.\"	$OpenBSD: lim_cur.9,v 1.2 2019/06/21 12:56:46 visa Exp $
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.\" Copyright (c) 2019 Visa Hankala
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.Dd $Mdocdate: June 21 2019 $
.Dt LIM_CUR 9
.Os
.Sh NAME
.Nm lim_cur ,
.Nm lim_cur_proc ,
.Nm lim_fork ,
.Nm lim_free ,
.Nm lim_read_enter ,
.Nm lim_read_leave
.Nd Resource limit interface
.Sh SYNOPSIS
.In sys/types.h
.In sys/resourcevar.h
.Ft rlim_t
.Fn "lim_cur" "int which"
.Ft rlim_t
.Fn "lim_cur_proc" "struct proc *p" "int which"
.Ft struct plimit *
.Fn "lim_fork" "struct process *parent" "struct process *child"
.Ft void
.Fn "lim_free" "struct plimit *limit"
.Ft struct plimit *
.Fn "lim_read_enter"
.Ft void
.Fn "lim_read_leave" "struct plimit *limit"
.Sh DESCRIPTION
The resource limit interface provides read access to the resource limits
of the process.
.Pp
.Fn lim_cur
returns the value of limit
.Fa which
of the current process.
The
.Fa which
can take one of the following values:
.Bd -literal
#define RLIMIT_CPU	0	/* cpu time in milliseconds */
#define RLIMIT_FSIZE	1	/* maximum file size */
#define RLIMIT_DATA	2	/* data size */
#define RLIMIT_STACK	3	/* stack size */
#define RLIMIT_CORE	4	/* core file size */
#define RLIMIT_RSS	5	/* resident set size */
#define RLIMIT_MEMLOCK	6	/* locked-in-memory address space */
#define RLIMIT_NPROC	7	/* number of processes */
#define RLIMIT_NOFILE	8	/* number of open files */
.Ed
.Pp
.Fn lim_cur_proc
is like
.Fn lim_cur
but returns the value of limit
.Fa which
of thread
.Fa p .
.Pp
.Fn lim_read_enter
begins read access to the current process' resource limit structure.
.Pp
.Fn lim_read_leave
finishes read access to the resource limit structure.
.Pp
Sections denoted by
.Fn lim_read_enter
and
.Fn lim_read_leave
cannot nest.
Using
.Fn lim_cur
inside the read section is not allowed
because the function uses
.Fn lim_read_enter
and
.Fn lim_read_leave
internally.
.Pp
.Fn lim_free
releases the reference
.Fa limit .
.Pp
.Fn lim_fork
makes the process
.Fa child
share the resource limits of process
.Fa parent .
.Sh CONTEXT
.Fn lim_cur ,
.Fn lim_cur_proc ,
.Fn lim_fork ,
.Fn lim_free ,
.Fn lim_read_enter
and
.Fn lim_read_leave
can be called during autoconf, or from process context.
.Sh RETURN VALUES
.Fn lim_cur
and
.Fn lim_cur_proc
return the value of the given resource limit.
.Pp
.Fn lim_read_enter
returns a read reference to the current process' resource limits.