60 lines
1001 B
C
60 lines
1001 B
C
/* Copyright 2002, Red Hat Inc. */
|
|
|
|
#include <mqueue.h>
|
|
#include <errno.h>
|
|
#include <sys/sem.h>
|
|
#include <string.h>
|
|
#define _LIBC
|
|
#include <sys/lock.h>
|
|
#undef _LIBC
|
|
|
|
#include "mqlocal.h"
|
|
|
|
int
|
|
mq_setattr (mqd_t msgid, const struct mq_attr *mqstat, struct mq_attr *omqstat)
|
|
{
|
|
struct libc_mq *info;
|
|
struct sembuf sb0 = {0, -1, 0};
|
|
int num_msgs;
|
|
int rc = 0;
|
|
|
|
info = __find_mq (msgid);
|
|
|
|
if (info == NULL)
|
|
{
|
|
errno = EBADF;
|
|
return -1;
|
|
}
|
|
|
|
/* temporarily lock message queue */
|
|
semop (info->semid, &sb0, 1);
|
|
|
|
/* make copy of old structure */
|
|
if (omqstat != NULL)
|
|
{
|
|
num_msgs = semctl (info->semid, 3, GETVAL);
|
|
if (num_msgs >= 0)
|
|
{
|
|
memcpy (omqstat, info->attr, sizeof(struct mq_attr));
|
|
omqstat->mq_curmsgs = num_msgs;
|
|
}
|
|
else
|
|
rc = -1;
|
|
}
|
|
|
|
/* only the mq_flags field can be changed */
|
|
info->attr->mq_flags = mqstat->mq_flags;
|
|
|
|
/* release message queue */
|
|
sb0.sem_op = 1;
|
|
semop (info->semid, &sb0, 1);
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|