Листинг 5.22. Функция mq_getattr
//my_pxmsg_mmap/mq_getattr.с
1 #include "unpipc.h"
2 #include "mqueue.h"
3 int
4 mymq_getattr(mymqd_t mqd, struct mymq_attr *mqstat)
5 {
6 int n;
7 struct mymq_hdr *mqhdr;
8 struct mymq_attr *attr;
9 struct mymq_info *mqinfo;
10 mqinfo = mqd;
11 if (mqinfo->mqi_magic != MQI_MAGIC) {
12 errno = EBADF;
13 return(-1);
14 }
15 mqhdr = mqinfo->mqi_hdr;
16 attr = &mqhdr->mqh_attr;
17 if ((n = pthread_mutex_lock(&mqhdr->mqh_lock)) != 0) {
18 errno = n;
19 return (-1);
20 }
21 mqstat->mq_flags = mqinfo->mqi_flags; /* для каждого open */
22 mqstat->mq_maxmsg = attr->mq_maxmsg; /* оставшиеся три – для очереди */
23 mqstat->mq_msgsize = attr->mq_msgsize;
24 mqstat->mq_curmsgs = attr->mq_curmsgs;
25 pthread_mutex_unlock(&mqhdr->mqh_lock);
26 return(0);
27 }