Architecture independent level 1 (DDI/DKI).

q

Pointer to a message queue belonging to the invoking module.

pri

Minimum priority level.

The invocation canputnext(q); is an atomic equivalent of the canput(q->q_next); routine. That is, the STREAMS framework provides whatever mutual exclusion is necessary to insure that dereferencing q through its q_next field and then invoking canput(9F) proceeds without interference from other threads.

bcanputnext(q, pri); is the equivalent of the bcanput(q->q_next, pri); routine.

canputnext(q); and bcanputnext(q, pri); should always be used in preference to canput(q->q_next); and bcanput(q->q_next, pri); respectively.

See canput(9F) and bcanput(9F) for further details.

1

If the message queue is not full.

0

If the queue is full.

canputnext() and bcanputnext() can be called from user or interrupt context.

Drivers are responsible for both testing a queue with canputnext() or bcanputnext() and refraining from placing a message on the queue if the queue is full.

bcanput(9F), canput(9F)

Writing Device Drivers

STREAMS Programming Guide