xref: /titanic_50/usr/src/man/man9f/putnextctl1.9f (revision 7b07063d906859b2be1e88791f801b3c96e432f6)
te
Copyright 1989 AT&T
Copyright (c) 2006, Sun Microsystems, Inc.,
All Rights Reserved
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
PUTNEXTCTL1 9F "Jan 16, 2006"
NAME
putnextctl1 - send a control message with a one-byte parameter to a queue
SYNOPSIS

#include <sys/stream.h>



int putnextctl1(queue_t *q, int type, int p);
INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI).

PARAMETERS
q

Queue to which the message is to be sent.

type

Type of message.

p

One-byte parameter.

DESCRIPTION

The putnextctl1() function, like putctl1(9F), tests the type argument to make sure a data type has not been specified, and attempts to allocate a message block. The p parameter can be used, for example, to specify how long the delay will be when an M_DELAY message is being sent. putnextctl1() fails if type is M_DATA, M_PROTO, or M_PCPROTO, or if a message block cannot be allocated. If successful, putnextctl1() calls the put(9E) routine of the queue pointed to by q with the newly allocated and initialized message.

A call to putnextctl1(q,type, p) is an atomic equivalent of putctl1(q->q_next, type, p). The STREAMS framework provides whatever mutual exclusion is necessary to insure that dereferencing q through its q_next field and then invoking putctl1(9F) proceeds without interference from other threads.

The putnextctl1() function should always be used in preference to putctl1(9F)

RETURN VALUES

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

CONTEXT

The putnextctl1() function can be called from user, interrupt, or kernel context.

EXAMPLES

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

SEE ALSO

put(9E), allocb(9F), datamsg(9F), putctl1(9F), putnextctl(9F)

Writing Device Drivers

STREAMS Programming Guide