NAME

canputnext, bcanputnext — test for room in next message queue

SYNOPSIS

#include <sys/stream.h>

int
canputnext(queue_t *q);

int
bcanputnext(queue_t *q, unsigned char pri);

DESCRIPTION

The canputnext() and bcanputnext() functions atomically test for available space in the next linked queue or priority band. They are preferable to and safer than calling canput(9F) and bcanput(9F) directly on the queue linked to by q->q_next.

Drivers and modules should call these routines to ensure that room on the next queue exists before calling putnext(9F).

INTERFACE LEVEL

Architecture independent (DDI/DDK).

PARAMETERS

q: STREAMS queue.
pri: Priority band to test.

CONTEXT

These functions may be called in user, kernel, or interrupt context.

RETURN VALUES

1: If the next message queue is not full.
0: If the next message queue is full.