NAME    [Toc]    [Back]

       canput - STREAMS: Tests for room in a message queue

SYNOPSIS    [Toc]    [Back]

       #include <sys/stream.h>

       int canput(
               queue_t *message_queue );

ARGUMENTS    [Toc]    [Back]

       Specifies  a  pointer  to  the  message queue. The typedef
       queue_t is an alternate name for struct queue_entry *.

DESCRIPTION    [Toc]    [Back]

       The canput interface searches through the stream (starting
       at the message queue identified by the message_queue argument)
 until it finds  a  queue  that  contains  a  service
       interface  where  the  message can be enqueued or until it
       reaches the end of the stream.  If canput finds a  service
       interface  in  a queue, it tests the queue to determine if
       there is space in the queue to accommodate a message.   If
       the  queue  is  full, canput sets the q_flag member of the
       queue_entry structure pointer (the message queue)  to  the
       constant QWANTW to back-enable the caller's service interface.

NOTES    [Toc]    [Back]

       You are responsible for both testing a queue  with  canput
       and not placing a message on the queue if canput fails.

RETURN VALUES    [Toc]    [Back]

       The  canput  interface returns a value of 1 if the message
       queue is not full. It returns the value zero  (0)  if  the
       message queue is full.

SEE ALSO    [Toc]    [Back]

       Kernel Interfaces: bcanput(9r), putbq(9r), putnext(9r)

       Programmer's Guide: STREAMS



                                                       canput(9r)