opensolaris man page for datamsg

datamsg(9F)						   Kernel Functions for Drivers 					       datamsg(9F)

NAME
       datamsg - test whether a message is a data message

SYNOPSIS
       #include <sys/stream.h>
       #include <sys/ddi.h>

       int datamsg(unsigned char type);

INTERFACE LEVEL
       Architecture independent level 1 (DDI/DKI).

PARAMETERS
       type    The  type  of  message  to  be  tested.	The db_type field of the  datab(9S) structure contains the message type. This field may be
	       accessed through the message block using mp->b_datap->db_type.

DESCRIPTION
       The datamsg() function tests the type of message to determine if it is a data message type (M_DATA, M_DELAY, M_PROTO , or M_PCPROTO).

RETURN VALUES
       datamsg returns

       1    if the message is a data message

       0    otherwise.

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

EXAMPLES
       The put(9E) routine enqueues all data messages for handling by the srv(9E) (service) routine. All non-data  messages  are  handled  in  the
       put(9E) routine.

	 1 xxxput(q, mp)
	 2	queue_t *q;
	 3	mblk_t *mp;
	 4 {
	 5    if (datamsg(mp->b_datap->db_type)) {
	 6	      putq(q, mp);
	 7	      return;
	 8    }
	 9    switch (mp->b_datap->db_type) {
	 10    case M_FLUSH:
			  ...
	 11    }
	 12 }

SEE ALSO
       put(9E), srv(9E), allocb(9F), datab(9S), msgb(9S)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.11							    16 Jan 2006 						       datamsg(9F)