putbq(9F) manual page
Table of Contents
putbq - place a message at the head of a queue
#include <sys/stream.h>
int putbq(queue_t *q, mblk_t *bp);
Architecture independent
level 1 (DDI/DKI).
- q
- Pointer to the queue.
- bp
- Pointer to the message
block.
putbq() places a message at the beginning of the appropriate
section of the message queue. There are always sections for high priority
and ordinary messages. If other priority bands are used, each will have
its own section of the queue, in priority band order, after high priority
messages and before ordinary messages. putbq() can be used for ordinary,
priority band, and high priority messages. However, unless precautions are
taken, using putbq() with a high priority message is likely to lead to
an infinite loop of putting the message back on the queue, being rescheduled,
pulling it off, and putting it back on.
This function is usually called
when bcanput(9F)
or canput(9F)
determines that the message cannot be passed
on to the next stream component. The flow control parameters are updated
to reflect the change in the queue’s status. If QNOENB
is not set, the
service routine is enabled.
putbq() returns 1 on success and
0 on failure.
putbq() can be called from user or interrupt context.
See the bufcall(9F)
function page for an example of putbq().
bcanput(9F)
, bufcall(9F)
, canput(9F)
, getq(9F)
, putq(9F)
Table of Contents
![[Go to CFHT Home Page]](/images/cfht-icon.gif){kind=icon}
Man Pages 
Back to Software Index 
Manpage Top Level