samestr(9f) [opensolaris man page]

SAMESTR(9F)						   Kernel Functions for Drivers 					       SAMESTR(9F)

NAME

       SAMESTR, samestr - test if next queue is in the same stream

SYNOPSIS

       #include <sys/stream.h>

       int SAMESTR(queue_t *q);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       q    Pointer to the queue.

DESCRIPTION

       The SAMESTR() function is used to see if the next queue in a stream (if it exists) is the same type as the current queue (that is, both are
       read queues or both are write queues). This function accounts for the twisted queue connections that occur in a STREAMS pipe and should	be
       used in preference to direct examination of the q_next field of queue(9S) to see if the stream continues beyond q.

RETURN VALUES

       The  SAMESTR() function returns 1 if the next queue is the same type as the current queue. It returns 0 if the next queue does not exist or
       if it is not the same type.

CONTEXT

       The SAMESTR() function can be called from user, interrupt, context.

SEE ALSO

       OTHERQ(9F)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.11							    16 Jan 2006 						       SAMESTR(9F)

canput(9F)						   Kernel Functions for Drivers 						canput(9F)

NAME

       canput - test for room in a message queue

SYNOPSIS

       #include <sys/stream.h>

       int canput(queue_t *q);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       q	Pointer to the message queue.

DESCRIPTION

       canput() 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 mes-
       sage in the queue.

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

RETURN VALUES

       1	If the message queue is not full.

       0	If the queue is full.

CONTEXT

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

SEE ALSO

       bcanput(9F), bcanputnext(9F), canputnext(9F), putbq(9F), putnext(9F)

       Writing Device Drivers

	STREAMS Programming Guide

WARNINGS

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

SunOS 5.10							    11 Apr 1991 							canput(9F)