Manual Pages for UNIX Operating System command usage for man canputnext

Kernel Functions for Drivers                       canputnext(9F)



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

SYNOPSIS
     #include 



     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 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.

RETURN VALUES
     1    If the message queue is not full.


     0    If the queue is full.




SunOS 5.11          Last change: 16 Jan 2006                    1






Kernel Functions for Drivers                       canputnext(9F)



CONTEXT
     The canputnext() and bcanputnext() functions can  be  called
     from user, interrupt, or kernel context.

WARNINGS
     Drivers are responsible for both testing a queue  with  can-
     putnext()  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 5.11          Last change: 16 Jan 2006                    2