xref: /freebsd/share/man/man3/pthread_create.3 (revision 4a0f765fbf09711e612e86fce8bb09ec43f482d9)
1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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31.Dd April 4, 1996
32.Dt PTHREAD_CREATE 3
33.Os BSD 4
34.Sh NAME
35.Nm pthread_create
36.Nd create a new thread
37.Sh SYNOPSIS
38.Fd #include <pthread.h>
39.Ft int
40.Fn pthread_create "pthread_t *thread" "const pthread_attr_t *attr" "void *(*start_routine)(void *)" "void *arg"
41.Sh DESCRIPTION
42The
43.Fn pthread_create
44function is used to create a new thread, with attributes specified by
45.Fa attr ,
46within a process. If
47.Fa attr
48is NULL, the default attributes are used. If the attributes specified by
49.Fa attr
50are modified later, the thread's attributes are not affected. Upon
51successful completion
52.Fn pthread_create
53will store the ID of the created thread in the location specified by
54.Fa thread .
55.Pp
56The thread is created executing
57.Fa start_routine
58with
59.Fa arg
60as its sole argument. If the
61.Fa start_routine
62returns, the effect is as if there was an implicit call to
63.Fn pthread_exit
64using the return value of
65.Fa start_toutine
66as the exit status. Note that the thread in which
67.Fn main
68was originally invoked differs from this. When it returns from
69.Fn main ,
70the effect is as if there was an implicit call to
71.Fn exit using the return value of
72.Fn main
73as the exit status.
74.Pp
75The signal state of the new thread is initialized as:
76.Bl -bullet -offset indent
77.It
78The signal mask is inherited from the creating thread.
79.It
80The set of signals pending for the new thread is empty.
81.El
82.Sh RETURN VALUES
83If successful,  the
84.Fn pthread_create
85function will return zero. Otherwise an error number will be returned to
86indicate the error.
87.Sh ERRORS
88.Fn pthread_create
89will fail if:
90.Bl -tag -width Er
91.It Bq Er EAGAIN
92The system lacked the necessary resources to create another thread, or
93the system-imposed limit on the total number of threads in a process
94[PTHREAD_THREADS_MAX] would be exceeded.
95.It Bq Er EINVAL
96The value specified by
97.Fa attr
98is invalid.
99.El
100.Pp
101.Sh SEE ALSO
102.Xr fork 2 ,
103.Xr pthread_exit 3 ,
104.Xr pthread_join 3
105.Sh STANDARDS
106.Fn pthread_create
107is expected to conform to IEEE
108.Pq Dq Tn POSIX
109Std 1003.1c when it is published.
110