putnextctl1(9f)

1putnextctl1(9F)          Kernel Functions for Drivers          putnextctl1(9F)
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NAME

6       putnextctl1  -  send  a  control message with a one-byte parameter to a
7       queue
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SYNOPSIS

10       #include <sys/stream.h>
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14       int putnextctl1(queue_t *q, int type, int p);
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INTERFACE LEVEL

18       Architecture independent level 1 (DDI/DKI).
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PARAMETERS

21       q       Queue to which the message is to be sent.
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24       type    Type of message.
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27       p       One-byte parameter.
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DESCRIPTION

31       The putnextctl1() function, like putctl1(9F), tests the  type  argument
32       to  make sure a data type has not been specified, and attempts to allo‐
33       cate a message block. The p parameter can  be  used,  for  example,  to
34       specify  how  long  the  delay will be when an M_DELAY message is being
35       sent. putnextctl1() fails if type is M_DATA, M_PROTO, or M_PCPROTO,  or
36       if  a  message  block cannot be allocated. If successful, putnextctl1()
37       calls the put(9E) routine of the queue pointed to by q with  the  newly
38       allocated and initialized message.
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41       A   call   to   putnextctl1(q,type,  p)  is  an  atomic  equivalent  of
42       putctl1(q->q_next, type, p). The STREAMS  framework  provides  whatever
43       mutual  exclusion  is  necessary to insure that dereferencing q through
44       its q_next field and then invoking putctl1(9F) proceeds without  inter‐
45       ference from other threads.
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48       The  putnextctl1()  function  should  always  be  used in preference to
49       putctl1(9F)
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RETURN VALUES

52       On success, 1 is returned. 0 is returned if type is a data type, or  if
53       a message block cannot be allocated.
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CONTEXT

56       The  putnextctl1() function can be called from user, interrupt, or ker‐
57       nel context.
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EXAMPLES

60       See the putnextctl(9F) function page for an example of putnextctl1().
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