xref: /freebsd/share/man/man3/pthread_create.3 (revision f856af0466c076beef4ea9b15d088e1119a945b8)
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31.\" $FreeBSD$
32.\"
33.Dd November 4, 2006
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 libpthread
41.Lb libthr
42.Sh SYNOPSIS
43.In pthread.h
44.Ft int
45.Fn pthread_create "pthread_t *thread" "const pthread_attr_t *attr" "void *(*start_routine)(void *)" "void *arg"
46.Sh DESCRIPTION
47The
48.Fn pthread_create
49function is used to create a new thread, with attributes specified by
50.Fa attr ,
51within a process.
52If
53.Fa attr
54is
55.Dv NULL ,
56the default attributes are used.
57If the attributes specified by
58.Fa attr
59are modified later, the thread's attributes are not affected.
60Upon
61successful completion
62.Fn pthread_create
63will store the ID of the created thread in the location specified by
64.Fa thread .
65.Pp
66The thread is created executing
67.Fa start_routine
68with
69.Fa arg
70as its sole argument.
71If the
72.Fa start_routine
73returns, the effect is as if there was an implicit call to
74.Fn pthread_exit
75using the return value of
76.Fa start_routine
77as the exit status.
78Note that the thread in which
79.Fn main
80was originally invoked differs from this.
81When it returns from
82.Fn main ,
83the effect is as if there was an implicit call to
84.Fn exit
85using the return value of
86.Fn main
87as the exit status.
88.Pp
89The signal state of the new thread is initialized as:
90.Bl -bullet -offset indent
91.It
92The signal mask is inherited from the creating thread.
93.It
94The set of signals pending for the new thread is empty.
95.El
96.Sh RETURN VALUES
97If successful, the
98.Fn pthread_create
99function will return zero.
100Otherwise an error number will be returned to
101indicate the error.
102.Sh ERRORS
103The
104.Fn pthread_create
105function will fail if:
106.Bl -tag -width Er
107.It Bq Er EAGAIN
108The system lacked the necessary resources to create another thread, or
109the system-imposed limit on the total number of threads in a process
110[PTHREAD_THREADS_MAX] would be exceeded.
111.It Bq Er EPERM
112The caller does not have appropriate permission to set the required scheduling
113parameters or scheduling policy.
114.It Bq Er EINVAL
115The value specified by
116.Fa attr
117is invalid.
118.El
119.Sh SEE ALSO
120.Xr fork 2 ,
121.Xr pthread_attr 3 ,
122.Xr pthread_cleanup_pop 3 ,
123.Xr pthread_cleanup_push 3 ,
124.Xr pthread_exit 3 ,
125.Xr pthread_join 3
126.Sh STANDARDS
127The
128.Fn pthread_create
129function conforms to
130.St -p1003.1-96 .
131