xref: /openbsd/lib/libpthread/man/pthread_create.3 (revision 78b63d65)
1.\" $OpenBSD: pthread_create.3,v 1.7 2001/06/24 18:17:30 jasoni Exp $
2.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\" 3. All advertising materials mentioning features or use of this software
14.\"    must display the following acknowledgement:
15.\"	This product includes software developed by John Birrell.
16.\" 4. Neither the name of the author nor the names of any co-contributors
17.\"    may be used to endorse or promote products derived from this software
18.\"    without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\" $FreeBSD: pthread_create.3,v 1.8 1999/08/28 00:03:04 peter Exp $
33.\"
34.Dd April 4, 1996
35.Dt PTHREAD_CREATE 3
36.Os
37.Sh NAME
38.Nm pthread_create
39.Nd create a new thread
40.Sh SYNOPSIS
41.Fd #include <pthread.h>
42.Ft int
43.Fn pthread_create "pthread_t *thread" "const pthread_attr_t *attr" "void *(*start_routine)(void *)" "void *arg"
44.Sh DESCRIPTION
45The
46.Fn pthread_create
47function is used to create a new thread, with attributes specified by
48.Fa attr ,
49within a process. If
50.Fa attr
51is NULL, the default attributes are used. If the attributes specified by
52.Fa attr
53are modified later, the thread's attributes are not affected. Upon
54successful completion
55.Fn pthread_create
56will store the ID of the created thread in the location specified by
57.Fa thread .
58.Pp
59The thread is created executing
60.Fa start_routine
61with
62.Fa arg
63as its sole argument. If the
64.Fa start_routine
65returns, the effect is as if there was an implicit call to
66.Fn pthread_exit
67using the return value of
68.Fa start_routine
69as the exit status. Note that the thread in which
70.Fn main
71was originally invoked differs from this. When it returns from
72.Fn main ,
73the effect is as if there was an implicit call to
74.Fn exit
75using the return value of
76.Fn main
77as the exit status.
78.Pp
79The signal state of the new thread is initialized as:
80.Bl -bullet -offset indent
81.It
82The signal mask is inherited from the creating thread.
83.It
84The set of signals pending for the new thread is empty.
85.El
86.Sh RETURN VALUES
87If successful, the
88.Fn pthread_create
89function will return zero. Otherwise an error number will be returned to
90indicate the error.
91.Sh ERRORS
92.Fn pthread_create
93will fail if:
94.Bl -tag -width Er
95.It Bq Er EAGAIN
96The system lacked the necessary resources to create another thread, or
97the system-imposed limit on the total number of threads in a process
98[PTHREAD_THREADS_MAX] would be exceeded.
99.It Bq Er EINVAL
100The value specified by
101.Fa attr
102is invalid.
103.El
104.Sh SEE ALSO
105.Xr fork 2 ,
106.Xr pthread_attr_init 3 ,
107.Xr pthread_attr_setdetachstate 3 ,
108.Xr pthread_attr_setstackaddr 3 ,
109.Xr pthread_attr_setstacksize 3 ,
110.Xr pthread_cleanup_pop 3 ,
111.Xr pthread_cleanup_push 3 ,
112.Xr pthread_exit 3 ,
113.Xr pthread_join 3
114.Sh STANDARDS
115.Fn pthread_create
116conforms to ISO/IEC 9945-1 ANSI/IEEE
117.Pq Dq Tn POSIX
118Std 1003.1 Second Edition 1996-07-12.
119