xref: /freebsd/share/man/man3/pthread_condattr.3 (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
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28.\" $FreeBSD$
29.Dd May 31, 2016
30.Dt PTHREAD_CONDATTR 3
31.Os
32.Sh NAME
33.Nm pthread_condattr_init ,
34.Nm pthread_condattr_destroy ,
35.Nm pthread_condattr_getclock ,
36.Nm pthread_condattr_setclock ,
37.Nm pthread_condattr_getpshared ,
38.Nm pthread_condattr_setpshared
39.Nd condition attribute operations
40.Sh LIBRARY
41.Lb libpthread
42.Sh SYNOPSIS
43.In pthread.h
44.Ft int
45.Fn pthread_condattr_init "pthread_condattr_t *attr"
46.Ft int
47.Fn pthread_condattr_destroy "pthread_condattr_t *attr"
48.Ft int
49.Fn pthread_condattr_getclock "pthread_condattr_t * restrict attr" "clock_t * restrict clock_id"
50.Ft int
51.Fn pthread_condattr_setclock "pthread_condattr_t *attr" "clock_t clock_id"
52.Ft int
53.Fn pthread_condattr_getpshared "pthread_condattr_t * restrict attr" "int * restrict pshared"
54.Ft int
55.Fn pthread_condattr_setpshared "pthread_condattr_t *attr" "int pshared"
56.Sh DESCRIPTION
57Condition attribute objects are used to specify parameters to
58.Fn pthread_cond_init .
59.Pp
60The
61.Fn pthread_condattr_init
62function initializes a condition attribute object with the default attributes.
63.Pp
64The
65.Fn pthread_condattr_destroy
66function destroys a condition attribute object.
67.Pp
68The
69.Fn pthread_condattr_getclock
70function will put the value of the clock attribute from
71.Fa attr
72into the memory area pointed to by
73.Fa clock_id .
74The
75.Fn pthread_condattr_setclock
76function will set the clock attribute of
77.Fa attr
78to the value specified in
79.Fa clock_id .
80The clock attribute affects the interpretation of
81.Fa abstime
82in
83.Xr pthread_cond_timedwait 3
84and may be set to
85.Dv CLOCK_REALTIME
86(default)
87or
88.Dv CLOCK_MONOTONIC .
89.Pp
90The
91.Fn pthread_condattr_getpshared
92function will put the value of the process-shared attribute from
93.Fa attr
94into the memory area pointed to by
95.Fa pshared .
96The
97.Fn pthread_condattr_setpshared
98function will set the process-shared attribute of
99.Fa attr
100to the value specified in
101.Fa pshared .
102The argument
103.Fa pshared
104may have one of the following values:
105.Bl -tag -width ".Dv PTHREAD_PROCESS_PRIVATE"
106.It Dv PTHREAD_PROCESS_PRIVATE
107The condition variable it is attached to may only be accessed by
108threads in the same process as the one that created the object.
109.It Dv PTHREAD_PROCESS_SHARED
110The condition variable it is attached to may be accessed by
111threads in processes other than the one that created the object.
112.El
113.Sh RETURN VALUES
114If successful, these functions return 0.
115Otherwise, an error number is returned to indicate the error.
116.Sh ERRORS
117The
118.Fn pthread_condattr_init
119function will fail if:
120.Bl -tag -width Er
121.It Bq Er ENOMEM
122Out of memory.
123.El
124.Pp
125The
126.Fn pthread_condattr_destroy
127function will fail if:
128.Bl -tag -width Er
129.It Bq Er EINVAL
130Invalid value for
131.Fa attr .
132.El
133.Pp
134The
135.Fn pthread_condattr_setclock
136function will fail if:
137.Bl -tag -width Er
138.It Bq Er EINVAL
139The value specified in
140.Fa clock_id
141is not one of the allowed values.
142.El
143.Pp
144The
145.Fn pthread_condattr_setpshared
146function will fail if:
147.Bl -tag -width Er
148.It Bq Er EINVAL
149The value specified in
150.Fa pshared
151is not one of the allowed values.
152.El
153.Sh SEE ALSO
154.Xr pthread_cond_init 3 ,
155.Xr pthread_cond_timedwait 3
156.Sh STANDARDS
157The
158.Fn pthread_condattr_init
159and
160.Fn pthread_condattr_destroy
161functions conform to
162.St -p1003.1-96
163