bcanputnext(9f) [plan9 man page]

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

NAME

       canputnext, bcanputnext - test for room in next module's message queue

SYNOPSIS

       #include <sys/stream.h>

       int canputnext(queue_t *q);

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

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       q	Pointer to a message queue belonging to the invoking module.

       pri	Minimum priority level.

DESCRIPTION

       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  inter-
       ference 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); respec-
       tively.

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

RETURN VALUES

       1	If the message queue is not full.

       0	If the queue is full.

CONTEXT

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

WARNINGS

       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.

SEE ALSO

       bcanput(9F), canput(9F)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.10							    31 Jan 1993 						    canputnext(9F)

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

NAME

       canputnext, bcanputnext - test for room in next module's message queue

SYNOPSIS

       #include <sys/stream.h>

       int canputnext(queue_t *q);

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

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       q        Pointer to a message queue belonging to the invoking module.

       pri      Minimum priority level.

DESCRIPTION

       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  inter-
       ference 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); respec-
       tively.

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

RETURN VALUES

       1        If the message queue is not full.

       0        If the queue is full.

CONTEXT

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

WARNINGS

       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.

SEE ALSO

       bcanput(9F), canput(9F)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.10                                                          31 Jan 1993                                                     canputnext(9F)