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