NAME

bcanput − test for flow control in specified priority band

SYNOPSIS

#include <sys/stream.h>
int bcanput(queue_t ∗q, unsigned char pri);

ARGUMENTS

q Pointer to the message queue. 

pri Message priority. 

INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI). 

DESCRIPTION

bcanput() searches through the stream (starting at q) until it finds a queue containing a service routine where the message can be enqueued, or until it reaches the end of the stream.  If found, the queue containing the service routine is tested to see if there is room for a message of priority pri in the queue.  If the queue is full, bcanput() sets the QWANTW flag to back-enable the caller’s service routine. 

If pri is 0, the bcanput() call is equivalent to a call to canput(9F). 

RETURN VALUES

bcanput() returns a 1 if a message of priority pri can be placed on the queue.  It returns a 0 if the priority band is flow-controlled. 

CONTEXT

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

SEE ALSO

canput(9F), putbq(9F), putnext(9F), queue(9S)

SunOS 5.1 STREAMS Programmer’s Guide

NOTES

You are responsible for both testing a queue with bcanput() and refraining from placing a message on the queue if bcanput() fails.

SunOS 5.1  —  Last change: 11 Apr 1991