xref: /openbsd/lib/libpthread/man/pthread_create.3 (revision 404b540a)
1.\" $OpenBSD: pthread_create.3,v 1.13 2008/12/18 09:30:32 guenther Exp $
2.\"
3.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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16.\"	This product includes software developed by John Birrell.
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33.\" $FreeBSD: pthread_create.3,v 1.8 1999/08/28 00:03:04 peter Exp $
34.\"
35.Dd $Mdocdate: December 18 2008 $
36.Dt PTHREAD_CREATE 3
37.Os
38.Sh NAME
39.Nm pthread_create
40.Nd create a new thread
41.Sh SYNOPSIS
42.Fd #include <pthread.h>
43.Ft int
44.Fn pthread_create "pthread_t *thread" "const pthread_attr_t *attr" "void *(*start_routine)(void *)" "void *arg"
45.Sh DESCRIPTION
46The
47.Fn pthread_create
48function is used to create a new thread, with attributes specified by
49.Fa attr ,
50within a process.
51If
52.Fa attr
53is NULL, the default attributes are used.
54If the attributes specified by
55.Fa attr
56are modified later, the thread's attributes are not affected.
57Upon successful completion
58.Fn pthread_create
59will store the ID of the created thread in the location specified by
60.Fa thread .
61.Pp
62The thread is created executing
63.Fa start_routine
64with
65.Fa arg
66as its sole argument.
67If the
68.Fa start_routine
69returns, the effect is as if there was an implicit call to
70.Fn pthread_exit
71using the return value of
72.Fa start_routine
73as the exit status.
74Note that the thread in which
75.Fn main
76was originally invoked differs from this.
77When it returns from
78.Fn main ,
79the effect is as if there was an implicit call to
80.Fn exit
81using the return value of
82.Fn main
83as the exit status.
84.Pp
85The signal state of the new thread is initialized as:
86.Bl -bullet -offset indent
87.It
88The signal mask is inherited from the creating thread.
89.It
90The set of signals pending for the new thread is empty.
91.El
92.Sh RETURN VALUES
93If successful, the
94.Fn pthread_create
95function will return zero.
96Otherwise an error number will be returned to indicate the error.
97.Sh ERRORS
98.Fn pthread_create
99will fail if:
100.Bl -tag -width Er
101.It Bq Er EAGAIN
102The system lacked the necessary resources to create another thread, or
103the system-imposed limit on the total number of threads in a process
104[PTHREAD_THREADS_MAX] would be exceeded.
105.It Bq Er EINVAL
106The value specified by
107.Fa attr
108is invalid.
109.El
110.Sh SEE ALSO
111.Xr fork 2 ,
112.Xr pthread_attr_init 3 ,
113.Xr pthread_attr_setdetachstate 3 ,
114.Xr pthread_attr_setguardsize 3 ,
115.Xr pthread_attr_setstack 3 ,
116.Xr pthread_attr_setstackaddr 3 ,
117.Xr pthread_attr_setstacksize 3 ,
118.Xr pthread_cleanup_pop 3 ,
119.Xr pthread_cleanup_push 3 ,
120.Xr pthread_exit 3 ,
121.Xr pthread_join 3
122.Sh STANDARDS
123.Fn pthread_create
124conforms to
125.St -p1003.1-96 .
126