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/*
* NOTE: The structure of the routines is identical to that of POSIX
* Message_queues to leave the option of having unnamed message
* queues at a future date. They are currently not part of the
* POSIX standard but unnamed message_queues are. This is also
* the reason for the apparently unnecessary tracking of
* the process_shared attribute. [In addition to the fact that
* it would be trivial to add pshared to the mq_attr structure
* and have process private message queues.]
*
* This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open
* time.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdarg.h>
#include <pthread.h>
#include <limits.h>
#include <errno.h>
#include <fcntl.h>
#include <mqueue.h>
#include <rtems/system.h>
#include <rtems/score/watchdog.h>
#include <rtems/seterr.h>
#include <rtems/posix/mqueue.h>
#include <rtems/posix/time.h>
/*PAGE
*
* 15.2.7 Set Message Queue Attributes, P1003.1b-1993, p. 281
*/
int mq_setattr(
mqd_t mqdes,
const struct mq_attr *mqstat,
struct mq_attr *omqstat
)
{
register POSIX_Message_queue_Control *the_mq;
CORE_message_queue_Control *the_core_mq;
Objects_Locations location;
CORE_message_queue_Attributes *the_mq_attr;
if ( !mqstat )
set_errno_and_return_minus_one( EINVAL );
the_mq = _POSIX_Message_queue_Get( mqdes, &location );
switch ( location ) {
case OBJECTS_ERROR:
set_errno_and_return_minus_one( EBADF );
case OBJECTS_REMOTE:
_Thread_Dispatch();
return POSIX_MP_NOT_IMPLEMENTED();
set_errno_and_return_minus_one( EINVAL );
case OBJECTS_LOCAL:
the_core_mq = &the_mq->Message_queue;
/*
* Return the old values.
*/
/* XXX this is the same stuff as is in mq_getattr... and probably */
/* XXX should be in an inlined private routine */
if ( omqstat ) {
omqstat->mq_flags = the_mq->oflag;
omqstat->mq_msgsize = the_core_mq->maximum_message_size;
omqstat->mq_maxmsg = the_core_mq->maximum_pending_messages;
omqstat->mq_curmsgs = the_core_mq->number_of_pending_messages;
}
/*
* If blocking was in effect and is not now, then there
* may be threads blocked on this message queue which need
* to be unblocked to make the state of the message queue
* consistent for future use.
*/
the_mq_attr = &the_core_mq->Attributes;
if ( !(the_mq->oflag & O_NONBLOCK) && /* were blocking */
(mqstat->mq_flags & O_NONBLOCK) ) { /* and now are not */
_CORE_message_queue_Flush_waiting_threads( the_core_mq );
}
the_mq->oflag = mqstat->mq_flags;
_Thread_Enable_dispatch();
return 0;
}
return POSIX_BOTTOM_REACHED();
}
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