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   mq_setattr.3p    ( 3 )

установить атрибуты очереди сообщений (REALTIME) (set message queue attributes (REALTIME))

Пролог (Prolog)

This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

Имя (Name)

mq_setattr — set message queue attributes (REALTIME)

Синопсис (Synopsis)

#include <mqueue.h>

int mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat, struct mq_attr *restrict omqstat);


Описание (Description)

The mq_setattr() function shall 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 shall be set to the specified values upon successful completion of mq_setattr():

mq_flags The value of this member is the bitwise-logical OR of zero or more of O_NONBLOCK and any implementation- defined flags.

The values of the mq_maxmsg, mq_msgsize, and mq_curmsgs members of the mq_attr structure shall be ignored by mq_setattr().

If omqstat is non-NULL, the mq_setattr() function shall store, in the location referenced by omqstat, the previous message queue attributes and the current queue status. These values shall be the same as would be returned by a call to mq_getattr() at that point.


Возвращаемое значение (Return value)

Upon successful completion, the function shall return a value of
       zero and the attributes of the message queue shall have been
       changed as specified.

Otherwise, the message queue attributes shall be unchanged, and the function shall return a value of -1 and set errno to indicate the error.


Ошибки (Error)

The mq_setattr() function shall fail if:

EBADF The mqdes argument is not a valid message queue descriptor.

The following sections are informative.


Примеры (Examples)

None.

Использование в приложениях (Application usage)

None.

Обоснование (Rationale)

None.

Будущие направления (Future directions)

None.

Смотри также (See also)

mq_open(3p), mq_send(3p), msgctl(3p), msgget(3p), msgrcv(3p),
       msgsnd(3p)

The Base Definitions volume of POSIX.1‐2017, mqueue.h(0p)