xref: /freebsd/share/man/man3/pthread_create.3 (revision 21a4258d89a4e27632cfd87e5ad6e8538a6e77a2)
1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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31.\" $FreeBSD$
32.\"
33.Dd June 2, 2016
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.Sh SYNOPSIS
42.In 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
54.Dv NULL ,
55the default attributes are used.
56If the attributes specified by
57.Fa attr
58are modified later, the thread's attributes are not affected.
59Upon
60successful completion
61.Fn pthread_create
62will store the ID of the created thread in the location specified by
63.Fa thread .
64.Pp
65The thread is created executing
66.Fa start_routine
67with
68.Fa arg
69as its sole argument.
70If the
71.Fa start_routine
72returns, the effect is as if there was an implicit call to
73.Fn pthread_exit
74using the return value of
75.Fa start_routine
76as the exit status.
77Note that the thread in which
78.Fn main
79was originally invoked differs from this.
80When it returns from
81.Fn main ,
82the effect is as if there was an implicit call to
83.Fn exit
84using the return value of
85.Fn main
86as the exit status.
87.Pp
88The signal state of the new thread is initialized as:
89.Bl -bullet -offset indent
90.It
91The signal mask is inherited from the creating thread.
92.It
93The set of signals pending for the new thread is empty.
94.El
95.Sh RETURN VALUES
96If successful, the
97.Fn pthread_create
98function will return zero.
99Otherwise an error number will be returned to
100indicate the error.
101.Sh ERRORS
102The
103.Fn pthread_create
104function can return any of the following errors:
105.Bl -tag -width Er
106.It Bq Er ENOMEM
107The system lacked the necessary resources to create another thread.
108.It Bq Er EAGAIN
109The system-imposed limit on the total number of threads in a process
110.Dv [PTHREAD_THREADS_MAX]
111would be exceeded.
112.It Bq Er EAGAIN
113The
114.Dv RACCT_NTHR
115limit would be exceeded; see
116.Xr racct 2 .
117.It Bq Er EPERM
118The caller does not have permission to set the scheduling parameters or
119scheduling policy.
120.It Bq Er EINVAL
121A value specified by
122.Fa attr
123is invalid.
124.It Bq Er EDEADLK
125The CPU set specified by
126.Fa attr
127would prevent the thread from running on any CPU.
128.It Bq Er EFAULT
129The stack base specified by
130.Fa attr
131is invalid, or the kernel was unable to put required
132initial data on the stack.
133.El
134.Sh SEE ALSO
135.Xr cpuset_setaffinity 2 ,
136.Xr fork 2 ,
137.Xr racct 2 ,
138.Xr thr_new 2 ,
139.Xr pthread_attr 3 ,
140.Xr pthread_cancel 3 ,
141.Xr pthread_cleanup_pop 3 ,
142.Xr pthread_cleanup_push 3 ,
143.Xr pthread_exit 3 ,
144.Xr pthread_join 3
145.Sh STANDARDS
146The
147.Fn pthread_create
148function conforms to
149.St -p1003.1-96 .
150