putnextctl1(9F) Kernel Functions for Drivers putnextctl1(9F)NAMEputnextctl1 - 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 allo‐
cate 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 inter‐
ference 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 ker‐
nel context.
EXAMPLES
See the putnextctl(9F) function page for an example of putnextctl1().
SEE ALSOput(9E), allocb(9F), datamsg(9F), putctl1(9F), putnextctl(9F)
Writing Device Drivers
STREAMS Programming Guide
SunOS 5.10 16 Jan 2006 putnextctl1(9F)
