xref: /freebsd/share/man/man3/pthread_create.3 (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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31.\" $FreeBSD$
32.\"
33.Dd March 15, 2014
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 will fail if:
105.Bl -tag -width Er
106.It Bq Er EAGAIN
107The system lacked the necessary resources to create another thread, or
108the system-imposed limit on the total number of threads in a process
109[PTHREAD_THREADS_MAX] would be exceeded.
110.It Bq Er EPERM
111The caller does not have appropriate permission to set the required scheduling
112parameters or scheduling policy.
113.It Bq Er EINVAL
114The value specified by
115.Fa attr
116is invalid.
117.El
118.Sh SEE ALSO
119.Xr fork 2 ,
120.Xr pthread_attr 3 ,
121.Xr pthread_cancel 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