xref: /netbsd-src/lib/libc/sys/_lwp_create.2 (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1.\"	$NetBSD: _lwp_create.2,v 1.4 2008/04/30 13:10:51 martin Exp $
2.\"
3.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
4.\" All rights reserved.
5.\"
6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Jason R. Thorpe of Wasabi Systems, Inc.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\"    notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\"    notice, this list of conditions and the following disclaimer in the
16.\"    documentation and/or other materials provided with the distribution.
17.\"
18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28.\" POSSIBILITY OF SUCH DAMAGE.
29.\"
30.Dd January 13, 2003
31.Dt _LWP_CREATE 2
32.Os
33.Sh NAME
34.Nm _lwp_create
35.Nd create a new light-weight process
36.Sh LIBRARY
37.Lb libc
38.Sh SYNOPSIS
39.In lwp.h
40.Ft int
41.Fn _lwp_create "ucontext_t *context" "unsigned long flags" "lwpid_t *new_lwp"
42.Sh DESCRIPTION
43.Fn _lwp_create
44causes creation of a new light-weight process, or LWP, and adds it to the
45current process.
46The
47.Fa context
48argument specifies the initial execution context for the new LWP including
49signal mask, stack, and machine registers.
50.Pp
51The following flags affect the creation of the new LWP:
52.Bl -tag -width LWP_SUSPENDED
53.It LWP_DETACHED
54The LWP is created detached.
55The resources associated with a detached LWP will be automatically
56reclaimed by the system when the LWP exits.
57Otherwise, a terminated LWP's resources will not be reclaimed until
58its status is reported to another LWP via
59.Xr _lwp_wait 2 .
60.It LWP_SUSPENDED
61The LWP is created suspended, and will not begin execution until
62it is resumed by another LWP via
63.Xr _lwp_continue 2 .
64.\" __LWP_ASLWP is not yet implemented by the NetBSD kernel.
65.El
66.Pp
67The LWP ID of the new LWP is stored in the location pointed to by
68.Fa new_lwp .
69.Sh RETURN VALUES
70Upon successful completion,
71.Fn _lwp_create
72returns a value of 0.
73Otherwise, an error code is returned to indicate the error.
74.Sh ERRORS
75.Fn _lwp_create
76will fail and no LWP will be created if:
77.Bl -tag -width [EAGAIN]
78.It Bq Er EAGAIN
79The system-imposed limit on the total
80number of LWPs under execution would be exceeded.
81This limit is configuration-dependent.
82.It Bq Er ENOMEM
83There is insufficient swap space for the new LWP.
84.It Bq Er EFAULT
85The address pointed to by
86.Fa context
87or
88.Fa new_lwp
89is outside the process's allocated address space.
90.El
91.Sh SEE ALSO
92.Xr _lwp_continue 2 ,
93.Xr _lwp_exit 2 ,
94.Xr _lwp_wait 2 ,
95.Xr _lwp_makecontext 3
96.Sh HISTORY
97The
98.Fn _lwp_create
99system call first appeared in
100.Nx 2.0 .
101