1.\" Copyright (c) 2004 Michael Telahun Makonnen
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25.\" $FreeBSD$
26.\"
27.Dd August 17, 2018
28.Dt PTHREAD_BARRIERATTR 3
29.Os
30.Sh NAME
31.Nm pthread_barrierattr_destroy , pthread_barrierattr_getpshared ,
32.Nm pthread_barrierattr_init , pthread_barrierattr_setpshared
33.Nd "manipulate a barrier attribute object"
34.Sh LIBRARY
35.Lb libpthread
36.Sh SYNOPSIS
37.In pthread.h
38.Ft int
39.Fn pthread_barrierattr_destroy "pthread_barrierattr_t *attr"
40.Ft int
41.Fo pthread_barrierattr_getpshared
42.Fa "const pthread_barrierattr_t *restrict attr" "int *restrict pshared"
43.Fc
44.Ft int
45.Fn pthread_barrierattr_init "pthread_barrierattr_t *attr"
46.Ft int
47.Fo pthread_barrierattr_setpshared
48.Fa "pthread_barrierattr_t *attr" "int pshared"
49.Fc
50.Sh DESCRIPTION
51The
52.Fn pthread_barrierattr_init
53function will initialize
54.Fa attr
55with default attributes.
56The
57.Fn pthread_barrierattr_destroy
58function will destroy
59.Fa attr
60and release any resources that may have been allocated on its behalf.
61.Pp
62The
63.Fn pthread_barrierattr_getpshared
64function will put the value of the process-shared attribute from
65.Fa attr
66into the memory area pointed to by
67.Fa pshared .
68The
69.Fn pthread_barrierattr_setpshared
70function will set the process-shared attribute of
71.Fa attr
72to the value specified in
73.Fa pshared .
74The argument
75.Fa pshared
76may have one of the following values:
77.Bl -tag -width ".Dv PTHREAD_PROCESS_PRIVATE"
78.It Dv PTHREAD_PROCESS_PRIVATE
79The barrier object it is attached to may only be accessed by
80threads in the same process as the one that created the object.
81.It Dv PTHREAD_PROCESS_SHARED
82The barrier object it is attached to may be accessed by
83threads in processes other than the one that created the object.
84.El
85.Sh RETURN VALUES
86If successful, all these functions will return zero.
87Otherwise, an error number will be returned to indicate the error.
88.Pp
89None of these functions will return
90.Er EINTR .
91.Sh ERRORS
92The
93.Fn pthread_barrierattr_destroy ,
94.Fn pthread_barrierattr_getpshared
95and
96.Fn pthread_barrierattr_setpshared
97functions may fail if:
98.Bl -tag -width Er
99.It Bq Er EINVAL
100The value specified by
101.Fa attr
102is invalid.
103.El
104.Pp
105The
106.Fn pthread_barrierattr_init
107function will fail if:
108.Bl -tag -width Er
109.It Bq Er ENOMEM
110Insufficient memory to initialize the barrier attribute object
111.Fa attr .
112.El
113.Pp
114The
115.Fn pthread_barrierattr_setpshared
116function will fail if:
117.Bl -tag -width Er
118.It Bq Er EINVAL
119The value specified in
120.Fa pshared
121is not one of the allowed values.
122.El
123.Sh SEE ALSO
124.Xr pthread_barrier_destroy 3 ,
125.Xr pthread_barrier_init 3 ,
126.Xr pthread_barrier_wait 3
127.Sh HISTORY
128The
129.Fn pthread_barrierattr_*
130functions first appeared in
131.Lb libkse
132in
133.Fx 5.2 ,
134and in
135.Lb libthr
136in
137.Fx 5.3 .
138Support for process-shared barriers appeared in
139.Fx 11.0 .
140