MQ_SETATTR(3C) Standard C Library Functions MQ_SETATTR(3C)
NAME
mq_setattr - set/get message queue attributes
SYNOPSIS
#include <mqueue.h>
int mq_setattr(
mqd_t mqdes,
const struct mq_attr *mqstat,
struct mq_attr *omqstat);
DESCRIPTION
The
mq_setattr() function is used to set attributes associated with
the open message queue description referenced by the message queue
descriptor specified by
mqdes.
The message queue attributes corresponding to the following members
defined in the
mq_attr structure are set to the specified values upon
successful completion of
mq_setattr():
mq_flags The value of this member is either
0 or
O_NONBLOCK. The values of
mq_maxmsg,
mq_msgsize, and
mq_curmsgs are ignored by
mq_setattr().
If
omqstat is non-
NULL,
mq_setattr() stores, in the location
referenced by
omqstat, the previous message queue attributes and the
current queue status. These values are the same as would be returned
by a call to
mq_getattr() at that point.
RETURN VALUES
Upon successful completion,
mq_setattr() returns
0 and the attributes
of the message queue will have been changed as specified. Otherwise,
the message queue attributes are unchanged, and the function returns
-1 and sets
errno to indicate the error.
ERRORS
The
mq_setattr() function will fail if:
EBADF The
mqdes argument is not a valid message queue
descriptor.
ENOSYS The
mq_setattr() function is not supported by the system.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|MT-Level | MT-Safe |
+--------------------+-------------------+
|Standard | See
standards(7). |
+--------------------+-------------------+
SEE ALSO
msgctl(2),
msgget(2),
msgrcv(2),
msgsnd(2),
mq_getattr(3C),
mq_open(3C),
mq_receive(3C),
mq_send(3C),
mqueue.h(3HEAD),
attributes(7),
standards(7)NOTES
Solaris 2.6 was the first release to support the Asynchronous Input
and Output option. Prior to this release, this function always
returned
-1 and set
errno to
ENOSYS.
February 5, 2008 MQ_SETATTR(3C)
