[Go to CFHT Home Page] Man Pages
Back to Software Index  BORDER=0Manpage Top Level
    rmvq(9F) manual page Table of Contents

Name

rmvq - remove a message from a queue

Synopsis


#include <sys/stream.h>

void rmvq(queue_t *q, mblk_t *mp);

Interface Level

Architecture independent level 1 (DDI/DKI).

Arguments

q
Queue containing the message to be removed.
mp
Message to remove.

Description

rmvq() removes a message from a queue. A message can be removed from anywhere on a queue. To prevent modules and drivers from having to deal with the internals of message linkage on a queue, either rmvq() or getq(9F) should be used to remove a message from a queue.

Context

rmvq() can be called from user or interrupt context.

Example

This code fragment illustrates how one may flush one type of message from a queue. In this case, only M_PROTO T_DATA_IND messages are flushed. For each message on the queue, if it is an M_PROTO message (line 8) of type T_DATA_IND (line 10), save a pointer to the next message (line 11), remove the T_DATA_IND message (line 12) and free it (line 13). Continue with the next message in the list (line 19). 


 1  mblk_t *mp, *nmp;
 2  queue_t *q;
 3  union T_primitives *tp;
 4
 5    freezestr(q);
 6    mp = q->q_first;
 7    while (mp) {
 8        if (mp->b_datap->db_type == M_PROTO) {
 9            tp = (union T_primitives *)mp->b_rptr;
10            if (tp->type == T_DATA_IND) {
11                nmp = mp->b_next;
12                rmvq(q, mp);
13                freemsg(mp);
14                mp = nmp;
15            } else {
16                mp = mp->b_next;
17            }
18        } else {
19            mp = mp->b_next;
20        }
21    }
22    unfreezestr(q);

See Also

freemsg(9F) , freezestr(9F) , getq(9F) , insq(9F) , unfreezestr(9F)


Warnings

Make sure that the message mp is linked onto q to avoid a possible system panic.

Notes

The stream must be frozen using freezestr(9F) before calling rmvq().

Table of Contents