get_priority_max ,
103.Fn sched_get_priority_min ,
104and
105.Fn sched_rr_get_interval
106system calls are not supported by the implementation.
107.It Bq Er ESRCH
108No process can be found corresponding to that specified by
109.Fa pid .
110.El
111.Sh SEE ALSO
112.Xr sched_getparam 2 ,
113.Xr sched_getscheduler 2 ,
114.Xr sched_setparam 2 ,
115.Xr sched_setscheduler 2
116.Sh STANDARDS
117The
118.Fn sched_get_priority_max ,
119.Fn sched_get_priority_min ,
120and
121.Fn sched_rr_get_interval
122system calls conform to
123.St -p1003.1b-93 .
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\" notice, this list of conditions and the following disclaimer in the
11.\" documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
25.\" $FreeBSD: head/lib/libc/sys/sched_get_priority_max.2 131504 2004-07-02 23:52:20Z ru $
26.\"
27.Dd March 12, 1998
28.Dt SCHED_GET_PRIORITY_MAX 2
29.Os
30.Sh NAME
31.Nm sched_get_priority_max ,
32.Nm sched_get_priority_min ,
33.Nm sched_rr_get_interval
34.Nd get scheduling parameter limits
35.Sh LIBRARY
36.Lb libc
37.Sh SYNOPSIS
38.In sched.h
39.Ft int
40.Fn sched_get_priority_max "int policy"
41.Ft int
42.Fn sched_get_priority_min "int policy"
43.Ft int
44.Fn sched_rr_get_interval "pid_t pid" "struct timespec *interval"
45.Sh DESCRIPTION
46The
47.Fn sched_get_priority_max
48and
49.Fn sched_get_priority_min
50system calls return the appropriate maximum or minimum, respectively,
51for the scheduling policy specified by
52.Fa policy .
53The
54.Fn sched_rr_get_interval
55system call updates the
56.Fa timespec
57structure referenced by the
58.Fa interval
59argument to contain the current execution time limit (i.e., time
60quantum) for the process specified by
61.Fa pid .
62If
63.Fa pid
64is zero, the current execution time limit for the calling process is
65returned.
66.Pp
67The value of
68.Fa policy
69should be one of the scheduling policy values defined in
70.Fa <sched.h> :
71.Bl -tag -width [SCHED_OTHER]
72.It Bq Er SCHED_FIFO
73First-in-first-out fixed priority scheduling with no round robin scheduling;
74.It Bq Er SCHED_OTHER
75The standard time sharing scheduler;
76.It Bq Er SCHED_RR
77Round-robin scheduling across same priority processes.
78.El
79.Sh RETURN VALUES
80If successful, the
81.Fn sched_get_priority_max
82and
83.Fn sched_get_priority_min
84system calls shall return the appropriate maximum or minimum values,
85respectively.
86If unsuccessful, they shall return a value of -1 and set
87.Fa errno
88to indicate the error.
89.Pp
90.Rv -std sched_rr_get_interval
91.Sh ERRORS
92On failure
93.Va errno
94will be set to the corresponding value:
95.Bl -tag -width Er
96.It Bq Er EINVAL
97The value of the
98.Fa policy
99argument does not represent a defined scheduling policy.
100.It Bq Er ENOSYS
101The
102.Fn sched_get_priority_max ,
103.Fn sched_get_priority_min ,
104and
105.Fn sched_rr_get_interval
106system calls are not supported by the implementation.
107.It Bq Er ESRCH
108No process can be found corresponding to that specified by
109.Fa pid .
110.El
111.Sh SEE ALSO
112.Xr sched_getparam 2 ,
113.Xr sched_getscheduler 2 ,
114.Xr sched_setparam 2 ,
115.Xr sched_setscheduler 2
116.Sh STANDARDS
117The
118.Fn sched_get_priority_max ,
119.Fn sched_get_priority_min ,
120and
121.Fn sched_rr_get_interval
122system calls conform to
123.St -p1003.1b-93 .