xref: /freebsd/share/man/man3/pthread_create.3 (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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31.\" $FreeBSD$
32.\"
33.Dd April 4, 1996
34.Dt PTHREAD_CREATE 3
35.Os
36.Sh NAME
37.Nm pthread_create
38.Nd create a new thread
39.Sh LIBRARY
40.Lb libc_r
41.Lb libpthread
42.Lb libthr
43.Sh SYNOPSIS
44.In pthread.h
45.Ft int
46.Fn pthread_create "pthread_t *thread" "const pthread_attr_t *attr" "void *(*start_routine)(void *)" "void *arg"
47.Sh DESCRIPTION
48The
49.Fn pthread_create
50function is used to create a new thread, with attributes specified by
51.Fa attr ,
52within a process.
53If
54.Fa attr
55is
56.Dv NULL ,
57the default attributes are used.
58If the attributes specified by
59.Fa attr
60are modified later, the thread's attributes are not affected.
61Upon
62successful completion
63.Fn pthread_create
64will store the ID of the created thread in the location specified by
65.Fa thread .
66.Pp
67The thread is created executing
68.Fa start_routine
69with
70.Fa arg
71as its sole argument.
72If the
73.Fa start_routine
74returns, the effect is as if there was an implicit call to
75.Fn pthread_exit
76using the return value of
77.Fa start_routine
78as the exit status.
79Note that the thread in which
80.Fn main
81was originally invoked differs from this.
82When it returns from
83.Fn main ,
84the effect is as if there was an implicit call to
85.Fn exit
86using the return value of
87.Fn main
88as the exit status.
89.Pp
90The signal state of the new thread is initialized as:
91.Bl -bullet -offset indent
92.It
93The signal mask is inherited from the creating thread.
94.It
95The set of signals pending for the new thread is empty.
96.El
97.Sh RETURN VALUES
98If successful, the
99.Fn pthread_create
100function will return zero.
101Otherwise an error number will be returned to
102indicate the error.
103.Sh ERRORS
104The
105.Fn pthread_create
106function will fail if:
107.Bl -tag -width Er
108.It Bq Er EAGAIN
109The system lacked the necessary resources to create another thread, or
110the system-imposed limit on the total number of threads in a process
111[PTHREAD_THREADS_MAX] would be exceeded.
112.It Bq Er EINVAL
113The value specified by
114.Fa attr
115is invalid.
116.El
117.Sh SEE ALSO
118.Xr fork 2 ,
119.Xr pthread_cleanup_pop 3 ,
120.Xr pthread_cleanup_push 3 ,
121.Xr pthread_exit 3 ,
122.Xr pthread_join 3
123.Sh STANDARDS
124The
125.Fn pthread_create
126function conforms to
127.St -p1003.1-96 .
128