mirror of https://github.com/mkerrisk/man-pages
119 lines
3.4 KiB
Plaintext
119 lines
3.4 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "<sched.h>" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" <sched.h>
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.SH NAME
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sched.h \- execution scheduling (\fBREALTIME\fP)
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.SH SYNOPSIS
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.LP
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\fB#include <sched.h> \fP
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.SH DESCRIPTION
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.LP
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The \fI<sched.h>\fP header shall define the \fBsched_param\fP structure,
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which contains the scheduling parameters
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required for implementation of each supported scheduling policy. This
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structure shall contain at least the following member:
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.sp
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.RS
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.nf
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\fBint sched_priority \fP Process execution scheduling priority. \fB
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\fP
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.fi
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.RE
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.LP
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In addition, if _POSIX_SPORADIC_SERVER or _POSIX_THREAD_SPORADIC_SERVER
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is defined, the \fBsched_param\fP structure defined in
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\fI<sched.h>\fP shall contain the following members in addition to
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those specified above:
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.sp
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.RS
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.nf
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\fBint sched_ss_low_priority\fP Low scheduling priority for \fB
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\fP sporadic server. \fB
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struct timespec sched_ss_repl_period \fP Replenishment period for \fB
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\fP sporadic server. \fB
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struct timespec sched_ss_init_budget \fP Initial budget for sporadic server. \fB
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int sched_ss_max_repl \fP Maximum pending replenishments for \fB
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\fP sporadic server. \fB
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\fP
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.fi
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.RE
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.LP
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Each process is controlled by an associated scheduling policy and
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priority. Associated with each policy is a priority range.
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Each policy definition specifies the minimum priority range for that
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policy. The priority ranges for each policy may overlap the
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priority ranges of other policies.
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.LP
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Four scheduling policies are defined; others may be defined by the
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implementation. The four standard policies are indicated by
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the values of the following symbolic constants:
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.TP 7
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SCHED_FIFO
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First in-first out (FIFO) scheduling policy.
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.TP 7
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SCHED_RR
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Round robin scheduling policy.
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.TP 7
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SCHED_SPORADIC
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Sporadic server scheduling policy.
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.TP 7
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SCHED_OTHER
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Another scheduling policy.
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.sp
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.LP
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The values of these constants are distinct.
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.LP
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The following shall be declared as functions and may also be defined
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as macros. Function prototypes shall be provided.
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.sp
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.RS
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.nf
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\fB
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int sched_get_priority_max(int);
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int sched_get_priority_min(int);
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int sched_getparam(pid_t, struct sched_param *);
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int sched_getscheduler(pid_t);
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int sched_rr_get_interval(pid_t, struct timespec *);
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int sched_setparam(pid_t, const struct sched_param *);
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int sched_setscheduler(pid_t, int, const struct sched_param *);
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int sched_yield(void);
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\fP
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.fi
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.RE
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.LP
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Inclusion of the \fI<sched.h>\fP header may make visible all symbols
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from the \fI<time.h>\fP header.
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.LP
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\fIThe following sections are informative.\fP
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fI<time.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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